CHAPTER 43
WATER SUPPLIES—DESIGN AND OPERATION
[Prior to 12/12/90, portions of this chapter appeared in 567—Ch 41]
567—43.1(455B) General information.
	43.1(1) Emergency actions regarding water supplies. When, in the opinion of the director, an actual or imminent hazard exists, the supplier of water shall comply with the directives or orders of the director necessary to eliminate or minimize that hazard.
	43.1(2) Prohibition on the use of lead pipes, solder and flux. Any pipe, solder or flux which is used in the installation or repair of any public water supply system or any plumbing in a residential or nonresidential facility providing water for human consumption which is connected to a public water supply system shall be lead-free as defined in 567—40.2(455B). This action shall not apply to leaded joints necessary for the repair of cast iron pipe.
	43.1(3) Use of noncentralized treatment devices.
	a. 	Community PWS. Community public water systems shall not use bottled water, point-of-use (POU) or point-of-entry (POE) devices to achieve permanent compliance with a maximum contaminant level, action level, or treatment technique requirement in 567—Chapters 41 and 43.
	b. 	Noncommunity PWS. Noncommunity public water supply systems may be allowed by the department to use point-of-use devices to achieve MCL compliance provided the contaminant does not pose an imminent threat to health (such as bacteria) nor place a sensitive population at risk (such as infants for nitrate or nitrite).
	c. 	Reduced monitoring requirements. Bottled water, point-of-use, or point-of-entry devices cannot be used to avoid the monitoring requirements of 567—Chapters 41 and 43, but the department may allow reduced monitoring requirements in specific instances.
	d. 	Bottled water requirements. The department may require a public water system exceeding a maximum contaminant level, action level, or treatment technique requirement specified in 567—Chapters 41 and 43 to use bottled water as a condition of an interim compliance schedule or as a temporary measure to avoid an unreasonable risk to health. Any bottled water must, at a minimum, meet the federal Food and Drug Administration bottled water standards, listed in the Code of Federal Regulations, Title 21, Chapter 165.110. The system must meet the following requirements:
	(1)	Monitoring program. Submit for approval to the department a monitoring program for bottled water. The monitoring program must provide reasonable assurances that the bottled water complies with all maximum contaminant levels, action levels, or treatment technique requirements in 567—Chapters 41 and 43. The public water system must monitor a representative sample of bottled water for all contaminants regulated under 567—Chapters 41 and 43 the first quarter that it supplies the bottled water to the public, and annually thereafter. Results of the monitoring program shall be provided to the department annually. If the bottled water is from a community public water system that currently meets all of the federal Safe Drinking Water Act requirements, the monitoring requirements of this subparagraph shall be waived by the department. The specific supplier of the bottled water must be identified in order for the department to waive the monitoring requirements.
	(2)	Certification requirements. The public water system must receive a certification from the bottled water company that the bottled water supplied has been taken from an “approved source”; the bottled water company has conducted monitoring in accordance with 43.1(3)“b”(1); and the bottled water meets MCLs, action levels, or treatment technique requirements as set out in 567—Chapters 41 and 43. The public water system shall provide the certification to the department the first quarter after it supplies bottled water and annually thereafter.
	(3)	Provision of bottled water to consumers. The public water supply system is fully responsible for the provision of sufficient quantities of bottled water to every person supplied by the public water system via door-to-door bottled water delivery.
	e. 	Point-of-use devices. Reserved.
	f. 	Point-of-entry devices. Reserved.
	43.1(4) Cross-connection control. To prevent backflow or backsiphonage of contaminants into a public water supply, connection shall not be permitted between a public water supply and any other system which does not meet the monitoring and drinking water standards required by this chapter except as provided below in “a” or “b.”
	a. 	Piping and plumbing systems. Piping systems or plumbing equipment carrying nonpotable water, contaminated water, stagnant water, liquids, mixtures or waste mixtures shall not be connected to a public water supply unless properly equipped with an antisiphon device or backflow preventer acceptable to the department.
	b. 	Bulk water loading stations. Positive separation shall be provided through the use of an air gap separation or a backflow preventer, which is acceptable to the department, at all loading stations for bulk transport tanks.
	(1)	Minimum air gap. The minimum required air gap shall be twice the diameter of the discharge pipe.
	(2)	Backflow preventer criteria. An approved backflow preventer for this application shall be a reduced pressure backflow preventer or an antisiphon device which complies with the standards of the American Water Works Association and has been approved by the Foundation for Cross-Connection Control and Hydraulic Research, University of Southern California.
When, in the opinion of the department, evidence clearly indicates the source of contamination within the system is the result of a cross-connection, the department may require a public water supply to conduct public notification, identify and eliminate the connection, and implement a systemwide cross-connection program.
	43.1(5) Requirement for certified operator. The department maintains a list of operators who are certified in accordance with 567—Chapter 81. The list includes the operator’s name, certification classification (Water Treatment, Water Distribution, or Grade A Water System), and grade (A, I, II, III, or IV), and is periodically updated during the year.
	a. 	CWS and NTNC systems. All community and nontransient noncommunity public water supply systems must have a certified operator in direct responsible charge of the treatment and distribution systems, in accordance with 567—Chapters 40 through 44 and 81.
	b. 	TNC systems. Any transient noncommunity public water supply system which is owned by the state or federal government, such as a state park, state hospital, or interstate rest stop, or is using a groundwater under the direct influence of surface water or surface water source, must have a certified operator in direct responsible charge of the treatment and distribution systems, in accordance with 567—Chapters 40 through 44 and 81. Any TNC which uses chlorine dioxide as a disinfectant or oxidant must have a certified operator in direct responsible charge of the system, pursuant to 567—Chapter 81. The department may require any TNC to have a certified operator in direct responsible charge.
	43.1(6) Return water in public water supply systems. Steam condensate, cooling water from engine jackets, water used in conjunction with heat exchange devices, or treated wastewater shall not be returned to the public water supply system.
	43.1(7) Sanitary surveys. Each public water supply system must have a periodic sanitary survey, conducted by the department or its designee, which is a records review and on-site inspection of the system. Systems must provide the department, at its request, any existing information that will enable the department to conduct the sanitary survey. The inspection evaluates the system’s ability to produce and distribute safe drinking water and identifies improvements necessary to maintain or improve drinking water quality. The sanitary survey includes review and inspection of the following areas: water source; treatment facilities; distribution system; finished water storage; pumps, pump facilities, controls and other equipment; monitoring, reporting, and data verification, including self-monitoring requirements; system operation and management; maintenance; properly certified operators; and records. A report of the sanitary survey is issued by the department or its designee, and may include both enforceable required actions for remedying significant deficiencies and nonenforceable recommended actions. The frequency of the sanitary survey inspection must be at least once every five years for noncommunity systems and once every three years for community systems. The department or its designee must provide the system with a written notice describing any significant deficiencies identified no later than 30 days after the department identifies the significant deficiency. The notice may be included in the sanitary survey report and may specify corrective actions and deadlines for completion of corrective actions. Systems must respond in writing to significant deficiencies outlined in the sanitary survey report or written notice within the time period specified in the report, indicating how and on what schedule the system will address significant deficiencies noted in the survey. At a maximum, the written response must be received within 30 days of receiving the survey report. All systems must take the steps necessary to address significant deficiencies identified in the sanitary survey report that are within the control of the system and its governing body.
[ARC 9915B, IAB 12/14/11, effective 1/18/12; ARC 3735C, IAB 4/11/18, effective 5/16/18]
567—43.2(455B) Permit to operate.
	43.2(1) Operation fees.
	a. 	Annual fee. A fee for the operation of a public water supply system shall be paid annually. The fee will not be prorated and is nonrefundable. The fee shall be based on the population served. The fee shall be the greater of $25 per year or $0.14 multiplied by the total population served by the public water supply for all community and nontransient noncommunity public water supply systems. The fee shall be $25 per year for all transient noncommunity water systems. Where a system provides water to another public water supply system (consecutive public water supply system) which is required to have an operation permit, the population of the recipient water supply shall not be counted as a part of the water system providing the water.
	b. 	Fee notices. The department will send annual notices to public water supply systems at least 60 days prior to the date that the operation fee is due.
	c. 	Fee payments. The annual operation fee must be paid to the department by September 1 each year.
	d. 	Fee schedule adjustment. The department may adjust the per capita fee payment by up to +/– $0.02 per person served so as to achieve the targeted revenue of $350,000 during each fiscal year. The environmental protection commission must approve any per capita fee rate above $0.14 per person. The extent of the fee adjustment must comply with Iowa Code section 455B.183A.
	e. 	Exempted public water supply systems. Public water supply systems located on Indian lands are exempt from the fee requirements.
	f. 	Late fees. When the owner of a public water supply fails to make timely application or to remit payment of fees by September 1, the department will notify the system by a single notice of violation. In addition, a late fee of $100 will be assessed for failure to remit the operation fee by September 1. The department may thereafter issue an administrative order pursuant to Iowa Code section 455B.175(1) or request a referral to the attorney general under Iowa Code section 455B.175(3) as necessary.
	43.2(2) Operation permit requirement. Except as provided in 43.2(3) and 43.2(4), no person shall operate any public water supply system or part thereof without, or contrary to any condition of, an operation permit issued by the director.
	43.2(3) Application for operation permit. The owner of any public water supply system or part thereof must make application for an operation permit. No such system shall be operated without an operation permit, unless proper application has been made. Upon submission of a completed application form, the time requirement for having a valid operation permit is automatically extended until the application has either been approved or disapproved by the director.
	43.2(4) Operation permit application form issuance.
	a. 	Operation permit application form. Application for operation permits shall be made on forms provided by the department. The application for an operation permit shall be filed at least 90 days prior to the date operation is scheduled to begin unless a shorter time is approved by the director. The director shall issue or deny operation permits for facilities within 60 days of receipt of a completed application, unless a longer period is required and the applicant is so notified. The director may require the submission of additional information deemed necessary to evaluate the application. If the application is incomplete or otherwise deficient, processing of the application shall not be completed until such time as the applicant has supplied the missing information or otherwise corrected the deficiency.
	b. 	Identity of signatories of operation permit applications. The person who signs the application for an operation permit shall be:
	(1)	Corporation. In the case of a corporation, a principal executive officer of at least the level of vice president. The corporation has the option of appointing a designated signatory to satisfy this requirement.
	(2)	Partnership. In the case of a partnership, a general partner.
	(3)	Sole proprietorship. In the case of a sole proprietorship, the proprietor.
	(4)	Public facility. In the case of a municipal, state or other public facility, by either the principal executive officer or the ranking elected official.
	c. 	Appeal. The denial of a permit, or any permit condition, may be appealed by the applicant to the environmental protection commission pursuant to 567—Chapter 7.
	43.2(5) Operation permit conditions.
	a. 	Operation permit conditions. Operation permits may contain such conditions as are deemed necessary by the director to ensure compliance with all applicable rules of the department, to ensure that the public water supply system is properly operated and maintained, to ensure that potential hazards to the water consumer are eliminated promptly, and to ensure that the requirements of the Safe Drinking Water Act are met.
	b. 	Compliance schedule. Where one or more maximum contaminant levels, treatment techniques, designated health advisories, or action levels cannot be met immediately, a compliance schedule for achieving compliance with standards may be made a condition of the permit. A compliance schedule requiring alterations in accordance with the standards for construction in 43.3(1) and 43.3(2) may also be included for any supply that, in the opinion of the director, contains a potential hazard.
	c. 	Treatment. If the department determines that a treatment method identified in 43.3(10) is technically feasible, the department may require the system to install or use that treatment method in connection with a compliance schedule issued under the provisions of 43.2(5)“b.” The department’s determination shall be based upon studies by the system and other relevant information.
	43.2(6) Notification of change in operation permit application conditions. The owner of a public water supply system shall notify the director within 30 days of any change in conditions identified in the permit application. This notice does not relieve the owner of the responsibility to obtain a construction permit as required by 567—43.3(455B).
	43.2(7) Renewal of operation permits. The department may issue operation permits for durations of up to five years. Operation permits must be renewed prior to expiration in order to remain valid. The renewal date shall be specified in the permit or in any renewal. Application for renewal must be received by the director, or postmarked, 60 days prior to the renewal date, on forms provided by the department.
	43.2(8) Denial, modification, or suspension of operation permit. The director may deny renewal of, modify, or suspend, in whole or in part, any operation permit for good cause. Denial of a new permit, renewal of an existing permit, or modification of a permit, may be appealed to the environmental protection commission pursuant to 567—Chapter 7. Suspension or revocation may occur after hearing, pursuant to 567—Chapter 7. Good cause includes the following:
	a. 	Violation of any term or condition of the permit.
	b. 	Obtaining a permit by misrepresentation of fact or failure to disclose fully all material facts.
	c. 	A change in any condition that requires either a permanent or temporary modification of a permit condition.
	d. 	Failure to submit such records and information as the director may require both generally and as a condition of the operation permit in order to ensure compliance with conditions specified in the permit.
	e. 	Violation of any of the requirements contained in 567—Chapters 40 to 43.
	f. 	Inability of a system to either achieve or maintain technical, managerial, or financial viability, as determined in rule 567—43.8(455B).
567—43.3(455B) Public water supply system construction.
	43.3(1) Standards for public water supplies. Any public water supply that does not meet the drinking water standards contained in 567—Chapters 41 and 43 shall make the alterations in accordance with the standards for construction contained in 43.3(2) necessary to comply with the drinking water standards unless the public water supply has been granted a variance from a maximum contaminant level or treatment technique as a provision of its operation permit pursuant to 567—43.2(455B), provided that the public water supply meets the schedule established pursuant to 567—43.2(455B). Any public water supply that, in the opinion of the director, contains a potential hazard shall make the alterations in accordance with the standards for construction contained in this rule necessary to eliminate or minimize that hazard. A system that is not operating within the design standards may be required by the department via a compliance schedule to upgrade the deficient areas of the system before a construction permit will be issued for any work in the system that does not address the current deficiencies.
	43.3(2) Standards for construction.
	a. 	The standards for a project are the Ten States Standards as adopted through 2012 and the American Water Works Association (AWWA) Standards as adopted through 2016 and 43.3(7) to 43.3(9). To the extent of any conflict between the Ten States Standards and the American Water Works Association Standards and 43.3(7) to 43.3(9), the Ten States Standards, 43.3(2), and 43.3(7) to 43.3(9) shall prevail. Additional standards include the following:
	(1)	Polyvinyl chloride (PVC) pipe manufactured in accordance with ASTM D2241, AWWA C900, AWWA C905, ASTM F1483, or AWWA C909 may be used for water main construction. The maximum allowable pressure for PVC or polyethylene (PE) pipe shall be determined based on a safety factor of 2.0 and a surge allowance of no less than two feet per second (2 fps).
	(2)	For CWS groundwater systems, a minimum of two wells shall be provided, unless the system demonstrates to the department’s satisfaction that a single well will provide a reliable and adequate source. For NTNC and TNC groundwater systems, a single well is acceptable.
	(3)	Separation of water mains from sanitary and combined sewers.
	1.	Horizontal separation of water mains from gravity sanitary and combined sewers. Water mains shall be separated from gravity sanitary and combined sewer mains by a horizontal distance of at least ten feet measured edge to edge unless the bottom of the water main is at least 18 inches above the top of the sewer, and either:
	●	The water main is placed in a separate trench, or
	●	The water main is located on a bench of undisturbed earth at a minimum horizontal separation of three feet from the sewer.
If it is not possible to obtain a horizontal separation of three feet and a vertical separation of 18 inches between the bottom of the water main and the top of the sewer, a linear separation of at least two feet shall be provided, and one of the following shall be utilized:
	●	The water main shall be enclosed in watertight casing pipe with an evenly spaced annular gap and watertight end seals, or
	●	The sewer shall be constructed of water main materials.
The separation distance between the water main and the sewer shall be the maximum feasible in all cases.
	2.	Horizontal separation of water mains from sanitary sewer force mains. Water mains shall be separated from sanitary sewer force mains by a horizontal distance of at least ten feet measured edge to edge unless the sanitary sewer force main is constructed of water main materials and the water main is laid at least four feet horizontally from the sanitary sewer force main. The separation distance between the water main and the sanitary sewer force main shall be the maximum feasible in all cases.
	3.	Vertical separation of water mains from sanitary and combined sewer crossovers. Vertical separation of water mains crossing over any sanitary or combined sewers shall be at least 18 inches when measured from the bottom of the water main to the top of the sewer. If it is not possible to maintain the required vertical separation, one of the following shall be utilized:
	●	The bottom of the water main shall not be placed closer than six inches above the top of a sewer, or
	●	The top of the water main shall not be placed closer than 18 inches below the bottom of a sewer.
When a water main crosses below or less than 18 inches above a sanitary or combined sewer, one of the following shall be utilized within ten feet measured edge to edge horizontally, centered on the crossing:
	●	The water main shall be enclosed in watertight casing pipe with an evenly spaced annular gap and watertight ends, or
	●	Sewer pipe of water main material shall be installed.
The separation distance shall be the maximum feasible in all cases. Wherever a water main crosses a sanitary or combined sewer, the water main and sanitary or combined sewer pipes must be adequately supported. A low permeability soil shall be used for backfill material within ten feet of the point of crossing along the water main.
	4.	Horizontal separation of water mains from sanitary and combined sewer manholes. No water pipe shall pass through or come in contact with any part of a sanitary or combined sewer manhole. A minimum horizontal separation of three feet shall be maintained.
	(4)	Separation of water mains from storm sewers.
	1.	Horizontal separation of water mains from gravity storm sewers. Water mains shall be separated horizontally from gravity storm sewers by at least ten feet measured edge to edge. If it is not possible to maintain the required horizontal separation of ten feet, a minimum of three feet of separation shall be maintained and one of the following shall be utilized within ten feet measured edge to edge:
	●	The water main shall be constructed of ductile iron pipe with gaskets impermeable to hydrocarbons, or
	●	The water main shall be enclosed in watertight casing pipe with an evenly spaced annular gap and watertight end seals, or
	●	Storm sewer pipe of water main material shall be installed, or
	●	Reinforced concrete pipe storm sewers shall be constructed with gaskets manufactured in accordance with ASTM C443.
	2.	Vertical separation of water mains from storm sewer crossovers. Water mains shall be vertically separated from storm sewers by at least 18 inches between the outside edges of the water main and the storm sewer. The separation distance shall be the maximum feasible in all cases. In all cases where a water main crosses a storm sewer, the water main and storm sewer pipes must be adequately supported. A low permeability soil shall be used for backfill material within ten feet of the point of crossing along the water main. If it is not possible to obtain 18 inches of vertical separation where the water main crosses above a storm sewer, a minimum of 6 inches vertical separation shall be maintained and one of the following shall be utilized within ten feet measured edge to edge horizontally, centered on the crossing:
	●	The water main shall be constructed of ductile iron pipe with gaskets impermeable to hydrocarbons, or
	●	The water main shall be enclosed in watertight casing pipe with an evenly spaced annular gap and watertight end seals, or
	●	Storm sewer pipe of water main material shall be installed, or
	●	Reinforced concrete pipe storm sewers shall be constructed with gaskets manufactured in accordance with ASTM C443.
	b. 	Variance. When engineering justification satisfactory to the director is provided substantially demonstrating that variation from the design standards will result in equivalent or improved effectiveness, such a variation from design standards may be accepted by the director. A variance denial may be appealed to the environmental protection commission pursuant to 567—Chapter 7. Variance requests for projects qualifying for a waiver from the engineering requirement of 43.3(4) may be made without the retained services of a professional engineer.
	43.3(3) Construction permits. No person shall construct, install or modify any project without first obtaining, or contrary to any condition of, a construction permit issued by the director or by a local public works department authorized to issue permits under 567—Chapter 9 except as provided in 43.3(3)“b,”43.3(4) and 43.3(6). Construction permits are not required for point-of-use treatment devices installed by a noncommunity water system except those devices required by the department to meet a drinking water standard pursuant to 567—Chapters 41 and 43. No construction permit will be issued for a new public water supply system without a completed viability assessment, which has been approved by the department, and demonstrates that the system is viable, pursuant to 567—43.8(455B).
	a. 	Construction permit issuance conditions. A permit to construct shall be issued by the director if the director concludes from the application and specifications submitted pursuant to 43.3(4) and 567—40.4(455B) that the project will comply with the rules of the department. The construction of the project must begin within one year from the date the permit was issued; if it is not, the permit is no longer valid. If construction is ongoing and continuous (aside from delays due to winter or exceptional weather) and the permitted project cannot be completed within one year, the permit shall remain valid until the project is completed. The department may grant an extension of the permit for a multiphase project, for a maximum two additional years.
	b. 	Construction permit application. Application for any project shall be submitted to the department at least 30 days prior to the proposed date for commencing construction or awarding of contracts. This requirement may be waived when it is determined by the department that an imminent health hazard exists to the consumers of a public water supply. Under this waiver, construction, installation, or modification may be allowed by the department prior to review and issuance of a permit if all the following conditions are met:
	(1)	The construction, installation or modification will alleviate the health hazard;
	(2)	The construction is done in accordance with the standards for construction pursuant to 43.3(2);
	(3)	Plans and specifications are submitted within 30 days after construction;
	(4)	A professional engineer, licensed in the state of Iowa, supervises the construction; and
	(5)	The supplier of water receives approval of this waiver prior to any construction, installation, or modification.
	c. 	Construction permit fees. A nonrefundable fee for a construction permit issued in accordance with subrules 43.3(3) and 43.3(4) and 567—subrules 40.3(1) and 40.4(1) shall be submitted with the application for a construction permit prior to the authorization to commence construction. The construction permit fee shall be based upon the following rate structure:
	(1)	Routine construction permits. The fee shall be determined based upon the total length of water main plus the non-water-main-related construction costs, calculated as follows:
1. Water mains (minimum fee of $100; maximum fee of $5,000):

Length of permitted water main	Rate	
First 1,000 ft.	$100	
Next 19,000 ft.	$0.10/ft.	
Next 300,000 ft.	$0.01/ft.	
Over 320,000 ft.	No additional charge	
2. Non-water-main-related construction costs, including source, treatment, pumping, storage and waste handling (minimum fee of $100; maximum fee of $16,000):

Estimated construction cost	Rate	
First $50,000	$100	
Next $950,000	0.2% of estimated construction cost	
Next $14,000,000	0.1% of estimated construction cost	
Over $15,000,000	No additional charge	
	(2)	“As-built” construction. “As-built” construction is defined as construction that occurred before a construction permit is issued. The fee shall be calculated according to 43.3(3)“c”(1), plus an additional fee of $200, and is effective for construction that occurred after December 1, 2003. The fee for water main projects permitted in accordance with paragraph 43.3(3)“e” shall be calculated in accordance with subparagraph 43.3(3)“c”(1); however, the additional “as-built” fee of $200 shall not be assessed for these projects.
	(3)	Change orders, addenda, permit supplements, and request for time extensions. A fee for change orders, addenda, or permit supplements will only be charged if the aggregate of the changes approved for the project to date causes the total project construction cost to exceed the original project construction cost by at least 5 percent. For water main extensions, the fee will be charged if the total length of water main exceeds the original approved length by 5 percent. The request for a time extension is a flat fee.

Categories	Rate	
Change orders, addenda, and permit supplements for water mains	$0.10/ft. of additional water main, minimum fee: $50	
Change orders, addenda, and permit supplements for non-water-main-
related construction costs	0.2% of additional non-water-main-related construction costs, minimum fee: $50	
Request for time extension	$50	
	(4)	Calendar year construction permit fee cap. The total amount of construction permit fees for a public water supply system owner during any calendar year shall not exceed $5,000 for water mains and $16,000 for non-water-main-related construction projects.
	d. 	Water well construction. All water well construction must be performed by a certified well contractor in accordance with 567—Chapter 82. It is the responsibility of the public water supply and certified well contractor to ensure that a public well construction permit has been issued by the department prior to initiation of well construction and to ensure that all well construction is performed in accordance with the provisions of this chapter.
	e. 	Minor water main construction permit. A public water system may obtain a minor water main construction permit from the department for construction or replacement of minor water mains that serve additional users. By obtaining this permit, the system is able to construct new minor water mains or extend or replace existing minor water mains without obtaining an individual construction permit for each specific water main. The permit shall allow construction or replacement of minor water mains that do not exceed six inches in diameter and, in aggregation, do not increase the average daily demand (in gallons per day) of the public water supply system by more than 5 percent over the duration of the permit.
The additional users must have been included in the system’s hydraulic analysis that has been approved by the department. The water demands of the additional users must be consistent with the water demands in the approved hydraulic analysis.
	(1)	A minor water main construction permit shall be issued subject to the following conditions:
	1.	The system has standard specifications for water main construction approved and on file with the department;
	2.	The system has adequate source capacity and, where treatment is provided, adequate treatment plant capacity to meet the peak day demand of all existing users and the proposed additional users covered under the permit;
	3.	The system has adequate storage capacity to meet the average day demand of all existing users and the proposed additional users covered under the permit; and
	4.	The system submits an application for a minor water main construction permit prior to the construction or replacement of any water main covered by the permit. The permit application must be submitted to the department 90 days before the anticipated first use of the permit, and construction shall not commence prior to the issuance of the permit. The minor water main construction permit expires on December 31 of the year in which it is issued. The application shall include the following:
	●	An up-to-date hydraulic analysis of the system, prepared and submitted by a licensed professional engineer, must be either on file with the department or submitted with the permit application. The hydraulic basis of flow (gallons per minute per connection) used in the analysis must be acceptable to the department. The hydraulic analysis shall include:
○	All existing water mains within the system;
○	All proposed water mains intended to be covered by the permit;
○	A demonstration that the system has adequate hydraulic capacity to serve the existing and new users under peak flow conditions without causing the pressure to fall below 20 psi anywhere within the system;
○	The location of all potential users of the system;
○	The diameter of all existing and proposed pipes;
○	The projected system flows; and
○	The static and dynamic pressures anticipated throughout the system with the addition of the new users incorporated in the analysis.
	●	A completed Schedule 1b, Minor Water Main Construction Permit Application (Form 542-3151), listed in 567—subrule 40.3(1).
	(2)	The system must submit completed Schedule 2c, Notification of Minor Water Main Construction (Form 542-3152), prior to the construction or replacement of each minor water main covered by this permit. Each water main covered by the permit must have either been included in the previously submitted hydraulic analysis or must be included in an update to the hydraulic analysis, submitted with Schedule 2c. If an update to the hydraulic analysis is submitted with Schedule 2c, it must include all portions of the distribution system potentially affected by the new construction.
	(3)	By January 31 of the following year, the system shall submit the following to the department:
	1.	A complete set of plans for all water main extensions constructed under the permit. The plans must be prepared and submitted by a licensed professional engineer.
	2.	Completed Schedules 1a, 1c, and 2a, listed in 567—subrule 40.3(1).
	3.	The construction permit fee calculated in accordance with subparagraph 43.3(3)“c”(1). The fee calculation shall be based upon the total length of water main constructed under the permit. For the purpose of calculating the total amount of water main construction permit fees, paid by the system in accordance with subparagraph 43.3(3)“c”(4), the fee shall be credited to the calendar year in which the actual fee was received by the department.
	(4)	A permit shall contain such conditions as are deemed necessary by the director to ensure compliance with all applicable rules of the department.
	(5)	The director may modify the permit, in whole or in part, at any time. The director may suspend or revoke the permit, in whole or in part, at any time by providing written notice to the permit holder and is not obligated to renew the permit. Cause for modification, suspension, or revocation of the permit includes, but is not limited to, the following:
	1.	Violation of any term or condition of the permit;
	2.	Misrepresentation of fact or failure to disclose fully all material facts in order to obtain a permit;
	3.	Failure to submit the records and information as required by the director, both generally and as condition of the permit;
	4.	Failure to submit timely reports from previous permits;
	5.	Failure to construct in accordance with approved design standards in accordance with subrule 43.3(2); or
	6.	Failure to construct in accordance with the system’s approved standard specifications.
	(6)	No variance to the design standards is allowed under this permit. If a variance to the design standards is needed, the system must apply for an individual construction permit following the procedures in 567—subrule 40.4(1).
	43.3(4) Waiver from engineering requirements. The requirement for plans and specifications prepared by a licensed professional engineer may be waived for the following types of projects, provided the improvement complies with the standards for construction. This waiver does not relieve the supplier of water from meeting the application and permit requirements pursuant to 43.3(3), except that the applicant need not obtain a written permit prior to installing the equipment.
	a. 	Simple chemical feed, if all the following conditions are met:
	(1)	The improvement consists only of a simple chemical solution application or installation, which in no way affects the performance of a larger treatment process, or is included as part of a larger treatment project;
	(2)	The chemical application is by a positive displacement pump (of the piston type with a solenoid operated diaphragm), the acceptability of said pump to be determined by the department;
	(3)	The supplier of water provides the department with a schematic of the installation and manufacturer’s specifications sufficient enough to determine if the simple chemical feed installation meets, where applicable, standards for construction pursuant to 43.3(2);
	(4)	The final installation is approved based on an on-site review and inspection by department staff; and
	(5)	The installation includes only the prepackaged delivery of chemicals (from sacks, containers, or carboys) and does not include the bulk storage or transfer of chemicals (from a delivery vehicle).
	b. 	Self-contained treatment unit, if all the following conditions are met:
	(1)	The equipment is of a type which can be purchased “off the shelf,” is self-contained requiring only a piping hookup for installation and operates throughout a range of 35 to 80 pounds per square inch;
	(2)	The plant is designed to serve no more than an average of 250 individuals per day;
	(3)	The department receives adequate information from the supplier of water on the type of treatment unit, such as manufacturer’s specifications, a schematic indicating the installation’s location within the system and any other information necessary for review by the department to determine if the installation will alleviate the maximum contaminant level violation; and
	(4)	The final installation is approved based on an on-site inspection by department staff.
	43.3(5) Project planning and basis of design. An engineering report containing information and data necessary to determine the conformance of the project to the standards for construction and operation in 43.3(2) and the adequacy of the project to supply water in sufficient quantity and at sufficient pressure and of a quality that complies with drinking water standards pursuant to 567—Chapters 41 and 43 must be submitted to the department either with the project or in advance.
	a. 	Such information and data must supply pertinent information as set forth in part one of the Ten States Standards.
	b. 	The department may reject receipt or delay review of the plans and specifications until an adequate basis of design is received.
	43.3(6) Standard specifications for water main construction. Standard specifications for water main construction by an entity may be submitted to the department or an authorized local public works department for approval. Such approval shall apply to all future water main construction by or for that entity for which plans are submitted with a statement requiring construction in accordance with all applicable approved standard specifications unless the standards for public water supply systems specified in 43.3(2) are modified subsequent to such approval and the standard specifications would not be approvable under the modified standards. In those cases where such approved specifications are on file, construction may commence 30 days following receipt of such plans by the department or an authorized local public works department if no response has been received indicating construction shall not commence until a permit is issued.
	43.3(7) Site, separation distance, and monitoring requirements for new raw water source(s) and underground finished water storage facilities.
	a. 	Approval required. The site for each proposed raw water supply source or finished water below-ground level storage facility must be approved by the department prior to the submission of plans and specifications.
	b. 	Criteria for approval. A site may be approved by the director if the director concludes that the criteria in this paragraph are met.
	(1)	Groundwater source. Wells shall be planned and constructed to adapt to the geologic and groundwater conditions of the proposed well site to ensure production of water from the wells that is both microbially safe and free of substances that could cause harmful human health effects. Groundwater wells must meet the following requirements:
	1.	Drainage must be directed away from the well in all directions for a minimum radius of 15 feet.
	2.	A well site must be separated from contamination sources by the distances specified in Table A at a minimum.
	3.	After the well site has received preliminary approval from the department, the owner of the proposed well must submit proof of legal control of the land for a 200-foot radius around the well, through purchase, lease, easement, ordinance, or other similar means. Proof of legal control must be submitted as part of the construction permit application, prior to construction. The legal control must be maintained by the public water system for the life of the well, and the system must ensure that the siting criteria indicated in Table A are met.
However, if the proposed well is for an existing noncommunity water system and is replacing an existing well that either does not meet the current standards or is in poor condition, the requirement of 200-foot legal control may be waived by the department provided that:
	●	The proposed well is located on the best available site;
	●	The existing facility does not have adequate land to provide the 200-foot control zone;
	●	The owner has attempted to obtain legal control without success; and
	●	There is no other public water supply available to which the supply could connect.
4. When the proposed well is located in an existing well field and will withdraw water from the same aquifer as the existing well(s), individual separation distances may be waived if substantial historical data are available indicating that no contamination has resulted.
	5.	No well shall be constructed within the projected plume of any known anthropogenic groundwater contamination without the department’s written approval. The department may allow a well to be constructed within a contamination plume if the applicant can provide adequate treatment to ensure that all drinking water standards are met and that the pumpage of the proposed well will not cause migration of the plume such that it impacts the water quality of other nearby wells. The applicant must demonstrate, using a hydrogeologic model acceptable to the department, that the time of transport is greater than two years for a viral, bacterial, or other microorganism contaminant and greater than ten years for all chemical contaminants. At a minimum, modeling of the projected plume must take into account the proposed pumpage rate of the well. The department may require additional construction standards for these situations to ensure protection of the groundwater from contamination.
	6.	The department may require that an identification tag be applied to each well and may supply the numbered tag. The responsibility for ensuring that the tag is properly attached to the well is with the certified water well contractor for new wells and with the department for existing wells.
	(2)	Surface water source. The applicant must submit proof that a proposed surface water source can, through readily available treatment methodology, comply with 567—Chapters 41 and 43, and that the raw water source is adequately protected against potential health hazards including, but not limited to, point source discharges, hazardous chemical spills, and the potential sources of contamination listed in Table A.
After a surface water impoundment has received preliminary approval from the department for use as a raw water source, the owner of the water supply system shall submit proof of legal control through ownership, lease, easement, or other similar means, of contiguous land for a distance of 400 feet from the shoreline at the maximum water level. Legal control shall be for the life of the impoundment and shall control location of sources of contamination within the 400-foot distance. Proof of legal control should be submitted as part of the construction permit application and shall be submitted prior to issuance of a permit to construct.
	(3)	Below-ground storage facilities. The minimum separation between a below-ground level finished water storage facility and any source of contamination listed in Table A as being 50 feet or more shall be 50 feet. The specific separation distances listed in Table A that are less than 50 feet shall apply to a below-ground level finished water storage facility as indicated in the table.
	(4)	Separation distances. Greater separation distances may be required where necessary to ensure that no adverse effects to water supplies or the existing environment will result. Lesser separation distances may be considered if detailed justification is provided by the applicant’s engineer showing that no adverse effects will result from a lesser separation distance, and the regional staff recommends approval of the lesser distance. Such exceptions must be based on special construction techniques or localized geologic or hydrologic conditions.
	c. 	New source water monitoring requirements. Water quality monitoring shall be conducted on all new water sources and results submitted to the department prior to placing the new water source into service.
	(1)	All sources. Water samples shall be collected from each new water source and analyzed for all appropriate contaminants as specified in 567—Chapter 41 consistent with the particular water system classification. If multiple new sources are being added, compositing of the samples (within a single system) shall be allowed in accordance with the composite sampling requirements outlined in 567—Chapter 41. A single sample may be allowed to meet this requirement, if approved by the department.
Subsequent water testing shall be conducted consistent with the water system’s water supply operation permit monitoring schedule.
	(2)	Groundwater sources. Water samples collected from groundwater sources in accordance with 43.3(7)“c”(1) shall be conducted at the conclusion of the drawdown/yield test pumping procedure, with the exception of bacteriological monitoring. Bacteriological monitoring must be conducted after disinfection of each new well and subsequent pumping of the chlorinated water to waste. Water samples must be analyzed for ammonia. Water samples should also be analyzed for alkalinity, pH, calcium, chloride, copper, hardness, iron, magnesium, manganese, potassium, silica, specific conductance, sodium, sulfate, filterable and nonfilterable solids, and zinc.
	(3)	Surface water sources. Water samples collected from surface water sources in accordance with 43.3(7)“c”(1) should be collected prior to the design of the surface water treatment facility and shall be conducted and analyzed prior to utilization of the source. The samples shall be collected during June, July, and August. In addition, quarterly monitoring shall be conducted in March, June, September, and December at a location representative of the raw water at its point of withdrawal. Monitoring shall be for turbidity, alkalinity, pH, calcium, chloride, color, copper, hardness, iron, magnesium, manganese, potassium, silica, specific conductance, sodium, sulfate, filterable and nonfilterable solids, carbonate, bicarbonate, algae (qualitative and quantitative), total organic carbon, five-day biochemical oxygen demand, dissolved oxygen, surfactants, nitrogen series (organic, ammonia, nitrite, and nitrate), and phosphate.
TABLE A: SEPARATION DISTANCES

SOURCE OF CONTAMINATION	REQUIRED MINIMUM LATERAL DISTANCE FROM WELL AS HORIZONTAL ON THE GROUND SURFACE,
IN FEET	
 	Deep Well1	Shallow Well1	
WASTEWATER STRUCTURES:	
Point of Discharge to Ground Surface	
Sanitary & industrial discharges	400	400	
Water treatment plant wastes	50	50	
Well house floor drains	5	5	
Sewers & Drains2	
Sanitary & storm sewers, drains	0 – 25 feet: prohibited
25 – 75 feet if water main pipe
75 – 200 feet if sanitary sewer pipe	0 – 25 feet: prohibited
25 – 75 feet if water main pipe
75 – 200 feet if sanitary sewer main pipe	
Sewer force mains	0 – 75 feet: prohibited
75 – 400 feet if water main pipe
400 – 1000 feet if sanitary sewer pipe	0 – 75 feet: prohibited
75 – 400 feet if water main pipe
400 – 1000 feet if sanitary sewer main pipe	
Water plant treatment process wastes that are treated onsite	0 – 5 feet: prohibited
5 – 50 feet if sanitary sewer pipe	0 – 5 feet: prohibited
5 – 50 feet if sanitary sewer main pipe	
Water plant wastes to sanitary sewer	0 – 25 feet: prohibited
25 – 75 feet if water main pipe
75 – 200 feet if sanitary sewer pipe	0 – 25 feet: prohibited
25 – 75 feet if water main pipe
75 – 200 feet if sanitary sewer main pipe	
Well house floor drains to sewers	0 – 25 feet: prohibited
25 – 75 feet if water main pipe
75 – 200 feet if sanitary sewer pipe	0 – 25 feet: prohibited
25 – 75 feet if water main pipe
75 – 200 feet if sanitary sewer main pipe	
Well house floor drains to surface	0 – 5 feet: prohibited
5 – 50 feet if sanitary sewer pipe	0 – 5 feet: prohibited
5 – 50 feet if sanitary sewer main pipe	
Land Disposal of Treated Wastes	
Irrigation of wastewater	200	400	
Land application of solid wastes3	200	400	
Other	
Private sewage disposal systems and onsite treatment systems – open portion of treatment system4	200	400	
Private sewage disposal systems and onsite treatment systems – closed portion of treatment system4	100	200	
Lagoons	400	1000	
Mechanical wastewater treatment plants	200	400	
CHEMICALS:	
Chemical application to ground surface	100	200	
Chemical & mineral storage above ground5,6	100	200	
Chemical & mineral storage on or under ground	200	400	
Transmission pipelines (such as fertilizer, liquid petroleum, or anhydrous ammonia)	200	400	
ANIMALS:	
Animal pasturage	50	50	
Animal enclosure	200	400	
Earthen silage storage trench or pit	100	200	
Animal Wastes	
Land application of liquid or slurry	200	400	
Land application of solids	200	400	
Solids stockpile	200	400	
Storage basin or lagoon	400	1000	
Storage tank	200	400	
MISCELLANEOUS:	
Basements, pits, sumps	10	10	
Cemeteries	200	200	
Cisterns	50	100	
Flowing streams or other surface water bodies	50	50	
GHEX loop boreholes	200	200	
Railroads	100	200	
Private wells	200	400	
Solid waste landfills and disposal sites 7	1000	1000	
1Deep and shallow wells, as defined in 567—40.2(455B): A deep well is a well located and constructed in such a manner that there is a continuous layer of low permeability soil or rock at least 5 feet thick located at least 25 feet below the normal ground surface and above the aquifer from which water is to be drawn. A shallow well is a well located and constructed in such a manner that there is not a continuous layer of low permeability soil or rock (or equivalent retarding mechanism acceptable to the department) at least 5 feet thick, the top of which is located at least 25 feet below the normal ground surface and above the aquifer from which water is to be drawn.
2The separation distances are dependent upon two factors: the type of piping that is in the existing sewer or drain, as noted in the table, and that the piping was properly installed in accordance with the standards.
3Solid wastes are those derived from the treatment of water or wastewater. Certain types of solid wastes from water treatment processes may be land-applied within the separation distance on an individual, case-by-case basis.
4Private sewage disposal system is defined in 567—subrule 69.1(2). “Onsite treatment system” includes any wastewater treatment system not included in the definition of a private sewage disposal system that is utilizing onsite wastewater treatment technologies to treat domestic waste, such as those specified in 567—Chapter 69 (but excluding waste stabilization ponds). Open portions of treatment systems include subsurface absorption systems, mound systems, intermittent sand filters, constructed wetlands, open bottom media filters, and waste stabilization ponds. Closed portions of treatment systems include septic tanks, aerobic treatment units, fully contained media filters and impervious vault toilets. These separation distances also apply to septic systems that are not considered privately owned.
5The minimum separation distance for liquid fuel storage associated with standby power generators shall be 50 feet if secondary containment is provided. Secondary containment shall provide for a minimum of 110 percent of the liquid fuel storage capacity. Double-walled storage tanks shall not be considered as secondary containment. The separation distance for liquefied petroleum gas (LPG) storage shall be 15 feet.
6Electrical power transformers mounted on a single utility pole are exempt from the minimum separation distance requirements.
7Solid waste means garbage, refuse, rubbish, and other similar discarded solid or semisolid materials, including but not limited to such materials resulting from industrial, commercial, agricultural, and domestic activities.
	43.3(8) Drinking water system components. Any drinking water system component which comes into contact with raw, partially treated, or finished water must be suitable for the intended use in a potable water system. The component must be certified by an American National Standards Institute (ANSI) accredited third party for conformance with American National Standards Institute/National Sanitation Foundation (ANSI/NSF) Standard 61 specifications, if such specification exists for the particular product, unless approved components are not reasonably available for use, in accordance with guidance provided by the department. If the component does not meet the ANSI/NSF Standard 61 specifications or no specification is available, the person seeking to supply or use the component must prove to the satisfaction of the department that the component is not toxic or otherwise a potential hazard in a potable public water supply system.
	43.3(9) Water treatment filter media material. For single media filters, grain sizes up to 0.8 mm effective size may be approved for filters designed to remove constituents other than those contained in the primary drinking water standards. Pilot or full-scale studies demonstrating satisfactory treatment efficiency and operation with the proposed media will be required prior to issuing any construction permits which allow filter media sizes greater than 0.55 mm.
	43.3(10) Best available treatment technology.
	a. 	BATs for organic compounds. The department identifies as indicated in the table below either granular activated carbon (GAC), packed tower aeration (PTA), or oxidation (OXID) as the best available technology, treatment technique, or other means available for achieving compliance with the maximum contaminant level for organic contaminants identified in 567—paragraph 41.5(1)“b.”  For the purposes of setting MCLs for synthetic organic chemicals, any BAT must be at least as effective as granular activated carbon.

ORGANIC CONTAMINANT	GAC	PTA	OXID	
Alachlor	x	 	 	
Aldicarb	x	 	 	
Aldicarb sulfone	x	 	 	
Aldicarb sulfoxide	x	 	 	
Atrazine	x	 	 	
Benzene	x	x	 	
Benzo(a)pyrene	x	 	 	
Carbofuran	x	 	 	
Carbon tetrachloride	x	x	 	
Chlordane	x	 	 	
2,4-D	x	 	 	
Dalapon	x	 	 	
Dibromochloropropane (DBCP)	x	x	 	
o-Dichlorobenzene	x	x	 	
p-Dichlorobenzene	x	x	 	
1,2-Dichloroethane	x	x	 	
cis-1,2-Dichloroethylene	x	x	 	
trans-1,2-Dichloroethylene	x	x	 	
1,1-Dichloroethylene	x	x	 	
Dichloromethane	 	x	 	
1,2-Dichloropropane	x	x	 	
Di(2-ethylhexyl)adipate	x	x	 	
Di(2-ethylhexyl)phthalate	x	 	 	
Dinoseb	x	 	 	
Diquat	x	 	 	
Endothall	x	 	 	
Endrin	x	 	 	
Ethylene dibromide (EDB)	x	x	 	
Ethylbenzene	x	x	 	
Glyphosate	 	 	x	
Heptachlor	x	 	 	
Heptachlor epoxide	x	 	 	
Hexachlorobenzene	x	 	 	
Hexachlorocyclopentadiene	x	x	 	
Lindane	x	 	 	
Methoxychlor	x	 	 	
Monochlorobenzene	x	x	 	
Oxamyl (Vydate)	x	 	 	
Pentachlorophenol	x	 	 	
Picloram	x	 	 	
Polychlorinated biphenyls (PCB)	x	 	 	
Simazine	x	 	 	
Styrene	x	x	 	
2,4,5-TP (Silvex)	x	 	 	
Tetrachloroethylene	x	x	 	
1,2,4-Trichlorobenzene	x	x	 	
1,1,1-Trichloroethane	x	x	 	
1,1,2-Trichloroethane	x	x	 	
Trichloroethylene	x	x	 	
2,3,7,8-TCDD (Dioxin)	x	 	 	
Toluene	x	x	 	
Toxaphene	x	 	 	
Vinyl chloride	 	x	 	
Xylene	x	x	 	
	b. 	BATs for inorganic compounds and radionuclides.
	(1)	Inorganic compounds. The department identifies the following as the best technology, treatment techniques, or other means available for achieving compliance with the maximum contaminant levels for the inorganic contaminants listed in 567—paragraph 41.3(1)“b,” except fluoride.

INORGANIC CHEMICAL	BAT(s)	
Antimony	2, 7	
Arsenicd	1, 2, 5, 6, 7, 9, 11e	
Asbestos	2, 3, 8	
Barium	5, 6, 7, 9	
Beryllium	1, 2, 5, 6, 7	
Cadmium	2, 5, 6, 7	
Chromium	2, 5, 6b, 7	
Cyanide	5, 7, 12	
Mercury	2a, 4, 6a, 7a	
Nickel	5, 6, 7	
Nitrate	5, 7, 9	
Nitrite	5, 7	
Selenium	1, 2c, 6, 7, 9	
Thallium	1, 5	
Key to BATs

1=Activated Alumina	5=Ion Exchange	9=Electrodialysis	
2=Coagulation/Filtration*	6=Lime Softening*	10=Chlorine	
3=Direct and Diatomite Filtration	7=Reverse Osmosis	11=Oxidation/Filtration	
4=Granular Activated Carbon	8=Corrosion Control	12=Alkaline Chlorination (pH greater than or equal to 8.5)	
*not BAT for systems with less than 500 service connections
aBAT only if influent Hg concentrations are less than or equal to 10 micrograms/liter.
bBAT for Chromium III only.
cBAT for Selenium IV only.
dBAT for Arsenic V. Preoxidation may be required to convert Arsenic III to Arsenic V.
eTo obtain high removals, iron to arsenic ratio must be at least 20:1.
	(2)	Small system compliance technologies for arsenic. The department identifies in the following table the affordable technology, treatment techniques, or other means available to systems serving 10,000 or fewer persons for achieving compliance with the arsenic maximum contaminant level.
SMALL SYSTEM COMPLIANCE TECHNOLOGIES FOR ARSENIC1

Technology	Affordable for listed small system categories2	
Activated alumina	All size categories	
Coagulation/filtration3	501 – 3,300 and 3,301 – 10,000	
Coagulation-assisted microfiltration	501 – 3,300 and 3,301 – 10,000	
Electrodialysis reversal4	501 – 3,300 and 3,301 – 10,000	
Enhanced coagulation/filtration	All size categories	
Enhanced lime softening (pH > 10.5)	All size categories	
Ion exchange	All size categories	
Lime softening3	501 – 3,300 and 3,301 – 10,000	
Oxidation/filtration5	All size categories	
Reverse osmosis4	501 – 3,300 and 3,301 – 10,000	
1Technologies are for Arsenic V. Preoxidation may be required to convert Arsenic III to Arsenic V.
2There are three categories of small systems: those serving 25 to 500 people, those serving 501 to 3,300 people, and those serving 3,301 to 10,000 people.
3Unlikely to be installed solely for arsenic removal. May require pH adjustment to optimal range if high removals are needed.
4Technologies reject a large volume of water. May not be appropriate for areas where water quantity may be an issue.
5To obtain high removals, iron to arsenic ratio must be at least 20:1.
	(3)	Radionuclides.
	1.	The department identifies in the following table the best available technology for achieving compliance with the radionuclide maximum contaminant levels as indicated.
RADIONUCLIDE BAT

Contaminant	Best Available Technology	
Gross alpha particle activity
(excluding radon and uranium)	Reverse osmosis	
Beta particle and photon radioactivity	Ion exchange, reverse osmosis	
Combined radium-226 and radium-228	Ion exchange, reverse osmosis, lime softening	
Uranium	Ion exchange, reverse osmosis, lime softening, coagulation/filtration	
	2.	Small system compliance technologies. The following technologies are identified as radionuclide BAT for systems serving 10,000 or fewer people.
RADIONUCLIDES SMALL SYSTEM COMPLIANCE TECHNOLOGIES

Contaminant	Compliance Technologya	
Gross alpha particle activity	2	
Beta particle and photon radioactivity	1, 2	
Combined radium-226 and radium-228	1, 2, 3, 4, 5, 6, 7	
Uranium	1, 2b, 3b, 8, 9	

 	aCompliance technologies are listed with their corresponding number and potential limitations for use, as follows:	
 	1: Ion exchange. The regeneration solution contains high concentrations of the contaminant ions. Disposal options should be carefully considered before choosing this technology.
2: Reverse osmosis. Reject water disposal options should be carefully considered before choosing this technology.
3: Lime softening. The complexity of the water chemistry may make this technology too complex for small systems.
4: Green sand filtration. Removal efficiencies can vary depending on water quality.
5: Coprecipitation with barium sulfate. This technology has limited applications to small systems, and is most applicable to systems with sufficiently high sulfate levels that already have a suitable filtration treatment train in place.
6: Electrodialysis/electrodialysis reversal.
7: Pre-formed hydrous manganese oxide filtration. This technology is most applicable to small systems that have existing filtration technology.
8: Activated alumina. The regeneration solution contains high concentrations of the contaminant ions. Disposal options should be carefully considered before choosing this technology. Handling of chemicals required during regeneration and pH adjustment requires an adequately trained operator.
9: Enhanced coagulation/filtration. This technology assumes that it is a modification to an existing coagulation/filtration process.	
 	bNot recommended for systems serving 25 to 500 persons.	
	c. 	BATs for disinfection byproducts and disinfectants. The department identifies the following as the best technology, treatment techniques, or other means available for achieving compliance with the maximum contaminant levels for the disinfection byproducts listed in 567—paragraph 41.5(2)“b,” and the maximum residual disinfectant levels listed in 567—paragraph 41.5(2)“c.”

DBP
MCL or MRDL	Best Available Technology	
Bromate MCL	Control of ozone treatment process to reduce production of bromate	
Chlorite MCL	Control of treatment processes to reduce disinfectant demand and control of disinfection treatment processes to reduce disinfectant levels	
HAA5 and TTHM MCL running annual average	Enhanced coagulation or enhanced softening or GAC10, with chlorine as the primary and residual disinfectant	
HAA5 and TTHM MCL LRAA	<fo:wrapper font-family="Times">•</fo:wrapper>	Non-consecutive system: Enhanced coagulation or enhanced softening, plus GAC10; or nanofiltration with a molecular weight cutoff that is less than or equal to 1000 Daltons; or GAC20
<fo:wrapper font-family="Times">•</fo:wrapper>	Consecutive system serving at least 10,000 persons*: Improved distribution system and storage tank management to reduce residence time, plus the use of chloramines for disinfectant residual maintenance
<fo:wrapper font-family="Times">•</fo:wrapper>	Consecutive system serving fewer than 10,000 persons*: Improved distribution system and storage tank management to reduce residence time	
MRDL	Control of treatment processes to reduce disinfectant demand and control of disinfection treatment processes to reduce disinfectant levels	
* Applies only to the disinfected water that consecutive systems buy or otherwise receive.
	d. 	Requirement to install BAT. The department shall require community water systems and nontransient noncommunity water systems to install and use any treatment method identified in 43.3(10) as a condition for granting an interim contaminant level except as provided in paragraph “e.” If, after the system’s installation of the treatment method, the system cannot meet the maximum contaminant level, the system shall be eligible for a compliance schedule with an interim contaminant level granted under the provisions of 567—subrule 42.1(9) and rule 567—43.2(455B).
	e. 	Engineering assessment option. If a system can demonstrate through comprehensive engineering assessments, which may at the direction of the department include pilot plant studies, that the treatment methods identified in 43.3(10) would only achieve a de minimis reduction in contaminants, the department may issue a schedule of compliance that requires the system being granted the variance to examine other treatment methods as a condition of obtaining the interim contaminant level.
	f. 	Compliance schedule. If the department determines that a treatment method identified in 43.3(10)“a,” “b,” and “c” is technically feasible, the department may require the system to install or use that treatment method in connection with a compliance schedule issued under the provisions of 567—subrule 42.1(9) and rule 567—43.2(455B). The determination shall be based upon studies by the system and other relevant information.
	g. 	Avoidance of unacceptable risk to health (URTH). The department may require a public water system to use bottled water, point-of-use devices, point-of-entry devices or other means as a condition of granting a variance or an exemption, or issuance of a compliance schedule, from the requirements of 43.3(10) to avoid an unreasonable risk to health.
[ARC 9915B, IAB 12/14/11, effective 1/18/12; ARC 3735C, IAB 4/11/18, effective 5/16/18; ARC 6190C, IAB 2/9/22, effective 3/16/22]
567—43.4(455B) Certification of completion. Within 30 days after completion of construction, installation or modification of any project, the permit holder shall submit a certification by a licensed professional engineer that the project was completed in accordance with the approved plans and specifications except if the project received a waiver pursuant to 43.3(4).
567—43.5(455B) Filtration and disinfection for surface water and influenced groundwater public water supply systems.
	43.5(1) Applicability/general requirements.
	a. 	These rules apply to all public water supply systems using surface water or groundwater under the direct influence of surface water, in whole or in part, and establish criteria under which filtration is required as a treatment technique. In addition, these rules establish treatment technique requirements in lieu of maximum contaminant levels for Giardia lamblia, heterotrophic plate count bacteria, Legionella, viruses and turbidity. Each public water system with a surface water source or a groundwater source under the direct influence of surface water must provide treatment of that source water which complies with these treatment technique requirements. Systems which serve at least 10,000 persons must also comply with the requirements of 567—43.9(455B). Systems which serve fewer than 10,000 persons must also comply with the requirements of 567—43.10(455B). The treatment technique requirements consist of installing and properly operating water treatment processes which reliably achieve:
	(1)	At least 99.9 percent (3-log) removal or inactivation of Giardia lamblia cysts between a point where the raw water is not subject to recontamination by surface water runoff and a point downstream before or at the first customer; and
	(2)	At least 99.99 percent (4-log) removal or inactivation of viruses between a point where the raw water is not subject to recontamination by surface water runoff and a point downstream before or at the first customer.
	b. 	Criteria for identification of groundwater under the direct influence of surface water. “Groundwater under the direct influence of surface water” means any water beneath the surface of the ground with: (1) significant occurrence of insects or other macroorganisms, algae, or large-diameter pathogens such as Giardia lamblia, or (2) significant and relatively rapid shifts in water characteristics such as turbidity (particulate content), temperature, conductivity, or pH which closely correlate to climatological or surface water conditions. Direct influence must be determined for individual sources in accordance with criteria established by the department. The department determination of direct influence may be based on site-specific measurements of water quality or documentation of well construction characteristics and geology with field evaluation. Only surface water and groundwater sources under the direct influence of surface water that are at risk to the contamination from Giardia cysts are subject to the requirements of this rule. Groundwater sources shall not be subject to this rule. The evaluation process shall be used to delineate between surface water, groundwater under the direct influence of surface water and groundwater. The identification of a source as surface water and groundwater under the direct influence of surface water shall be determined for an individual source, by the department, in accordance with the following criteria. The public water supply shall provide to the department that information necessary to make the determination. The evaluation process will involve one or more of the following steps:
	(1)	Preliminary evaluation. The department shall conduct a preliminary evaluation of information on the source provided by the public water supply to determine if the source is an obvious surface water (e.g., pond, lake, stream) or groundwater under the direct influence of surface water. The source shall be evaluated during that period of highest susceptibility to influence from surface water. The preliminary evaluation may include a review of surveys, reports, geological information of the area, physical properties of the source, and a review of departmental and public water system records. If the source is identified as a surface water, no additional evaluation shall be conducted. If the source is a groundwater and identified as a deep well, it shall be classified as a groundwater not under the direct influence of surface water and no additional evaluation shall be conducted, unless through direct knowledge or documentation the source does not meet the requirements of 43.5(1)“b”(2). The deep well shall then be evaluated in accordance with 43.5(1)“b”(3). If the source is a shallow well, the source shall be evaluated in accordance with 43.5(1)“b”(2). If the source is a spring, infiltration gallery, radial collector well, or any other subsurface source, it shall be evaluated in accordance with 43.5(1)“b”(3).
	(2)	Well source evaluation. Shallow wells greater than 50 feet in lateral distance from a surface water source shall be evaluated for direct influence of surface water through a review of departmental or public water system files in accordance with 43.5(1)“b”(2)“1” and 43.5(1)“b”(2)“2.” Sources that meet the criteria shall be considered to be not under the direct influence of surface water. No additional evaluation will be required. Shallow wells 50 feet or less in lateral distance from a surface water shall be in accordance with 43.5(1)“b”(3) and (4).
	1.	Well construction criteria. The well shall be constructed so as to prevent surface water from entering the well or traversing the casing.
	2.	Water quality criteria. Water quality records shall indicate:
	●	No record of total coliform or fecal coliform contamination in untreated samples collected over the past three years.
	●	No history of turbidity problems associated with the well, other than turbidity as a result of inorganic chemical precipitates.
	●	No history of known or suspected outbreak of Giardia or other pathogenic organisms associated with surface water (e.g., Cryptosporidium) which has been attributed to the well.
	3.	Other available data. If data on particulate matter analysis of the well are available, there shall be no evidence of particulate matter present that is associated with surface water. If information on turbidity or temperature monitoring of the well and nearby surface water is available, there shall be no data on the source which correlates with that of a nearby surface water.
	4.	Further evaluation. Wells that do not meet all the requirements listed shall require further evaluation in accordance with 43.5(1)“b”(3) and (4).
	(3)	Formal evaluation. The evaluation shall be conducted by the department or a licensed professional engineer at the direction of the public water supply. The evaluation shall include:
	1.	Complete file review. In addition to the information gathered in 43.5(1)“b”(1), the complete file review shall consider but not be limited to: design and construction details; evidence of direct surface water contamination; water quality analysis; indications of waterborne disease outbreaks; operational procedures; and customer complaints regarding water quality or water-related infectious illness. Sources other than a well source shall be evaluated in a like manner to include a field survey.
	2.	Field survey. A field survey shall substantiate findings of the complete file review and determine if the source is at risk to pathogens from direct surface water influence. The field survey shall examine the following criteria for evidence that surface water enters the source through defects in the source which include but are not limited to: a lack of a surface seal on wells, infiltration gallery laterals exposed to surface water, springs open to the atmosphere, surface runoff entering a spring or other collector, and distances to obvious surface water sources.
A report summarizing the findings of the complete file review and field survey shall be submitted to the department for final review and classification of the source. If the complete file review or field survey demonstrates conclusively that the source is subject to the direct surface water influence, the source shall be classified as under the direct influence of surface water. Either method or both may be used to demonstrate that the source is a surface water or groundwater under the direct influence of surface water. If the findings do not demonstrate conclusive evidence of direct influence of surface water, the analysis outlined in 43.5(1)“b”(4) should be conducted.
	(4)	Particulate analysis and physical properties evaluation.
	1.	Surface water indicators. Particulate analysis shall be conducted to identify organisms which only occur in surface waters as opposed to groundwaters, and whose presence in a groundwater would indicate the direct influence of surface water.
	●	Identification of a Giardia cyst, live diatoms, and blue-green, green, or other chloroplast containing algae in any source water shall be considered evidence of direct surface water influence.
	●	Rotifers and insect parts are indicators of surface water. Without knowledge of which species is present, the finding of rotifers indicates that the source is either directly influenced by surface water, or the water contains organic matter sufficient to support the growth of rotifers. Insects or insect parts shall be considered strong evidence of surface water influence, if not direct evidence.
	●	The presence of coccidia (e.g., Cryptosporidium) in the source water is considered a good indicator of direct influence of surface water. Other macroorganisms (greater than 7 um) which are parasitic to animals and fish such as, but not limited to, helminths (e.g., tapeworm cysts), ascaris, and Diphyllobothrium, shall be considered as indicators of direct influence of surface water.
	2.	Physical properties. Turbidity, temperature, pH and conductivity provide supportive, but less direct, evidence of direct influence of surface water. Turbidity fluctuations of greater than 0.5-1.0 NTU over the course of a year may be indicative of direct influence of surface water. Temperature fluctuations may also indicate surface water influence. Changes in other chemical parameters such as pH, conductivity, or hardness may also give an indirect indication of influence by nearby surface water.
	c. 	Compliance. A public water system using a surface water source or a groundwater source under the direct influence of surface water is considered to be in compliance with the requirements of this subrule if it meets the filtration requirements in 43.5(3) and the disinfection requirements in 43.5(2) in accordance with the effective dates specified within the respective subrules.
	d. 	Certified operator requirement. Each public water system using a surface water source or a groundwater source under the direct influence of surface water must be operated by a certified operator who meets the requirements of 567—Chapter 81.
	43.5(2) Disinfection. All community and noncommunity public water supply systems using surface water or groundwater under the direct influence of surface water in whole or in part shall be required to provide disinfection in compliance with this subrule and filtration in compliance with 43.5(3). If the department has determined that filtration is required, the system must comply with any interim disinfection requirements the department deems necessary before filtration is installed. A system providing filtration on or before December 30, 1991, must meet the disinfection requirements of this subrule beginning June 29, 1993. A system providing filtration after December 30, 1991, must meet the disinfection requirements of this subrule when filtration is installed. Failure to meet any requirement of this subrule after the applicable date specified in this subrule is a treatment technique violation. The disinfection requirements are as follows:
	a. 	Disinfection treatment criteria. The disinfection treatment must be sufficient to ensure that the total treatment processes of that system achieve at least 99.9 percent (3-log) inactivation or removal of Giardia lamblia cysts and at least 99.99 percent (4-log) inactivation or removal of viruses, acceptable to the department. At least 0.5 log inactivation of Giardia lamblia cysts must be achieved through disinfection treatment using a chemical disinfectant even if the required inactivation or removal is met or exceeded through physical treatment processes. Each system is required to calculate the total inactivation ratio (CTcalculated/CTrequired) each day the treatment plant is in operation. The system’s total inactivation ratio must be equal to or greater than 1.0 in order to ensure that the minimum inactivation and removal requirements have been achieved. If the system’s total inactivation ratio for the day is below 1.0, the system must notify the department within 24 hours.
	b. 	Disinfection system. The disinfection system must include:
	(1)	Redundant components, including an auxiliary power supply with automatic start-up and alarm to ensure that disinfectant application is maintained continuously while water is being delivered to the distribution system, or
	(2)	Automatic shutoff of delivery of water to the distribution system whenever there is less than 0.3 mg/L of residual disinfectant concentration in the water. If the department determines that automatic shutoff would cause unreasonable risk to health or interfere with fire protection, the system must comply with 43.5(2)“b”(1).
	c. 	Residual disinfectant entering system. The residual disinfectant concentration in the water entering the distribution system, measured as specified in 43.5(4)“a”(5) and 43.5(4)“b”(2), cannot be less than 0.3 mg/L free residual or 1.5 mg/L total residual chlorine for more than four hours.
	d. 	Residual disinfectant in the system. The residual disinfectant concentration in the distribution system, measured as total chlorine, combined chlorine, or chlorine dioxide, as specified in 43.5(4)“a”(5) and 43.5(4)“b”(2), cannot be undetectable in more than 5 percent of the samples each month for any two consecutive months that the system serves water to the public. Water within the distribution system with a heterotrophic plate count bacteria concentration less than or equal to 500/mL, measured as heterotrophic plate count (HPC) as specified in 567—paragraph 41.2(3)“e,” is deemed to have a detectable disinfectant residual for purposes of determining compliance with this requirement. Therefore, the value “V” in the following formula cannot exceed 5 percent in one month for any two consecutive months.

V	=	[	c + d + e	]	×	100	
			a + b				
where:

a =	number of instances in which the residual disinfectant concentration is measured;	
b =	number of instances in which the residual disinfectant concentration is not measured but heterotrophic plate count bacteria (HPC) is measured;	
c =	number of instances in which the residual disinfectant concentration is measured but not detected and no HPC is measured;	
d =	number of instances in which no residual disinfectant concentration is detected and where the HPC is greater than 500/mL; and	
e =	number of instances in which the residual disinfectant concentration is not measured and HPC is greater than 500/mL.	
	43.5(3) Filtration.
	a. 	Applicability. A public water system that uses a surface water source or a groundwater source under the direct influence of surface water must provide treatment consisting of both disinfection, as specified in 43.5(2), and filtration treatment which complies with the turbidity requirements of subrules 43.5(3), 43.5(4), and 43.5(5). A system providing or required to provide filtration on or before December 30, 1991, must meet the requirements of this subrule by June 29, 1993. A system providing or required to provide filtration after December 30, 1991, must meet the requirements of this subrule when filtration is installed. Beginning January 1, 2002, systems serving at least 10,000 people must meet the turbidity requirements in 567—43.9(455B). Beginning January 1, 2005, systems serving fewer than 10,000 people must meet the turbidity requirements in 567—43.10(455B). A system shall install filtration within 18 months after the department determines, in writing, that filtration is required. The department may require and the system shall comply with any interim turbidity requirements the department deems necessary. Failure to meet any requirements of the referenced subrules after the dates specified is a treatment technique violation.
	b. 	Conventional filtration treatment or direct filtration.
	(1)	For systems using conventional filtration or direct filtration, the turbidity level of representative samples of a system’s filtered water must be less than or equal to 0.5 nephelometric turbidity units (NTU) in at least 95 percent of the measurements taken each month when measured as specified in 43.5(4)“a”(1) and 43.5(4)“b”(1).
	(2)	The turbidity level of representative samples of a system’s filtered water must at no time exceed 5 NTU when measured as specified in 43.5(4)“a”(1) and 43.5(4)“b”(1).
	c. 	Slow sand filtration.
	(1)	For systems using slow sand filtration, the turbidity level of representative samples of a system’s filtered water must be less than or equal to 1 NTU in at least 95 percent of the measurements taken each month when measured as specified in 43.5(4)“a”(1) and 43.5(4)“b”(1).
	(2)	The turbidity level of representative samples of a system’s filtered water must at no time exceed 5 NTU when measured as specified in 43.5(4)“a”(1) and 43.5(4)“b”(1).
	d. 	Diatomaceous earth filtration.
	(1)	For systems using diatomaceous earth filtration, the turbidity level of representative samples of a system’s filtered water must be less than or equal to 1 NTU in at least 95 percent of the measurements taken each month when measured as specified in 43.5(4)“a”(1) and 43.5(4)“b”(1).
	(2)	The turbidity level of representative samples of a system’s filtered water must at no time exceed 5 NTU when measured as specified in 43.5(4)“a”(1) and 43.5(4)“b”(1).
	e. 	Other filtration technologies. A public water system may use either a filtration technology not listed in 43.5(3)“b” to 43.5(3)“d” or a filtration technology listed in 43.5(3)“b” or 43.5(3)“c” at a higher turbidity level if it demonstrates to the department through a preliminary report submitted by a licensed professional engineer, using pilot plant studies or other means, that the alternative filtration technology in combination with disinfection treatment that meets the requirements of 43.5(2) consistently achieves 99.9 percent removal or inactivation of Giardia lamblia and 99.99 percent removal or inactivation of viruses. For a system that uses alternative filtration technology and makes this demonstration, the turbidity treatment technique requirements are as follows:
	(1)	The turbidity level of representative samples of a system’s filtered water must be less than or equal to 1 NTU in at least 95 percent of the measurements taken each month when measured as specified in 43.5(4)“a”(1) and 43.5(4)“b”(1).
	(2)	The turbidity level of representative samples of a system’s filtered water must at no time exceed 5 NTU when measured as specified in 43.5(4)“a”(1) and 43.5(4)“b”(1).
Beginning January 1, 2002, systems serving at least 10,000 people must meet the requirements for other filtration technologies in 43.9(3)“b.”
Beginning January 1, 2005, systems serving fewer than 10,000 people must meet the requirements for other filtration technologies in 567—43.10(455B).
	43.5(4) Analytical and monitoring requirements.
	a. 	Analytical requirements. Only the analytical method(s) specified in this paragraph, or otherwise approved by the department, may be used to demonstrate compliance with the requirements of 43.5(2) and 43.5(3). Measurements for pH, temperature, turbidity, and residual disinfectant concentrations must be conducted by a Grade II, III or IV operator meeting the requirements of 567—Chapter 81, any person under the supervision of a Grade II, III or IV operator meeting the requirements of 567—Chapter 81, or a laboratory certified by the department to perform analysis under 567—Chapter 83. For consecutive public water supplies from a surface water or groundwater under the direct influence of surface water system, the disinfectant concentration analyses must be conducted by a certified operator who meets the requirements of 567—Chapter 81. Measurements for heterotrophic plate count bacteria must be conducted by a laboratory certified by the department to do such analysis.
	(1)	Turbidity analytical methodology. Turbidity analysis shall be conducted using the methodology in the following table. Each turbidimeter must be calibrated at least once every 90 days with a primary standard. The calibration of each turbidimeter used for compliance must be verified at least once per week with a primary standard, secondary standards, or the manufacturer’s proprietary calibration confirmation device or by a method approved by the department. If the verification is not within plus or minus 0.05 NTU for measurements of less than or equal to 0.5 NTU, or within plus or minus 10 percent of measurements greater than 0.5 NTU, the turbidimeter must be recalibrated.

 	Analytical Method	
Methodology	EPA	SM	GLI	HACH	Other	
Nephelometric5	180.11	2130B2	Method 23	FilterTrak 101334	 	
Laser Nephelometry (online)	 	 	 	 	Mitchell M52716; Mitchell M5331 Rev.	1.210	
LED Nephelometry (online)	 	 	 	 	Mitchell M53317; Mitchell M5331 Rev.	1.210; AMI Turbiwell9	
LED Nephelometry (portable)	 	 	 	 	Orion AQ45008	
360-degree
Nephelometry	 	 	 	 	Hach Method 1025811	
1“Methods for the Determination of Inorganic Substances in Environmental Samples,” EPA-600/R-93-100, August 1993. Available at NTIS, PB94-121811.
2Standard Methods for the Examination of Water and Wastewater, 18th edition, 1992, 19th edition, 1995, 20th edition, 1998, 21st edition, 2005, and 22nd edition, 2012 (any of these editions may be used), American Public Health Association, 800 I Street, NW, Washington, DC 20001-3710.
3GLI Method 2, “Turbidity,” November 2, 1992, Great Lakes Instruments, Inc., 8855 North 55th Street, Milwaukee, WI 53223.
4Hach FilterTrak Method 10133, “Determination of Turbidity by Laser Nephelometry,” January 2000, Revision 2.0, Hach Co., P.O. Box 389, Loveland, CO 80539-0389, telephone (800)227-4224.
5Styrene divinyl benzene beads (e.g., AMCO-AEPA-1 or equivalent) and stabilized formazin (e.g., Hach StablCalTM or equivalent) are acceptable substitutes for formazin.
6Mitchell Method M5271, Revision 1.1. “Determination of Turbidity by Laser Nephelometry,” March 5, 2009. Available at www.nemi.gov or from Leck Mitchell, 656 Independence Valley Drive, Grand Junction, CO 81507.
7Mitchell Method M5331, Revision 1.1. “Determination of Turbidity by LED Nephelometry,” March 5, 2009. Available at www.nemi.gov or from Leck Mitchell, 656 Independence Valley Drive, Grand Junction, CO 81507.
8Orion Method AQ4500, Revision 1.0. “Determination of Turbidity by LED Nephelometry,” May 8, 2009. Available at www.nemi.gov or from Thermo Scientific, 166 Cummings Center, Beverly, MA 01915, www.thermo.com.
9AMI Turbiwell, “Continuous Measurement of Turbidity Using a SWAN AMI Turbiwell Turbidimeter,” August 2009. Available at www.nemi.gov or from Markus Bernasconi, SWAN Analytische Instrumente AG, Studbachstrasse 13, CH-8340 Hinwil, Switzerland.
10Mitchell Method M5331, Revision 1.2. “Determination of Turbidity by LED or Laser Nephelometry,” February 2016. Available from Leck Mitchell, 656 Independence Valley Drive, Grand Junction, CO 81507.
11Hach Company. “Hach Method 10258 – Determination of Turbidity by 360-Degree Nephelometry,” January 2016. Available at www.hach.com.
	(2)	Temperature analytical methodology. The temperature shall be determined in compliance with the methodology listed in 567—subparagraph 41.4(1)“g”(1).
	(3)	pH (hydrogen ion concentration) analytical methodology. The pH shall be determined in compliance with the methodology listed in 567—subparagraph 41.4(1)“g”(1).
	(4)	Heterotrophic plate count bacteria analytical methodology. The heterotrophic plate count bacteria sampling and analysis shall be conducted in compliance with 567—subrule 41.2(3) and 43.5(2)“d.” The time from sample collection to initiation of analysis shall not exceed eight hours, and the samples must be held below 10 degrees C during transit.
	(5)	Residual disinfectant analytical methodology. The residual disinfectant concentrations shall be determined in compliance with one of the analytical methods in the following table. Residual disinfectant concentrations for free chlorine and combined chlorine may also be measured by using DPD colorimetric test kits. Free and total chlorine residuals may be measured continuously by adapting a specified chlorine residual method for use with a continuous monitoring instrument provided the chemistry, accuracy and precision remain the same. Instruments used for continuous monitoring must be verified with a grab sample measurement at least every seven days. The analyzer concentration must be within plus or minus 0.1 mg/L or plus or minus 15 percent (whichever is larger) of the grab sample measurement. If the verification is not within this range, immediate actions must be taken to resolve the issue and another verification must be conducted.
Disinfectant Analytical Methodology

Residual	Methodology	Standard Methods1,2	Standard Methods Online6	Other	
Free chlorine	Amperometric Titration	4500-Cl D	4500-Cl D-00	D1253-034, 08, 14	
	DPD Ferrous Titrimetric	4500-Cl F	4500-Cl F-00	 	
	DPD Colorimetric	4500-Cl G	4500-Cl G-00	Hach Method 1026010	
	Syringaldazine (FACTS)	4500-Cl H	4500-Cl H-00	 	
	Online Chlorine Analyzer	 	 	EPA 334.07	
	Amperometric Sensor	 	 	ChloroSense8	
	Indophenol Colorimetric	 	 	Hach Method 1024111	
Total chlorine	Amperometric Titration	4500-Cl D	4500-Cl D-00	D1253-034, 08, 14	
	Amperometric Titration (low-level measurement)	4500-Cl E	4500-Cl E-00	 	
	DPD Ferrous Titrimetric	4500-Cl F	4500-Cl F-00	 	
	DPD Colorimetric	4500-Cl G	4500-Cl G-00	Hach Method 1026010	
	Iodometric Electrode	4500-Cl I	4500-Cl I-00	 	
	Online Chlorine Analyzer	 	 	EPA 334.07	
	Amperometric Sensor	 	 	ChloroSense8	
Chlorine dioxide	Amperometric Titration	4500-ClO2 C	4500-C102 C-00	 	
	DPD Method	4500-ClO2 D	 	 	
	Amperometric Titration	4500-ClO2 E	4500-C102 E-00	 	
	Amperometric Sensor	 	 	ChlordioX Plus9	
	Spectrophotometric	 	 	327.0, Revision 1.15	
Ozone	Indigo method	4500-O3 B3	4500-O3 B-97	 	
1Standard Methods for the Examination of Water and Wastewater, 18th edition, 1992, 19th edition, 1995, 20th edition, 1998, 21st edition, 2005, or 22nd edition, 2012 (any of these editions may be used), American Public Health Association, 800 I Street, NW, Washington, DC 20001-3710. Only the 18th, 19th, and 20th editions may be used for chlorine dioxide Method 4500-ClO2 D.
2Other analytical test procedures are contained within Technical Notes on Drinking Water Methods, EPA-600/R-94-173, October 1994, which is available as NTIS PB95-104766.
3Standard Methods for the Examination of Water and Wastewater, 18th edition (1992), 19th edition (1995), 21st edition (2005), and 22nd edition (2012) ( any edition may be used); American Public Health Association, 800 I Street, NW, Washington, DC 20001-3710.
4Annual Book of ASTM Standards, Vol. 11.01, 2004; ASTM International; any year containing the cited version of the method may be used. Copies of this method may be obtained from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959.
5EPA Method 327.0, Revision 1.1, “Determination of Chlorine Dioxide and Chlorite Ion in Drinking Water Using Lissamine Green B and Horseradish Peroxidase with Detection by Visible Spectrophotometry,” US EPA, May 2005, EPA 815-R-05-008. Available online at www.nemi.gov.
6Standard Methods Online is available at www.standardmethods.org. The year in which each method was approved by the Standard Methods Committee is designated by the last two digits in the method number. The methods listed are the only online versions that may be used.
7EPA Method 334.0, “Determination of Residual Chlorine in Drinking Water Using an On-Line Chlorine Analyzer,” August 2009. EPA 815-B-09-013. Available at www.nemi.gov.
8ChloroSense, “Measurement of Free and Total Chlorine in Drinking Water by Palintest ChloroSense,” September 2009. Available at www.nemi.gov or from Palintest Ltd., 21 Kenton Lands Road, P.O. Box 18395, Erlanger, KY 41018.
9ChlordioX Plus. “Chlorine Dioxide and Chlorite in Drinking Water by Amperometry Using Disposable Sensors,” November 2013. Available from Palintest Ltd., Jamike Avenue (Suite 100), Erlanger, KY 41018.
10Hach Company. “Hach Method 10260 – Determination of Chlorinated Oxidants (Free and Total) in Water Using Disposable Planar Reagent-Filled Cuvettes and Mesofluidic Channel Colorimetry,” April 2013. Available at www.hach.com.
11Hach Company. “Hach Method 10241 – Spectophotometric Measurement of Free Chlorine in Finished Drinking Water,” November 2015, Revision 1.2. Available at www.hach.com.
	b. 	Monitoring requirements. A public water system that uses a surface water source or groundwater source under the influence of surface water must monitor in accordance with this paragraph.
	(1)	Turbidity.
	1.	Routine turbidity monitoring requirements. Turbidity measurements as required by 43.5(3) must be performed on representative samples of the system’s filtered water every four hours (or more frequently as long as measurements are recorded at equal time intervals and detailed in the turbidity protocol) that the system serves water to the public. A public water system may substitute continuous turbidity monitoring for grab sample monitoring or may monitor more frequently than every four hours if it validates the continuous measurement for accuracy on a regular basis using a turbidity protocol approved by the department and audited for compliance during sanitary surveys. Major elements of the protocol shall include, but are not limited to: sample measurement location, method of calibration, calibration frequency, calibration standards, method of verification, verification frequency, documentation, data collection, data recording frequency, and data reporting. For any systems using slow sand filtration or filtration treatment other than conventional treatment, direct filtration, or diatomaceous earth filtration, the department may reduce the sampling frequency to once per day if it determines that less frequent monitoring is sufficient to indicate effective filtration performance. For systems serving 500 or fewer persons, the department may reduce the turbidity sampling frequency to once per day, regardless of the type of filtration treatment used, if the department determines that less frequent monitoring is sufficient to indicate effective filtration performance. Approval shall be based upon documentation provided by the system, acceptable to the department and pursuant to the conditions of an operation permit.
	2.	Turbidity monitoring requirements for population greater than 100,000. A supplier of water serving a population or population equivalent of greater than 100,000 persons shall provide a continuous or rotating cycle turbidity monitoring and recording device or take hourly grab samples to determine compliance with 43.5(3). The system must meet the requirements in 43.5(4)“b”(1)“1,” including the turbidity protocol.
	3.	Failure of the continuous turbidity monitoring equipment. If there is a failure in the continuous turbidity monitoring equipment, the system must conduct grab sampling every four hours in lieu of continuous monitoring until the turbidimeter is repaired and back online. A system has a maximum of five working days after failure to repair the equipment or else the system is in violation. The system must notify the department within 24 hours of both when the turbidimeter was taken offline and when it was returned online.
	(2)	Residual disinfectant.
	1.	Residual disinfectant entering the system. The residual disinfectant concentration of the water entering the distribution system shall be monitored continuously, and the lowest value recorded each day, except that if there is a failure in the continuous monitoring equipment, grab sampling every four hours may be conducted in lieu of continuous monitoring, but not to exceed five working days following the failure of the equipment. If acceptable to the department, systems serving 3,300 or fewer persons may take grab samples in lieu of providing continuous monitoring on an ongoing basis at the frequencies prescribed below:
Residual Disinfectant Samples Required of Surface Water or IGW PWS

System size (persons served)	Samples per day*	
500 or fewer	1	
501 to 1,000	2	
1,001 to 2,500	3	
2,501 to 3,300	4	

*When more than one grab sample is required per day, the day’s samples cannot be taken at the same time. The sampling intervals must be at a minimum of four-hour intervals.	
If at any time the disinfectant concentration falls below 0.3 mg/L free residual or 1.5 mg/L total residual chlorine in a system using grab sampling in lieu of continuous monitoring, the system shall take a grab sample every four hours until the residual disinfectant concentration is equal to or greater than 0.3 mg/L free residual or 1.5 mg/L total residual chlorine.
	2.	Residual disinfectant in the system. The residual disinfectant concentration must be measured at least daily in the distribution system. Residual disinfectant measurements that are required as part of the total coliform bacteria sample collection under 567—subparagraph 41.2(1)“c”(7) shall be used to satisfy this requirement on the day(s) when a bacteria sample(s) is collected. The department may allow a public water system that uses both a groundwater source and a surface water source or a groundwater source under direct influence of surface water to take residual disinfectant samples at points other than the total coliform sampling points, if these points are included as a part of the coliform sample site plan meeting the requirements of 567—paragraph 41.2(1)“c”(1)“1” and if the department determines that such points are representative of treated (disinfected) water quality within the distribution system. Heterotrophic plate count bacteria (HPC) may be measured in lieu of residual disinfectant concentration, using the analytical methods specified in 567—subparagraph 41.2(3)“e”(1). The time from sample collection to initiation of analysis shall not exceed eight hours. HPC samples must be kept below 10 degrees C during transit to the laboratory. All HPC samples must be analyzed by a department-certified laboratory meeting the requirements of 567—Chapter 83.
	43.5(5) Reporting requirements. Public water supplies shall report the results of routine monitoring required to demonstrate compliance with 567—43.5(455B) and treatment technique violations as follows:
	a. 	Waterborne disease outbreak. Each system, upon discovering that a waterborne disease outbreak potentially attributable to that water system has occurred, must report that occurrence to the department as soon as possible, but no later than by the end of the next business day.
	b. 	Turbidity exceeds 5 NTU. If at any time the turbidity exceeds 5 NTU, the system must inform the department as soon as possible, but no later than 24 hours after the exceedance is known, in accordance with the public notification requirements under 567—subparagraph 42.1(3)“b”(3).
	c. 	Residual disinfectant entering distribution system below 0.3 mg/L free residual chlorine or 1.5 mg/L total residual chlorine. If at any time the residual falls below 0.3 mg/L free residual chlorine or 1.5 mg/L total residual chlorine in the water entering the distribution system, the system must notify the department as soon as possible, but no later than by the end of the next business day. The system also must notify the department by the end of the next business day whether or not the residual was restored to at least 0.3 mg/L free residual chlorine or 1.5 mg/L total residual chlorine within four hours.
	d. 	Routine monitoring reporting requirements. Routine monitoring results shall be provided as part of the monthly operation reports in accordance with 567—40.3(455B) and 567—subrule 42.4(3).
	e. 	Total inactivation ratio below 1.0. If the system’s total inactivation ratio for the day is below 1.0, the system must notify the department within 24 hours.
	43.5(6) Filter backwash recycle provisions. All surface water or influenced groundwater systems that employ conventional filtration or direct filtration treatment and that recycle spent filter backwash water, thickener supernatant, or liquids from dewatering processes must meet the requirements of this subrule.
	a. 	Reporting. A system must notify the department in writing by December 8, 2003, if the system recycles spent filter backwash water, thickener supernatant, or liquids from dewatering processes. This notification must include the following information at a minimum:
	(1)	A plan schematic showing the origin of all flows which are recycled (including, but not limited to, spent filter backwash water, thickener supernatant, and liquids from dewatering processes), the hydraulic conveyance used to transport them, and the location where they are reintroduced back into the treatment plant.
	(2)	Typical recycle flow in gallons per minute (gpm), the highest observed plant flow experience in the previous year (in gpm), design flow for the treatment plant (in gpm), the minimum plant rate (in gpm) during which the filter backwash will be recycled, and department-approved operating capacity for the plant where the department has made such determinations.
	b. 	Treatment technique requirement. Any system that recycles spent filter backwash water, thickener supernatant, or liquids from dewatering processes must return these flows through the processes of a system’s existing conventional or direct filtration system as defined in 567—40.2(455B) or at an alternate location approved by the department by June 8, 2004. However, if capital improvements are required to modify the recycle location to meet this requirement, all capital improvements must be completed no later than June 8, 2006.
	c. 	Record keeping. The system must collect and retain on file the recycle flow information specified below for review and evaluation by the department beginning June 8, 2004.
	(1)	A copy of the recycle notification and information submitted to the department under paragraph “a” of this subrule.
	(2)	A list of all recycle flows and the frequency with which they are returned.
	(3)	The average and maximum backwash flow rate through the filters and the average and maximum duration of the filter backwash process in minutes.
	(4)	The typical filter run length and a written summary of how filter run length is determined.
	(5)	The type of treatment provided for the recycle flow.
	(6)	Data on the physical dimensions of the equalization and treatment units, typical and maximum hydraulic loading rates, type of treatment chemicals used including average dose and frequency of use, and frequency at which solids are removed, if applicable.
[ARC 9915B, IAB 12/14/11, effective 1/18/12; ARC 3735C, IAB 4/11/18, effective 5/16/18]
567—43.6(455B) Residual disinfectant and disinfection byproduct precursors.
	43.6(1) Residual disinfectant.
	a. 	Applicability.
	(1)	CWS and NTNC systems. This rule establishes criteria under which CWS and NTNC public water supply systems that add a chemical disinfectant to the water in any part of the drinking water treatment process or that provide water that contains a chemical disinfectant must modify their practices to meet the MCLs listed in 567—41.6(455B), the maximum residual disinfectant levels (MRDL) listed in this subrule, and treatment technique requirements for disinfection byproduct precursors listed in subrule 43.6(3).
	(2)	TNC systems with chlorine dioxide disinfection. This rule establishes criteria under which TNC public water supply systems that use chlorine dioxide as a disinfectant or oxidant must modify their practices to meet the chlorine dioxide MRDL listed in paragraph 43.6(1)“b.”
	(3)	Compliance dates. Compliance dates for this rule are based upon the source water type and the population served. Systems are required to comply with this rule as follows, unless otherwise noted:
	1.	Surface water and IGW CWS and NTNC. CWS and NTNC systems using surface water or groundwater under the direct influence of surface water (IGW) in whole or in part and which serve 10,000 or more persons must comply with this rule beginning January 1, 2002. CWS and NTNC surface water or IGW systems serving fewer than 10,000 persons must comply with this rule beginning January 1, 2004.
	2.	Groundwater CWS and NTNC. CWS and NTNC systems using only groundwater not under the direct influence of surface water must comply with this rule beginning January 1, 2004.
	3.	TNC using chlorine dioxide. TNC systems serving over 10,000 persons and using surface water or groundwater under the direct influence of surface water and using chlorine dioxide as a disinfectant or oxidant must comply with any requirements for chlorine dioxide in this rule beginning January 1, 2002. TNC systems serving 10,000 persons or less, regardless of source water type, and using chlorine dioxide as a disinfectant or oxidant must comply with any requirements for chlorine dioxide in this rule beginning January 1, 2004.
	4.	Extension of compliance period for GAC or membrane technology installation. A system that is installing GAC or membrane technology to comply with this rule may apply to the department for an extension of up to 24 months past the dates in 43.6(1)“a”(3), but not beyond December 31, 2003. In granting the extension, the department will set a schedule for compliance and may specify any interim measures the system must take. Failure to meet a compliance schedule or interim treatment requirements constitutes a violation of the public drinking water supply rules, requires public notification per 567—subrule 42.1(1), and may result in an administrative order.
	(4)	Control of residual disinfectants. Notwithstanding the MRDLs in this rule, systems may increase residual disinfectant levels of chlorine or chloramines (but not chlorine dioxide) in the distribution system to a level and for a time necessary to protect public health, to address specific microbiological contamination problems caused by circumstances such as, but not limited to, distribution line breaks, storm run-off events, source water contamination events, or cross-connection events.
	(5)	Consecutive systems. Consecutive systems that provide water containing a disinfectant or oxidant are required to comply with this rule.
	(6)	Systems with multiple water sources. Systems with water sources that are used independently from each other, are not from the same source as determined by the department, or do not go through identical treatment processes are required to conduct the monitoring for the applicable disinfectants or oxidants and disinfection byproducts during operation of each source. The system must comply with this rule during the use of each water source.
	b. 	Maximum residual disinfectant levels. Maximum residual disinfectant levels (MRDLs) are as follows:

Disinfection Residual	MRDL (mg/L)	
Chloramines	4.0 as Cl2	
Chlorine	4.0 as Cl2	
Chlorine dioxide	0.8 as ClO2	
	c. 	Monitoring requirements for residual disinfectants.
	(1)	General requirements.
	1.	Systems must take all samples during normal operating conditions. If the system does not use the disinfectant or oxidant on a daily basis, the system must conduct the required daily monitoring each day the disinfectant or oxidant is used, and any required monthly monitoring during those months in which the disinfectant or oxidant is used during any portion of the month.
	2.	Failure to monitor in accordance with the monitoring plan required under 43.6(1)“c”(1)“5” is a monitoring violation.
	3.	Failure to monitor is a violation for the entire period covered by the annual average where compliance is based on a running annual average of monthly or quarterly samples or averages and the system’s failure to monitor makes it impossible to determine compliance with MRDLs.
	4.	Systems may use only data collected under the provisions of this rule or of 567—41.6(455B) to qualify for reduced monitoring.
	5.	Systems required to monitor under the provisions of this rule or of 567—41.6(455B) must develop and implement a monitoring plan, in accordance with 567—paragraph 41.6(1)“c”(1)“6.”
	(2)	Chlorine and chloramines.
	1.	Routine monitoring. Community and nontransient noncommunity water systems that use chlorine or chloramines must measure the residual disinfectant level at the same points in the distribution system and at the same time as total coliforms are sampled, as specified in 567—subrule 41.2(1). Surface water and groundwater under the direct influence of surface water systems may use the results of residual disinfectant concentration sampling conducted under 43.5(4)“b”(2)“2,” in lieu of taking separate samples.
	2.	Reduced monitoring. Chlorine and chloramine monitoring may not be reduced.
	(3)	Chlorine dioxide.
	1.	Routine monitoring. Any public water supply systems that use chlorine dioxide for disinfection or oxidation must take daily samples at the entrance to the distribution system. For any daily sample that exceeds the MRDL, the system must take samples in the distribution system the following day at the locations required by 43.6(1)“c”(3)“2,” in addition to the sample required at the entrance to the distribution system.
	2.	Additional monitoring. On each day following a routine sample monitoring result that exceeds the MRDL, the system is required to take three chlorine dioxide distribution system samples.
	●	If chlorine dioxide or chloramines are used to maintain a residual disinfectant in the distribution system, or if chlorine is used to maintain a residual disinfectant in the distribution system and there are no disinfection addition points after the entrance to the distribution system (i.e., no booster chlorination), the system must take three samples as close to the first customer as possible, at intervals of at least six hours.
	●	If chlorine is used to maintain a residual disinfectant in the distribution system and there are one or more disinfection addition points after the entrance to the distribution system (i.e., booster chlorination), the system must take one sample at each of the following locations: as close to the first customer as possible, in a location representative of average residence time, and as close to the end of the distribution system as possible (reflecting maximum residence time in the distribution system).
	3.	Reduced monitoring. Chlorine dioxide monitoring may not be reduced.
	d. 	Analytical requirements for residual disinfectants.
	(1)	Analytical methods. Systems must measure residual disinfectant concentrations for free chlorine, combined chlorine (chloramines), and chlorine dioxide by the methods listed in the following table:
Approved Methods for Residual Disinfectant Compliance Monitoring

Methodology	Standard Methods	Other Method	Residual measured1	
			Free
Chlorine	Combined Chlorine	Total
Chlorine	Chlorine Dioxide	
Amperometric Titration	4500-Cl D	ASTM: D 1253-86 (96), 03, 08, 14	X	X	X	 	
Low Level Amperometric Titration	4500-Cl E	 	 	 	X	 	
DPD Ferrous Titrimetric	4500-Cl F	 	X	X	X	 	
DPD Colorimetric	4500-Cl G	Hach Method 102604	X	X	X	 	
Syringaldazine (FACTS)	4500-Cl H	 	X	 	 	 	
Amperometric Sensor	 	ChloroSense3	X	 	X	 	
Online Chlorine Analyzer	 	EPA 334.02	X	 	X	 	
Indophenol Colorimetric	 	Hach Method 102416	X	X	X	 	
Iodometric Electrode	4500-Cl I	 	 	 	X	 	
DPD	4500-ClO2 D	 	 	 	 	X	
Amperometric Method II	4500-ClO2 E	 	 	 	 	X	
Lissamine Green Spectrophotometric	 	EPA: 327.0 Rev.	1.1	 	 	 	X	
Amperometric Sensor	 	ChlordioX Plus5	 	 	 	X	
The procedures shall be done in accordance with the documents listed below. The incorporation by reference of the following documents was approved by the Director of the Federal Register on February 16, 1999, in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies of the documents may be obtained from the sources listed below. Information regarding obtaining these documents can be obtained from the Safe Drinking Water Hotline at (800)426-4791. Documents may be inspected at EPA’s Drinking Water Docket, 401 M Street, SW, Washington, DC 20460 (telephone: (202)260-3027); or at the Office of Federal Register, 800 North Capitol Street, NW, Suite 700, Washington, DC 20408.
The following method is available from the American Society for Testing and Materials, 100 Barr Harbor Drive, West Conshohocken, PA 19428:
Annual Book of ASTM Standards, Volume 11.01, American Society for Testing and Materials, 1996: Method D 1253-86.
The following methods are available from the American Public Health Association, 800 I Street, NW, Washington, DC 20001-3710:
Standard Methods for the Examination of Water and Wastewater, 19th  (1995), 20th (1998), 21st (2005), and 22nd (2012) editions, American Public Health Association: Methods: 4500-Cl D, 4500-Cl E, 4500-Cl F, 4500-Cl G, 4500-Cl H, 4500-Cl I, 4500-ClO2 E. Only the 19th and 20th editions may be used for the chlorine dioxide Method 4500-ClO2 D.
The following methods are available from the National Technical Information Service, U.S. Department of Commerce, 5285 Port Royal Road, Springfield, VA 22161 (telephone: (800)553-6847):
“Determination of Chlorine Dioxide and Chlorite Ion in Drinking Water Using Lissamine Green B and Horseradish Peroxidase with Detection by Visible Spectrophotometry, Revision 1.1,” USEPA, May 2005, EPA 815-R-05-008.
1X indicates method is approved for measuring specified residual disinfectant. Free chlorine or total chlorine may be measured for demonstrating compliance with the chlorine MRDL, and combined chlorine or total chlorine may be measured for demonstrating compliance with the chloramine MRDL.
2EPA Method 334.0, “Determination of Residual Chlorine in Drinking Water Using an On-Line Chlorine Analyzer,” August 2009. EPA 815-B-09-013. Available at www.epa/gov/safewater/methods/analyticalmethods_ogwdw.html.
3ChloroSense, “Measurement of Free and Total Chlorine in Drinking Water by Palintest ChloroSense,” September 2009. Available at www.nemi.gov or from Palintest Ltd., 21 Kenton Lands Road, P.O. Box 18395, Erlanger, KY 41018.
4Hach Method 10260, “Determination of Chlorinated Oxidants (Free and Total) in Water Using Disposable Planar Reagent-Filled Cuvettes and Mesofluidic Channel Colorimetry,” April 2013. Available at Hach Company, P.O. Box 389, Loveland, CO 80539, or www.hach.com.
5ChlordioX Plus. “Chlorine Dioxide and Chlorite in Drinking Water by Amperometry Using Disposable Sensors,” November 2013. Available from Palintest Ltd., Jamike Avenue (Suite 100), Erlanger, KY 41018.
6Hach Company. “Hach Method 10241 – Spectrophotometric Measurement of Free Chlorine in Finished Drinking Water,” November 2015, Revision 1.2. Available at www.hach.com.
	(2)	Test kit use. Systems may also measure residual disinfectant concentrations for chlorine, chloramines, and chlorine dioxide by using DPD colorimetric test kits acceptable to the department. Free and total chlorine residual disinfectant concentrations may be measured continuously by adapting a specified chlorine residual method for use with a continuous monitoring instrument provided the chemistry, accuracy, and precision remain the same. Instruments used for continuous monitoring must be calibrated with a grab sample measurement at least every five days.
	(3)	Operator requirement. Measurements for residual disinfectant concentration shall be conducted by a Grade A through IV operator meeting the requirements of 567—Chapter 81, any person under the direct supervision of a Grade A through IV operator meeting the requirements of 567—Chapter 81, or a laboratory certified by the department to perform analysis under 567—Chapter 83.
	e. 	Compliance requirements for residual disinfectants.
	(1)	General requirements.
	1.	When compliance is based on a running annual average of monthly or quarterly samples or averages and the system’s failure to monitor makes it impossible to determine compliance with MRDLs for chlorine and chloramines, this failure to monitor will be treated as a monitoring violation for the entire period covered by the annual average.
	2.	All samples taken and analyzed under the provisions of this rule must be included in determining compliance, even if that number is greater than the minimum required.
	(2)	Chlorine and chloramines.
	1.	Compliance must be based on a running annual arithmetic average, computed quarterly, of monthly averages of all samples collected by the system under 43.6(1)“c”(2). If the average covering any consecutive four-quarter period exceeds the MRDL, the system is in violation of the MRDL and must notify the public pursuant to 567—42.1(455B), in addition to reporting to the department pursuant to 567—paragraph 42.4(3)“d.”
	2.	In cases where systems switch between the use of chlorine and chloramines for residual disinfection during the year, compliance must be determined by including together all monitoring results of both chlorine and chloramines in calculating compliance. Reports submitted pursuant to 567—paragraph 42.4(3)“d” must clearly indicate which residual disinfectant was analyzed for each sample.
	(3)	Chlorine dioxide.
	1.	Acute violations. Compliance must be based on consecutive daily samples collected by the system under 43.6(1)“c”(3). If any daily sample taken at the entrance to the distribution system exceeds the MRDL, and on the following day one or more of the three samples taken in the distribution system exceed the MRDL, the system is in violation of the MRDL and shall take immediate corrective action to lower the level of chlorine dioxide below the MRDL and shall notify the public pursuant to the Tier 1 requirements in 567—subrule 42.1(2) in addition to reporting to the department pursuant to 567—paragraph 42.4(3)“d.” Failure to take samples in the distribution system the day following an exceedance of the chlorine dioxide MRDL at the entrance to the distribution system will also be considered an MRDL violation and the system must notify the public of the violation in accordance with the provisions for Tier 1 violations in 567—subrule 42.1(2), in addition to reporting to the department pursuant to 567—paragraph 42.4(3)“d.”
	2.	Nonacute violations. Compliance must be based on consecutive daily samples collected by the system under 43.6(1)“c”(3). If any two consecutive daily samples taken at the entrance to the distribution system exceed the MRDL and all distribution system samples taken are below the MRDL, the system is in violation of the MRDL and must take corrective action to lower the level of chlorine dioxide below the MRDL at the point of sampling and will notify the public pursuant to the Tier 2 requirements in 567—subrule 42.1(3), in addition to reporting to the department pursuant to 567—paragraph 42.4(3)“d.” Failure to monitor at the entrance to the distribution system the day following an exceedance of the chlorine dioxide MRDL at the entrance to the distribution system is also an MRDL violation and the system must notify the public of the violation in accordance with the provisions for Tier 2 violations in 567—subrule 42.1(3), in addition to reporting to the department pursuant to 567—paragraph 42.4(3)“d.”
	f. 	Reporting requirements for disinfectants. Systems required to sample quarterly or more frequently must report to the department within ten days after the end of each quarter in which samples were collected, notwithstanding the public notification provisions of 567—42.1(455B). Systems required to sample less frequently than quarterly must report to the department within ten days after the end of each monitoring period in which samples were collected. The specific reporting requirements for disinfectants are listed in 567—subparagraph 42.4(3)“d”(3).
	43.6(2) Disinfection byproduct precursors.
	a. 	Applicability.
	(1)	Surface water or IGW CWS and NTNC systems with conventional filtration. This rule establishes criteria under which surface water or influenced groundwater CWS and NTNC public water supply systems using conventional filtration treatment, as defined in 567—40.2(455B), that add a chemical disinfectant to the water in any part of the drinking water treatment process or which provide water that contains a chemical disinfectant must modify their practices to meet the MCLs listed in 567—41.6(455B) and the maximum residual disinfectant levels (MRDL) and treatment technique requirements for disinfection byproduct precursors listed in this rule.
	(2)	CWS and NTNC systems using ozone treatment. CWS and NTNC systems that use ozone in their treatment process must comply with the bromide requirements of this subrule.
	(3)	Compliance dates. Compliance dates for this rule are based upon the population served. CWS and NTNC systems using surface water or groundwater under the direct influence of surface water in whole or in part and which serve 10,000 or more persons must comply with this rule beginning January 1, 2002; while those systems serving fewer than 10,000 persons must comply with this rule beginning January 1, 2004.
	(4)	The department may require groundwater systems to conduct monitoring for disinfection byproduct precursors as a part of an operation permit.
	b. 	Monitoring requirements for disinfection byproduct precursors.
	(1)	Routine monitoring for total organic carbon (TOC).
	1.	Surface water and groundwater under the direct influence of surface water systems which use conventional filtration treatment must monitor each treatment plant for total organic carbon (TOC) no later than at the point of combined filter effluent turbidity monitoring and representative of the treated water. The systems must also monitor for TOC in the source water prior to any treatment at the same time as monitoring for TOC in the treated water. These samples (source water and treated water) are referred to as paired samples. At the same time the source water sample is taken, all systems must monitor for alkalinity in the source water prior to any treatment. Systems must take one paired set of source water and treated water samples and one source water alkalinity sample per month per plant at a time representative of normal operating conditions and influent water quality.
	2.	Surface water and groundwater under the direct influence of surface water systems which do not use conventional filtration treatment must conduct the TOC monitoring under 43.6(2)“b”(1)“1” in order to qualify for reduced disinfection byproduct monitoring for TTHM and HAA5 under 567—paragraph 41.6(1)“c”(4)“2.” The source water TOC running annual average must be less than or equal to 4.0 mg/L based on the most recent four quarters of monitoring on a continuing basis at each treatment plant to reduce or remain on reduced monitoring for TTHM and HAA5. Once qualified for reduced monitoring for TTHM and HAA5, a system may reduce source water TOC monitoring to quarterly TOC samples taken every 90 days at a location prior to any treatment.
	(2)	Reduced monitoring. The department may allow surface water and groundwater under the direct influence of surface water systems with an average treated water TOC of less than 2.0 mg/L for two consecutive years, or less than 1.0 mg/L for one year, to reduce monitoring for both TOC and alkalinity to one set of paired samples and one source water alkalinity sample per plant per quarter. The system must revert to routine monitoring in the month following the quarter when the annual average treated water TOC is greater than or equal to 2.0 mg/L.
	(3)	Bromide. The department may allow systems required to analyze for bromate to reduce bromate monitoring from monthly to once per quarter, if the system demonstrates that the average source water bromide concentration is less than 0.05 mg/L based upon representative monthly measurements for one year. The system must continue bromide monitoring to remain on reduced bromate monitoring.
	(4)	The department may assign disinfection byproduct precursor monitoring prior to the compliance dates in 43.6(2)“a”(3) as part of an operation permit.
	c. 	Analytical requirements for disinfection byproduct precursors.
	(1)	Analytical methods. Systems required to monitor disinfectant byproduct precursors must use the following methods, which must be conducted by a certified laboratory pursuant to 567—Chapter 83, unless otherwise specified.
Approved Methods for Disinfection Byproduct Precursor Monitoring1

Analyte	Methodology	EPA	Standard
Methods	ASTM	Other	
Alkalinity6	Titrimetric	 	2320B	D 1067-92B	 	
 	Electrometric titration	 	 	 	I-1030-85	
Bromide	Ion chromatography	300.0	 	 	 	
 	 	300.1	 	 	 	
 	 	317.0 Rev.	2.0	 	 	 	
 	 	326.0	 	 	 	
 	 	 	 	D 6581-00	 	
Dissolved Organic Carbon2 (DOC)	High temperature combustion	415.3 Rev.	1.2	5310B or 5310B-00	 	 	
 	Persulfate-UV or heated-persulfate oxidation	415.3 Rev.	1.2	5310C or 5310C-00	 	 	
 	Wet oxidation	415.3 Rev.	1.1, 415.3 Rev.	1.2	5310D or 5310D-00	 	 	
pH3	Electrometric	150.1	4500-H+-B	D 1293-84	 	
 	 	150.2	 	 	 	
Specific Ultraviolet Absorbance (SUVA)	Calculation using DOC and UV254 data	415.3 Rev.	1.2	 	 	 	
Total Organic Carbon4	High temperature combustion	415.3 Rev.	1.2	5310B or 5310B-00	 	 	
 	Persulfate-UV or heated-persulfate oxidation	415.3 Rev.	1.2	5310C or 5310C-00	 	Hach Method 102677	
 	Wet oxidation	415.3 Rev.	1.1, 415.3 Rev.	1.2	5310D or 5310D-00	 	 	
 	Ozone Oxidation	 	 	 	Hach Method 102618	
Ultraviolet Absorption at
254 nm5	Spectrophotometry	415.3 Rev.	1.1, 415.3 Rev.	1.2	5910B or 5910B-00, 11	 	 	
1The procedures shall be done in accordance with the documents listed below. The incorporation by reference of the following documents was approved by the Director of the Federal Register on February 16, 1999, in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies of the documents may be obtained from the sources listed below. Information regarding obtaining these documents can be obtained from the Safe Drinking Water Hotline at (800)426-4791. Documents may be inspected at EPA’s Drinking Water Docket, 401 M Street, SW, Washington, DC 20460 (telephone: (202)260-3027); or at the Office of Federal Register, 800 North Capitol Street, NW, Suite 700, Washington, DC 20408.
The following methods are available from the American Society for Testing and Materials, 100 Barr Harbor Drive, West Conshohocken, PA 19428:
Annual Book of ASTM Standards, Volume 11.01, American Society for Testing and Materials, 1996: Method D 1067-92B and Method D 1293-84.
Annual Book of ASTM Standards, Volume 11.01, American Society for Testing and Materials, 2001 (or any year containing the cited version): Method D 6581-00.
The following methods are available from the National Technical Information Service, U.S. Department of Commerce, 5285 Port Royal Road, Springfield, VA 22161 (telephone: (800)553-6847):
“Determination of Inorganic Anions in Drinking Water by Ion Chromatography, Revision 1.0,” EPA-600/R-98/118, 1997 (NTIS, PB98-169196): Method 300.1.
Methods for Chemical Analysis of Water and Wastes, EPA-600/4-79-020, March 1983, (NTIS PB84-128677): Methods 150.1 and 150.2.
Methods for the Determination of Inorganic Substances in Environmental Samples, EPA-600/R-93/100, August 1993, (NTIS PB94-121811): Method 300.0.
“Determination of Inorganic Oxyhalide Disinfection By-Products in Drinking Water Using Ion Chromatography with the Addition of a Postcolumn Reagent for Trace Bromate Analysis, Revision 2.0,” USEPA, July 2001, EPA 815-B-01-001: Method 317.0.
“Determination of Inorganic Oxyhalide Disinfection By-Products in Drinking Water Using Ion Chromatography Incorporating the Addition of a Suppressor Acidified Postcolumn Reagent for Trace Bromate Analysis, Revision 1.0,” USEPA, June 2002, EPA 815-R-03-007: Method 326.0.
“Determination of Total Organic Carbon and Specific UV Absorbance at 254 nm in Source Water and Drinking Water, Revision 1.1,” USEPA, February 2005, EPA/600/R-05/055: Method 415.3 Revision 1.1.
“Determination of Total Organic Carbon and Specific UV Absorbance at 254 nm in Source Water and Drinking Water, Revision 1.2,” USEPA, September 2009, EPA/600/R-09/122: Method 415.3 Revision 1.2.
The following methods are available from the American Public Health Association, 800 I Street, NW, Washington, DC 20001-3710:
Standard Methods for the Examination of Water and Wastewater, 19th (1995), 21st (2005), and 22nd (2012) editions, American Public Health Association: Methods: 2320B (20th edition, 1998, is also accepted for this method), 4500-H+-B, and 5910B (22nd edition, 2012, is also accepted for this method).
Standard Methods for the Examination of Water and Wastewater, Supplement to the 19th edition (1996), 21st (2005), and 22nd editions, American Public Health Association: Methods: 5310B, 5310C, and 5310D.
For method numbers ending “-00”, the year in which each method was approved by the Standard Methods Committee is designated by the last two digits in the method number. The methods listed are the only online versions that are IBR-approved.
Method I-1030-85 is available from the Books and Open-File Reports Section, U.S. Geological Survey, Federal Center, Box 25425, Denver, CO 80225-0425.
2Dissolved Organic Carbon (DOC). DOC and UV254 samples used to determine a SUVA value must be taken at the same time and at the same location, prior to the addition of any disinfectant or oxidant by the system. Prior to analysis, DOC samples must be filtered through a 0.45 μ pore-diameter filter, as soon as practical after sampling, not to exceed 48 hours. After filtration, DOC samples must be acidified to achieve pH less than or equal to 2 with minimal addition of the acid specified in the method or by the instrument manufacturer. Acidified DOC samples must be analyzed within 28 days. Inorganic carbon must be removed from the samples prior to analysis. Water passed through the filter prior to filtration of the sample must serve as the filtered blank. This filtered blank must be analyzed using procedures identical to those used for analysis of the samples and must meet a DOC concentration of <0.5 mg/L.
3pH must be measured by a laboratory certified by the department to perform analysis under 567—Chapter 83; a Grade II, III or IV operator meeting the requirements of 567—Chapter 81; or any person under the supervision of a Grade II, III or IV operator meeting the requirements of 567—Chapter 81.
4Total Organic Carbon (TOC). Inorganic carbon must be removed from the samples prior to analysis. TOC samples may not be filtered prior to analysis. TOC samples must be acidified at the time of sample collection to achieve a pH less than or equal to 2 with minimal addition of the acid specified in the method or by the instrument manufacturer. Acidified TOC samples must be analyzed within 28 days.
5Ultraviolet Absorption at 254 nm (UV254). DOC and UV254 samples used to determine a SUVA value must be taken at the same time and at the same location, prior to the addition of any disinfectant or oxidant by the system. UV absorption must be measured at 253.7 nm (may be rounded off to 254 nm). Prior to analysis, UV254 samples must be filtered through a 0.45 µ pore-diameter filter. The pH of UV254 samples may not be adjusted. Samples must be analyzed as soon as practical after sampling, not to exceed 48 hours.
6Alkalinity must be measured by a laboratory certified by the department to perform analysis under 567—Chapter 83; a Grade II, III or IV operator meeting the requirements of 567—Chapter 81; or any person under the supervision of a Grade II, III or IV operator meeting the requirements of 567—Chapter 81. Only the listed titrimetric methods are acceptable.
7Hach Company. “Hach Method 10267 – Spectrophotometric Measurement of Total Organic Carbon (TOC) in Finished Drinking Water,” December 2015, Revision 1.2. Available at www.hach.com.
8Hach Company. “Hach Method 10261 – Total Organic Carbon in Finished Drinking Water by Catalyzed Ozone Hydroxyl Radical Oxidation Infrared Analysis,” December 2015, Revision 1.2. Available at www.hach.com.
	(2)	SUVA. Specific Ultraviolet Absorbance (SUVA) is equal to the UV absorption at 254nm (UV254) (measured in m-1) divided by the dissolved organic carbon (DOC) concentration (measured as mg/L). In order to determine SUVA, it is necessary to separately measure UV254 and DOC. When determining SUVA, systems must use the methods stipulated in subparagraph 43.6(1)“c”(1) to measure DOC and UV254. SUVA must be determined on water prior to the addition of disinfectants/oxidants by the system. DOC and UV254 samples used to determine an SUVA value must be taken at the same time and at the same location.
	(3)	Magnesium. All methods approved for magnesium in 567—subparagraph 41.3(1)“e”(1) are approved for use in measuring magnesium under this rule.
	d. 	Compliance requirements for disinfection byproduct precursors.
	(1)	General requirements. All samples taken and analyzed under the provisions of this rule must be included in determining compliance, even if that number is greater than the minimum required.
	(2)	Compliance determination. Compliance must be determined as specified by 43.6(3)“c.” The department may assign monitoring through an operation permit, or systems may begin monitoring to determine whether Step 1 TOC removals can be met 12 months prior to the compliance date for the system. This monitoring is not required and failure to monitor during this period is not a violation. However, any system that does not monitor during this period and then determines in the first 12 months after the compliance date that it is not able to meet the Step 1 requirements in 43.6(3)“b”(2), and must therefore apply for alternate minimum TOC removal (Step 2) requirements, is not eligible for retroactive approval of alternate minimum TOC removal (Step 2) requirements as allowed pursuant to 43.6(3)“b”(3) and is in violation. Systems may apply for alternate minimum TOC removal (Step 2) requirements anytime after the compliance date. For systems required to meet Step 1 TOC removals, if the value calculated under 43.6(3)“c”(1)“4” is less than 1.00, the system is in violation of the treatment technique requirements and must notify the public pursuant to 567—42.1(455B), in addition to reporting to the department pursuant to 567—paragraph 42.4(3)“d.”
	e. 	Reporting requirements for disinfection byproduct precursors. Systems required to sample quarterly or more frequently must report to the department within ten days after the end of each quarter in which samples were collected, notwithstanding the public notification provisions of 567—42.1(455B). Systems required to sample less frequently than quarterly must report to the department within ten days after the end of each monitoring period in which samples were collected. The specific reporting requirements for disinfection byproduct precursors are listed in 567—subparagraph 42.4(3)“d”(4).
	43.6(3) Treatment technique for control of disinfection byproduct precursors.
	a. 	Applicability.
	(1)	Systems using surface water or groundwater under the direct influence of surface water and conventional filtration treatment (as defined in 567—40.2(455B)) must operate with enhanced coagulation or enhanced softening to achieve the TOC percent removal levels specified in paragraph “b” of this subrule unless the system meets at least one of the alternative compliance criteria listed in 43.6(3)“a”(2) or (3).
	(2)	Alternative compliance criteria for enhanced coagulation and enhanced softening systems. Systems using surface water or groundwater under the direct influence of surface water and conventional filtration treatment may use the alternative compliance criteria in 43.6(3)“a”(2)“1” through “6” to comply with this subrule in lieu of complying with 43.6(3)“b.” Systems must still comply with monitoring requirements in 43.6(2)“b.”
	1.	The system’s source water TOC level, measured according to 43.6(2)“c”(1), is less than 2.0 mg/L, calculated quarterly as a running annual average.
	2.	The system’s treated water TOC level, measured according to 43.6(2)“c”(1), is less than 2.0 mg/L, calculated quarterly as a running annual average.
	3.	The system’s source water TOC level, measured according to 43.6(2)“c”(1), is less than 4.0 mg/L, calculated quarterly as a running annual average; the source water alkalinity, measured according to 43.6(2)“c”(1), is greater than 60 mg/L as CaCO3, calculated quarterly as a running annual average; and either the TTHM and HAA5 running annual averages are no greater than 0.040 mg/L and 0.030 mg/L, respectively; or prior to the effective date for compliance in 567—subparagraph 41.6(1)“a”(3) and in 43.6(1)“a”(3) and 43.6(2)“a”(3), the system has made a clear and irrevocable financial commitment not later than the effective date for compliance in 567—subparagraph 41.6(1)“a”(3) and in 43.6(1)“a”(3) and 43.6(2)“a”(3), to use of technologies that will limit the levels of TTHMs and HAA5 to no more than 0.040 mg/L and 0.030 mg/L, respectively. Systems must submit evidence of a clear and irrevocable financial commitment, in addition to a schedule containing milestones and periodic progress reports for installation and operation of appropriate technologies, to the department for approval not later than the effective date for compliance in 567—subparagraph 41.6(1)“a”(3) and in 43.6(1)“a”(3) and 43.6(2)“a”(3). These technologies must be installed and operating not later than June 30, 2005. Failure to install and operate these technologies by the date in the approved schedule will constitute a treatment technique violation.
	4.	The TTHM and HAA5 running annual averages are less than or equal to 0.040 mg/L and 0.030 mg/L, respectively, and the system uses only chlorine for primary disinfection and maintenance of a residual in the distribution system.
	5.	The system’s source water SUVA, prior to any treatment and measured monthly according to 43.6(2)“c,” is less than or equal to 2.0 L/mg-m, calculated quarterly as a running annual average.
	6.	The system’s finished water SUVA, measured monthly according to 43.6(2)“c,” is less than or equal to 2.0 L/mg-m, calculated quarterly as a running annual average.
	(3)	Additional alternative compliance criteria for softening systems. Systems practicing enhanced softening that cannot achieve the TOC removals required by 43.6(3)“b”(2) may use the alternative compliance criteria in 43.6(3)“a”(3)“1” and “2” in lieu of complying with 43.6(3)“b.” Systems must still comply with monitoring requirements in 43.6(2)“b.”
	1.	Softening that lowers the treated water alkalinity to less than 60 mg/L as CaCO3, measured monthly according to 43.6(2)“c” and calculated quarterly as a running annual average.
	2.	Softening that removes at least 10 mg/L of magnesium hardness as CaCO3, measured monthly and calculated quarterly as a running annual average.
	b. 	Enhanced coagulation and enhanced softening performance requirements.
	(1)	Systems must achieve the percent reduction of TOC specified in 43.6(3)“b”(2) between the source water and the combined filter effluent, unless the department approves a system’s request for alternate minimum TOC removal (Step 2 requirements under 43.6(3)“b”(3)).
	(2)	Required Step 1 TOC reductions, indicated in the following table, are based upon specified source water parameters measured in accordance with 43.6(2)“c.” Systems using softening are required to meet the Step 1 TOC reductions in the right-hand column (Source water alkalinity > 120 mg/L) for the specified source water TOC:
Step 1 Required Removal of TOC by Enhanced Coagulation and Enhanced Softening for Surface Water or IGW Systems Using Conventional Treatment1,2

Source water TOC, mg/L	Source water Alkalinity, mg/L as CaCO3	
	0-60	>60-120	>1203	
>2.0 - 4.0	35.0%	25.0%	15.0%	
>4.0 - 8.0	45.0%	35.0%	25.0%	
>8.0	50.0%	40.0%	30.0%	
1Systems meeting at least one of the conditions in 43.6(3)“a”(2)“1” to “6” are not required to operate with enhanced coagulation.
2Softening systems meeting one of the alternative compliance criteria in 43.6(3)“a”(3) are not required to operate with enhanced softening.
3Systems practicing softening must meet the TOC removal requirements in this column.
	(3)	Surface water and groundwater under the influence of surface water systems using conventional treatment that cannot achieve the Step 1 TOC removals required by 43.6(3)“b”(2) due to water quality parameters or operational constraints must apply to the department for approval of alternative minimum Step 2 TOC removal requirements submitted by the system within three months of failure to achieve the TOC removals required by 43.6(3)“b”(2). If the department approves the alternative minimum Step 2 TOC removal requirements, the department may make those requirements retroactive for the purposes of determining compliance. The system must meet the Step 1 TOC removals contained in 43.6(3)“b”(2) until the department approves the alternate minimum Step 2 TOC removal requirements.
	(4)	Alternate minimum Step 2 TOC removal requirements. Applications made to the department by enhanced coagulation systems for approval of alternate minimum Step 2 TOC removal requirements under 43.6(3)“b”(3) must include, as a minimum, results of bench-scale or pilot-scale testing conducted under 43.6(3)“b”(4)“1” below and be used to determine the alternate enhanced coagulation level.
	1.	Alternate enhanced coagulation level. Alternate enhanced coagulation level is defined as coagulation at a coagulant dose and pH as determined by the method described in 43.6(3)“b”(4)“1” to “5” such that an incremental addition of 10 mg/L of alum (or equivalent amount of ferric salt) results in a TOC removal of less than or equal to 0.3 mg/L. The percent removal of TOC at this point on the “TOC removal versus coagulant dose” curve is then defined as the minimum TOC removal required for the system. Once approved by the department, this minimum requirement supersedes the minimum TOC removal required by the table in 43.6(3)“b”(2). This requirement will be effective until such time as the department approves a new value based on the results of a new bench-scale or pilot-scale test. Failure to achieve department-set alternative minimum TOC removal levels is a treatment technique violation.
	2.	Bench-scale or pilot-scale testing of enhanced coagulation must be conducted by using representative water samples and adding 10 mg/L increments of alum (or equivalent amounts of ferric salt) until the pH is reduced to a level less than or equal to the enhanced coagulation Step 2 target pH shown in the following table:
Enhanced Coagulation Step 2 Target pH

Alkalinity (mg/L as CaCO3)	Target pH	
0-60	5.5	
>60-120	6.3	
>120-240	7.0	
>240	7.5	
	3.	For waters with alkalinities of less than 60 mg/L for which addition of small amounts of alum or equivalent addition of iron coagulant drives the pH below 5.5 before significant TOC removal occurs, the system must add necessary chemicals to maintain the pH between 5.3 and 5.7 in samples until the TOC removal of 0.3 mg/L per 10 mg/L alum added (or equivalent addition of iron coagulant) is reached.
	4.	The system may operate at any coagulant dose or pH necessary (consistent with other public drinking water rules in 567—Chapters 41 through 43) to achieve the minimum TOC percent removal approved under 43.6(3)“b”(3).
	5.	If the TOC removal is consistently less than 0.3 mg/L of TOC per 10 mg/L of incremental alum dose at all dosages of alum (or equivalent addition of iron coagulant), the water is deemed to contain TOC not amenable to enhanced coagulation. The system may then apply to the department for a waiver of enhanced coagulation requirements.
	c. 	Compliance calculations.
	(1)	Surface water or groundwater under the influence of surface water systems other than those identified in 43.6(3)“a”(2) or (3) must comply with requirements contained in 43.6(3)“b”(2) or (3). Systems must calculate compliance quarterly, beginning after the system has collected 12 months of data, by determining an annual average using the following method:
	1.	Step 1: Determine actual monthly TOC percent removal using the following equation, to two decimal places:

Actual monthly TOC percent removal	=	1	-	(	treated water TOC	)	×	100	
					source water TOC				
	2.	Step 2: Determine the required monthly TOC percent removal from either 43.6(3)“b”(2) or (3).
	3.	Step 3: Divide the “actual monthly TOC percent removal” value (from Step 1) by the “required monthly TOC percent removal” value (from Step 2). Determine this value for each of the last 12 months.

Monthly percent removal ratio	=	actual monthly TOC percent removal	
		required monthly TOC percent removal	
	4.	Step 4: Add together the “monthly percent removal ratio” values from Step 3 for each of the last 12 months and divide by 12, to determine the annual average value.

Annual average	=	<fo:wrapper font-size="11pt">Σ</fo:wrapper> monthly percent removal ratio	
		12	
	5.	Step 5: If the “annual average” value calculated in Step 4 is less than 1.00, the system is not in compliance with the TOC percent removal requirements.
	(2)	Systems may use the provisions in 43.6(3)“c”(2)“1” through “5” in lieu of the calculations in 43.6(3)“c”(1)“1” through “5” to determine compliance with TOC percent removal requirements.
	1.	In any month that the system’s treated or source water TOC level, measured according to 43.6(2)“c”(1), is less than 2.0 mg/L, the system may assign a monthly value of 1.0 (in lieu of the value calculated in 43.6(3)“c”(1)“3”) when calculating compliance under the provisions of 43.6(3)“c”(1).
	2.	In any month that a system practicing softening removes at least 10 mg/L of magnesium hardness as CaCO3, the system may assign a monthly value of 1.0 (in lieu of the value calculated in 43.6(3)“c”(1)“3”) when calculating compliance under the provisions of 43.6(3)“c”(1).
	3.	In any month that the system’s source water SUVA, prior to any treatment and measured according to 43.6(2)“c”(2), is less than or equal to 2.0 L/mg-m, the system may assign a monthly value of 1.0 (in lieu of the value calculated in 43.6(3)“c”(1)“3”) when calculating compliance under the provisions of 43.6(3)“c”(1).
	4.	In any month that the system’s finished water SUVA, measured according to 43.6(2)“c”(2), is less than or equal to 2.0 L/mg-m, the system may assign a monthly value of 1.0 (in lieu of the value calculated in 43.6(3)“c”(1)“3”) when calculating compliance under the provisions of 43.6(3)“c”(1).
	5.	In any month that a system using enhanced softening lowers alkalinity below 60 mg/L as CaCO3, the system may assign a monthly value of 1.0 (in lieu of the value calculated in 43.6(3)“c”(1)“3”) when calculating compliance under the provisions of 43.6(3)“c”(1).
	(3)	Surface water or groundwater under the direct influence of surface water systems using conventional treatment may also comply with the requirements of this subrule by meeting the criteria in 43.6(3)“a”(2) or (3).
	d. 	Treatment technique requirements for disinfection byproduct precursors. The treatment techniques to control the level of disinfection byproduct precursors in drinking water treatment and distribution systems, for surface water or groundwater under the direct influence of surface water systems using conventional filtration treatment, are enhanced coagulation or enhanced softening.
[ARC 9915B, IAB 12/14/11, effective 1/18/12; ARC 3735C, IAB 4/11/18, effective 5/16/18]
567—43.7(455B) Lead and copper treatment techniques.
	43.7(1) Corrosion control treatment for lead and copper control.
	a. 	Applicability. Systems shall complete the applicable corrosion control treatment requirements by the deadlines specified in the following rules:
	(1)	Large systems serving more than 50,000 persons. A large system (serving greater than 50,000 persons) shall complete the corrosion control treatment steps specified in 43.7(1)“d,” unless the system is deemed to have optimized corrosion control under 43.7(1)“b”(2) or (3).
	(2)	Small and medium-size systems serving 50,000 or fewer persons. A small system (serving less than or equal to 3,300 persons) or a medium-size system (serving greater than 3,300 and less than or equal to 50,000 persons) shall complete the corrosion control treatment steps specified in 43.7(1)“e,” unless the system has optimized corrosion control under 43.7(1)“b”(1), (2), or (3).
	b. 	Determination that a system has optimized corrosion control. A public water supply system has optimized corrosion control and is not required to complete the applicable corrosion control treatment steps identified in this subrule if the system satisfies one of the criteria specified in subparagraphs 43.7(1)“b”(1) through (3). Any such system deemed to have optimized corrosion control under this paragraph and which has treatment in place shall continue to operate and maintain optimal corrosion control treatment and meet any requirements that the department determines appropriate to ensure optimal corrosion control treatment is maintained.
	(1)	A small or medium-size water supply system has optimized corrosion control if the system meets the lead and copper action levels during each of two consecutive six-month monitoring periods, conducted in accordance with 567—paragraph 41.4(1)“c.”
	(2)	Any public water supply system may be deemed to have optimized corrosion control treatment if the system demonstrates to the satisfaction of the department that it has conducted activities equivalent to the corrosion control steps applicable to such system under this subrule. If the department makes this determination, it shall provide the water supply system with written notice explaining the basis for its decision and shall specify the water quality control parameters representing optimal corrosion control in accordance with 43.7(2)“f.” Systems deemed to have optimized corrosion control under this paragraph shall operate in compliance with the department-designated optimal water quality control parameters in accordance with paragraph 43.7(1)“g” and continue to conduct lead and copper tap and water quality parameter sampling in accordance with 567—paragraph 41.4(1)“c”(4)“3” and 567—subparagraph 41.4(1)“d”(4), respectively. A system shall provide the department with the following information in order to support a determination under this paragraph:
	1.	The results of all test samples collected for each of the water quality parameters in 43.7(2)“c”(3);
	2.	A report explaining the test methods used by the water system to evaluate the corrosion control treatments listed in 43.7(2)“c”(1), the results of all tests conducted, and the basis for the system’s selection of optimal corrosion control treatment;
	3.	A report explaining how corrosion control was installed and how it is being maintained to ensure minimal lead and copper concentrations at consumers’ taps; and
	4.	The results of tap water samples collected in accordance with 567—paragraph 41.4(1)“c” at least once every six months for one year after corrosion control has been installed.
	(3)	Any water system has optimized corrosion control if it submits results of tap water monitoring conducted in accordance with 567—paragraph 41.4(1)“c” and source water monitoring conducted in accordance with 567—paragraph 41.4(1)“e” that demonstrate for two consecutive six-month monitoring periods that the difference between the 90th percentile tap water lead level computed under 567—subparagraph 41.4(1)“b”(3) and the highest source water lead concentration is less than the practical quantitation level for lead specified in 567—paragraph 41.4(1)“g.”
	1.	Those systems whose highest source water lead level is below the method detection limit may also be deemed to have optimized corrosion control under this paragraph if the 90th percentile tap water lead level is less than or equal to the practical quantitation level for lead for two consecutive six-month monitoring periods.
	2.	Any water system deemed to have optimized corrosion control in accordance with this paragraph shall continue monitoring for lead and copper at the tap no less frequently than once every three calendar years using the reduced number of sites specified in 567—subparagraph 41.4(1)“c”(3) and collecting the samples at times and locations specified in 567—paragraph 41.4(1)“c”(4)“4,” fourth bulleted paragraph.
	3.	Any water system deemed to have optimized corrosion control pursuant to this paragraph shall notify the department in writing pursuant to 567—subparagraph 42.4(2)“a”(3) of any upcoming long-term change in treatment or the addition of a new source as described in 567—subparagraph 42.4(2)“a”(3). The department must review and approve the addition of a new source or long-term change in water treatment before it is implemented by the water system.
	4.	Unless a system meets the copper action level, it is not deemed to have optimized corrosion control under this paragraph and shall implement corrosion control treatment pursuant to 43.7(1)“b”(3)“5.”
	5.	Any system triggered into corrosion control because it is no longer deemed to have optimized corrosion control under this paragraph shall implement corrosion control treatment in accordance with the deadlines in paragraph 43.7(1)“e.” Any such large system shall adhere to the schedule specified in that paragraph for medium-size systems, with the time periods for completing each step being triggered by the date the system is no longer deemed to have optimized corrosion control under this paragraph.
	c. 	Requirements to recommence corrosion control steps. Any small or medium-size water system that is required to complete the corrosion control steps due to its exceedance of the lead or copper action level may cease completing the treatment steps whenever the system meets both action levels during each of two consecutive monitoring periods conducted pursuant to 567—paragraph 41.4(1)“c” and submits the results to the department. If any such water system thereafter exceeds the lead or copper action level during any monitoring period, the system shall recommence completion of the applicable treatment steps, beginning with the first treatment step which was not previously completed in its entirety. The department may require a system to repeat treatment steps previously completed by the system when it is determined by the department that this is necessary to implement properly the treatment requirements of this rule. The department will notify the system in writing of such a determination and explain the basis for its decision. The requirement for any small or medium-size system to implement corrosion control treatment steps in accordance with 43.7(1)“e” (including systems deemed to have optimized corrosion control under 43.7(1)“b”(1)) is triggered whenever any small or medium-size system exceeds the lead or copper action level.
	d. 	Treatment steps and deadlines for large systems. Except as provided in 43.7(1)“b”(2) or (3), large systems shall complete the following corrosion control treatment steps (described in the referenced portions of 43.7(1)“b,” subrule 43.7(2), and 567—paragraphs 41.4(1)“c” and “d”) by the dates indicated below.
	(1)	Step 1. The system shall conduct initial monitoring pursuant to 567—paragraph 41.4(1)“c”(4)“1” and 567—subparagraph 41.4(1)“d”(2) during two consecutive six-month monitoring periods by January 1, 1993.
	(2)	Step 2. The system shall complete corrosion control studies pursuant to 43.7(2)“c” by July 1, 1994.
	(3)	Step 3. The department will designate optimal corrosion control treatment within six months of receiving the corrosion control study results (by January 1, 1995).
	(4)	Step 4. The system shall install optimal corrosion control treatment by January 1, 1997.
	(5)	Step 5. The system shall complete follow-up sampling pursuant to 567—paragraph 41.4(1)“c”(4)“2” and 567—subparagraph 41.4(1)“d”(3) by January 1, 1998.
	(6)	Step 6. The department will review installation of treatment and designate optimal water quality control parameters pursuant to 43.7(2)“f” by July 1, 1998.
	(7)	Step 7. The system shall operate in compliance with optimal water quality control parameters delineated by the department and continue to conduct tap sampling.
	e. 	Treatment steps and deadlines for small and medium-size systems. Except as provided in 43.7(2), small and medium-size systems shall complete the following corrosion control treatment steps (described in subrule 43.7(2) and 567—paragraphs 41.4(1)“c” and “d”) by the indicated time periods listed below.
	(1)	Step 1. The system shall conduct initial tap sampling pursuant to 567—paragraph 41.4(1)“c”(4)“1” and 567—subparagraph 41.4(1)“d”(2) until the system either exceeds the lead or copper action level or becomes eligible for reduced monitoring under 567—paragraph 41.4(1)“c”(4)“4.” A system exceeding the lead or copper action level shall recommend optimal corrosion control treatment under 43.7(2)“a” within six months after the end of the monitoring period during which it exceeds one of the action levels.
	(2)	Step 2. Within 12 months after the end of the monitoring period during which a system exceeds the lead or copper action level, the department may require the system to perform corrosion control studies under 43.7(2)“b.” If the system is not required to perform such studies, the department will specify optimal corrosion control treatment under 43.7(2)“d” as follows: for medium-size systems, within 18 months after the end of the monitoring period during which such system exceeds the lead or copper action level, and, for small systems, within 24 months after the end of the monitoring period during which such system exceeds the lead or copper action level.
	(3)	Step 3. If a system is required to perform corrosion control studies under Step 2, the system shall complete the studies (under 43.7(2)“c”) within 18 months after such studies are required to commence.
	(4)	Step 4. If the system has performed corrosion control studies under Step 2, the department will designate optimal corrosion control treatment under 43.7(2)“d” within six months after completion of Step 3.
	(5)	Step 5. The system shall install optimal corrosion control treatment under 43.7(2)“e” within 24 months after such treatment is designated.
	(6)	Step 6. The system shall complete follow-up sampling pursuant to 567—paragraph 41.4(1)“c”(4)“2” and 567—subparagraph 41.4(1)“d”(3) within 36 months after optimal corrosion control treatment is designated.
	(7)	Step 7. The department will review the system’s installation of treatment and designate optimal water quality control parameters pursuant to 43.7(2)“f” within six months after completion of Step 6.
	(8)	Step 8. The system shall operate in compliance with the department-designated optimal water quality control parameters under 43.7(2)“f” (and continue to conduct tap sampling as per 567—paragraph 41.4(1)“c”(4)“3” and 567—subparagraph 41.4(1)“d”(4)).
	43.7(2) Description of corrosion control treatment requirements. Each public water supply system shall complete the corrosion control treatment requirements described below which are applicable to such systems under 43.7(1).
	a. 	Public water supply system recommendation regarding corrosion control treatment. Based upon the results of lead and copper tap monitoring and water quality parameter monitoring, small and medium-size water systems exceeding the lead or copper action level shall recommend installation of one or more of the corrosion control treatments listed in 43.7(2)“c” which the system believes constitute optimal corrosion control for that system. The department may require the system to conduct additional water quality parameter monitoring in accordance with 567—subparagraph 41.4(1)“d”(2) to assist in reviewing the system’s recommendation.
	b. 	Department decision to require studies of corrosion control treatment (applicable to small and medium-size systems). The department may require any small or medium-size system that exceeds the lead or copper action level to perform corrosion control studies under 43.7(2)“c” to identify optimal corrosion control treatment for the system.
	c. 	Performance of corrosion control studies.
	(1)	Any public water supply system performing corrosion control studies shall evaluate the effectiveness of each of the following treatments and, if appropriate, combinations of the following treatments to identify the optimal corrosion control treatment: alkalinity and pH adjustment; calcium hardness adjustment; and the addition of a phosphate or silicate-based corrosion inhibitor at a concentration sufficient to maintain an effective residual concentration in all test tap samples.
	(2)	The water system shall evaluate each of the corrosion control treatments using either pipe rig/loop tests, metal coupon tests, partial-system tests, or analyses based on documented analogous treatments with other systems of similar size, water chemistry and distribution system configuration.
	(3)	The public water supply system shall measure the following water quality parameters in any tests conducted under this paragraph before and after evaluating the corrosion control treatments listed above:
	1.	Lead;
	2.	Copper;
	3.	pH;
	4.	Alkalinity;
	5.	Calcium;
	6.	Conductivity;
	7.	Orthophosphate (when an inhibitor containing a phosphate compound is used);
	8.	Silicate (when an inhibitor containing a silicate compound is used);
	9.	Water temperature.
	(4)	The public water supply system shall identify all chemical or physical constraints that limit or prohibit the use of a particular corrosion control treatment and outline such constraints with the following: data and documentation showing that a particular corrosion control treatment has adversely affected other water treatment processes when used by another water system with comparable water quality characteristics; or data and documentation demonstrating that the water system has previously attempted to evaluate a particular corrosion control treatment and has found that the treatment is ineffective or adversely affects other water quality treatment processes.
	(5)	The water system shall evaluate the effect of the chemicals used for corrosion control treatment on other water quality treatment processes.
	(6)	On the basis of an analysis of the data generated during each evaluation, the water system shall recommend in writing to the department the treatment option that the corrosion control studies indicate constitutes optimal corrosion control treatment for that system. The water system shall provide a rationale for its recommendation along with all supporting documentation required by 43.7(2)“c”(1) through (5).
	d. 	Department designation of optimal corrosion control treatment.
	(1)	Based upon consideration of available information including, where applicable, studies performed under 43.7(2)“c” and a system’s recommended treatment alternative, the department will either approve the corrosion control treatment option recommended by the public water supply system, or designate alternative corrosion control treatment(s) from among those listed in 43.7(2)“c.” The department will consider the effects that additional corrosion control treatment will have on water quality parameters and on other water quality treatment processes (when designating optimal corrosion control treatment).
	(2)	The department will notify the public water supply system of its decision on optimal corrosion control treatment in writing and explain the basis for this determination. If the department requests additional information to aid its review, the public water supply system shall provide the information.
	e. 	Installation of optimal corrosion control. Each public water supply system shall properly install and operate throughout its distribution system the optimal corrosion control treatment designated under 43.7(2)“d.”
	f. 	Department review of treatment and specification of optimal water quality control parameters.
	(1)	The department will evaluate the results of all lead and copper tap samples and water quality parameter samples submitted by the public water supply system and determine whether the system has properly installed and operated the optimal corrosion control treatment designated in 43.7(2)“d.” Upon reviewing the results of tap water and water quality parameter monitoring by the public water supply system, both before and after the system installs optimal corrosion control treatment, the department will designate the following:
	1.	A minimum value or a range of values for pH measured at each entry point to the distribution system;
	2.	A minimum pH value, measured in all tap samples. Such value shall be equal to or greater than 7.0 unless meeting a pH level of 7.0 is not technologically feasible or is not necessary for the public water supply system to optimize corrosion control;
	3.	If a corrosion inhibitor is used, a minimum concentration or a range of concentrations for the inhibitor, measured at each entry point to the distribution system and in all tap samples, necessary to form a passivating film on the interior walls of the pipes of the distribution system;
	4.	If alkalinity is adjusted as part of optimal corrosion control treatment, a minimum concentration or a range of concentrations for alkalinity, measured at each entry point to the distribution system and in all tap samples; or
	5.	If calcium carbonate stabilization is used as part of corrosion control, a minimum concentration or a range of concentrations for calcium, measured in all tap samples.
	(2)	The values for the applicable water quality control parameters listed above shall be those which reflect optimal corrosion control treatment for the public water supply system. The department may designate values for additional water quality control parameters determined by the department to reflect optimal corrosion control for the system. The department will notify the system in writing of these determinations and explain the basis for its decisions.
	g. 	Continued operation with optimized corrosion control and water quality parameter monitoring compliance determination. All systems optimizing corrosion control shall continue to operate and maintain optimal corrosion control treatment, including maintaining water quality parameters at or above minimum values or within ranges designated by the department under paragraph 43.7(2)“f,” in accordance with this paragraph for all samples collected under 567—subparagraphs 41.4(1)“d”(4) through (6). Compliance with the requirements of this paragraph shall be determined every six months, as specified under 567—subparagraph 41.4(1)“d”(4). A water system is out of compliance with the requirements of this paragraph for a six-month period if it has excursions for any department-specified parameter on more than nine days during the period. An excursion occurs whenever the daily value for one or more of the water quality parameters measured at a sampling location is below the minimum value or outside the range designated by the department. Daily values are calculated as follows. The department has the discretion to invalidate results of obvious sampling errors from this calculation.
	(1)	On days when more than one measurement for the water quality parameter is collected at the sampling location, the daily value shall be the average of all results collected during the day regardless of whether they are collected through continuous monitoring, grab sampling, or a combination of both.
	(2)	On days when only one measurement for the water quality parameter is collected at the sampling location, the daily value shall be the result of that measurement.
	(3)	On days when no measurement is collected for the water quality parameter at the sampling location, the daily value shall be the daily value calculated on the most recent day on which the water quality parameter was measured at the sample site.
	h. 	Modification of department treatment decisions. A determination of the optimal corrosion control treatment under 43.7(2)“d” or optimal water quality control parameters under 43.7(2)“f” may be modified. A request for modification by a public water supply system or other interested party shall be in writing, explain why the modification is appropriate, and provide supporting documentation. The department may modify its determination when it concludes that such change is necessary to ensure that the public water supply system continues to optimize corrosion control treatment. A revised determination will be made in writing, which will set forth the new treatment requirements, explain the basis for the decision, and provide an implementation schedule for completing the treatment modifications.
	43.7(3) Source water treatment requirements. Public water supply systems shall complete the applicable source water monitoring and treatment requirements, as described in the referenced portions of 43.7(3)“b,” and in 567—paragraphs 41.4(1)“c” and “e,” by the following deadlines.
	a. 	Deadlines for completing source water treatment steps.
	(1)	Step 1. A public water supply system exceeding the lead or copper action level shall complete lead and copper source water monitoring under 567—subparagraph 41.4(1)“e”(2) and make a written treatment recommendation to the department no later than 180 days after the end of the monitoring period during which the lead or copper action level was exceeded.
	(2)	Step 2. The department will make a determination regarding source water treatment pursuant to 43.7(3)“b”(2) within six months after submission of monitoring results under Step 1.
	(3)	Step 3. If installation of source water treatment is required, the system shall install the treatment pursuant to 43.7(3)“b”(3) within 24 months after completion of Step 2.
	(4)	Step 4. The public water supply system shall complete follow-up tap water monitoring under 567—paragraph 41.4(1)“c”(4)“2” and source water monitoring under 567—subparagraph 41.4(1)“e”(3) within 36 months after completion of Step 2.
	(5)	Step 5. The department will review the system’s installation and operation of source water treatment and specify maximum permissible source water levels under 43.7(3)“b”(4) within six months after completion of Step 4.
	(6)	Step 6. The public water supply system shall operate in compliance with the specified maximum permissible lead and copper source water levels under 43.7(3)“b”(4) and continue source water monitoring pursuant to 567—subparagraph 41.4(1)“e”(4).
	b. 	Description of source water treatment requirements.
	(1)	System treatment recommendation. Any system which exceeds the lead or copper action level shall recommend in writing to the department the installation and operation of one of the source water treatments listed in 43.7(3)“b”(2). A system may recommend that no treatment be installed based upon a demonstration that source water treatment is not necessary to minimize lead and copper levels at users’ taps.
	(2)	Source water treatment determinations. The department will complete an evaluation of the results of all source water samples submitted by the public water supply system to determine whether source water treatment is necessary to minimize lead or copper levels in water delivered to users’ taps. If the department determines that treatment is needed, the department will require installation and operation of the source water treatment recommended by the public water supply system or require the installation and operation of another source water treatment from among the following: ion exchange, reverse osmosis, lime softening or coagulation/filtration. If the department requests additional information to aid in its review, the water system shall provide the information by the date specified in its request. The department will notify the system in writing of its determination and set forth the basis for its decision.
	(3)	Installation of source water treatment. Public water supply systems shall properly install and operate the source water treatment designated by the department under 43.7(3)“b”(2).
	(4)	Department review of source water treatment and specification of maximum permissible source water levels. The department will review the source water samples taken by the water supply system both before and after the system installs source water treatment and determine whether the public water supply system has properly installed and operated the designated source water treatment. Based upon its review, the department will designate maximum permissible lead and copper concentrations for finished water entering the distribution system. Such levels shall reflect the contaminant removal capability of the treatment (properly operated and maintained). The department will notify the public water supply system in writing and explain the basis for its decision.
	(5)	Continued operation and maintenance. Each public water supply system shall maintain lead and copper levels below the maximum permissible concentrations designated by the department at each sampling point monitored in accordance with 567—paragraph 41.4(1)“e.” The system is out of compliance with this paragraph if the level of lead or copper at any sampling point is greater than the maximum permissible designated concentration.
	(6)	Modification of source water treatment decisions. The department may modify its determination of the source water treatment under 43.7(3)“b”(6), or maximum permissible lead and copper concentrations for finished water entering the distribution system under 43.7(3)“b”(4). A request for modification by a public water supply system or other interested party shall be in writing, explain why the modification is appropriate, and provide supporting documentation. The department may modify its determination where it concludes that such change is necessary to ensure that the system continues to minimize lead and copper concentrations in source water. A revised determination will be made in writing, set forth the new treatment requirements, explain the basis for the decision, and provide an implementation schedule for completing the treatment modifications.
	43.7(4) Lead service line replacement requirements.
	a. 	Applicability. Public water supply systems that fail to meet the lead action level in tap samples taken pursuant to 567—paragraph 41.4(1)“c”(4)“2” after installing corrosion control or source water treatment (whichever sampling occurs later) shall replace lead service lines in accordance with the requirements of this subrule. If a system is in violation of 43.7(1) and 43.7(3) for failure to install source water or corrosion control treatment, the department may require the system to commence lead service line replacement under this subrule after the date by which the system was required to conduct monitoring under 567—paragraph 41.4(1)“c”(4)“2” has passed.
	b. 	Lead service line replacement schedule. A public water supply system shall replace annually at least 7 percent of the initial number of lead service lines in its distribution system. The initial number of lead service lines is the number of lead lines in place at the time the replacement program begins. The system shall identify the initial number of lead service lines in its distribution system, including an identification of the portion(s) owned by the system, based upon a materials evaluation, including the evaluation required under 567—subparagraph 41.4(1)“c”(1), and relevant legal authorities regarding the portion owned by the system such as contracts and local ordinances.
	(1)	The first year of lead service line replacement shall begin on the first day following the end of the monitoring period in which the action level was exceeded in tap sampling referenced in 43.7(4)“a.” If monitoring is required annually or less frequently, the end of the monitoring period is September 30 of the calendar year in which the sampling occurs. If the department has established an alternate monitoring period, then the end of the monitoring period will be the last day of that period.
	(2)	Any water system resuming a lead service line replacement program after the cessation of its lead service line replacement program as allowed by 43.7(4)“g” shall update its inventory of lead service lines to include those sites that were previously determined not to require replacement through the sampling provision under 43.7(4)“c.” The system will then divide the updated number of remaining lead service lines by the number of remaining years in the program to determine the number of lines that must be replaced per year. Seven percent lead service line replacement is based on a 15-year replacement program. For example, systems resuming lead service line replacement after previously conducting two years of replacement would divide the updated inventory by 13.
	(3)	For those systems that have completed a 15-year lead service line replacement program, the department will determine a schedule for replacing or retesting lines that were previously exempted through testing under 43.7(4)“c” from the replacement program when the system re-exceeds the action level.
	c. 	Exemption to lead service line replacement requirement. A public water supply system is not required to replace an individual lead service line if the lead concentration in all service line samples from that line, taken pursuant to 567—paragraph 41.4(1)“c”(2)“3,” is less than or equal to 0.015 mg/L.
	d. 	Lead service line replacement requirements. A water system shall replace that portion of the lead service line that it owns. In cases where the system does not own the entire lead service line, the system shall notify the owner of the line, or the owner’s authorized agent, that the system will replace the portion of the service line that it owns and shall offer to replace the owner’s portion of the line. A system is not required to bear the cost of replacing the privately owned portion of the line, nor is it required to replace the privately owned portion of the line where the owner chooses not to pay the cost of replacing the privately owned portion of the line, or where replacing the privately owned portion would be precluded by state, local, or common law. A water system that does not replace the entire length of the service line shall complete the following tasks.
	(1)	Notification of residents. At least 45 days prior to commencing with the partial replacement of a lead service line, the water system shall provide to the resident(s) of all buildings served by the line notice explaining that the resident(s) may experience a temporary increase of lead levels in their drinking water, along with guidance on measures consumers may take to minimize their exposure to lead. The department may allow the water system to provide this notice less than 45 days prior to commencing partial lead service line replacement where such replacement is in conjunction with emergency repairs. In addition, the water system shall inform the resident(s) served by the line that the system will, at the system’s expense, collect from each partially replaced lead service line a sample that is representative of the water in the service line for analysis of lead content, as prescribed under 567—paragraph 41.4(1)“c”(2)“3,” within 72 hours after the completion of the partial replacement of the service line. The system shall collect the sample and report the results of the analysis to the owner and the resident(s) served by the line within three business days of receiving the results. Mailed notices postmarked within three business days of receiving the results shall be considered “on time.”
	(2)	Notification methods. The water system shall provide the information required by subparagraph 43.7(4)“d”(1) to the residents of individual dwellings by mail or by other methods approved by the department. In instances where multifamily dwellings are served by the line, the water system shall have the option to post the information at a conspicuous location.
	e. 	Lead service line control—department review. Rescinded IAB 1/7/04, effective 2/11/04.
	f. 	Lead service line replacement schedule. The department may require a public water supply system to replace lead service lines on a shorter schedule than that required by this subrule, taking into account the number of lead service lines in the system, where such a shorter replacement schedule is feasible. The department will make this determination in writing and notify the system of its finding within six months after the system is triggered into lead service line replacement based on monitoring referenced in 43.7(4)“a.”
	g. 	Cessation of lead service line replacement. Any public water supply system may cease replacing lead service lines whenever first draw samples collected pursuant to 567—paragraph 41.4(1)“c”(2)“2” meet the lead action level during each of two consecutive monitoring periods and the system submits the results. If the first draw tap samples collected in any such water system thereafter exceed the lead action level, the system shall recommence replacing lead service lines, as detailed in 43.7(4)“b.”
	h. 	Lead service line replacement reporting requirements. To demonstrate compliance with 43.7(4)“a” through “d,” a system shall report the information specified in 567—paragraph 42.4(2)“e.”
[ARC 9915B, IAB 12/14/11, effective 1/18/12; ARC 3735C, IAB 4/11/18, effective 5/16/18]
567—43.8(455B) Viability assessment.
	43.8(1) Definitions specific to viability assessment.
“New system” for viability assessment purposes includes public water supply systems which are newly constructed after the effective date of this rule, as well as systems which do not currently meet the definition of a PWS, but which expand their infrastructure and thereby grow to become a PWS. Systems not currently meeting the definition of a PWS and which add additional users and thereby become a PWS without constructing any additional infrastructure are not “new systems” for the purposes of this subrule.
“Nonviable system” for viability assessment purposes means a system lacking the technical, financial, and managerial ability to comply with 567—Chapters 40 through 43 and 81.
“Significant noncompliance (SNC)” for viability assessment purposes means the failure to comply with any drinking water standard as adopted by the state of Iowa as designated by the department.
“Viability” for viability assessment purposes is the ability to remain in compliance insofar as the requirements of the federal Safe Drinking Water Act and 567—Chapters 40 through 43 and 81.
“Viable system” for viability assessment purposes means a system with the technical, financial, and managerial ability to comply with applicable drinking water standards adopted by the state of Iowa.
	43.8(2) Applicability and purpose. These rules apply to all new and existing public water supplies, including the following: new systems commencing operation after October 1, 1999; systems deemed to be in significant noncompliance with the primary drinking water standards; DWSRF applicants; and existing systems. The purpose of the viability assessment program is to ensure the safety of the public drinking water supplies and ensure the viability of new public water supply systems upon commencement of operation. The department may assess public notification requirements and administrative penalties to any public water supply system which fails to fulfill the requirements of this rule.
	43.8(3) Contents of a viability assessment. The viability assessment must address the areas of technical, financial, and managerial viability for a public water supply system. The assessment must include evaluation of the following areas at a minimum, and the public water supply system may be required to include additional information as directed by the department. The viability of a system should be forecast for a 20-year period.
	a. 	Technical viability.
	(1)	Supply sources and facilities
	(2)	Treatment
	(3)	Infrastructure (examples: pumping, storage, distribution)
	b. 	Financial viability.
	(1)	Capital and operating costs
	(2)	Revenue sources
	(3)	Contingency plans
	c. 	Managerial viability.
	(1)	Operation
	(2)	Maintenance
	(3)	Management
	(4)	Administration
	43.8(4) New systems.
	a. 	Submission of system viability assessment. New public water supply systems (including community, nontransient noncommunity systems, and transient noncommunity systems) commencing operation after the effective date of this rule are required to submit a completed system viability assessment for review by the department, prior to obtaining a construction permit. The viability assessment may be submitted with the application for a construction permit. The department may reject receipt or delay review of the construction plans and specifications until an adequate viability assessment is provided. If the department finds, upon review and approval of the viability assessment, that the PWS will be viable, a construction permit will be issued in accordance with 567—Chapters 40 and 43. Prior to beginning operation, a public water supply operation permit must be obtained in accordance with 567—43.2(455B) and 567—40.5(455B).
	b. 	Review of the viability assessment. If the department declines to approve the viability assessment as submitted by the applicant, or if the department finds that the PWS is not viable, approval of construction and operation permit applications will be denied. If the viability assessment is conditionally approved, construction and operation permits will be issued, with conditions and a schedule to achieve compliance specified in the operation permit.
	43.8(5) Existing systems.
	a. 	Submission of system viability assessment. Any community, nontransient noncommunity, or transient noncommunity water system which operated prior to October 1, 1999, and was regulated as a public water system by the department shall be considered an existing system. Any system which does not currently meet the definition of a PWS, but which expands their infrastructure and thereby grows to become a PWS is considered a new system. Systems not currently meeting the definition of a PWS and which add additional users and thereby become a PWS without constructing any additional infrastructure are considered existing systems for the purposes of this subrule. All PWSs should complete a viability assessment. However, only those existing PWSs which meet one or more of the following criteria are required to complete a viability assessment for the department’s review and approval.
	(1)	Systems applying for DWSRF loan funds.
	(2)	Systems categorized as being in significant noncompliance by the department, due to their history of failure to comply with drinking water standards.
	(3)	Systems identified by the department via a sanitary survey as having technical, managerial, or financial problems as evidenced by such conditions as poor operational control, a poor state of repair or maintenance, vulnerability to contamination, or inability to maintain adequate distribution system operating pressures.
	(4)	Systems which have been unable to retain a certified operator in accordance with 567—Chapter 81.
	b. 	Review of viability assessments for systems required to submit an assessment. If the assessment is incomplete and does not include all of the required elements, the supply will be notified in writing and will be given an opportunity to modify and resubmit the assessment within the time period specified by the department. If the system fails to resubmit a completed viability assessment as specified by the department, the department may find that the system is not viable. If the submitted assessment is complete, the department will either indicate that the system is viable or not viable after the assessment review process. The system will be notified of the results of the evaluation by the department.
	c. 	Review of voluntarily submitted viability assessments. It is recommended that all existing systems complete the viability assessment and submit it to the department. Voluntarily submitted assessments may be reviewed upon request and will be exempt from any requirements to modify the assessment if it is not approved, or from a determination that the system is not viable, providing the system does not meet any of the criteria for mandatory completion of a viability assessment as set forth in 43.8(4)“a” above.
	43.8(6) Systems which are determined to be not viable.
	a. 	Applicability. The following applies to community, nontransient noncommunity, and transient noncommunity systems:
	(1)	Systems applying for DWSRF loan funds must be viable, or the loan funds must be used to assist the system in attaining viable status. If a system making a loan application is found to be not viable, and loan funds will not be sufficient or available to ensure viability, then the situation must be corrected to the department’s satisfaction prior to qualification to apply for loan funds.
	(2)	Systems which meet the department’s criteria of significant noncompliance are not considered viable. The viability assessment completed by the public water supply and the most recent sanitary survey results will be evaluated by the department to assist the system in returning to and remaining in compliance, which would achieve viability. Required corrective actions will be specified in the system’s operation permit and will include a compliance schedule. Field office inspections will be conducted on an as-needed basis to assist the system in implementing the required system improvements.
	(3)	Systems experiencing technical, managerial, or financial problems as noted by department in the sanitary survey will be considered not viable. The viability assessment completed by the public water supply will be evaluated by the department to assist the system in attaining viability, and any required corrective actions will be specified in the system’s operation permit.
	(4)	Systems unable to retain a certified operator will be considered not viable. All community and nontransient noncommunity water systems, and transient noncommunity water systems as denoted by the department, are required to have a certified operator who meets the requirements of 567—Chapter 81. The viability assessment completed by the public water supply will be used to determine the source of the problem, and required corrective actions will be specified in the system’s operation permit.
	b. 	Reserved.
	43.8(7) Revocation or denial of operation or construction permit.
	a. 	Revocation or denial of an operation permit. Failure to correct the deficiencies regarding viability, as identified in accordance with a compliance schedule set by the department, may result in revocation or denial of the system’s operation permit. If the department revokes or denies the operation permit, the owner of the system must negotiate an alternative arrangement with the department for providing treatment or water supply services within 30 days of receipt of the notification by the department unless the owner of the supply appeals the decision to the department. The public water supply is required to provide water that continually meets all health-based standards during the appeal process.
	b. 	Denial of new construction permits for an existing system. In addition to the criteria provided in 567—Chapters 40 through 44, new construction permits for water system improvements may be denied until the system makes the required corrections and attains viable status unless the proposed project is necessary to attain viability.
	c. 	Failure to conform to approved construction plans and specifications, or to comply with the requirements of 567—Chapters 40 to 44. Failure of a project to conform to approved construction plans and specifications, or failure to comply with the requirements of 567—Chapters 40 to 44, constitutes grounds for the director to withhold the applicable construction and operation permits. The system is then responsible for ensuring that the identified problem with the project is rectified so that permits may be issued. Once an agreement for correcting the problem is reached between the department and the system, the department will issue the appropriate permits according to the provisions of the agreement. If an agreement cannot be reached within a reasonable time period, the permit shall be denied.
	d. 	Contents of the notification denying the permit. The notification of denial or withholding approval of the operation or construction permit will state the department’s reasons for withholding or denying permit approval.
	43.8(8) Appeals.
	a. 	Request for formal review of determination of viability. A person or entity who disagrees with the decision regarding the viability of a public water supply system may request a formal review of the action. A request for review must be submitted in writing to the director by the owner or their designee within 30 days of the date of notification by the department of the viability decision.
	b. 	Appeal of denial of operation or construction permit. A decision to deny an operation or construction permit may be appealed by the applicant to the environmental protection commission pursuant to 567—Chapter 7. The appeal must be made in writing to the director within 30 days of receiving the notice of denial by the owner of the public water supply.
567—43.9(455B) Enhanced filtration and disinfection requirements for surface water and IGW systems serving at least 10,000 people.
	43.9(1) General requirements.
	a. 	Applicability. The requirements of this rule constitute national primary drinking water regulations. This rule establishes the filtration and disinfection requirements that are in addition to criteria under which filtration and disinfection are required in 567—43.5(455B). The requirements of this rule are applicable, beginning January 1, 2002, to all public water systems using surface water or groundwater under the direct influence of surface water, in whole or in part, and which serve at least 10,000 people. This rule establishes or extends treatment technique requirements in lieu of maximum contaminant levels for the following contaminants: Giardia lamblia, viruses, heterotrophic plate count bacteria, Legionella, Cryptosporidium, and turbidity. Each surface water or groundwater under the direct influence of surface water system serving at least 10,000 people must provide treatment of its source water that complies with these treatment technique requirements and they are in addition to those identified in subrule 43.5(1). The treatment technique requirements consist of installing and properly operating water treatment processes that reliably achieve:
	(1)	At least 99 percent (2-log) removal of Cryptosporidium between a point where the raw water is not subject to recontamination by surface water runoff and a point downstream before or at the first customer for filtered systems.
	(2)	Compliance with the profiling and benchmark requirements under 43.9(2).
	(3)	The department may require other surface water or groundwater under the direct influence of surface water systems to comply with this rule, through an operation permit.
	b. 	Compliance determination. A public water system subject to the requirements of this rule is considered to be in compliance with the requirements of 43.9(1)“a” if it meets the applicable filtration requirements in either 43.5(3) or 43.9(3) and the disinfection requirements in 43.5(2) and 43.6(2).
	c. 	Prohibition of new construction of uncovered intermediate or finished water storage facilities. Systems that are required to comply with this rule may construct only covered intermediate or finished water storage facilities. For the purposes of this rule, an intermediate storage facility is defined as a storage facility or reservoir after the clarification treatment process.
	d. 	Systems with populations that increased after January 1, 2002, to more than 10,000 people served. Systems using surface water or influenced groundwater sources that did not conduct optional monitoring under 43.9(2) because they served fewer than 10,000 persons when such monitoring was required, but serve more than 10,000 persons prior to January 1, 2005, must comply with 43.9(1), 43.9(3), 43.9(4), and 43.9(5). These systems must also consult with the department to establish a disinfection benchmark. A system that decides to make a significant change to its disinfection practice as described in 43.9(2)“c”(1)“1” through “4” must consult with the department prior to making such a change.
	43.9(2) Disinfection profiling and benchmarking.
	a. 	Determination of systems required to profile. A public water system subject to the requirements of this rule must determine its total trihalomethane (TTHM) and haloacetic acid (HAA5) annual averages using the procedures listed below. The annual average is the arithmetic average of the quarterly averages of four consecutive quarters of monitoring. Both the TTHM and HAA5 samples must be collected as paired samples during the same time period in order for each parameter to have the same annual average period for result comparison. A paired sample is one that is collected at the same location and time and is analyzed for both TTHM and HAA5 parameters.
	(1)	Allowance of information collection rule data. Those systems that collected data under the provisions of the federal Information Collection Rule listed in Code of Federal Regulations Title 40, Part 141, Subpart M, must use the results of the TTHM and HAA5 samples collected during the last four quarters of monitoring required under 40 CFR 141.142. The system must have submitted the results of the samples collected during the last 12 months of required monitoring.
	(2)	Systems that have not collected TTHM and HAA5 data under 43.9(2)“a”(1). Those systems that have not collected four consecutive quarters of paired TTHM and HAA5 samples as described under 43.9(2)“a”(1) must comply with all other provisions of this subrule as if the HAA5 monitoring had been conducted and the results of that monitoring required compliance with 43.9(2)“b.” The system that elects this option must notify the department in writing of its decision.
	(3)	The department may require that a system use a more representative annual data set than the data set determined under 567—subparagraph 42.9(2)“a”(1) for the purpose of determining applicability of the requirements of this subrule.
	(4)	Profiling determination criteria. Any system having either a TTHM annual average greater than 0.064 mg/L or an HAA5 annual average greater than 0.048 mg/L during the period identified in 43.9(2)“a”(1) through (3) must comply with 43.9(2)“b.”
	b. 	Disinfection profiling.
	(1)	Applicability. Any system that meets the criteria in 43.9(2)“a”(4) must develop a disinfection profile of its disinfection practice for a period of up to three years.
	(2)	Monitoring requirements. The system must monitor daily for a period of 12 consecutive calendar months to determine the total logs of inactivation for each day of operation, based on the CT99.9 values in Tables 1 through 8 in Appendix A, as appropriate, through the entire treatment plant. This system must begin this monitoring as directed by the department. As a minimum, the system with a single point of disinfectant application prior to entrance to the distribution system must conduct the monitoring in 43.9(2)“b”(2)“1” through “4.” A system with more than one point of disinfectant application must conduct the monitoring in 43.9(2)“b”(2)“1” through “4” for each disinfection segment. The system must monitor the parameters necessary to determine the total inactivation ratio, using analytical methods in 43.5(4)“a” as follows:
	1.	The temperature of the disinfected water must be measured once per day at each residual disinfectant concentration sampling point during peak hourly flow.
	2.	If the system uses chlorine, the pH of the disinfected water must be measured once per day at each chlorine residual disinfectant concentration sampling point during peak hourly flow.
	3.	The disinfectant contact time(s) (“T”) must be determined for each day during peak hourly flow.
	4.	The residual disinfectant concentration(s) (“C”) of the water before or at the first customer and prior to each additional point of disinfection must be measured each day during peak hourly flow.
	(3)	Use of existing data. A system that has existing operational data may use those data to develop a disinfection profile for additional years, in addition to the disinfection profile generated under 43.9(2)“b”(2). Such systems may use these additional yearly disinfection profiles to develop a benchmark under the provisions of 43.9(2)“c.” The department must determine whether these operational data are substantially equivalent to data collected under the provisions of 43.9(2)“b”(2). These data must also be representative of inactivation through the entire treatment plant and not just of certain treatment segments.
	(4)	Calculation of the total inactivation ratio. The system must calculate the total inactivation ratio as follows, using the CT99.9 values from Tables 1 through 8 listed in Appendix A:
1. If the system uses only one point of disinfectant application, the system may determine the total inactivation ratio for the disinfection segment based on either of the following two methods:
	●	Determine one inactivation ratio (CTcalc/CT99.9) before or at the first customer during peak hourly flow.
	●	Determine successive CTcalc/CT99.9 values, representing sequential inactivation ratios, between the point of disinfectant application and a point before or at the first customer during peak hourly flow. Under this alternative, the system must calculate the total inactivation ratio by determining (CTcalc/CT99.9) for each sequence and then adding the (CTcalc/CT99.9) values together to determine Σ(CTcalc/CT99.9).
2. If the system uses more than one point of disinfectant application before the first customer, the system must determine the CT value of each disinfection segment immediately prior to the next point of disinfectant application, or for the final segment, before or at the first customer, during peak hourly flow. The CTcalc/CT99.9 value of each segment and Σ(CTcalc/CT99.9) must be calculated using the method in 43.9(2)“b”(4)“1.”
	3.	The system must determine the total logs of inactivation by multiplying the value calculated in 43.9(2)“b”(4)“1” or “2” by 3.0.
	(5)	Systems using chloramines or ozone. A system that uses either chloramines or ozone for primary disinfection must also calculate the logs of inactivation for viruses using a method approved by the department.
	(6)	Profile retention requirements. The system must retain disinfection profile data in graphic form, as a spreadsheet, or in some other format acceptable to the department for review as part of sanitary surveys conducted by the department. The department may require the system to submit the data to the department directly or as part of a monthly operation report.
	c. 	Disinfection benchmarking.
	(1)	Significant change to disinfection practice. Any system required to develop a disinfection profile under the provisions of 43.9(2)“a” or “b” that decides to make a significant change to its disinfection practice must obtain department approval prior to making such change. Significant changes to disinfection practice are:
	1.	Changes to the point of disinfection;
	2.	Changes to the disinfectant(s) used in the treatment plant;
	3.	Changes to the disinfection process; and
	4.	Any other modification identified by the department.
	(2)	Calculation of the disinfection benchmark. Any system that is modifying its disinfection practice must calculate its disinfection benchmark using the procedure specified below:
	1.	For each year of profiling data collected and calculated under 43.9(2)“b,” the system must determine the lowest average monthly Giardia lamblia inactivation in each year of profiling data. The system must determine the average Giardia lamblia inactivation for each calendar month for each year of profiling data by dividing the sum of daily Giardia lamblia inactivation by the number of values calculated for that month.
	2.	The disinfection benchmark is the lowest monthly average value (for systems with one year of profiling data) or average of lowest monthly average values (for systems with more than one year of profiling data) of the monthly logs of Giardia lamblia inactivation in each year of profiling data.
	(3)	A system that uses either chloramines or ozone for primary disinfection must also calculate the disinfection benchmark for viruses using a method approved by the department.
	(4)	The system must submit the following information to the department as part of its consultation process:
	1.	A description of the proposed change;
	2.	The disinfection profile for Giardia lamblia (and, if necessary, viruses) under 43.9(2)“b” and the disinfection benchmark as required by 43.9(2)“c”(2); and
	3.	An analysis of how the proposed change will affect the current levels of disinfection.
	43.9(3) Filtration.
	a. 	Conventional filtration treatment or direct filtration.
	(1)	Turbidity requirement in 95 percent of samples. For systems using conventional filtration or direct filtration, the turbidity level of representative samples of a system’s filtered water (combined filter effluent or CFE) must be less than or equal to 0.3 NTU in at least 95 percent of the measurements taken each month, measured as specified in 43.5(4)“a”(1) and 43.5(4)“b”(1).
	(2)	Maximum turbidity level. The turbidity level of representative samples of a system’s filtered water (combined filter effluent or CFE) must at no time exceed 1 NTU, measured as specified in 43.5(4)“a”(1) and 43.5(4)“b”(1). If at any time the combined filter effluent turbidity exceeds 1 NTU, either in a grab sample used for compliance or in a continuously monitored flow, the system must inform the department as soon as possible, but no later than 24 hours after the exceedance is known, in accordance with the public notification requirements under 567—subparagraph 42.1(3)“b”(3).
	(3)	Systems with lime-softening treatment. A system that uses lime softening may acidify representative samples prior to analysis using a protocol approved by the department.
	b. 	Filtration technologies other than conventional filtration treatment, direct filtration, slow sand filtration, or diatomaceous earth filtration. The department may allow a public water system to use a filtration technology not listed in 43.9(3)“a” or 43.5(3)“c” or “d” if it demonstrates to the department, using pilot plant studies or other means, that the alternative filtration technology, in combination with disinfection treatment that meets the requirements of 43.5(2), consistently achieves 99.9 percent removal or inactivation of Giardia lamblia cysts, 99.99 percent removal or inactivation of viruses, and 99 percent removal of Cryptosporidium oocysts and the department approves the use of the filtration technology. For each approval, the department will set turbidity performance requirements that the system must meet at least 95 percent of the time and the requirement that the system shall not exceed at any time at a level that consistently achieves 99.9 percent removal or inactivation of Giardia lamblia cysts, 99.99 percent removal or inactivation of viruses, and 99 percent removal of Cryptosporidium oocysts.
	43.9(4) Filtration sampling requirements.
	a. 	Monitoring requirements for systems using filtration treatment. In addition to monitoring required by 43.5(4), a public water system subject to the requirements of this rule that provides conventional filtration treatment or direct filtration must conduct continuous monitoring of turbidity for each individual filter using an approved method in 43.5(4)“a”(1) and must calibrate turbidimeters at least every 90 days with a primary standard. The calibration of each turbidimeter used for compliance must be verified at least once per week with a primary standard, secondary standards, or the manufacturer’s proprietary calibration confirmation device or by a method approved by the department. If the verification is not within plus or minus 0.05 NTU for measurements of less than or equal to 0.5 NTU, or within plus or minus 10 percent of measurements greater than 0.5 NTU, then the turbidimeter must be recalibrated. Systems must record the results of individual filter monitoring every 15 minutes.
	b. 	Failure of the continuous turbidity monitoring equipment. If there is a failure in the continuous turbidity monitoring equipment, the system must conduct grab sampling every four hours in lieu of continuous monitoring until the turbidimeter is repaired and back online. A system has a maximum of five working days after failure to repair the equipment, or else it is in violation.
	43.9(5) Reporting and record-keeping requirements. In addition to the reporting and record-keeping requirements in 567—paragraph 42.4(3)“c,” a system subject to the requirements of this rule that provides conventional filtration treatment or direct filtration must report monthly to the department the information specified in 43.9(5)“a” and “b” beginning January 1, 2002. In addition to the reporting and record-keeping requirements in 567—paragraph 42.4(3)“c,” a system subject to the requirements of this rule that provides filtration approved under 43.9(3)“b” must report monthly to the department the information specified in 43.9(5)“a” beginning January 1, 2002. The reporting in 43.9(5)“a” is in lieu of the reporting specified in 567—subparagraph 42.4(3)“c”(1).
	a. 	Turbidity. Turbidity measurements as required by 43.9(3) must be reported in a format acceptable to the department and within ten days after the end of each month that the system serves water to the public. Information that must be reported includes:
	(1)	The total number of filtered water (combined filter effluent or CFE) turbidity measurements taken during the month;
	(2)	The number and percentage of filtered water (combined filter effluent or CFE) turbidity measurements taken during the month which are less than or equal to the turbidity limits specified in 43.9(3)“a” or “b”; and
	(3)	The date and value of any combined filter effluent or CFE turbidity measurements taken during the month which exceed 1 NTU for systems using conventional filtration treatment or direct filtration or which exceed the maximum level set by the department under 43.9(3)“b.”
	(4)	The dates and summary of calibration and verification of all compliance turbidimeters.
	b. 	Individual filter turbidity monitoring. Systems must maintain the results of individual filter turbidity per monitoring taken under 43.9(4) for at least three years. Systems must report to the department that they have conducted individual filter turbidity monitoring under 43.9(4) within ten days after the end of each month that the system serves water to the public. Systems must report to the department individual filter turbidity measurement results taken under 43.9(4) within ten days after the end of each month that the system serves water to the public only if measurements demonstrate one or more of the conditions specified in 43.9(5)“b”(1) through (4). Systems that use lime softening may apply to the department for alternative exceedance levels for the levels specified in 43.9(5)“b”(1) through (4) if they can demonstrate that higher turbidity levels in individual filters are due to lime carryover only and not due to degraded filter performance.
	(1)	For any individual filter that has a measured turbidity level of greater than 1.0 NTU in two consecutive measurements taken 15 minutes apart, the system must report the filter number, the turbidity measurement, and the date(s) on which the exceedance occurred. In addition, the system must either produce a filter profile for the filter within seven days of the exceedance (if the system is not able to identify an obvious reason for the abnormal filter performance) and report that the profile has been produced or report the obvious reason for the exceedance.
	(2)	For any individual filter that has a measured turbidity level of greater than 0.5 NTU in two consecutive measurements taken 15 minutes apart anytime following the first four hours of continuous filter operation after the filter has been backwashed or otherwise taken offline, the system must report the filter number, the turbidity, and the date(s) on which the exceedance occurred. In addition, the system must either produce a filter profile for the filter within seven days of the exceedance (if the system is not able to identify an obvious reason for the abnormal filter performance) and report that the profile has been produced or report the obvious reason for the exceedance.
	(3)	For any individual filter that has a measured turbidity level of greater than 1.0 NTU in two consecutive measurements taken 15 minutes apart at any time in each month of three consecutive months, the system must report the filter number, the turbidity measurement, and the date(s) on which the exceedance occurred. In addition, the system must conduct a self-assessment of the filter within 14 days of the exceedance and report that the self-assessment was conducted. The self-assessment must consist of at least the following components: assessment of filter performance; development of a filter profile; identification and prioritization of factors limiting filter performance; assessment of the applicability of corrections; and preparation of a filter self-assessment report.
	(4)	For any individual filter that has a measured turbidity level of greater than 2.0 NTU in two consecutive measurements taken 15 minutes apart at any time in each month of two consecutive months, the system must report the filter number, the turbidity measurement, and the date(s) on which the exceedance occurred. In addition, the system must arrange for a comprehensive performance evaluation to be conducted by the department or a third party approved by the department no later than 30 days following the exceedance and have the evaluation completed and submitted to the department no later than 90 days following the exceedance.
	c. 	Additional reporting requirement for turbidity combined filter effluent.
	(1)	If at any time the turbidity exceeds 1 NTU in representative samples of filtered water (combined filter effluent or CFE) in a system using conventional filtration treatment or direct filtration, the system must consult with the department as soon as practical, but no later than 24 hours after the exceedance is known, in accordance with the public notification requirements under 567—subparagraph 42.1(3)“b”(3).
	(2)	If at any time the turbidity in representative samples of filtered water (combined filter effluent or CFE) exceeds the maximum level set by the department under 43.9(3)“b” for filtration technologies other than conventional filtration treatment, direct filtration, slow sand filtration, or diatomaceous earth filtration, the system must consult with the department as soon as practical, but no later than 24 hours after the exceedance is known, in accordance with the public notification requirements under 567—subparagraph 42.1(3)“b”(3).
[ARC 9915B, IAB 12/14/11, effective 1/18/12; ARC 3735C, IAB 4/11/18, effective 5/16/18]
567—43.10(455B) Enhanced filtration and disinfection requirements for surface water and IGW systems serving fewer than 10,000 people.
	43.10(1) General requirements.
	a. 	Applicability. The requirements of this rule constitute national primary drinking water regulations. This rule establishes requirements for filtration and disinfection that are in addition to criteria under which filtration and disinfection are required in 567—43.5(455B). The requirements of this rule are applicable beginning January 1, 2005, unless otherwise noted, to all public water systems using surface water or groundwater under the direct influence of surface water, in whole or in part, and which serve less than 10,000 people. This rule establishes or extends treatment technique requirements in lieu of maximum contaminant levels for the following contaminants: Giardia lamblia, viruses, heterotrophic plate count bacteria, Legionella, Cryptosporidium, and turbidity. The treatment technique requirements consist of installing and properly operating water treatment processes which reliably achieve:
	(1)	At least 99 percent (2 log) removal of Cryptosporidium between a point where the raw water is not subject to recontamination by surface water runoff and a point downstream before or at the first customer for filtered systems; and
	(2)	Compliance with the profiling and benchmark requirements in subrules 43.10(2) and 43.10(3).
	b. 	Prohibition of new construction of uncovered intermediate or finished water storage facilities. Systems that are required to comply with this rule may construct only covered intermediate or finished water storage facilities. For the purposes of this rule, an intermediate storage facility is defined as a storage facility or reservoir after the clarification treatment process.
	43.10(2) Disinfection profile.
	a. 	Applicability. A disinfection profile is a graphical representation of a system’s level of Giardia lamblia or virus inactivation measured during the course of a year. All systems required to comply with this rule must develop a disinfection profile unless the department determines that such a profile is unnecessary. Records must be maintained according to subrule 43.10(7).
	(1)	The department may approve the use of a more representative data set for disinfection profiling than the data set required in paragraph 43.10(2)“b.”
	(2)	The department may determine that a system’s profile is unnecessary only if a system’s TTHM and HAA5 levels are below 0.064 mg/L and 0.048 mg/L, respectively. To determine these levels, TTHM and HAA5 samples must be collected after January 1, 1998, during the month with the warmest water temperature, and at the point of maximum residence time in the distribution system. The department may approve the use of a more representative annual data set for purpose of determining applicability of the requirements of this subrule. The annual data set must be calculated on an annual average, of the arithmetic average of the quarterly averages of four consecutive quarters of monitoring. At least 25 percent of the samples collected in each quarter must be collected at the maximum residence time location in the distribution system.
1. For systems that provide water to other public water supplies, if the producing system meets the byproduct level requirements of less than 0.064 mg/L for TTHM and less than 0.048 mg/L for HAA5, it will not be required to develop a disinfection profile and benchmark unless:
	●	The consecutive system cannot meet in its distribution system the byproduct level requirements of less than 0.064 mg/L for TTHM and less than 0.048 mg/L for HAA5, and
	●	The producing system wants to make a significant change to its disinfection practices.
2. The department will then assign the requirement to the producing system to conduct the disinfection profiling study and determine a disinfection benchmark.
	b. 	Required elements of a disinfection profile.
	(1)	Collection of the following data for 12 consecutive months, beginning by July 1, 2003, for systems serving 500 to 9,999 people, and by January 1, 2004, for systems serving fewer than 500 people. A system must monitor the following parameters to determine the total log inactivation by using the analytical methods in paragraph 43.5(4)“a,” once per week on the same calendar day, over 12 consecutive months.
	1.	Temperature of the disinfected water at each residual disinfectant concentration sampling point during peak hourly flow, measured in degrees Celsius;
	2.	For systems using chlorine, the pH of the disinfected water at each residual disinfectant concentration sampling point during peak hourly flow, measured in standard pH units;
	3.	The disinfectant contact time (“T”) during peak hourly flow, measured in minutes; and
	4.	The residual disinfectant concentration(s) (“C”) of the water following each point of disinfection at a point(s) prior to each subsequent point of disinfection and at the entry point to the distribution system or at a location just prior to the first customer during peak hourly flows, measured in mg/L.
	(2)	The data collected in 43.10(2)“b”(1) must be used to calculate the weekly log inactivation, along with the CT99.9 tables listed in Appendix A. The system must calculate the total inactivation ratio as follows and multiply the value by 3.0 to determine log inactivation of Giardia lamblia:
	1.	If the system uses only one point of disinfectant application, it must determine:
	●	One inactivation ratio (CT calc/CT99.9) before or at the first customer during peak hourly flow, or
	●	Successive (CT calc/CT99.9) values, representing sequential inactivation ratios, between the point of disinfection application and a point before or at the first customer during peak hourly flow. Under this alternative, the system must calculate the total inactivation ratio by determining (CT calc/CT99.9) for each sequence and then adding the (CT calc/CT99.9) values together to determine (ƩCT calc/CT99.9).
	2.	If a system uses more than one point of disinfectant application before the first customer, the system must determine the (CT calc/CT99.9) value of each disinfection segment immediately prior to the next point of disinfectant application, or for the final segment, before or at the first customer, during peak hourly flow using the procedure specified in 43.10(2)“b”(2) “1,” second bulleted paragraph.
	3.	If a system uses chloramines, ozone, or chlorine dioxide for primary disinfection, the system must also calculate the inactivation logs for viruses and develop an additional disinfection profile for viruses using methods approved by the department.
	(3)	The weekly log inactivations are used to develop a disinfection profile, as follows:
	1.	The disinfection profile is developed by graphing each log inactivation data point versus time. Each log inactivation serves as a data point in the disinfection profile. The system will have obtained 52 measurements at a minimum, one for each week of the year.
	2.	The disinfection profile depicts the variation of microbial inactivation over the course of the year.
	3.	The system must retain the disinfection profile data both in a graphic form and in a spreadsheet, which must be available for review by the department.
	4.	This profile is used to calculate a disinfection benchmark if the system is considering changes to its disinfection practices.
	43.10(3) Disinfection benchmark.
	a. 	Applicability. Any system required to develop a disinfection profile under 43.10(2) must develop a disinfection benchmark prior to making any significant change in disinfection practice. The system must receive department approval before any significant change in disinfection practice is implemented. Records must be maintained according to subrule 43.10(7).
	b. 	Significant changes to disinfection practice. Significant changes to disinfection practice include:
	(1)	Changes to the point of disinfection;
	(2)	Changes to the disinfectant(s) used in the treatment plant;
	(3)	Changes to the disinfection process; or
	(4)	Any other modification identified by the department.
	c. 	Calculation of the disinfection benchmark. The system must calculate the disinfection benchmark in the following manner:
	(1)	Step 1. Using the data collected to develop the disinfection profile, the system must determine the average Giardia lamblia inactivation for each calendar month by dividing the sum of all Giardia lamblia inactivations for that month by the number of values calculated for that month.
	(2)	Step 2. The system must determine the lowest monthly average value out of the 12 values. This value becomes the disinfection benchmark.
	d. 	Information required for department approval of a change in disinfection practice. Any significant change in disinfection practice must have been approved by the department before the system institutes the change. The following information must be submitted by the system to the department as part of the consultation and approval process.
	(1)	A description of the proposed change;
	(2)	The disinfection profile for Giardia lamblia and, if necessary, viruses;
	(3)	The disinfection benchmark;
	(4)	An analysis of how the proposed change will affect the current levels of disinfection; and
	(5)	Any additional information requested by the department.
	e. 	Additional benchmark requirements if chloramines, ozone, or chlorine dioxide is used for primary disinfection. If a system uses chloramines, ozone, or chlorine dioxide for primary disinfection, the system must calculate the disinfection benchmark from the data collected for viruses to develop the disinfection profile in addition to the Giardia lamblia disinfection benchmark calculated in paragraph 43.10(3)“c.” This viral benchmark must be calculated in the same manner used to calculate the Giardia lamblia disinfection benchmark in paragraph 43.10(3)“c.”
	43.10(4) Combined filter effluent turbidity requirements. All systems using surface water or groundwater under the direct influence of surface water which serve less than 10,000 people must use filtration, and the turbidity limits that must be met depend upon the type of filtration used. Systems using lime softening may acidify representative combined filter effluent turbidity samples prior to analysis, using a protocol approved by the department.
	a. 	Conventional filtration treatment or direct filtration.
	(1)	Turbidity must be measured in the combined filter effluent as described in paragraphs 43.5(4)“a” and “b.”
	(2)	The turbidity in the combined filter effluent must be less than or equal to 0.3 NTU in 95 percent of the turbidity measurements taken each month.
	(3)	The turbidity in the combined filter effluent must never exceed 1 NTU at any time during the month. If at any time the combined filter effluent turbidity exceeds 1 NTU, either in a grab sample used for compliance or in a continuously monitored flow, the system must inform the department as soon as possible, but no later than 24 hours after the exceedance is known, in accordance with the public notification requirements under 567—subparagraphs 42.1(3)“b”(3) and 42.1(2)“a”(8).
	(4)	The monthly reporting requirements are listed in subrule 43.10(6).
	b. 	Slow sand filtration or diatomaceous earth filtration.
	(1)	Turbidity must be measured in the combined filter effluent as described in paragraphs 43.5(4)“a” and “b.”
	(2)	The combined filter effluent turbidity limits of subrule 43.5(3) must be met.
	(3)	The monthly reporting requirements are listed in subrule 43.10(6).
	c. 	Other alternative filtration technologies. By using pilot studies or other means, a system using alternative filtration must demonstrate to the satisfaction of the department that the system’s filtration, in combination with disinfection treatment, consistently achieves 99 percent removal of Cryptosporidium oocysts; 99.9 percent removal, inactivation, or a combination of both, of Giardia lamblia cysts; and 99.99 percent removal, inactivation, or a combination of both, of viruses. The department will then use the pilot study data to determine system-specific turbidity limits.
	(1)	Turbidity must be measured in the combined filter effluent as described in paragraphs 43.5(4)“a” and “b.”
	(2)	The turbidity must be less than or equal to a value set by the department in 95 percent of the combined filter effluent turbidity measurements taken each month, based on the pilot study. The value may not exceed 1 NTU.
	(3)	The combined filter effluent turbidity must never exceed a value set by the department, based on the pilot study. The value may not exceed 5 NTU.
	(4)	The monthly reporting requirements are listed in subrule 43.10(6).
	43.10(5) Individual filter turbidity requirements. All systems utilizing conventional filtration or direct filtration must conduct continuous monitoring of turbidity for each individual filter. Records must be maintained according to subrule 43.10(7).
	a. 	Continuous turbidity monitoring requirements. Following are the continuous turbidity monitoring requirements.
	(1)	Monitoring must be conducted using an approved method listed in paragraph 43.5(4)“a”;
	(2)	Calibration of turbidimeters must be conducted at least every 90 days with a primary standard. The calibration of each turbidimeter used for compliance must be verified at least once per week with a primary standard, secondary standards, or the manufacturer’s proprietary calibration confirmation device or by a method approved by the department. If the verification is not within plus or minus 0.05 NTU for measurements of less than or equal to 0.5 NTU, or within plus or minus 10 percent of measurements greater than 0.5 NTU, the turbidimeter must be recalibrated;
	(3)	Results of turbidity monitoring must be recorded at least every 15 minutes;
	(4)	Monthly reporting must be completed according to subrule 43.10(6); and
	(5)	Records must be maintained according to 43.10(7).
	b. 	Failure of continuous turbidity monitoring equipment. If there is a failure in the continuous turbidity monitoring equipment, the system must conduct grab sampling every four hours in lieu of continuous monitoring until the turbidimeter is back on-line. A system has a maximum of 14 days after failure to repair the equipment, or else the system is in violation. The system must notify the department within 24 hours of both when the turbidimeter was taken off-line and when it was returned on-line.
	c. 	Special provision for one-filter or two-filter systems. If a system has only one or two filters, it may conduct continuous monitoring of the combined filter effluent turbidity instead of individual effluent turbidity monitoring. The continuous monitoring of the combined filter effluent turbidity must meet the requirements listed in 43.10(5)“a” and “b.”
	d. 	Alternative turbidity levels for systems using lime softening. Systems using lime softening may apply to the department for alternative turbidity exceedance levels for the levels specified in 43.10(5)“e.” The system must be able to demonstrate to the satisfaction of the department that higher turbidity levels are due to lime carryover only, and not due to degraded filter performance.
	e. 	Requirements triggered by the individual filter turbidity monitoring data. Systems are required to conduct additional activities based upon their individual filter turbidity monitoring data, as listed in this paragraph.
	(1)	If the turbidity of an individual filter (or the turbidity of the combined filter effluent for a system with one or two filters, pursuant to 43.10(5)“c”) exceeds 1.0 NTU in two consecutive recordings taken 15 minutes apart, the system must report the following information in the monthly operation report to the department by the tenth day of the following month:
	1.	The filter number(s);
	2.	Corresponding date(s);
	3.	Turbidity value(s) which exceeded 1.0 NTU; and
	4.	The cause of the exceedance(s), if known.
	(2)	If the turbidity of an individual filter (or the turbidity of the combined filter effluent for a system with one or two filters, pursuant to 43.10(5)“c”) exceeds 1.0 NTU in two consecutive recordings 15 minutes apart in three consecutive months, the system must meet the following requirements:
	1.	The system must conduct a self-assessment of the filter(s) within 14 days of the day the filter exceeded 1.0 NTU in two consecutive measurements for the third straight month, unless a comprehensive performance evaluation as specified in the following paragraph is required. Two-filter systems that monitor the combined filter effluent turbidity instead of the individual filters must conduct a self-assessment of both filters.
	2.	The self-assessment must consist of at least the following components:
	●	Assessment of filter performance;
	●	Development of a filter profile;
	●	Identification and prioritization of factors limiting filter performance;
	●	Assessment of the applicability of corrections;
	●	Preparation of a filter self-assessment report;
	●	Date the self-assessment requirement was triggered; and
	●	Date the self-assessment was completed.
	(3)	If the turbidity of an individual filter (or the turbidity of the combined filter effluent for a system with one or two filters, pursuant to 43.10(5)“c”) exceeds 2.0 NTU in two consecutive recordings 15 minutes apart in two consecutive months, the system must meet the following requirements:
	1.	The system must arrange to have a comprehensive performance evaluation (CPE) conducted by the department or a third party approved by the department no later than 60 days following the day the filter exceeded 2.0 NTU in two consecutive measurements for the second straight month. The CPE report must be completed and submitted to the department within 120 days following the day the filter exceeded 2.0 NTU in two consecutive measurements for the second straight month.
	2.	A new CPE is not required if a CPE has been completed by the department or a third party approved by the department within the prior 12 months or if the system and department are jointly participating in an ongoing comprehensive technical assistance project at the system.
	(4)	The department may conduct a CPE at a system regardless of individual filter turbidity levels.
	43.10(6) Reporting requirements. The system must meet the following reporting requirements:
	a. 	Combined filter effluent turbidity monitoring.
	(1)	The following information must be reported in the monthly operation report to the department by the tenth day of the following month.
	1.	Total number of filtered water turbidity measurements taken during the month.
	2.	The number and percentage of filtered water turbidity measurements taken during the month which are less than or equal to the system’s required 95th percentile limit.
	3.	The date and analytical result of any turbidity measurements taken during the month which exceeded the maximum turbidity limit for the system, in addition to the requirements of (2).
	4.	The dates and summary of calibration and verification of all compliance turbidimeters.
	(2)	For an exceedance of the combined filter effluent maximum turbidity limit, the following requirements must be met.
	1.	If at any time the turbidity exceeds 1 NTU in representative samples of filtered water in a system using conventional filtration treatment or direct filtration, the system must consult with the department as soon as practical, but no later than 24 hours after the exceedance is known, in accordance with the public notification requirements under 567—subparagraph 42.1(3)“b”(3).
	2.	If at any time the turbidity in representative samples of filtered water exceeds the maximum level under subrule 43.5(3) for slow sand filtration or diatomaceous earth filtration, the system must consult with the department as soon as practical, but no later than 24 hours after the exceedance is known, in accordance with the public notification requirements under 567—subparagraph 42.1(3)“b”(3).
	3.	If at any time the turbidity in representative samples of filtered water exceeds the maximum level set by the department under paragraph 43.10(4)“c” for filtration technologies other than conventional filtration treatment, direct filtration, slow sand filtration, or diatomaceous earth filtration, the system must consult with the department as soon as practical, but no later than 24 hours after the exceedance is known, in accordance with the public notification requirements under 567—subparagraph 42.1(3)“b”(3).
	b. 	Individual filter effluent turbidity monitoring. The following information must be reported in the monthly operation report to the department by the tenth day of the following month, unless otherwise noted.
	(1)	That the system conducted individual filter turbidity monitoring during the month.
	(2)	For any filter that had two consecutive measurements taken 15 minutes apart that exceeded 1.0 NTU, the following information must be reported:
	1.	The filter number(s);
	2.	The corresponding dates;
	3.	The turbidity values that exceeded 1.0 NTU; and
	4.	The cause, if known, of the exceedance.
	(3)	If a self-assessment was required, the date it was triggered and the date the assessment was completed must be reported. If the self-assessment requirement was triggered in the last four days of the month, the information must be reported to the department by the 14th day of the following month.
	(4)	If a comprehensive performance evaluation was required, the date it was triggered must be reported. A copy of the CPE report must be submitted to the department within 120 days of when the CPE requirement was triggered.
	(5)	The dates and summary of calibration and verification of all compliance turbidimeters.
	c. 	Disinfection profiling. The following information must be reported to the department by January 1, 2004, for systems serving fewer than 500 people.
	(1)	Results of disinfection byproduct monitoring that indicate TTHM levels less than 0.064 mg/L and HAA5 levels less than 0.048 mg/L; or
	(2)	That the system has begun to collect the profiling data.
	d. 	Disinfection benchmarking. Before a system that was required to develop a disinfection profile makes a significant change to its disinfection practice, it must report the following information to the department, and the system must receive department approval before any significant change in disinfection practice is implemented.
	(1)	Description of the proposed change in disinfection practice;
	(2)	The system’s disinfection profile for Giardia lamblia and, if applicable, for viruses;
	(3)	The system’s disinfection benchmark; and
	(4)	An analysis of how the proposed change will affect the current levels of disinfection.
	43.10(7) Record-keeping requirements. The system must meet the following record-keeping requirements, in addition to the record-keeping requirements in 567—paragraph 42.4(3)“c” and 567—42.5(455B).
	a. 	Individual filter effluent turbidity requirements. The results of the individual filter effluent turbidity monitoring must be kept for at least three years.
	b. 	Disinfection profiling requirements. The results of the disinfection profile, including raw data and analysis, must be kept indefinitely.
	c. 	Disinfection benchmarking requirements. The results of the disinfection benchmark, including raw data and analysis, must be kept indefinitely.
[ARC 9915B, IAB 12/14/11, effective 1/18/12; ARC 3735C, IAB 4/11/18, effective 5/16/18]
567—43.11(455B) Enhanced treatment for Cryptosporidium.
	43.11(1) Applicability. The requirements of this rule are national primary drinking water regulations and establish or extend treatment technique requirements in lieu of maximum contaminant levels for Cryptosporidium. These requirements are in addition to the filtration and disinfection requirements of 567—43.5(455B), 567—43.9(455B) and 567—43.10(455B) and apply to all Iowa public water systems supplied by surface water or influenced groundwater sources.
	a. 	Wholesale systems. Wholesale systems must comply with the requirements based on the population of the largest system in the combined distribution system.
	b. 	Filtered systems. The requirements of this rule for filtered systems apply to systems that are required to provide filtration treatment pursuant to 567—43.5(455B), whether or not the system is currently operating a filtration system.
	43.11(2) General requirements. Systems subject to this rule must comply with the following requirements:
	a. 	Source water monitoring. Systems must conduct two rounds of source water monitoring for each plant that treats a surface water or influenced groundwater source. This monitoring may include sampling for Cryptosporidium, E. coli, and turbidity, as described in 43.11(3), to determine what level, if any, of additional Cryptosporidium  treatment the systems must provide.
	b. 	Disinfection profiles and benchmarks. Systems that plan to make a significant change to their disinfection practice must develop disinfection profiles and calculate disinfection benchmarks, as described in 43.11(4).
	c. 	Cryptosporidium treatment bin determination. Systems must determine their Cryptosporidium treatment bin classification and provide additional treatment for Cryptosporidium, if required, according to the prescribed schedule.
	d. 	Additional treatment for Cryptosporidium. Systems required to provide additional treatment for Cryptosporidium must implement microbial toolbox options that are designed and operated as described in 43.11(8) through 43.11(13).
	e. 	Record keeping and reporting. Systems must comply with the applicable record-keeping and reporting requirements described in 43.11(14) and 43.11(15).
	f. 	Significant deficiencies. Systems must address significant deficiencies identified during sanitary surveys as described in 43.1(7).
	43.11(3) Source water monitoring.
	a. 	Schedule. Systems must conduct the source water monitoring no later than the month and year listed in Table 1. A system may avoid the source water monitoring if the system provides a total of at least 5.5-log treatment for Cryptosporidium, equivalent to meeting the treatment requirements of Bin 4 in 43.11(6). The system must install and operate technologies to provide this level of treatment by the applicable treatment compliance date specified in 43.11(7).
Table 1: Source Water Monitoring Schedule

System	First round of monitoring	Second round of monitoring	
Serves at least 100,000 people	October 2006	April 2015	
Serves 50,000-99,999 people	April 2007	October 2015	
Serves 10,000-49,999 people	April 2008	October 2016	
Serves fewer than 10,000 people and only conducts E. coli monitoring	October 2008	October 2017	
Serves fewer than 10,000 people and conducts Cryptosporidium monitoring	April 2010	April 2019	
	b. 	Monitoring requirements. The minimum monitoring requirements are listed below. Systems may sample more frequently, provided the sampling frequency is evenly spaced throughout the monitoring period.
	(1)	Systems serving at least 10,000 people. Systems serving at least 10,000 people must sample their source water for Cryptosporidium, E. coli, and turbidity at least monthly for 24 months.
	(2)	Systems serving fewer than 10,000 people. Systems serving fewer than 10,000 people are allowed to first conduct E. coli monitoring to determine if further monitoring for Cryptosporidium is required.
	1.	Systems must sample their source water for E. coli at least once every two weeks for 12 months. If the annual mean E. coli concentration is at or below 100 E. coli per 100 mL, the system can avoid further Cryptosporidium monitoring in that sampling round.
	2.	A system may avoid E. coli monitoring if the system notifies the department no later than three months prior to the E. coli monitoring start date that the system will conduct Cryptosporidium monitoring.
	3.	Systems that fail to conduct the required E. coli monitoring or that cannot meet the E. coli annual mean limit are required to conduct Cryptosporidium monitoring. The system must sample its source water for Cryptosporidium either at least twice per month for 12 months or at least monthly for 24 months.
	4.	A system that begins monitoring for E. coli and determines during the sampling period that the system mathematically cannot meet the applicable E. coli annual mean limit may discontinue the E. coli sampling. The system is then required to start Cryptosporidium monitoring according to the schedule in Table 1.
	(3)	Plants operating only part of the year. Systems with surface water or influenced groundwater treatment plants that operate for only part of the year must conduct source water monitoring in accordance with this rule, but with the following modifications.
	1.	Systems must sample their source water only during the months that the plant operates unless the department specifies another monitoring period based on plant operating practices.
	2.	Systems with plants that operate less than six months per year and that monitor for must collect at least six samples per year for two years. The samples must be evenly spaced throughout the period the plant operates.
	(4)	New sources. A system that begins using a new surface water or influenced groundwater source after the dates in Table 1 must monitor according to a schedule approved by the department and meet the requirements of this subrule. The system must also meet the requirements of the bin classification and Cryptosporidium treatment for the new source on a schedule approved by the department. The system must conduct the second round of source water monitoring no later than six years following the initial bin classification or determination of the mean Cryptosporidium level, as applicable.
	(5)	Monitoring violation determination. Failure to collect any source water sample required under this subrule in accordance with the sampling plan, location, analytical method, approved laboratory, or reporting requirements of 43.11(3)“c” through 43.11(3)“e” is a monitoring violation.
	(6)	Grandfathered monitoring data. Systems were allowed to use source water monitoring Cryptosporidium data collected prior to the applicable start date in Table 1 to meet the requirements of the first round of monitoring, a process referred to as grandfathering data. This grandfathered data substituted for an equivalent number of months at the end of the monitoring period and had to meet the requirements of 40 CFR 141.707 as adopted on January 5, 2006, which the department hereby adopts by reference. Department approval of the grandfathered data application is required.
	c. 	Sampling plan. Systems must submit a sampling plan that specifies the sampling locations in relation to the sources and treatment processes and the calendar dates when the system will collect each required sample. The specific treatment process locations that must be included in the plan are pretreatment, points of chemical treatment, and filter backwash recycle.
	(1)	The sampling plan must be submitted no later than three months prior to the applicable monitoring date in Table 1. If the department does not respond to a system regarding the submitted sampling plan prior to the start of the monitoring period, the system must sample according to the submitted sampling plan.
	(2)	The plan must be submitted in a form acceptable to the department.
	(3)	The system must monitor within two days of the date specified in the plan, unless one of the following conditions occurs.
	1.	If an extreme condition or situation exists that may pose danger to the sample collector, or that cannot be avoided, and causes the system to be unable to sample in the scheduled five-day period, the system must sample as close to the scheduled date as is feasible unless the department approves an alternative sampling date. The system must submit an explanation for the delayed sampling date to the department within one week of the missed sampling period. A replacement sample must be collected.
	2.	If a system is unable to report a valid analytical result for a scheduled sampling date due to equipment failure, loss of or damage to the sample, failure to comply with the analytical method or quality control requirements, or failure of the laboratory to analyze the sample, the system must notify the department of the cause of the delay and collect a replacement sample.
	3.	A replacement sample must be collected within 21 days of the scheduled sampling period or on the resampling date approved by the department.
	(4)	Missed sampling dates. Systems that fail to meet the dates in their sampling plan for any source water sample must revise their sampling plan to add dates for collecting all missed samples. The revised schedule must be submitted to the department for approval prior to the collection of the missed samples.
	d. 	Sampling locations. Systems must collect samples for each treatment plant that treats a surface water or influenced groundwater source. If multiple plants draw water from the same influent (same pipe or intake), the department may approve one set of monitoring results to be used to satisfy the requirements for those plants.
	(1)	Chemical treatment location. Systems must collect source water samples prior to chemical treatment. If the system cannot feasibly collect a sample prior to chemical treatment, the department may grant approval for the system to collect the sample after chemical treatment. This approval would only be granted if the department determines in writing that collecting the samples prior to chemical treatment is not feasible for the system and that the chemical treatment is unlikely to have a significant adverse effect on the analysis of the sample.
	(2)	Filter backwash recycle return location. Systems that recycle filter backwash water must collect the source water samples prior to the point of filter backwash water addition.
	(3)	Bank filtration credit sampling location.
	1.	Systems that receive Cryptosporidium treatment credit for bank filtration under 43.9(3)“b” or 43.10(4)“c” must collect source water samples in the surface water source prior to bank filtration.
	2.	Systems that use bank filtration as pretreatment to a filtration plant must collect source water samples from the well, which is after bank filtration has occurred. Use of bank filtration during monitoring must be consistent with routine operational practice. Systems collecting samples after a bank filtration process may not receive treatment credit for the bank filtration under 43.11(10)“c.”
	(4)	Multiple sources. Systems with plants that use multiple water sources, including multiple surface water sources and blended surface water and groundwater sources, must collect samples as follows:
	1.	The use of multiple sources during monitoring must be consistent with routine operational practice.
	2.	If a sampling tap is available where the sources are combined prior to treatment, the system must collect samples from that tap.
	3.	If a sampling tap where the sources are combined prior to treatment is not available, the system must collect samples at each source near the intake on the same day and must use either of the following options for sample analysis.
	●	Physically composite the source samples into a single sample for analysis. Systems may composite the sample from each source into one sample prior to analysis. The volume of the sample from each source must be weighted according to the proportion of the source in the total plant flow at the time the sample is collected.
	●	Analyze the samples separately and mathematically composite the results. Systems may analyze samples from each source separately and calculate a weighted average of the analytical results for each sampling date. The weighted average must be calculated by multiplying the analytical result for each source by the fraction that source contributed to the total plant flow at the time the sample was collected and then summing the weighted analytical results.
	e. 	Analytical methodology, laboratory certification, and data reporting requirements. Systems must have samples analyzed pursuant to the specifications listed in this paragraph. The system must report, in a format acceptable to the department, the analytical results from the source water monitoring no later than ten days after the end of the first month following the month when the sample is collected.
	(1)	Cryptosporidium. Systems must have Cryptosporidium samples analyzed by a laboratory that is approved under EPA’s Laboratory Quality Assurance Evaluation Program for Analysis of Cryptosporidium in Water.
	1.	These are the approved analytical methods for Cryptosporidium:
	●	“Method 1623: Cryptosporidium and Giardia in Water by Filtration/IMS/FA,” 2005, US EPA, EPA-815-R-05-002. Available at www.nemi.gov;
	●	“Method 1622: Cryptosporidium in Water by Filtration/IMS/FA,” 2005, US EPA, EPA-815-R-05-001. Available at www.nemi.gov; and
	●	“Method 1623.1: Cryptosporidium and Giardia in Water by Filtration/Immunomagnetic Separation/Immunofluorescence Assay Microscopy,” 2012, EPA-816-R-12-001. Available at www.nepis.epa.gov.
	2.	Using one of the approved methods, the laboratory must analyze at least a 10 L sample or a packed pellet volume of at least 2 mL. Systems unable to process a 10 L sample must analyze as much sample volume as can be filtered by two filters specified in the method, up to a packed pellet volume of at least 2 mL.
	3.	A matrix spike (MS) sample must be spiked and filtered by the laboratory according to the approved method. If the volume of the MS sample is greater than 10 L, the system may filter all but 10 L of the MS sample in the field and ship the filtered sample and the remaining 10 L of source water to the laboratory. In this case, the laboratory must spike the remaining 10 L of water and filter it through the filter used to collect the balance of the sample in the field.
	4.	Flow cytometer-counted spiking suspensions must be used for the matrix spike samples and the ongoing precision and recovery samples.
	5.	The following data elements must be reported for each Cryptosporidium analysis:
	●	PWSID.
	●	Facility ID.
	●	Sample collection date.
	●	Sample type (i.e., field or matrix spike).
	●	Sample volume filtered (L), to the nearest 0.25 L.
	●	Whether 100 percent of the filtered volume was examined by the laboratory.
	●	Number of oocysts counted.
	●	For matrix spike samples: sample volume spiked and estimated number of oocysts spiked.
	●	For samples in which less than 10 L is filtered or less than 100 percent of the sample volume is examined: the number of filters used and the packed pellet volume.
	●	For samples in which less than 100 percent of sample volume is examined: the volume of resuspended concentrate and the volume of this resuspension processed through immunomagnetic separation.
	(2)	E. coli. Systems must have the E. coli samples analyzed by a laboratory certified by EPA, the National Environmental Laboratory Accreditation Conference, or the department for total coliform or fecal coliform analysis in drinking water samples using the same approved E. coli method for the analysis of source water.
1. The approved analytical methods for the enumeration of E. coli in source water are shown in Table 2.
Table 2: E. coli Analytical Methods

Method	EPA	Standard Methods	Other	
Most probable number with multiple tube or multiple well1, 2	 	9223 B11	991.154
Colilert3, 5
Colilert-183, 5, 6	
Membrane filtration, single step1, 7, 8	16039	 	m-ColiBlue2410	
Membrane filtration, two step	 	9222D/9222G12	 	
1Tests must be conducted to provide organism enumeration (i.e., density). Select the appropriate configuration of tubes/filtrations and dilutions/volumes to account for the quality, consistency, and anticipated organism density in the water sample.
2Samples shall be enumerated by the multiple-tube or multiple-well procedure. Using multiple-tube procedures, employ an appropriate tube and dilution configuration of the sample as needed and report the Most Probable Number (MPN). Samples tested with Colilert® may be enumerated with the multiple-well procedures, Quanti-Tray®, Quanti-Tray® 2000, and the MPN calculated from the table provided by the manufacturer.
3These tests are collectively known as defined enzyme substrate tests, where, for example, a substrate is used to detect the enzyme beta-glucouronidase produced by E. coli.
4Association of Official Analytical Chemists, International. “Official Methods of Analysis of AOAC International, 16th Ed., Volume 1, Chapter 17, 1995. AOAC, 481 N. Frederick Ave., Suite 500, Gaithersburg, MD 20877-2417.
5Descriptions of the Colilert®, Colilert-18®, Quanti-Tray®, and Quanti-Tray® 2000 may be obtained from IDEXX Laboratories, Inc., 1 IDEXX Drive, Westbrook, ME 04092.
6Colilert-18® is an optimized formulation of the Colilert® for the determination of total coliforms and E. coli that provides results within 18 hours of incubation at 35 degrees C rather than the 24 hours required for the Colilert® test.
7The filter must be a 0.45 micron membrane filter or a membrane filter with another pore size certified by the manufacturer to fully retain organisms to be cultivated and to be free of extractables which could interfere with organism growth.
8When the membrane filter method has been used previously to test waters with high turbidity or large numbers of noncoliform bacteria, a parallel test should be conducted with a multiple-tube technique to demonstrate applicability and comparability of results.
9“Method 1603: Escherichia coli (E. coli) in Water by Membrane Filtration Using Modified Membrane-Thermotolerant Escherichia coli Agar (modified mTEC), USEPA, July 2006.” US EPA, Office of Water, Washington, DC, EPA 821-R-06-011. Available at www.nepis.epa.gov.
10A description of the m-ColiBlue24® test, Total Coliforms and E. coli, is available from Hach Company, 100 Dayton Ave., Ames, IA 50010.
11Standard Methods for the Analysis of Water and Wastewater, 18th (1992), 19th (1995), and 20th (1998) editions, American Public Health Association. Available from APHA, 800 I Street, NW, Washington, DC 20001-3710.
12Standard Methods for the Examination of Water and Wastewater, 20th edition (1998). Available from APHA, 800 I Street, NW, Washington, DC 20001-3710.
2. The holding time (the time period from sample collection to initiation of analysis) shall not exceed 30 hours. The department may approve on a case-by-case basis an extension of the holding time to 48 hours, if the 30-hour holding time is not feasible. If the extension is allowed, the laboratory must use the Colilert® reagent version of the Standard Methods 9223B to conduct the analysis.
3. The samples must be maintained between 0 and 10 degrees C during storage and transit to the laboratory.
4. The following data elements must be reported for each E. coli analysis:
	●	PWSID.
	●	Facility ID.
	●	Sample collection date.
	●	Analytical method number.
	●	Method type.
	●	Source type (flowing stream or river; lake or reservoir; or influenced groundwater).
	●	Number of E. coli per 100 mL.
	●	Turbidity in NTU.
	(3)	Turbidity. The approved analytical methods for turbidity are listed in 43.5(4)“a”(1). Measurements of turbidity must be made by a party approved by the department, and reported on the laboratory data sheet with the corresponding E. coli sample.
	43.11(4) Disinfection profiling and benchmarking.
	a. 	General requirements. Following completion of the first round of source water monitoring, a system that plans to make a significant change to its disinfection practice must develop disinfection profiles and calculate disinfection benchmarks for Giardia lamblia and viruses.
	(1)	Notification to the department. The system must notify the department prior to changing its disinfection practice and must include in the notice the completed disinfection profile and disinfection benchmark for Giardia lamblia and viruses, a description of the proposed change in disinfection practice, and an analysis of how the proposed change will affect the current level of disinfection.
	(2)	Definition of “significant change.” A significant change to the disinfection practice is defined as follows:
	1.	Any change to the point of disinfection;
	2.	Any change to the disinfectant(s) used in the treatment plant;
	3.	Any change to the disinfection process; or
	4.	Any other modification identified by the department as a significant change to disinfection practice.
	b. 	Developing the disinfection profile. In order to develop a disinfection profile, a system must monitor at least weekly for a period of 12 consecutive months to determine the total log inactivation for Giardia lamblia and viruses. If a system monitors more frequently, the monitoring frequency must be evenly spaced. A system that operates for fewer than 12 months per year must monitor weekly during the period of operation. A system must determine log inactivation for Giardia lamblia through the entire plant, based on CT99.9 values in Appendix A, Tables 1 through 6, as applicable. Systems must determine log inactivation for viruses through the entire treatment plant based on a protocol approved by the department.
	(1)	Monitoring requirements. Systems with a single point of disinfectant application prior to the entrance to the distribution system must conduct the monitoring listed in this subparagraph. Systems with multiple points of disinfectant application must conduct the same monitoring for each disinfection segment. Systems must monitor the parameters necessary to determine the total inactivation ratio. The analytical methods for the parameters are listed in 43.5(4)“a.” All measurements must be taken during peak hourly flow.
	1.	For systems using a disinfectant other than UV, the temperature of the disinfected water must be measured in degrees Celsius at each residual disinfectant concentration sampling point or at an alternative location approved by the department.
	2.	For systems using chlorine, the pH of the disinfected water must be measured at each chlorine residual disinfectant concentration sampling point or at an alternative location approved by the department.
	3.	The disinfectant contact time must be determined in minutes.
	4.	The residual disinfectant concentrations of the water must be determined in mg/L before or at the first customer and prior to each additional point of disinfectant application.
	5.	A system may use existing data to meet the monitoring requirements if the data are substantially equivalent to the required data, the system has not made any significant change to its treatment practice, and the system has the same source water as it had when the data were collected. Systems may develop disinfection profiles using up to three years of existing data.
	6.	A system may use disinfection profiles developed under 43.9(2) or 43.10(2) if the system has not made a significant change to its treatment practice and has the same source water as it had when the profile was developed. The virus profile must be developed using the same data on which the Giardia lamblia profile is based.
	(2)	Calculation of the total inactivation ratio for Giardia lamblia.
	1.	Systems using only one point of disinfectant application may determine the total inactivation ratio (CTcalc/CT99.9) for the disinfection segment using either of the following methods.
	●	Determine one inactivation ratio before or at the first customer during peak hourly flow.
	●	Determine successive sequential inactivation ratios between the point of disinfectant application and a point before or at the first customer during peak hourly flow. Calculate the total inactivation ratio by determining the inactivation ratio for each sequence (CTcalc/CT99.9) and adding the values together.
	2.	Systems using more than one point of disinfectant application before the first customer must determine the CT value of each disinfection segment immediately prior to the next point of disinfectant application, or for the final segment, before or at the first customer, during peak hourly flow. Calculate the (CTcalc/CT99.9) value of each segment and add the values together to determine the total inactivation ratio.
	3.	Systems must then determine the total logs of inactivation by multiplying the total inactivation ratio by 3.0.
	(3)	Calculation of the total inactivation ratio for viruses. The system must calculate the log of inactivation for viruses using a protocol approved by the department.
	c. 	Calculation of the disinfection benchmark.
	(1)	For each year of profiling data collected and calculated under this subrule, systems must determine the lowest mean monthly level of both Giardia lamblia and virus inactivation. Systems must determine the mean Giardia lamblia and virus inactivation for each calendar month for each year of profiling data by dividing the sum of daily or weekly Giardia lamblia and virus log inactivation by the number of values calculated for that month.
	(2)	For a system with one year of profiling data, the disinfection benchmark is the lowest monthly mean value. For a system with more than one year of profiling data, the disinfection benchmark is the mean of the lowest monthly mean values of Giardia lamblia and virus log inactivation in each year of profiling data.
	43.11(5) Bin classification.  Upon completion of the first round of source water monitoring, systems must calculate an initial Cryptosporidium bin concentration for each plant for which monitoring was required. Calculation of the bin concentration must use the Cryptosporidium results reported under 43.11(3)“a.”
	a. 	Calculation of mean Cryptosporidium or bin concentration value.
	(1)	Systems that collect at least 48 samples. For systems that collect a total of at least 48 samples, the bin concentration is equal to the arithmetic mean of all sample concentrations.
	(2)	Systems that collect 24 to 47 samples. For systems that collect at least 24 samples but not more than 47 samples, the bin concentration is equal to the highest arithmetic mean of all sample concentrations in any 12 consecutive months during which Cryptosporidium samples were collected.
	(3)	Systems serving fewer than 10,000 people and monitoring for only one year. For systems that serve fewer than 10,000 people and monitor Cryptosporidium for only one year (i.e., 24 samples in 12 months), the bin concentration is equal to the arithmetic mean of all sample concentrations.
	(4)	Systems with plants operating on a part-time basis. For systems with plants operating only part of the year that monitor fewer than 12 months per year, the bin concentration is equal to the highest arithmetic mean of all sample concentrations during any year of Cryptosporidium monitoring.
	(5)	If the monthly Cryptosporidium sampling frequency varies, systems must first calculate a monthly average for each month of monitoring. Systems must then use these monthly average concentrations, rather than individual sample concentrations, in the applicable calculation for bin classification.
	b. 	Determination of bin classification.
	(1)	First monitoring round. A system must determine the bin classification from Table 3, using its calculated bin concentration from 43.11(5)“a.”
Table 3: Bin Classification Table

System Type	Cryptosporidium Concentration, in oocysts/L	Bin Classification	
Systems required to monitor for Cryptosporidium under 43.11(3)“b”(1) or 43.11(3)“b”(2)“3”	Fewer than 0.075 oocysts/L	Bin 1	
	Between 0.075 and fewer than 1.0 oocysts/L	Bin 2	
	Between 1.0 and fewer than 3.0 oocysts/L	Bin 3	
	3.0 oocysts/L or greater	Bin 4	
Systems serving fewer than 10,000 and not required to monitor for Cryptosporidium, pursuant to 43.11(3)“b”(2)“1”	Not applicable	Bin 1	
	(2)	Second monitoring round. Following completion of the second round of source water monitoring, a system must recalculate its bin concentration and determine its new bin classification, using the same protocols outlined in 43.11(5)“a” and “b.”
	c. 	Reporting bin classification to the department. Within six months of the end of the sampling period, the system must report its bin classification to the department for approval. The report must also include a summary of the source water monitoring data and the calculation procedure used to determine the bin classification.
	d. 	Treatment technique violation. Failure to comply with 43.11(5)“b” and “c” is a violation of the treatment technique requirement.
	43.11(6) Additional Cryptosporidium treatment requirements.  A system must provide the level of additional treatment for Cryptosporidium specified in Table 4 based on its bin classification determined in 43.11(5) and according to the schedule in 43.11(7).
	a. 	Determination of additional Cryptosporidium treatment requirements. Using Table 4, a system must determine any additional treatment requirements based upon its bin classification. The Bin 1 classification does not require any additional treatment. Bins 2 through 4 require additional Cryptosporidium treatment.
Table 4: Additional Cryptosporidium Treatment Requirements

Bin Classification	Treatment Used by the System for Compliance with 43.5, 43.9, and 43.10	
	Conventional filtration (including softening)	Direct filtration	Slow sand or diatomaceous earth filtration	Alternative filtration technologies	
Bin 1	No additional treatment	No additional treatment	No additional treatment	No additional treatment	
Bin 2	1-log treatment	1.5-log treatment	1-log treatment	At least 4.0-log1	
Bin 3	2-log treatment	2.5-log treatment	2-log treatment	At least 5.0-log1	
Bin 4	2.5-log treatment	3-log treatment	2.5-log treatment	At least 5.5-log1	
1The total Cryptosporidium removal and inactivation must be at least this value, as determined by the department.
	b. 	Treatment requirements for Bins 2 through 4. A system that is classified as Bin 2, 3, or 4 must use one or more of the treatment and management options listed in 43.11(8) to comply with the required additional Cryptosporidium treatment. Systems classified as Bins 3 and 4 must achieve at least 1-log of the additional Cryptosporidium treatment required by using either one or a combination of the following: bag filters, bank filtration, cartridge filters, chlorine dioxide, membranes, ozone, or UV, as listed in 43.11(9) through 43.11(13).
	c. 	Treatment technique violation. Failure by a system in any month to achieve treatment credit by meeting criteria in 43.11(9) through 43.11(13) that is at least equal to the level of treatment required in 43.11(6)“a” is a violation of the treatment technique requirement.
	d. 	Significant changes to the watershed. If, after the system’s completion of source water monitoring (either round), the department determines during a sanitary survey or an equivalent source water assessment that significant changes occurred in the system’s watershed that could lead to increased contamination of the source water by Cryptosporidium, the system must take actions specified by the department to address the contamination. These actions may include additional source water monitoring and implementing microbial toolbox options listed in 43.11(8).
	43.11(7) Schedule for compliance with Cryptosporidium treatment requirements.   Following the initial bin classification under 43.11(5), systems must provide the level of treatment for Cryptosporidium required in 43.11(6), according to the schedule in Table 5. If the bin classification of a system changes following the second round of source water monitoring, the system must provide the level of treatment for Cryptosporidium required in 43.11(6), on a schedule approved by the department.
Table 5: Cryptosporidium Treatment Compliance Dates

Schedule	Population Served by System	Compliance Date for Cryptosporidium treatment requirements1	
1	At least 100,000 people	April 1, 2012	
2	From 50,000 to 99,999 people	October 1, 2012	
3	From 10,000 to 49,999 people	October 1, 2013	
4	Fewer than 10,000 people	October 1, 2014	
1The department may allow up to an additional two years for compliance with the treatment requirement if the system must make capital improvements.
	43.11(8) Microbial toolbox options for meeting Cryptosporidium treatment requirements. Systems receive the treatment credits listed in Table 6 by meeting the conditions for microbial toolbox options described in 43.11(9) through 43.11(13). Systems apply these treatment credits to meet the treatment requirements in 43.11(6). Table 6 summarizes options in the microbial toolbox.
Table 6: Microbial Toolbox Summary Table: Options, Treatment Credits, and Criteria

Toolbox Option	Specific Criteria Rule	Cryptosporidium treatment credit with design and implementation criteria	
Source Protection and Management Toolbox Options	
Watershed control program	43.11(9)	0.5-log credit for department-approved program comprising required elements, annual program status report to department, and regular watershed survey.	
Alternative source/intake management	43.11(9)“b”	No prescribed credit. Systems may conduct simultaneous monitoring for treatment bin classification at alternative intake locations or under alternative intake management strategies.	
Prefiltration Toolbox Options	
Presedimentation basin with coagulation	43.11(10)“a”	0.5-log credit during any month that presedimentation basins achieve a monthly mean reduction of 0.5-log or greater in turbidity or alternative department-approved performance criteria. To be eligible, basins must be operated continuously with coagulant addition and all plant flow must pass through the basins.	
Two-stage lime softening	43.11(10)“b”	0.5-log credit for two-stage softening where chemical addition and hardness precipitation occur in both stages. All plant flow must pass through both stages. Single-stage softening is credited as equivalent to conventional treatment.	
Bank filtration	43.11(10)“c”	0.5-log credit for 25-foot setback; 1.0-log credit for 50-foot setback; aquifer must be unconsolidated sand containing at least 10 percent fines; average turbidity in wells must be less than 1 NTU. A system using a well followed by filtration when conducting source water monitoring must sample the well to determine bin classification and is not eligible for additional credit.	
Treatment Performance Toolbox Options	
Combined filter performance	43.11(11)“a”	0.5-log credit for combined filter effluent turbidity less than or equal to 0.15 NTU in at least 95 percent of measurements each month.	
Individual filter performance	43.11(11)“b”	0.5-log credit (in addition to the 0.5-log combined filter performance credit) if individual filter effluent turbidity is less than or equal to 0.15 NTU in at least 95 percent of samples each month in each filter and is never greater than 0.3 NTU in two consecutive measurements in any filter.	
Demonstration of performance	43.11(11)“c”	Credit awarded to unit process or treatment train based on a demonstration to the department with a department-approved protocol.	
Additional Filtration Toolbox Options	
Bag or cartridge filters (individual filters)	43.11(12)“a”	Up to 2-log credit based on the removal efficiency demonstrated during challenge testing with a 1.0-log factor of safety.	
Bag or cartridge filters (in series)	43.11(12)“a”	Up to 2.5-log credit based on the removal efficiency demonstrated during challenge testing with a 0.5-log factor of safety.	
Membrane filtration	43.11(12)“b”	Log credit equivalent to removal efficiency demonstrated in challenge test for device if supported by direct integrity testing.	
Second-stage filtration	43.11(12)“c”	0.5-log credit for second separate granular media filtration stage if treatment train includes coagulation prior to first filter.	
Slow sand filtration	43.11(12)“d”	2.5-log credit as a secondary filtration step; 3.0-log credit as a primary filtration process. No prior chlorination for either option.	
Inactivation Toolbox Options	
Chlorine dioxide	43.11(13)	Log credit based on measured CT in relation to CT table.	
Ozone	43.11(13)	Log credit based on measured CT in relation to CT table.	
Ultraviolet light (UV)	43.11(13)	Log credit based on validated UV dose in relation to UV dose table; reactor validation testing required to establish UV dose and associated operating conditions.	
	43.11(9) Source toolbox components.
	a. 	Watershed control program. Systems receive 0.5-log Cryptosporidium treatment credit for implementing a watershed control program that meets the requirements of this paragraph.
	(1)	Notification. Systems that intend to apply for the watershed control program credit must notify the department of this intent no later than two years prior to the treatment compliance date in 43.11(7) applicable to the system.
	(2)	Proposed watershed control plan. Systems must submit to the department a proposed watershed control plan no later than one year before the applicable treatment compliance date in 43.11(7). The department must approve the watershed control plan for the system to receive watershed control program treatment credit. The watershed control plan must include the following elements:
	1.	Identification of an “area of influence” outside of which the likelihood of Cryptosporidium or fecal contamination affecting the treatment plant intake is not significant. This is the area to be evaluated in future watershed surveys under 43.11(9)“a”(5)“2.”
	2.	Identification of both potential and actual sources of Cryptosporidium contamination and an assessment of the relative impact of these sources on the system’s source water quality.
	3.	An analysis of the effectiveness and feasibility of control measures that could reduce Cryptosporidium loading from sources of contamination to the system’s source water.
	4.	A statement of goals and specific actions the system will undertake to reduce source water Cryptosporidium levels. The plan must explain how the actions are expected to contribute to specific goals, identify watershed partners and their roles, identify resource requirements and commitments, and include a schedule for plan implementation with deadlines for completing specific actions identified in the plan.
	(3)	Existing watershed control programs. Systems with watershed control programs that were in place on January 5, 2006, are eligible to seek this credit. The systems’ watershed control plans must meet the criteria in 43.11(9)“a”(2) and must specify ongoing and future actions that will reduce source water Cryptosporidium levels.
	(4)	Department response to submitted plan. If the department does not respond to a system regarding approval of a watershed control plan submitted under this subrule and the system meets the other requirements of this subrule, the watershed control program will be considered approved and 0.5-log Cryptosporidium treatment credit will be awarded unless and until the department subsequently withdraws such approval.
	(5)	System requirements to maintain 0.5-log credit. Systems must complete the following actions to maintain the 0.5-log credit.
	1.	Submit an annual watershed control program status report to the department. The annual watershed control program status report must describe the system’s implementation of the approved plan and assess the adequacy of the plan to meet its goals. The plan must explain how the system is addressing any shortcomings in plan implementation, including those previously identified by the department or as a result of the watershed survey conducted under 43.11(9)“a”(5)“2.” It must also describe any significant changes that have occurred in the watershed since the last watershed sanitary survey. If a system determines during implementation that making a significant change to its approved watershed control program is necessary, the system must notify the department prior to making any such changes. If any change is likely to reduce the level of source water protection, the system must also list in its notification the actions the system will take to mitigate this effect.
	2.	Undergo a watershed sanitary survey every three years for community water systems and every five years for noncommunity water systems and submit the survey report to the department. The survey must be conducted according to department guidelines and by persons acceptable to the department.
	●	The watershed sanitary survey must meet the following criteria: encompass the region identified in the department-approved watershed control plan as the area of influence; assess the implementation of actions to reduce source water Cryptosporidium levels; and identify any significant new sources of Cryptosporidium.
	●	If the department determines that significant changes may have occurred in the watershed since the previous watershed sanitary survey, systems must undergo another watershed sanitary survey by the date specified by the department, which may be earlier than the regular schedule of a three- or five-year frequency.
	3.	The system must make the watershed control plan, annual status reports, and watershed sanitary survey reports available to the public upon request. These documents must be in a plain language style and include criteria by which to evaluate the success of the program in achieving plan goals. The department may approve systems to withhold portions of an annual status report, watershed control plan, and watershed sanitary survey from the public, based on water supply security considerations.
	(6)	Withdrawal of watershed control program treatment credit. If the department determines that a system is not carrying out the approved watershed control plan, the department may withdraw the watershed control program treatment credit.
	b. 	Alternative source. A system may conduct source water monitoring that reflects a different intake location (either in the same source or for an alternate source) or a different procedure for the timing or level of withdrawal from the source (alternative source monitoring). If the department approves, a system may determine its bin classification under 43.11(5) based on alternative source monitoring results.
	(1)	Systems conducting alternative source monitoring must also monitor their current plan intake concurrently, as described in 43.11(3).
	(2)	Alternative source monitoring must meet the requirements for source monitoring to determine bin classification, as described in 43.11(3). Systems must report to the department the alternative source monitoring results and provide supporting information documenting the operating conditions under which the samples were collected.
	(3)	If a system determines its bin classification under 43.11(5) using alternative source monitoring results that reflect a different intake location or a different procedure for managing the timing or level of withdrawal from the source, the system must relocate the intake or permanently adopt the withdrawal procedure, as applicable, no later than the applicable treatment compliance date in 43.11(7).
	43.11(10) Prefiltration treatment toolbox components.
	a. 	Presedimentation. Systems receive 0.5-log Cryptosporidium treatment credit for a presedimentation basin during any month the process meets the criteria in this paragraph.
	(1)	The presedimentation basin must be in continuous operation and must treat the entire plant flow taken from a surface water or influenced groundwater source.
	(2)	The system must continuously add a coagulant to the presedimentation basin.
	(3)	The presedimentation basin must achieve either of the following performance criteria:
	1.	Demonstrates at least 0.5-log mean reduction of influent turbidity. This reduction must be determined using daily turbidity measurements in the presedimentation process influent and effluent and must be calculated as follows: LOG10(monthly mean of daily influent turbidity) – LOG10(monthly mean of daily effluent turbidity).
	2.	Complies with department-approved performance criteria that demonstrate at least 0.5-log mean removal of micron-sized particulate material through the presedimentation process.
	b. 	Two-stage lime softening. Systems receive an additional 0.5-log Cryptosporidium treatment credit for a two-stage lime softening plant if chemical addition and hardness precipitation occur in two separate and sequential softening stages prior to filtration. Both softening stages must treat the entire plant flow taken from a surface water or influenced groundwater source.
	c. 	Bank filtration. Systems receive Cryptosporidium treatment credit for bank filtration that serves as pretreatment to a filtration plant by meeting the criteria in this paragraph. Systems using bank filtration when they begin source water monitoring under 43.11(3)“a” must collect samples as described in 43.11(3)“d”(3) and are not eligible for this credit.
	(1)	Treatment credit. Wells with a groundwater flow path of at least 25 feet receive 0.5-log treatment credit; wells with a groundwater flow path of at least 50 feet receive 1.0-log treatment credit. The groundwater flow path must be determined as specified in 43.11(10)“c”(4).
	(2)	Granular aquifers only. Only wells in granular aquifers are eligible for treatment credit. Granular aquifers are those comprised of sand, clay, silt, rock fragments, pebbles or larger particles, and minor cement. A system must characterize the aquifer at the well site to determine aquifer properties. Systems must extract a core from the aquifer and demonstrate that in at least 90 percent of the core length, grains less than 1.0 mm in diameter constitute at least 10 percent of the core material.
	(3)	Horizontal and vertical wells only. Only horizontal and vertical wells are eligible for treatment credit.
	(4)	Measurement of groundwater flow path. For vertical wells, the groundwater flow path is the measured distance from the edge of the surface water body under high flow conditions (determined by the 100-year floodplain elevation boundary or by the floodway, as defined in Federal Emergency Management Agency flood hazard maps) to the well screen. For horizontal wells, the groundwater flow path is the measured distance from the bed of the river under normal flow conditions to the closest horizontal well lateral screen.
	(5)	Turbidity monitoring at the wellhead. Systems must monitor each wellhead for turbidity at least once every four hours while the bank filtration process is in operation. If monthly average turbidity levels, based on daily maximum values in the well, exceed 1 NTU, the system must report this result to the department and conduct an assessment within 30 days to determine the cause of the high turbidity levels in the well. If the department determines that microbial removal has been compromised, the department may revoke treatment credit until the system implements corrective actions approved by the department to remediate the problem.
	(6)	Springs and infiltration galleries. This treatment credit is not eligible for springs and infiltration galleries. Springs and infiltration galleries are eligible for credit through demonstration of performance study under 43.11(11)“c.”
	(7)	Bank filtration demonstration of performance. The department may approve Cryptosporidium treatment credit for bank filtration based on a demonstration of performance study that meets the criteria in this subparagraph. This treatment credit may be greater than 1.0-log and may be awarded to bank filtration that does not meet the criteria in 43.11(10)“c”(1) to (5).
	1.	The study must follow a protocol approved by the department and must involve the collection of data on the removal of Cryptosporidium or a surrogate for Cryptosporidium and related hydrogeologic and water quality parameters during the full range of operating conditions.
	2.	The study must include sampling both from the production well(s) and from monitoring wells that are screened and located along the shortest flow path between the surface water source and the production well(s).
	43.11(11) Treatment performance toolbox components. This option pertains to physical treatment processes.
	a. 	Combined filter performance. Systems using conventional filtration treatment or direct filtration treatment receive an additional 0.5-log Cryptosporidium treatment credit during any month the system meets the criteria in this paragraph. Combined filter effluent (CFE) turbidity must be less than or equal to 0.15 NTU in at least 95 percent of the measurements. Turbidity must be measured as described in 43.5(4) and, if applicable, 43.10(4).
	b. 	Individual filter performance. Systems using conventional filtration treatment or direct filtration treatment receive 0.5-log Cryptosporidium treatment credit during any month the system meets the criteria in this paragraph, which can be in addition to the CFE 0.5-log credit from 43.11(11)“a.” Compliance with these criteria must be based on individual filter turbidity monitoring as described in 43.9(4) or 43.10(5), as appropriate.
	(1)	The filtered water turbidity for each individual filter must be less than or equal to 0.15 NTU in at least 95 percent of the measurements recorded each month.
	(2)	No individual filter may have a measured turbidity greater than 0.3 NTU in two consecutive measurements taken 15 minutes apart.
	(3)	Any system that has received treatment credit for individual filter performance and fails to meet the requirements of 43.11(11)“b”(2) and (3) during any month shall not receive a treatment technique violation under 43.11(6) if the department determines the following:
	1.	The failure was due to unusual and short-term circumstances that could not reasonably be prevented through optimizing the treatment plant design, operation, and maintenance.
	2.	The system has experienced no more than two such failures in any calendar year.
	c. 	Demonstration of performance. The department may approve Cryptosporidium treatment credit for drinking water treatment processes based on a demonstration of performance study that meets the criteria in this paragraph. This treatment credit may be greater than or less than the prescribed treatment credits in 43.11(6) or 43.11(10) through 43.11(13) and may be awarded to treatment processes that do not meet the criteria for the prescribed credits.
	(1)	Systems cannot receive the prescribed treatment credit for any toolbox option in 43.11(10) through 43.11(13) if that toolbox option is included in a demonstration of performance study for which treatment credit is awarded under this paragraph.
	(2)	The demonstration of performance study must follow a department-approved protocol and must demonstrate the level of Cryptosporidium reduction the treatment process will achieve under the full range of expected operating conditions for the system.
	(3)	Approval by the department must be in writing and may include monitoring and treatment performance criteria that the system must demonstrate and report on an ongoing basis to remain eligible for the treatment credit. The department may designate such criteria where necessary to verify that the conditions under which the demonstration of performance credit was approved are maintained during routine operation.
	43.11(12) Additional filtration toolbox components.
	a. 	Bag and cartridge filters. By meeting the criteria in this paragraph, systems receive Cryptosporidium treatment credit of up to 2.0-log for the use of individual bag or cartridge filters and up to 2.5-log for the use of bag or cartridge filters operated in series. To be eligible for this credit, systems must report the results of challenge testing that meets the requirements of 43.11(12)“a”(2) through 43.11(12)“a”(9) to the department. The filters must treat the entire plant flow taken from a surface water or influenced groundwater source.
	(1)	The Cryptosporidium treatment credit awarded for use of bag or cartridge filters must be based on the removal efficiency demonstrated during challenge testing that is conducted in accordance with the criteria in 43.11(12)“a”(2) through 43.11(12)“a”(9). A safety factor equal to 1-log for individual bag or cartridge filters and 0.5-log for bag or cartridge filters in series must be applied to challenge testing results to determine removal credit. Systems may use results from challenge testing conducted prior to January 5, 2006, if the prior testing was consistent with the criteria specified in this paragraph.
	(2)	Challenge testing must be performed on full-scale bag or cartridge filters, and the associated filter housing or pressure vessel, that are identical in material and construction to the filters and housings the system will use for removal of Cryptosporidium. Bag or cartridge filters must be challenge tested in the same configuration that the system will use, either as individual filters or as a series configuration of filters.
	(3)	Challenge testing must be conducted using Cryptosporidium or a surrogate that is removed no more efficiently than Cryptosporidium. The microorganism or surrogate used during challenge testing is referred to as the challenge particulate. The concentration of the challenge particulate must be determined using a method capable of discretely quantifying the specific microorganisms or surrogate used in the test; gross measurements such as turbidity shall not be used.
	(4)	The maximum feed water concentration that can be used during a challenge test must be based on the detection limit of the challenge particulate in the filtrate (i.e., filtrate detection limit) and must be calculated using this equation:
Maximum Feed Water Concentration = 10,000 × Filtrate Detection Limit
	(5)	Challenge testing must be conducted at the maximum design flow rate for the filter as specified by the manufacturer.
	(6)	Each filter evaluated must be tested for a duration sufficient to reach 100 percent of the terminal pressure drop, which thereby establishes the maximum pressure drop under which the filter may be used to comply with the requirements of this paragraph.
	(7)	Removal efficiency of a filter must be determined from the results of the challenge test and expressed in terms of log removal values using the following equation:
LRV = LOG10(Cf) – LOG10(Cp)
Where:
LRV = log removal value demonstrated during challenge test;
Cf = the feed concentration measured during the challenge test; and
Cp = the filtrate concentration measured during the challenge test.
Equivalent units must be used for the feed and filtrate concentrations. If the challenge particulate is not detected in the filtrate, the term Cp must be set equal to the detection limit.
	(8)	Each filter tested must be challenged with the challenge particulate during three periods over the filtration cycle: within two hours of start-up of a new filter; when the pressure drop is between 45 and 55 percent of the terminal pressure drop; and at the end of the cycle after the pressure drop has reached 100 percent of the terminal pressure drop. An LRV must be calculated for each of these challenge periods for each filter tested. The LRV for the filter (LRVfilter) must be assigned the value of the minimum LRV observed during the three challenge periods for that filter.
	(9)	If fewer than 20 filters are tested, the overall removal efficiency for the filter product line must be set equal to the lowest LRVfilter among the filters tested. If 20 or more filters are tested, the overall removal efficiency for the filter product line must be set equal to the tenth percentile of the set of LRVfilter values for the various filters tested. The percentile is defined by [i/(n+1)] where “i” is the rank of “n” individual data points ordered lowest to highest. If necessary, the tenth percentile may be calculated using linear interpolation.
	(10)	If a previously tested filter is modified in a manner that could change the removal efficiency of the filter product line, challenge testing to demonstrate the removal efficiency of the modified filter must be conducted and submitted to the department.
	b. 	Membrane filtration.
	(1)	Systems receive Cryptosporidium treatment credit for using membrane filtration that meets the criteria of this paragraph. Systems using membrane cartridge filters that meet the definition of membrane filtration in 567—40.2(455B) are eligible for this credit. The level of treatment credit a system receives is equal to the lower of the values determined under the following two paragraphs:
	1.	The removal efficiency demonstrated during challenge testing conducted under the criteria in 43.11(12)“b”(2).
	2.	The maximum removal efficiency that can be verified through direct integrity testing used with the membrane filtration process under the conditions in 43.11(12)“b”(3).
	(2)	Challenge testing. The membrane used by the system must undergo challenge testing to evaluate removal efficiency, and the system must report the results of challenge testing to the department. Challenge testing must be conducted according to the criteria listed in this subparagraph. Systems may use data from challenge testing conducted prior to January 5, 2006, if the prior testing was consistent with the criteria listed in this subparagraph.
	1.	Challenge testing must be conducted on either a full-scale membrane module, identical in material and construction to the membrane modules used in the system’s treatment facility, or a smaller-scale membrane module, identical in material and similar in construction to the full-scale module. A module is defined as the smallest component of a membrane unit in which a specific membrane surface area is housed in a device with a filtrate outlet structure.
	2.	Challenge testing must be conducted using Cryptosporidium oocysts or a surrogate that is removed no more efficiently than Cryptosporidium oocysts. The organisms or surrogate used during challenge testing is referred to as the challenge particulate. The concentration of the challenge particulate, in both the feed and filtrate water, must be determined using a method capable of discretely quantifying the specific challenge particulate used in the test; gross measurements such as turbidity shall not be used.
	3.	The maximum feed water concentration that can be used during a challenge test is based on the detection limit of the challenge particulate in the filtrate and must be determined according to the following equation:
Maximum Feed Water Concentration = 3,160,000 × Filtrate Detection Limit
	4.	Challenge testing must be conducted under representative hydraulic conditions at the maximum design flux and maximum design process recovery specified by the manufacturer for the membrane module. Flux is defined as the throughput of a pressure-driven membrane process expressed as flow per unit of membrane area. Recovery is defined as the volumetric percent of feed water that is converted to filtrate over the course of an operating cycle uninterrupted by events such as chemical cleaning or a solids removal process (i.e., backwashing).
	5.	Removal efficiency of a membrane module must be calculated from the challenge test results and expressed as a log removal value according to the following equation:
LRV = LOG10(Cf) – LOG10(Cp)
Where:
LRV = log removal value demonstrated during challenge test;
Cf = the feed concentration measured during the challenge test; and
Cp = the filtrate concentration measured during the challenge test.
Equivalent units must be used for the feed and filtrate concentrations. If the challenge particulate is not detected in the filtrate, the term Cp must be set equal to the detection limit for the purpose of calculating the LRV. An LRV must be calculated for each membrane module evaluated during the challenge test.
	6.	The removal efficiency of a membrane filtration process demonstrated during challenge testing must be expressed as a log removal value (LRVC-Test). If fewer than 20 modules are tested, then LRVC-Test is equal to the lowest of the representative LRVs among the modules tested. If 20 or more modules are tested, then LRVC-Test  is equal to the tenth percentile of the representative LRVs among the modules tested. The percentile is defined by [i/(n+1)] where “i” is the rank of “n” individual data points ordered lowest to highest. If necessary, the tenth percentile may be calculated using linear interpolation.
	7.	The challenge test must establish a quality control release value (QCRV) for a nondestructive performance test that demonstrates the Cryptosporidium removal capability of the membrane filtration module. In order to verify Cryptosporidium removal capability, this performance test must be applied to each production membrane module that was not directly challenge tested but was used by the system. Production modules that do not meet the established QCRV are not eligible for the treatment credit demonstrated during the challenge test.
	8.	If a previously tested membrane is modified in a manner that could change the removal efficiency of the membrane or the applicability of the nondestructive performance test and associated QCRV, additional challenge testing to demonstrate the removal efficiency of the modified membrane must be conducted and submitted to the department, along with determination of a new QCRV.
	(3)	Direct integrity testing. Systems must conduct direct integrity testing in a manner that demonstrates a removal efficiency equal to or greater than the removal credit awarded for the membrane filtration process and meets the requirements described in this subparagraph. A direct integrity test is defined as a physical test applied to a membrane unit in order to identify and isolate integrity breaches (i.e., one or more leaks that could result in contamination of the filtrate).
	1.	The direct integrity test must be independently applied to each membrane unit in service. A membrane unit is defined as a group of membrane modules that share common valving that allows the unit to be isolated from the rest of the system for the purpose of integrity testing or other maintenance.
	2.	The direct integrity method must have a resolution of 3 micrometers or less, where resolution is defined as the size of the smallest integrity breach that contributes to a response from the direct integrity test.
	3.	The direct integrity test must have a sensitivity sufficient to verify the log treatment credit awarded by the department for the membrane filtration process, where sensitivity is defined as the maximum log removal value that can be reliably verified by a direct integrity test. Sensitivity must be determined using the approach in either of the following paragraphs as applicable to the type of direct integrity test the system uses.
	●	For direct integrity tests using applied pressure or vacuum, the direct integrity test sensitivity must be calculated according to the following equation:
LRVDIT = LOG10 [Qp/(VCF × Qbreach)]
Where:
LRVDIT = the sensitivity of the direct integrity test;
Qp = total design filtrate flow from the membrane unit;
Qbreach = flow of water from an integrity breach associated with the smallest integrity test response that can be reliably measured; and
VCF = volumetric concentration factor, which is the ratio of the suspended solids concentration on the high-pressure side of the membrane relative to that in the feed water.
	●	For direct integrity tests using a particulate or molecular marker, the direct integrity test sensitivity must be calculated according to the following equation:
LRVDIT = LOG10 (Cf) – LOG10 (Cp)
Where:
LRVDIT = the sensitivity of the direct integrity test;
Cf = the typical feed concentration of the marker used in the test; and
Cp = the filtrate concentration of the marker from an integral membrane unit.
	4.	Systems must establish a control limit within the sensitivity limits of the direct integrity test that is indicative of an integral membrane unit capable of meeting the removal credit awarded by the department.
	5.	If the result of a direct integrity test exceeds the control limit established under 43.11(12)“b”(3)“4,” the system must remove the membrane unit from service. Systems must conduct a direct integrity test to verify any repairs and may return the membrane unit to service only if the direct integrity test is within the established control limit.
	6.	Systems must conduct direct integrity testing on each membrane unit at a frequency of not less than once each day that the membrane unit is in operation. The department may approve less frequent testing, based on demonstrated process reliability, the use of multiple barriers effective for Cryptosporidium, or reliable process safeguards.
	(4)	Indirect integrity monitoring. Systems must conduct continuous indirect integrity monitoring on each membrane unit according to the following criteria. Indirect integrity monitoring is defined as monitoring some aspect of filtrate water quality that is indicative of the removal of particulate matter. A system that implements continuous direct integrity testing of membrane units in accordance with the criteria in 43.11(12)“b”(3) is not subject to the requirements for continuous indirect integrity monitoring. Systems must submit a monthly report to the department summarizing all continuous indirect integrity monitoring results triggering direct integrity testing and the corrective action that was taken in each case.
	1.	Unless the department approves an alternative parameter, continuous indirect integrity monitoring must include continuous filtrate turbidity monitoring.
	2.	Continuous monitoring must be conducted at a frequency of no less than once every 15 minutes.
	3.	Continuous monitoring must be separately conducted on each membrane unit.
	4.	If indirect integrity monitoring includes turbidity and if the filtrate turbidity readings are above 0.15 NTU for a period greater than 15 minutes (i.e., two consecutive 15-minute readings above 0.15 NTU), direct integrity testing must immediately be performed on the associated membrane unit as specified in 43.11(12)“b”(3)“1” through 43.11(12)“b”(3)“5.”
	5.	If indirect integrity monitoring includes a department-approved alternative parameter and if the alternative parameter exceeds a department-approved control limit for a period greater than 15 minutes, direct integrity testing must immediately be performed on the associated membrane units as specified in 43.11(12)“b”(3)“1” through 43.11(12)“b”(3)“5.”
	c. 	Second-stage filtration. Systems receive 0.5-log Cryptosporidium treatment credit for using a separate second stage of filtration that consists of sand, dual media, GAC, or other fine-grain media following granular media filtration if the department approves. To be eligible for this credit, the first stage of filtration must be preceded by a coagulation step and both filtration stages must treat the entire plant flow taken from a surface water or influenced groundwater source. A cap, such as GAC, on a single stage of filtration is not eligible for this credit. The department must approve the treatment credit based on an assessment of the design characteristics of the filtration process.
	d. 	Slow sand filtration (as secondary filter). Systems are eligible to receive 2.5-log Cryptosporidium treatment credit for using a slow sand filtration process that follows a separate stage of filtration if both filtration stages treat entire plant flow taken from a surface water or influenced groundwater source and no disinfectant residual is present in the influent water to the slow sand filtration process. The department must base its approval of the treatment credit on an assessment of the design characteristics of the filtration process. This does not apply to treatment credit awarded for slow sand filtration used as a primary filtration process.
	43.11(13) Inactivation toolbox components.
	a. 	Calculation of CT values.
	(1)	CT is the product of the disinfectant contact time (T, in minutes) and disinfectant concentration (C, in milligrams per liter). Systems with treatment credit for chlorine dioxide or ozone under 43.11(13)“b” or “c” must calculate CT at least once each day, with both C and T measured during peak hourly flow as specified in 43.5(4).
	(2)	Systems with several disinfection segments in sequence may calculate CT for each segment, where a disinfection segment is defined as a treatment unit process with a measureable disinfectant residual level and a liquid volume. Under this approach, systems must add the Cryptosporidium CT values in each segment to determine the total CT for the treatment plant.
	b. 	CT values for chlorine dioxide and ozone.
	(1)	As described in 43.11(13)“a,” systems receive the Cryptosporidium treatment credit listed in Table 1 of Appendix B by meeting the corresponding chlorine dioxide CT value for the applicable water temperature.
	(2)	As described in 43.11(13)“a,” systems receive the Cryptosporidium treatment credit listed in Table 2 of Appendix B by meeting the corresponding ozone CT value for the applicable water temperature.
	c. 	Site-specific study. The department may approve alternative chlorine dioxide or ozone CT values to those listed in 43.11(13)“b” on a site-specific basis. The department must base its approval on a site-specific study conducted by the system. The study must follow a department-approved protocol.
	d. 	Ultraviolet light. Systems receive Cryptosporidium, Giardia lamblia, and virus treatment credits for ultraviolet (UV) light reactors by achieving the corresponding UV dose values shown in Table 3 of Appendix B. Systems must use the following procedures to validate and monitor UV reactors in order to demonstrate that the reactors are achieving a particular UV dose value for treatment credit.
	(1)	Reactor validation testing. Systems must use UV reactors that have undergone validation testing to determine the operating conditions under which the reactor delivers the required UV dose (i.e., validated operating conditions). These operating conditions must include flow rate, UV intensity as measured by a UV sensor, and UV lamp status.
	1.	When determining validated operating conditions, systems must account for the following factors: UV absorbance of the water; lamp fouling and aging; measurement uncertainty of on-line sensors; UV dose distributions arising from the velocity profiles through the reactor; failure of UV lamps or other critical system components; and inlet and outlet piping or channel configurations of the UV reactor.
	2.	Validation testing must include the following: full-scale testing of a reactor that conforms uniformly to the UV reactors used by the system and inactivation of a test microorganism whose dose response characteristics have been quantified with a low-pressure mercury vapor lamp.
	3.	The department may approve an alternative approach to validation testing.
	(2)	Reactor monitoring.
	1.	Systems must monitor their UV reactors to determine if the reactors are operating within validated conditions, as determined under 43.11(13)“d”(1). This monitoring must include UV sensor, flow rate, lamp status, and other parameters the department designates based on UV reactor operation. Systems must verify the calibration of UV sensors and must recalibrate sensors in accordance with a protocol approved by the department.
	2.	To receive treatment credit for UV light, systems must treat at least 95 percent of the water delivered to the public during each month by UV reactors operating within validated conditions for the required UV dose. Systems must demonstrate compliance with this condition by the monitoring required under 43.11(13)“d”(2)“1.”
	43.11(14) Reporting requirements.
	a. 	Sampling schedules and monitoring results. Systems must report source water sampling schedules and monitoring results under 43.11(3)“c” and 43.11(3)“e,” unless the systems notify the department that they will not conduct source water monitoring due to meeting the criteria of 5.5-log treatment for Cryptosporidium under 43.11(3)“a.”
	b. 	Cryptosporidium bin classification. Systems must report their Cryptosporidium bin classification determined under 43.11(5).
	c. 	Disinfection profiles and benchmarks. Systems must report disinfection profiles and benchmarks to the department as described in 43.11(4)“a” and 43.11(4)“b” prior to making a significant change in disinfection practice.
	d. 	Microbial toolbox options. Systems must report to the department in accordance with Table 7 for any microbial toolbox options used to comply with treatment requirements under 43.11(6).
Table 7: Microbial Toolbox Reporting Requirements

Toolbox Option	Systems must submit this information	Information must be submitted
on this schedule		
1. Watershed control program	Notice of intention to develop a new or continue an existing watershed control program	No later than two years before the applicable treatment compliance date in 43.11(7)		
	Watershed control plan	No later than one year before the applicable treatment compliance date in 43.11(7)		
	Annual watershed control program status report	Every 12 months, beginning one year after the applicable treatment compliance date in 43.11(7)		
	Watershed sanitary survey report	- For community water systems, every three years beginning three years after the applicable treatment compliance date in 43.11(7)
- For noncommunity water systems, every five years beginning five years after the applicable treatment compliance date in 43.11(7)		
2. Alternative source/intake
	management	Verification that system has relocated the intake or adopted the intake withdrawal procedure reflected in monitoring results	No later than the applicable treatment compliance date in 43.11(7)		
3. Presedimentation	Monthly verification of the following:
- Continuous basin operation
- Treatment of 100 percent of the flow
- Continuous addition of a coagulant
- At least 0.5-log mean reduction of influent turbidity or compliance with alternative department-approved performance criteria	Monthly reporting within 10 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 43.11(7)		

				
				
4. Two-stage lime softening	Monthly verification of the following:
- Chemical addition and hardness precipitation occurred in two separate and sequential softening stages prior to filtration
- Both stages treated 100 percent of plant flow	Monthly reporting within 10 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 43.11(7)		

5. Bank filtration	Initial demonstration of the following:
- Unconsolidated, predominantly sandy aquifer
- Setback distance of at least 25 feet for 0.5-log credit or 50 feet for 1.0-log credit	No later than the applicable treatment compliance date in 43.11(7)		

	If monthly average of daily maximum turbidity is greater than 1 NTU, then system must report result and submit an assessment of the cause.	Report within 30 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 43.11(7)		
6. Combined filter performance	Monthly verification of combined filter effluent (CFE) turbidity levels less than or equal to 0.15 NTU in at least 95 percent of the 4-hour CFE measurements taken each month	Monthly reporting within 10 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 43.11(7)		
7. Individual filter performance	Monthly verification of the following:
- Individual filter effluent (IFE) turbidity levels less than or equal to 0.15 NTU in at least 95 percent of samples each month in each filter
- No individual filter effluent turbidity levels greater than 0.3 NTU in two consecutive readings 15 minutes apart	Monthly reporting within 10 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 43.11(7)		

8. Demonstration of performance	Results from testing following a department-approved protocol	No later than the applicable treatment compliance date in 43.11(7)		
	As required by the department, monthly verification of operation within conditions of department approval for demonstration of performance credit	Within 10 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 43.11(7)		
9. Bag filters and cartridge filters	Demonstration that the following criteria are met:
- Process meets the definition of bag or cartridge filtration
- Removal efficiency established through challenge testing that meets criteria in this subpart	No later than the applicable treatment compliance date in 43.11(7)		

	Monthly verification that 100 percent of plant flow was filtered	Within 10 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 43.11(7)		
10. Membrane filtration	Results of verification testing demonstrating the following:
- Removal efficiency established through challenge testing that meets criteria
- Integrity test method and parameters, including resolution, sensitivity, test frequency, control limits, and associated baseline	No later than the applicable treatment compliance date in 43.11(7)		

	Monthly report summarizing the following:
- All direct integrity tests above the control limit
- If applicable, any turbidity or alternative department-approved indirect integrity monitoring results triggering direct integrity testing and the corrective action that was taken	Within 10 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 43.11(7)		

				
11. Second-stage filtration	Monthly verification that 100 percent of flow was filtered through both stages and that first stage was preceded by coagulation step	Within 10 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 43.11(7)		

12. Slow sand filtration as a
	secondary filter	Monthly verification that both a slow sand filter and a preceding separate stage of filtration treated 100 percent of the flow from surface or influenced groundwater sources	Within 10 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 43.11(7)		
13. Chlorine dioxide	Summary of CT values for each day as described in 43.11(13)	Within 10 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 43.11(7)		
14. Ozone	Summary of CT values for each day as described in 43.11(13)	Within 10 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 43.11(7)		
15. Ultraviolet light (UV)	Validation test results demonstrating operating conditions that achieve required UV dose	No later than the applicable treatment compliance date in 43.11(7)		
	Monthly report summarizing the percentage of water entering the distribution system that was not treated by UV reactors operating within validated conditions for the required dose as specified in 43.11(13)“d”	Within 10 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 43.11(7)		
	43.11(15) Record-keeping requirements.
	a. 	Source water monitoring records. Systems must keep results from the initial round of source water monitoring under 43.11(3)“a” and the second round of source water monitoring under 43.11(3)“b” until three years after bin classification under 43.11(5) for the particular round of monitoring.
	b. 	Systems meeting 5.5-log treatment for Cryptosporidium. Systems must keep for three years records of any notification to the department that the systems will meet the 5.5-log Cryptosporidium treatment requirements and avoid source water monitoring.
	c. 	Microbial toolbox treatment monitoring records. Systems must keep the results of treatment monitoring associated with microbial toolbox options under 43.11(8) through 43.11(13) for three years.
[ARC 9915B, IAB 12/14/11, effective 1/18/12; ARC 3735C, IAB 4/11/18, effective 5/16/18]
567—43.12(455B) Optimization goals.
	43.12(1) Turbidity optimization goals. Surface water and IGW systems must meet the requirements listed in 567—43.5(455B), 567—43.9(455B), and 567—43.10(455B). To encourage operational optimization, the department has adopted the following goals for systems using surface water or influenced groundwater and that wish to pursue the optimization of their existing treatment processes. These goals are voluntary. Data collected for optimization purposes will not be used to determine compliance with the requirements in 567—43.5(455B), 567—43.9(455B), 567—43.10(455B), or 567—43.11(455B) unless the optimization data are identical to the compliance data.
	a. 	Sedimentation performance goals. The sedimentation performance goals are based upon the average annual raw water turbidity levels.
	(1)	When the annual average raw water turbidity is less than or equal to 10 NTU over the course of the calendar year, the turbidity should be less than or equal to 1 NTU in at least 95 percent of measurements based on the maximum daily value of readings taken at least once every four hours from each sedimentation basin while the plant is operating.
	(2)	When the annual average raw water turbidity is more than 10 NTU over the course of the calendar year, the turbidity should be less than or equal to 2 NTU in at least 95 percent of measurements based on the maximum daily value of readings taken at least once every four hours from each sedimentation basin while the plant is operating.
	b. 	Individual filter performance goals. The individual filter performance goals depend upon the system’s capability of filtering to waste.
	(1)	For systems that have the capability of filtering to waste, the individual filter turbidity should be less than or equal to 0.10 NTU in at least 95 percent of measurements over the course of the calendar year, based on the daily maximum value of readings recorded at least once per minute while the plant is in operation. The maximum individual filter turbidity must not exceed 0.30 NTU at any time. The filter must return to service with a turbidity of 0.10 NTU or less.
	(2)	For systems that do not have the capability of filtering to waste, the individual filter turbidity should be less than or equal to 0.10 NTU in at least 95 percent of measurements over the course of the calendar year, excepting the 15 minutes following the completion of the backwash process, based on the daily maximum value of readings recorded at least once per minute while the plant is in operation. The maximum individual filter turbidity must not exceed 0.30 NTU following backwash and must return to a level at or below 0.10 NTU within 15 minutes of returning the filter to service.
	c. 	Combined filter performance goal. The combined filter performance goal has two components:
	(1)	Combined filter effluent turbidity should be less than or equal to 0.10 NTU in at least 95 percent of measurements over the course of the calendar year, based on daily maximum value of readings recorded at least once per minute while the plant is operating.
	(2)	The maximum individual filter turbidity must not exceed 0.30 NTU at any time.
	43.12(2) Disinfection optimization goals.  Reserved.
[ARC 9915B, IAB 12/14/11, effective 1/18/12]
TABLE A: SEPARATION DISTANCES FROM WELLS
Rescinded IAB 1/7/04, effective 2/11/04
TABLE B
Minimum Self-Monitoring Requirements
Public Water Supply Systems
[Prior to 12/12/90, appeared in 567—Ch 41, Table D]
Rescinded IAB 8/11/99, effective 9/15/99
APPENDIX A: CT99.9 TABLES FOR DISINFECTION PROFILING
TABLE 1: CT Values (CT99.9) for 99.9 Percent Inactivation of Giardia lamblia Cysts by Free Chlorine at 0.5°C or Lower1

Free Residual	pH	
Chlorine, mg/L	<fo:wrapper font-family="'Times New Roman'">≤</fo:wrapper>6.0	6.5	7.0	7.5	8.0	8.5	<fo:wrapper font-family="'Times New Roman'">≤</fo:wrapper>9.0	
<fo:wrapper font-family="'Times New Roman'">≤</fo:wrapper>0.4	137	163	195	237	277	329	390	
0.6	141	168	200	239	286	342	407	
0.8	145	172	205	246	295	354	422	
1.0	148	176	210	253	304	365	437	
1.2	152	180	215	259	313	376	451	
1.4	155	184	221	266	321	387	464	
1.6	157	189	226	273	329	397	477	
1.8	162	193	231	279	338	407	489	
2.0	165	197	236	286	346	417	500	
2.2	169	201	242	297	353	426	511	
2.4	172	205	247	298	361	435	522	
2.6	175	209	252	304	368	444	533	
2.8	178	213	257	310	375	452	543	
3.0	181	217	261	316	382	460	552	
1These CT values achieve greater than a 99.99 percent inactivation of viruses. Any CT values between the indicated pH values may be determined by linear interpolation. Any CT values between the indicated temperatures of different tables may be determined by linear interpolation. If no interpolation is used, use the CT99.9 value at the lower temperature and at the higher pH.
TABLE 2: CT Values (CT99.9) for 99.9 Percent Inactivation of Giardia lamblia Cysts by Free Chlorine at 5.0°C1

Free Residual	pH	
Chlorine, mg/L	<fo:wrapper font-family="'Times New Roman'">≤</fo:wrapper>6.0	6.5	7.0	7.5	8.0	8.5	<fo:wrapper font-family="'Times New Roman'">≤</fo:wrapper>9.0	
<fo:wrapper font-family="'Times New Roman'">≤</fo:wrapper>0.4	97	117	139	166	198	236	279	
0.6	100	120	143	171	204	244	291	
0.8	103	122	146	175	210	252	301	
1.0	105	125	149	179	216	260	312	
1.2	107	127	152	183	221	267	320	
1.4	109	130	155	187	227	274	329	
1.6	111	132	158	192	232	281	337	
1.8	114	135	162	196	238	287	345	
2.0	116	138	165	200	243	294	353	
2.2	118	140	169	204	248	300	361	
2.4	120	143	172	209	253	306	368	
2.6	122	146	175	213	258	312	375	
2.8	124	148	178	217	263	318	382	
3.0	126	151	182	221	268	324	389	
1These CT values achieve greater than a 99.99 percent inactivation of viruses. Any CT values between the indicated pH values may be determined by linear interpolation. Any CT values between the indicated temperatures of different tables may be determined by linear interpolation. If no interpolation is used, use the CT99.9 value at the lower temperature and at the higher pH.
TABLE 3: CT Values (CT99.9) for 99.9 Percent Inactivation of Giardia lamblia Cysts by Free Chlorine at 10.0°C1

Free Residual	pH	
Chlorine, mg/L	<fo:wrapper font-family="'Times New Roman'">≤</fo:wrapper>6.0	6.5	7.0	7.5	8.0	8.5	<fo:wrapper font-family="'Times New Roman'">≤</fo:wrapper>9.0	
<fo:wrapper font-family="'Times New Roman'">≤</fo:wrapper>0.4	73	88	104	125	149	177	209	
0.6	75	90	107	128	153	183	218	
0.8	78	92	110	131	158	189	226	
1.0	79	94	112	134	162	195	234	
1.2	80	95	114	137	166	200	240	
1.4	82	98	116	140	170	206	247	
1.6	83	99	119	144	174	211	253	
1.8	86	101	122	147	179	215	259	
2.0	87	104	124	150	182	221	265	
2.2	89	105	127	153	186	225	271	
2.4	90	107	129	157	190	230	276	
2.6	92	110	131	160	194	234	281	
2.8	93	111	134	163	197	239	287	
3.0	95	113	137	166	201	243	292	
1These CT values achieve greater than a 99.99 percent inactivation of viruses. Any CT values between the indicated pH values may be determined by linear interpolation. Any CT values between the indicated temperatures of different tables may be determined by linear interpolation. If no interpolation is used, use the CT99.9 value at the lower temperature and at the higher pH.
TABLE 4: CT Values (CT99.9) for 99.9 Percent Inactivation of Giardia lamblia Cysts by Free Chlorine at 15.0°C1

Free Residual	pH	
Chlorine, mg/L	<fo:wrapper font-family="'Times New Roman'">≤</fo:wrapper>6.0	6.5	7.0	7.5	8.0	8.5	<fo:wrapper font-family="'Times New Roman'">≤</fo:wrapper>9.0	
<fo:wrapper font-family="'Times New Roman'">≤</fo:wrapper>0.4	49	59	70	83	99	118	140	
0.6	50	60	72	86	102	122	146	
0.8	52	61	73	88	105	126	151	
1.0	53	63	75	90	108	130	156	
1.2	54	64	76	92	111	134	160	
1.4	55	65	78	94	114	137	165	
1.6	56	66	79	96	116	141	169	
1.8	57	68	81	98	119	144	173	
2.0	58	69	83	100	122	147	177	
2.2	59	70	85	102	124	150	181	
2.4	60	72	86	105	127	153	184	
2.6	61	73	88	107	129	156	188	
2.8	62	74	89	109	132	159	191	
3.0	63	76	91	111	134	162	195	
1These CT values achieve greater than a 99.99 percent inactivation of viruses. Any CT values between the indicated pH values may be determined by linear interpolation. Any CT values between the indicated temperatures of different tables may be determined by linear interpolation. If no interpolation is used, use the CT99.9 value at the lower temperature and at the higher pH.
TABLE 5: CT Values (CT99.9) for 99.9 Percent Inactivation of Giardia lamblia Cysts by Free Chlorine at 20.0°C1

Free Residual	pH	
Chlorine, mg/L	<fo:wrapper font-family="'Times New Roman'">≤</fo:wrapper>6.0	6.5	7.0	7.5	8.0	8.5	<fo:wrapper font-family="'Times New Roman'">≤</fo:wrapper>9.0	
<fo:wrapper font-family="'Times New Roman'">≤</fo:wrapper>0.4	36	44	52	62	74	89	105	
0.6	38	45	54	64	77	92	109	
0.8	39	46	55	66	79	95	113	
1.0	39	47	56	67	81	98	117	
1.2	40	48	57	69	83	100	120	
1.4	41	49	58	70	85	103	123	
1.6	42	50	59	72	87	105	126	
1.8	43	51	61	74	89	108	129	
2.0	44	52	62	75	91	110	132	
2.2	44	53	63	77	93	113	135	
2.4	45	54	65	78	95	115	138	
2.6	46	55	66	80	97	117	141	
2.8	47	56	67	81	99	119	143	
3.0	47	57	68	83	101	122	146	
1These CT values achieve greater than a 99.99 percent inactivation of viruses. Any CT values between the indicated pH values may be determined by linear interpolation. Any CT values between the indicated temperatures of different tables may be determined by linear interpolation. If no interpolation is used, use the CT99.9 value at the lower temperature and at the higher pH.
TABLE 6: CT Values (CT99.9) for 99.9 Percent Inactivation of Giardia lamblia Cysts
by Free Chlorine at 25.0°C and Higher1

Free Residual	pH	
Chlorine, mg/L	<fo:wrapper font-family="'Times New Roman'">≤</fo:wrapper>6.0	6.5	7.0	7.5	8.0	8.5	<fo:wrapper font-family="'Times New Roman'">≤</fo:wrapper>9.0	
<fo:wrapper font-family="'Times New Roman'">≤</fo:wrapper>0.4	24	29	35	42	50	59	70	
0.6	25	30	36	43	51	61	73	
0.8	26	31	37	44	53	63	75	
1.0	26	31	37	45	54	65	78	
1.2	27	32	38	46	55	67	80	
1.4	27	33	39	47	57	69	82	
1.6	28	33	40	48	58	70	84	
1.8	29	34	41	49	60	72	86	
2.0	29	35	41	50	61	74	88	
2.2	30	35	42	51	62	75	90	
2.4	30	36	43	52	63	77	92	
2.6	31	37	44	53	65	78	94	
2.8	31	37	45	54	66	80	96	
3.0	32	38	46	55	67	81	97	
1These CT values achieve greater than a 99.99 percent inactivation of viruses. Any CT values between the indicated pH values may be determined by linear interpolation. Any CT values between the indicated temperatures of different tables may be determined by linear interpolation. If no interpolation is used, use the CT99.9 value at the lower temperature and at the higher pH.
TABLE 7: CT Values (CT99.9) for 99.9 Percent Inactivation of Giardia lamblia Cysts by Chlorine Dioxide and Ozone1

 	Temperature, °C	
Disinfectant	<1	5	10	15	20	<fo:wrapper font-family="'Times New Roman'">≥</fo:wrapper>25	
Chlorine Dioxide	63	26	23	19	15	11	
Ozone	2.9	1.9	1.4	0.95	0.72	0.48	
1These CT values achieve greater than a 99.99 percent inactivation of viruses. Any CT values between the indicated temperatures may be determined by linear interpolation. If no interpolation is used, use the CT99.9 value at the lower temperature for determining CT99.9 values between indicated temperatures.
TABLE 8: CT Values (CT99.9) for 99.9 Percent Inactivation of Giardia lamblia Cysts by Chloramines1

Disinfectant	Temperature, °C	
	<1	5	10	15	20	25	
Chloramines	3800	2200	1850	1500	1100	750	
1These values are for pH values of 6 to 9. These CT values may be assumed to achieve greater than 99.99 percent inactivation of viruses only if chlorine is added and mixed in the water prior to the addition of ammonia. If this condition is not met, the system must demonstrate, based on on-site studies or other information, as approved by the department, that the system is achieving at least 99.99 percent inactivation of viruses. Any CT values between the indicated temperatures may be determined by linear interpolation. If no interpolation is used, use the CT99.9 value at the lower temperature for determining CT99.9 values between indicated temperatures.
APPENDIX B: CT TABLES FOR CRYPTOSPORIDIUM INACTIVATION
TABLE 1: CT Values (mg-min/L) for Cryptosporidium Inactivation by Chlorine Dioxide1

Log Credit	Water Temperature, °C	
	<fo:wrapper font-family="'Times New Roman'">≤</fo:wrapper>0.5	1	2	3	5	7	10	15	20	25	30	
0.25	159	153	140	128	107	90	69	45	29	19	12	
0.5	319	305	279	256	214	180	138	89	58	38	24	
1.0	637	610	558	511	429	360	277	179	116	75	49	
1.5	956	915	838	767	643	539	415	268	174	113	73	
2.0	1275	1220	1117	1023	858	719	553	357	232	150	98	
2.5	1594	1525	1396	1278	1072	899	691	447	289	188	122	
3.0	1912	1830	1675	1534	1286	1079	830	536	347	226	147	
1Systems may use this equation to determine log credit between the indicated values:
Log credit = [0.001506 × (1.09116)Temp] × CT
TABLE 2: CT Values (mg-min/L) for Cryptosporidium Inactivation by Ozone1

Log Credit	Water Temperature, °C	
	<fo:wrapper font-family="'Times New Roman'">≤</fo:wrapper>0.5	1	2	3	5	7	10	15	20	25	30	
0.25	6.0	5.8	5.2	4.8	4.0	3.3	2.5	1.6	1.0	0.6	0.39	
0.5	12	12	10	9.5	7.9	6.5	4.9	3.1	2.0	1.2	0.78	
1.0	24	23	21	19	16	13	9.9	6.2	3.9	2.5	1.6	
1.5	36	35	31	29	24	20	15	9.3	5.9	3.7	2.4	
2.0	48	46	42	38	32	26	20	12	7.8	4.9	3.1	
2.5	60	58	52	48	40	33	25	16	9.8	6.2	3.9	
3.0	72	69	63	57	47	39	30	19	12	7.4	4.7	
1Systems may use this equation to determine log credit between the indicated values:
Log credit = [0.0397 × (1.09757)Temp] × CT
TABLE 3: UV Dose for Cryptosporidium, Giardia lamblia, and Virus Inactivation Credit1

Log Credit	Cryptosporidium
UV dose (mJ/cm2)	Giardia lamblia
UV dose (mJ/cm2)	Virus UV dose
(mJ/cm2)	
0.5	1.6	1.5	39	
1.0	2.5	2.1	58	
1.5	3.9	3.0	79	
2.0	5.8	5.2	100	
2.5	8.5	7.7	121	
3.0	12	11	143	
3.5	15	15	163	
4.0	22	22	186	
1The treatment credits listed in Table 3 are for UV light at a wavelength of 254 nm as produced by a low-pressure mercury vapor lamp. To receive treatment credit for other lamp types, systems must demonstrate an equivalent germicidal dose through reactor validation testing. The UV dose values in this table are applicable only to post-filter applications of UV in filtered systems.
[ARC 9915B, IAB 12/14/11, effective 1/18/12]
 
TABLE 1: CT Values (mg-min/L) for Inactivation of Viruses by Free Chlorine, pH 6.0-9.01

Inactivation	Water Temperature, °C	
Log Credit	1	2	3	4	5	6	7	8	9	
2	5.8	5.3	4.9	4.4	4.0	3.8	3.6	3.4	3.2	
3	8.7	8.0	7.3	6.7	6.0	5.6	5.2	4.8	4.4	
4	11.6	10.7	9.8	8.9	8.0	7.6	7.2	6.8	6.4	
<fo:wrapper font-size="8pt">1</fo:wrapper>CT values provided in the table are modified by linear interpolation between 0.5°C increments.	

Inactivation	Water Temperature, °C	
Log Credit	10	11	12	13	14	15	16	17	
2	3.0	2.8	2.6	2.4	2.2	2.0	1.8	1.6	
3	4.0	3.8	3.6	3.4	3.2	3.0	2.8	2.6	
4	6.0	5.6	5.2	4.8	4.4	4.0	3.8	3.6	
<fo:wrapper font-size="8pt">1</fo:wrapper>CT values provided in the table are modified by linear interpolation between 0.5°C increments.	

Inactivation	Water Temperature, °C	
Log Credit	18	19	20	21	22	23	24	25	
2	1.4	1.2	1.0	1.0	1.0	1.0	1.0	1.0	
3	2.4	2.2	2.0	1.8	1.6	1.4	1.2	1.0	
4	3.4	3.2	3.0	2.8	2.6	2.4	2.2	2.0	
<fo:wrapper font-size="8pt">1</fo:wrapper>CT values provided in the table are modified by linear interpolation between 0.5°C increments.	
TABLE 2: CT Values (mg-min/L) for Inactivation of Viruses by Free Chlorine, pH 9.1-10.0

Inactivation	Water Temperature, °C	
Log Credit	0.5	5	10	15	20	25	
2	45	30	22	15	11	7	
3	66	44	33	22	16	11	
4	90	60	45	30	22	15	
TABLE 3: CT Values (mg-min/L) for Inactivation of Viruses by Chlorine Dioxide, pH 6.0-9.01

Inactivation	Water Temperature, °C	
Log Credit	1	2	3	4	5	6	7	8	9	
2	8.4	7.7	7.0	6.3	5.6	5.3	5.0	4.8	4.5	
3	25.6	23.5	21.4	19.2	17.1	16.2	15.4	14.5	13.7	
4	50.1	45.9	41.8	37.6	33.4	31.7	30.1	28.4	26.8	
<fo:wrapper font-size="8pt">1</fo:wrapper>CT values provided in the table are modified by linear interpolation between 0.5°C increments.	

Inactivation	Water Temperature, °C	
Log Credit	10	11	12	13	14	15	16	17	
2	4.2	3.9	3.6	3.4	3.1	2.8	2.7	2.5	
3	12.8	12.0	11.1	10.3	9.4	8.6	8.2	7.7	
4	25.1	23.4	21.7	20.1	18.4	16.7	15.9	15.0	
<fo:wrapper font-size="8pt">1</fo:wrapper>CT values provided in the table are modified by linear interpolation between 0.5°C increments.	

Inactivation	Water Temperature, °C	
Log Credit	18	19	20	21	22	23	24	25	
2	2.4	2.2	2.1	2.0	1.8	1.7	1.5	1.4	
3	7.3	6.8	6.4	6.0	5.6	5.1	4.7	4.3	
4	14.2	13.3	12.5	11.7	10.9	10.0	9.2	8.4	
<fo:wrapper font-size="8pt">1</fo:wrapper>CT values provided in the table are modified by linear interpolation between 0.5°C increments.	
TABLE 4: CT Values (mg-min/L) for Inactivation of Viruses by Ozone1

Inactivation	Water Temperature, °C	
Log Credit	1	2	3	4	5	6	7	8	9	
2	0.90	0.83	0.75	0.68	0.60	0.58	0.56	0.54	0.52	
3	1.40	1.28	1.15	1.03	0.90	0.88	0.86	0.84	0.82	
4	1.80	1.65	1.50	1.35	1.20	1.16	1.12	1.08	1.04	
<fo:wrapper font-size="8pt">1</fo:wrapper>CT values provided in the table are modified by linear interpolation between 0.5°C increments.	

Inactivation	Water Temperature, °C	
Log Credit	10	11	12	13	14	15	16	17	
2	0.50	0.46	0.42	0.38	0.34	0.30	0.29	0.28	
3	0.80	0.74	0.68	0.62	0.56	0.50	0.48	0.46	
4	1.00	0.92	0.84	0.76	0.68	0.60	0.58	0.56	
<fo:wrapper font-size="8pt">1</fo:wrapper>CT values provided in the table are modified by linear interpolation between 0.5°C increments.	

Inactivation	Water Temperature, °C	
Log Credit	18	19	20	21	22	23	24	25	
2	0.27	0.26	0.25	0.23	0.21	0.19	0.17	0.15	
3	0.44	0.42	0.40	0.37	0.34	0.31	0.28	0.25	
4	0.54	0.52	0.50	0.46	0.42	0.38	0.34	0.30	
<fo:wrapper font-size="8pt">1</fo:wrapper>CT values provided in the table are modified by linear interpolation between 0.5°C increments.	
No CT table is provided for chloramines or total chlorine because the CT values would be prohibitively high for groundwater systems.
Tables are from the EPA Groundwater Rule Implementation Guidance, EPA 816-R-09-004, January 2009, pages 97-98.
[ARC 3735C, IAB 4/11/18, effective 5/16/18]
These rules are intended to implement Iowa Code sections 455B.171 through 455B.188 and 455B.190 through 455B.192.
[Filed 11/26/90, Notice 6/13/90—published 12/12/90, effective 1/16/91]
[Filed 9/25/92, Notice 6/10/92—published 10/14/92, effective 11/18/92]
[Filed 7/30/93, Notice 5/12/93—published 8/18/93, effective 9/22/93]
[Filed 1/27/95, Notice 10/12/94—published 2/15/95, effective 3/22/951]
[Filed emergency 8/25/95—published 9/13/95, effective 8/25/95]
[Filed 3/22/96, Notice 11/8/95—published 4/10/96, effective 5/15/96]
[Filed 7/23/99, Notice 4/7/99—published 8/11/99, effective 9/15/99]
[Filed 9/29/00, Notice 6/14/00—published 10/18/00, effective 11/22/00]
[Filed 12/17/03, Notice 9/17/03—published 1/7/04, effective 2/11/04]
[Filed 12/12/06, Notice 10/11/06—published 1/3/07, effective 2/7/07]
[Filed 7/6/07, Notice 3/28/07—published 8/1/07, effective 9/5/07]
[Filed ARC 9915B (Notice ARC 9737B, IAB 9/7/11), IAB 12/14/11, effective 1/18/12]
[Filed ARC 3735C (Notice ARC 3568C, IAB 1/17/18), IAB 4/11/18, effective 5/16/18]
[Filed ARC 6190C (Notice ARC 6037C, IAB 11/17/21), IAB 2/9/22, effective 3/16/22]
1	Effective date of 43.2(3)“b”(1) to (9) and 43.3(3)“b”(1) and (2) delayed until adjournment of the 1995 General Assembly by the Administrative Rules Review Committee at its meeting held March 13, 1995.