ARC 3202C ENVIRONMENTAL PROTECTION COMMISSION[567]
Notice of Intended Action
Twenty-five interested persons, a governmental subdivision, an agency or association of 25 or more persons may demand an oral presentation hereon as provided in Iowa Code section 17A.4(1)“b.”

Notice is also given to the public that the Administrative Rules Review Committee may, on its own motion or on written request by any individual or group, review this proposed action under section 17A.8(6) at a regular or special meeting where the public or interested persons may be heard.

Pursuant to the authority of Iowa Code sections 455B.105(11)“a,” 455B.173(2) and 455B.173(3), the Environmental Protection Commission (Commission) hereby gives Notice of Intended Action to amend Chapter 61, “Water Quality Standards,” and Chapter 62, “Effluent and Pretreatment Standards: Other Effluent Limitations or Prohibitions,” Iowa Administrative Code.
The purposes of the proposed amendments are to:
Update the bacteria water quality criteria table in 61.3(3)“a”(1). The amendment will eliminate the single sample maximum values of 235 organisms per 100 milliliters of water for Recreational Use Classes A1 and A3 and 2,880 organisms per 100 milliliters of water for Recreational Use Class A2. The Commission has determined that the single sample maximum value is overly stringent and is not an appropriate measure for water quality assessment and permitting purposes. The geometric mean E. coli criterion is a more appropriate measure and will be retained.
Update the name of the document referenced in the rules from “Supporting Document for Iowa Water Quality Management Plans, Chapter IV, July 1976, as revised on November 11, 2009” to “Iowa Wasteload Allocation (WLA) Procedure” to more clearly reflect the contents of the document. A wasteload allocation (WLA) is the portion of a water body’s assimilative capacity that is allocated to an existing or future point source discharge. This document establishes the technical methodologies the Department of Natural Resources (Department) uses to develop WLAs and water quality-based effluent limits for point source dischargers. The revision of the document will make it more understandable and better describe the procedures used in WLA calculations. The revision will also provide greater flexibility to facilities seeking alternative permitting options.
The major elements of the Iowa WLA Procedure document revision are as follows:
Update the Stream Low-Flow Values for United States Geological Survey (USGS) gaged sites and ungaged sites based on the USGS low-flow study report “Methods for Estimating Selected Low-Flow Frequency Statistics and Harmonic Mean Flows for Streams in Iowa,” by David A. Eash and Kimberlee
K. Barnes, published in 2012 and revised in 2013.  This change will incorporate the most up-to-date stream critical low flows published by USGS to better reflect actual stream low flows;
Incorporate statewide default background chemical concentrations using the most up-to-date monitoring data available;
Incorporate statewide default effluent chemical concentrations for different types of wastewater treatment plants using the most up-to-date effluent monitoring data available;
Replace the total residual chlorine default decay value in the mixing zone with site-specific decay measurements;
Incorporate the current implementation procedures for the chloride and sulfate criteria that were adopted in 2009;
Revise the E. coli WLA procedures for both continuous and noncontinuous discharges to reflect the E. coli criteria changes in 61.3(3)“a”(1), as described above;
Revise the E. coli decay rate coefficient to be consistent with other Department programs;
Revise the temperature criteria implementation procedure to incorporate all elements of the temperature criteria in Chapter 61 for different designated uses. The proposed revision to the temperature criteria implementation procedure provides flexibility for facilities seeking alternative permitting options;

Modify the WLA procedure for pH so that pH criteria must be met at the boundary of the mixing zone instead of the boundary of the zone of initial dilution. This modification will result in increased dilution for pH WLA calculations;
Clarify that the fathead minnow is to be used as the most sensitive representative species for establishing acute toxicity effluent limits for general use water bodies;
Clarify the current mixing zone procedures and the requirements for mixing zone and diffuser studies;
Incorporate a Site-Specific Data Collection procedure in order to standardize the site-specific data collection process. The proposed revision will have fewer sampling requirements and will result in cost savings for point source discharge facilities seeking site-specific permit limits;
Revise the Water Quality Modeling section to replace previous models with commonly used and modernized QUALIIK and modified Streeter-Phelps models. The revisions will also update decay rates and reaeration rates to reflect the latest scientific data;
Add a reference to the antidegradation implementation procedure document;
Add a new section on Alternative Site-Specific Methodology for Water Quality Based Limits that provides point source discharge facilities with the flexibility to develop site-specific NPDES permit limits.
Other minor revisions to the document include improvements in the estimation of ammonia nitrogen decay calculations in discharge pipes and general use segments, clarification of the procedure for determining discharge flows used in WLAs, and clarification of various sections to make the document more understandable. The proposed “Iowa Wasteload Allocation (WLA) Procedure” document is available    at    www.iowadnr.gov/Environmental-Protection/Water-Quality/Wasteload-Allocations.
The proposed amendments also update references to the Department’s Web site.
Any person may submit written suggestions or comments on the proposed amendments through September 8, 2017. Such written material should be submitted to Ms. Dou, Water Quality Monitoring and Assessment Section, Iowa Department of Natural Resources, 502 East 9th Street, Des Moines, Iowa 50319-0034; fax (515)725-8202; or e-mailed to Connie.Dou@dnr.iowa.gov.  Persons who have questions may contact Connie Dou by e-mail or by telephone at (515)725-8400.
Persons are invited to present oral or written comments at a series of public hearings, which will be held throughout the state as follows:

Date
September 5, 2017	Time 4 p.m.	Location
State Bank Room	
		Washington Public Library 115 West Washington St. Washington, Iowa	
September 6, 2017	4 p.m.	Meeting Room B Urbandale Public Library 3520 86th St.
Urbandale, Iowa	
September 7, 2017	4 p.m.	Harlan Community Library 718 Court St.
Harlan, Iowa	

Persons attending a hearing will be asked to give their names and addresses for the record and to confine their remarks to the content of the proposed amendments.
Any person who intends to attend a public hearing and has special requirements, such as those related to mobility or hearing impairments, should contact the Department to advise of any specific needs.
After analysis and review of this rule making, these amendments are expected to have a positive impact on jobs. The amendments are projected to result in a total cost savings for cities, industries, and semipublic entities ranging between $26 million and $58 million. This total savings is expected to be

achieved by approximately 94 facilities across the state. These cost savings will likely lead to further investment in production and job growth.
The proposed amendments are intended to implement Iowa Code sections 455B.105(11)“a,” 455B.173(2) and 455B.173(3).
The following amendments are proposed.
ITEM 1.	Amend paragraph 61.2(4)“a” as follows:
Due to extreme variations in wastewater and receiving water characteristics, spatial dimensions of mixing zones shall be defined on a site-specific basis. These rules are not intended to define each individual mixing zone, but will set maximum limits which will satisfy most biological, chemical, physical and radiological considerations in defining a particular mixing zone. Additional details are noted in the “Supporting Document for Iowa Water Quality Management Plans,” Chapter IV, July 1976, as revised on November 11, 2009 “Iowa Wasteload Allocation (WLA) Procedure,” [effective date of this amendment], for considering unusual site-specific features such as side channels and sand bars which may influence a mixing zone. Applications for operation permits under 567—subrule 64.3(1) may be required to provide specific information related to the mixing zone characteristics below their outfall so that mixing zone boundaries can be determined.
ITEM 2.	Amend paragraph 61.2(4)“b,” introductory paragraph, as follows:
For parameters included in Table 1 only (which does not include ammonia nitrogen), the dimensions of the mixing zone and the zone of initial dilution will be calculated using a mathematical model presented in the “Supporting Document for Iowa Water Quality Management Plans,” Chapter IV, July 1976, as revised on November 11, 2009 “Iowa Wasteload Allocation (WLA) Procedure,” [effective date of this amendment], or from instream studies of the mixing characteristics during low flow. In addition, the most restrictive of the following factors will be met:
ITEM 3.	Amend subparagraph 61.2(4)“d”(4) as follows:
(4) A discharger to interior streams and rivers, the Big Sioux and Des Moines Rivers, and the Mississippi or Missouri Rivers may provide to the department, for consideration, instream data which technically supports the allowance of an increased percentage of the stream flow contained in the mixing zone due to rapid and complete mixing. Any allowed increase in mixing zone flow would still be governed by the mixing zone length restrictions. The submission of data should follow the guidance provided in the “Supporting Document for Iowa Water Quality Management Plans,” Chapter IV, July 1976, as revised on November 11, 2009 “Iowa Wasteload Allocation (WLA) Procedure,” [effective date of this amendment].
ITEM 4.	Amend paragraph 61.2(4)“e,” introductory paragraph, as follows:
For ammonia criteria noted in Table 3, the dimensions of the mixing zone and the zone of initial dilution will be calculated using a mathematical model presented in the “Supporting Document for Iowa Water Quality Management Plans,” Chapter IV, July 1976, as revised on November 11, 2009 “Iowa Wasteload Allocation (WLA) Procedure,” [effective date of this amendment], or from instream studies of the mixing characteristics during low flow. In addition, the most restrictive of the following factors will be met:
ITEM 5.	Amend paragraph 61.2(4)“f” as follows:
For ammonia criteria noted in Table 3, the stream flow used in determining wasteload allocations to ensure compliance with the chronic criteria of Table 3 will be that value contained at the boundary of the allowed mixing zone. This stream flow may not exceed the percentages of the design low stream flow noted in 61.2(4)“e”(1) as measured at the point of discharge.
The pH and temperature values at the boundary of the mixing zone used to select the chronic ammonia criteria of Table 3 will be from one of the following sources. The source of the pH and temperature data will follow the sequence listed below, if applicable data exists from the source.
Specific pH and temperature data provided by the applicant gathered at their mixing zone boundary.  Procedures for obtaining this data are noted in the “Supporting Document for Iowa Water

Quality Management Plans,” Chapter IV, July 1976, as revised on November 11, 2009 “Iowa Wasteload Allocation (WLA) Procedure,” [effective date of this amendment].
Regional background pH and temperature data provided by the applicant gathered along the receiving stream and representative of the background conditions at the outfall. Procedures for obtaining this data are noted in the “Supporting Document for Iowa Water Quality Management Plans,” Chapter IV, July 1976, as revised on November 11, 2009 “Iowa Wasteload Allocation (WLA) Procedure,” [effective date of this amendment].
The statewide average median background values presented in Table IV-2 of the “Supporting Document for Iowa Water Quality Management Plans,” Chapter IV, July 1976, as revised on November 11, 2009 as determined by the department.
The stream flow in the zone of initial dilution used in determining effluent limits to ensure compliance with the acute criteria of Table 3 may not exceed 5 percent of the calculated flow associated with the mixing zone for facilities with a dilution ratio of less than or equal to 2:1, and not exceed 10 percent of the calculated flow associated with the mixing zone for facilities with a dilution ratio of greater than 2:1. The pH and temperature values at the boundary of the zone of initial dilution used to select the acute ammonia criteria of Table 3 will be from one of the following sources and follow the sequence listed below, if applicable data exists from the source.
Specific effluent pH and temperature data if the dilution ratio is less than or equal to 2:1.
If the dilution ratio is greater than 2:1, the logarithmic average pH of the effluent and the regional or statewide pH provided in 61.2(4)“f” will be used. In addition, the flow proportioned average temperature of the effluent and the regional or statewide temperature provided in 61.2(4)“f” will be used. The procedures for calculating these data are noted in the “Supporting Document for Iowa Water Quality Management Plans,” Chapter IV, July 1976, as revised on November 11, 2009 “Iowa Wasteload Allocation (WLA) Procedure,” [effective date of this amendment].
ITEM 6.	Amend subparagraph 61.2(4)“g”(4) as follows:
A discharger to interior streams and rivers, the Big Sioux and Des Moines Rivers, and the Mississippi and Missouri Rivers may provide to the department, for consideration, instream data which technically supports the allowance of an increased percentage of the stream flow contained in the mixing zone due to rapid and complete mixing. Any allowed increase in mixing zone flow would still be governed by the mixing zone length restrictions. The submission of data should follow the guidance provided in the “Supporting Document for Iowa Water Quality Management Plans,” Chapter IV, July 1976, as revised on November 11, 2009 “Iowa Wasteload Allocation (WLA) Procedure,” [effective date of this amendment].
ITEM 7.	Amend paragraph 61.3(2)“g” as follows:
Cations and anions guideline values to protect livestock watering may be found in the “Supporting Document for Iowa Water Quality Management Plans,” Chapter IV, July  1976,  as revised on November 11, 2009 “Iowa Wasteload Allocation (WLA) Procedure,” [effective date of this amendment].
ITEM 8.	Amend paragraph 61.3(2)“h” as follows:
The Escherichia coli (E. coli) content of water which enters a sinkhole or losing stream segment, regardless of the water body’s designated use, shall not exceed a Geometric Mean value of 126 organisms/100 ml or a sample maximum value of 235 organisms/100 ml. No new wastewater discharges will be allowed on watercourses which directly or indirectly enter sinkholes or losing stream segments.
ITEM 9.	Amend subparagraph 61.3(3)“a”(1) as follows:
(1) The Escherichia coli (E. coli) content shall not exceed the levels noted in the Bacteria Criteria Table when the Class “A1,” “A2,” or “A3” uses can reasonably be expected to occur.

Bacteria Criteria Table (organisms/100 ml of water)

Use or Category	Geometric Mean	Sample Maximum	
Class A1			
3/15 – 11/15	126	235	
11/16 – 3/14	Does not apply	Does not apply	
Class A2 (Only)			
3/15 – 11/15	630	2880	
11/16 – 3/14	Does not apply	Does not apply	
[Class A2 and B(CW)] or OIW or ONRW			
Year-Round	630	2880	
Class A3			
3/15 – 11/15	126	235	
11/16 – 3/14	Does not apply	Does not apply	
Class A1 - Primary Contact Recreational Use
Class A2 - Secondary Contact Recreational Use Class A3 - Children’s Recreational Use	

When a water body is designated for more than one of the recreational uses, the most stringent criteria for the appropriate season shall apply.
ITEM 10.	Amend subrule 61.3(5) as follows:
61.3(5) Surface water classification. The department hereby incorporates by reference “Surface Water Classification,” effective June 17, 2015. This document may be obtained on the department’s Web site at http://www.iowadnr.gov/InsideDNR/RegulatoryWater/WaterQualityStandards/Rules.aspx  http://www.iowadnr.gov.
ITEM 11.	Amend subrule 61.3(6) as follows:
61.3(6) Cold water use designation assessment  protocol. The  department  hereby incorporates by reference “Cold Water Use Designation  Assessment  Protocol,”  effective December 15, 2004. This document may be obtained on the department’s Web site at  http://www.iowadnr.com/water/standards/index.html      http://www.iowadnr.gov.
ITEM 12.	Amend subrule 61.3(7) as follows:
61.3(7) Warm water stream use assessment and attainability analysis protocol. The department hereby incorporates by reference “Warm Water Stream Use Assessment and Attainability Analysis Protocol,” effective March 22, 2006. This document may be obtained on the departments department’s Web site at http://www.iowadnr.com/water/standards/index.html http://www.iowadnr.gov.
ITEM 13.	Adopt the following new subrule 61.3(9):
61.3(9) Iowa wasteload allocation (WLA) procedure. The  department hereby incorporates by reference “Iowa Wasteload Allocation (WLA) Procedure,” [effective date of this amendment]. This document may be obtained on the department’s Web site at http://www.iowadnr.gov.
ITEM 14.	Amend subrule 62.8(2) as follows:
62.8(2) Effluent limitations necessary to meet water quality standards. No effluent, alone or in combination with the effluent of other sources, shall cause a violation of any applicable water quality standard. When it is found that a discharge that would comply with applicable effluent standards in 567—62.3(455B), 567—62.4(455B) or 567—62.5(455B) or effluent limitations in 567—62.6(455B) would cause a violation of water quality standards, the discharge will be required to meet the water quality-based effluent limits (WQBELs) necessary to achieve the applicable water quality standards as established in 567—Chapter 61. Any such effluent limit shall be derived from the calculated waste load allocation, as described in “Supporting Document for Iowa Water Quality Management Plans,” Chapter

IV, July 1976, as revised on November 11, 2009 “Iowa Wasteload Allocation (WLA) Procedure,” [effective date of this amendment], or the waste load allocation as required by a total maximum daily load, whichever is more stringent. The translation of waste load allocations to WQBELs shall use Iowa permit derivation methods, as described in the “Supporting Document for Iowa Water Quality Management Plans,” Chapter IV, July 1976, as revised on November 11, 2009, except that the daily sample maximum criteria for E. coli set forth in Part E of the “Supporting Document for Iowa Water Quality Management Plans” shall not be used as an end-of-pipe permit limitation “Iowa Wasteload Allocation (WLA) Procedure,” [effective date of this amendment].