567—41.3(455B) Maximum contaminant levels (MCLs) and monitoring requirements for inorganic contaminants other than lead or copper.
	41.3(1) MCLs and other requirements for inorganic contaminants.
	a. 	Applicability. Maximum contaminant levels for inorganic contaminants (IOCs) specified in 41.3(1)“b” apply to community water systems and nontransient noncommunity water systems as specified herein. The maximum contaminant level specified for fluoride applies only to community water systems and nontransient noncommunity systems which primarily serve children (child care facilities and schools). The maximum contaminant levels specified for nitrate, nitrite, and total nitrate and nitrite apply to community, nontransient noncommunity, and transient noncommunity water systems. At the discretion of the department, nitrate levels not to exceed 20.0 mg/L may be allowed in a noncommunity water system if the supplier of water demonstrates to the satisfaction of the department that:
	(1)	Such water will not be available to children under 6 months of age; and
	(2)	The system is meeting the public notification requirements of rule 567—42.1(455B), including continuous posting of the fact that nitrate levels exceed 10 mg/L and the potential health effects of exposure; and
	(3)	The following public health authorities will be notified annually of nitrate levels that exceed 10 mg/L, in addition to the reporting requirements of 567—Chapters 41 and 42: county board of health, county health department, county sanitarian, county public health administrator, and Iowa department of public health; and
	(4)	No adverse health effects shall result.
The requirements also contain monitoring requirements, best available technology (BAT) identification, and analytical method requirements pursuant to 41.3(1)“c,” and 567—paragraphs 41.3(1)“e” and 43.3(10)“b,” respectively.
	b. 	Maximum contaminant levels for inorganic chemicals (IOCs).
	(1)	IOC MCLs. The following table specifies the MCLs for IOCs:

Contaminant	EPA Contaminant Code	Maximum Contaminant Level (mg/L)	
Antimony	1074	0.006	
Arsenic*	1005	0.010	
Asbestos	1094	7 million fibers/liter
(longer than 10 micrometers in length)	
Barium	1010	2	
Beryllium	1075	0.004	
Cadmium	1015	0.005	
Chromium	1020	0.1	
Cyanide (as free Cyanide)	1024	0.2	
Fluoride**	1025	4.0	
Mercury	1035	0.002	
Nitrate	1040	10 (as nitrogen)	
Nitrite	1041	1.0 (as nitrogen)	
Total Nitrate and Nitrite	1038	10 (as nitrogen)	
Selenium	1045	0.05	
Thallium	1085	0.002	
*The arsenic MCL changed from 0.05 mg/L to 0.010 mg/L on January 23, 2006.
**The recommended fluoride level is 0.7 milligrams per liter as published by the U.S. Department of Health and Human Services, Public Health Service (July-August 2015). At this optimum level in drinking water, fluoride has been shown to have beneficial effects in reducing the occurrence of tooth decay.
	(2)	Compliance calculations. Compliance with 41.3(1)“b”(1) shall be determined based on the analytical result(s) obtained at each source/entry point. When the department requires a system to collect nitrate or nitrite samples in its distribution system, compliance with 41.3(1)“b”(1) shall also be determined based on the analytical result(s) obtained at each discrete sampling point in the distribution system. Arsenic sampling results must be reported to the nearest 0.001 mg/L.
	1.	Sampling frequencies greater than annual (e.g., monthly or quarterly). For public water supply systems which are conducting monitoring at a frequency greater than annual, compliance with the maximum contaminant levels for antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, selenium, and thallium is determined by a running annual average at any sampling point. If the average at any sampling point is greater than the MCL, then the system is out of compliance. If any one sample would cause the annual average to be exceeded, then the system is out of compliance immediately. Any sample below the method detection limit shall be calculated at zero for the purpose of determining the annual average. If a system fails to collect the required number of samples, compliance (average concentration) will be based on the total number of samples collected.
	2.	Sampling frequencies of annual or less. For public water supply systems which are monitoring annually, or less frequently, the system is out of compliance with the maximum contaminant levels for antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, selenium, and thallium if the level of a contaminant at any sampling point is greater than the MCL. If a confirmation sample is required by the department, it must be collected as soon as possible from the same sampling location, but not to exceed two weeks, and the determination of compliance will be based on the average of the two samples. If a system fails to collect the required number of samples, compliance (average concentration) will be based on the total number of samples collected.
	3.	Compliance calculations for nitrate and nitrite. Compliance with the maximum contaminant levels for nitrate and nitrite is determined based on one sample if the level of these contaminants is below the MCLs. If the level of nitrate or nitrite exceeds the MCLs in the initial sample, a confirmation sample may be required in accordance with 41.3(1)“c”(7)“2,” and compliance shall be determined based on the average of the initial and confirmation samples.
	(3)	Additional requirements. The department may assign additional requirements as deemed necessary to protect the public health, including public notification requirements and earlier compliance dates than indicated in rule. When a system is not in compliance with an MCL as determined in subparagraph 41.3(1)“b”(2), the supplier of the water shall notify the department according to 567—subrule 42.4(1) and give notice to the public according to 567—42.1(455B).
	c. 	Inorganic chemicals—monitoring requirements.
	(1)	Routine IOC monitoring (excluding asbestos, nitrate, and nitrite). Community public water supply systems and nontransient noncommunity water systems shall conduct monitoring to determine compliance with the MCLs specified in 41.3(1)“b” in accordance with this subrule. Transient noncommunity water systems shall conduct monitoring to determine compliance with the nitrate and nitrite maximum contaminant levels in 41.3(1)“b” as required by 41.3(1)“c”(5) and (6). All new systems or systems that use a new source of water must demonstrate compliance with the MCLs specified in 41.3(1)“b” within a period of time specified by the department. The system must also comply with the initial sampling frequencies specified by the department to ensure the system can demonstrate compliance with the MCLs. Routine and increased monitoring frequencies shall be conducted in accordance with the requirements in paragraph 41.3(1)“c.” A source of water that is determined by the department to be a new source/entry point is considered to be a new source for the purposes of this rule.
	(2)	Department designated sampling schedules: Each public water system shall monitor at the time designated by the department during each compliance period. The monitoring protocol is as follows:
	1.	Groundwater sampling points. Groundwater systems shall take a minimum of one sample at every entry point to the distribution system which is representative of each well after treatment (hereafter called a source/entry point) beginning in the compliance period starting January 1, 1993. The system shall take each sample at the same sampling point unless conditions make another sampling point more representative of each source or treatment plant.
	2.	Surface water sampling points. Surface water systems shall take a minimum of one sample at every entry point to the distribution system after any application of treatment or in the distribution system at a point which is representative of each source after treatment (hereafter called a source/entry point) beginning in the compliance period starting January 1, 1993. (For purposes of this paragraph, surface water systems include systems with a combination of surface and ground sources.) The system shall take each sample at the same sampling point unless conditions make another sampling point more representative of each source or treatment plant.
	3.	Multiple sources. If a public water supply system draws water from more than one source and the sources are combined before distribution, the system must sample at an entry point to the distribution system during periods of normal operating conditions (i.e., when water is representative of all sources being used).
	4.	Composite sampling. The department may reduce the total number of samples which must be analyzed by the use of compositing. In systems serving less than or equal to 3,300 persons, composite samples from a maximum of five samples are allowed, provided that the detection limit of the method used for analysis is less than one-fifth of the MCL. Compositing of samples must be done in the laboratory. If the concentration in the composite sample is greater than or equal to one-fifth of the MCL of any inorganic chemical, then a follow-up sample must be taken within 14 days at each sampling point included in the composite. These samples must be analyzed for the contaminants which exceeded one-fifth of the MCL in the composite sample. If duplicates of the original sample taken from each sampling point used in the composite are available, the system may use these duplicates instead of resampling, provided the holding time of the duplicate samples is not exceeded. The duplicate must be analyzed and the results reported to the department within 14 days after completing analysis of the composite sample. If the population served by the system is greater than 3,300 persons, then compositing may only be permitted by the department as sampling points within a single system. In systems serving less than or equal to 3,300 persons, the department may permit compositing among different systems provided the five-sample limit is maintained. Detection limits for each inorganic contaminant analytical method are contained in 41.3(1)“e”(1).
	(3)	Asbestos routine and repeat monitoring frequency. The frequency of monitoring conducted to determine compliance with the maximum contaminant level for asbestos specified in 41.3(1)“b” shall be conducted as follows:
	1.	Initial sampling frequency. Each community and nontransient noncommunity water system is required to monitor for asbestos during the first three-year compliance period of each nine-year compliance cycle beginning in the compliance period starting January 1, 1993.
	2.	Sampling during waiver. If the public water supply system believes it is not vulnerable to either asbestos contamination in its source water or due to corrosion of asbestos-cement pipe, or both, it may apply for a waiver of the monitoring requirement in 41.3(1)“c”(3)“1.” If the department grants the waiver, the system is not required to monitor.
	3.	Bases of an asbestos waiver. The department may grant a waiver based on a consideration of potential asbestos contamination of the water source, the use of asbestos-cement pipe for finished water distribution, and the corrosive nature of the water.
	4.	Effect of an asbestos waiver. A waiver remains in effect until the completion of the three-year compliance period. Systems not receiving a waiver must monitor in accordance with 41.3(1)“c”(3)“1.”
	5.	Distribution system vulnerability for asbestos. A public water supply system vulnerable to asbestos contamination due solely to corrosion of asbestos-cement pipe shall take one sample at a tap served by asbestos-cement pipe and under conditions where asbestos contamination is most likely to occur.
	6.	Source water vulnerability for asbestos. A public water supply system vulnerable to asbestos contamination due solely to source water shall monitor in accordance with the provision of 41.3(1)“c”(2).
	7.	Combined asbestos vulnerability. A public water supply system vulnerable to asbestos contamination due both to its source water supply and corrosion of asbestos-cement pipe shall take one sample at a tap served by asbestos-cement pipe and under conditions where asbestos contamination is most likely to occur.
	8.	Exceedance of the asbestos MCL. A public water supply system which exceeds the maximum contaminant levels as determined in 41.3(1)“b” shall monitor quarterly beginning in the next quarter after the violation occurred.
	9.	Asbestos reliably and consistently below the MCL. The department may decrease the quarterly monitoring requirement to the frequency specified in 41.3(1)“c”(3)“1” provided the system is reliably and consistently below the maximum contaminant level. In no case can the department make this determination unless a groundwater system takes a minimum of two quarterly samples and a surface (or combined surface/ground) water system takes a minimum of four quarterly samples.
	10.	Grandfathered asbestos data. If monitoring data collected after January 1, 1990, are generally consistent with the requirements of 41.3(1)“c”(3), then the department may allow public water supply systems to use that data to satisfy the monitoring requirement for the initial compliance period beginning January 1, 1993.
	(4)	Monitoring frequency for other IOCs. The frequency of monitoring conducted to determine compliance with the maximum contaminant levels in 41.3(1)“b” for antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, selenium, and thallium shall be as follows:
	1.	IOCs sampling frequency. Groundwater systems shall take one sample at each sampling point once every three years. Surface water systems (or combined surface/groundwater systems) shall take one sample annually at each sampling point.
	2.	IOC sampling waiver. The public water supply system may apply for a waiver from the monitoring frequencies specified in 41.3(1)“c”(4)“1.”
	3.	IOC sampling during a waiver. A condition of the waiver shall require that a public water supply system shall take a minimum of one sample while the waiver is effective. The term during which the waiver is effective shall not exceed one compliance cycle (i.e., nine years).
	4.	Bases of an IOC waiver and grandfathered data. The department may grant a waiver provided surface water systems have monitored annually for at least three years and groundwater systems have conducted a minimum of three rounds of monitoring. (At least one sample shall have been taken since January 1, 1990.) Both surface and groundwater systems shall demonstrate that all previous analytical results were less than the maximum contaminant level. Systems that use a new water source are not eligible for a waiver until three rounds of monitoring from the new source have been completed. Systems may be granted a waiver for monitoring of cyanide, provided that the department determines that the system is not vulnerable due to lack of any industrial source of cyanide.
	5.	Bases of the IOC sampling frequency during a waiver. In determining the appropriate reduced monitoring frequency, the department will consider: reported concentrations from all previous monitoring; the degree of variation in reported concentrations; and other factors which may affect contaminant concentrations such as changes in groundwater pumping rates, changes in the system’s configuration, changes in the system’s operating procedures, or changes in stream flows or characteristics.
	6.	Effect of an IOC waiver. A decision to grant a waiver shall be made in writing and shall include the basis for the determination. The determination may be initiated by the department or upon an application by the public water supply system. The public water supply system shall specify the basis for its request. The department may review and, where appropriate, revise its determination of the appropriate monitoring frequency when the system submits new monitoring data or when other data relevant to the system’s appropriate monitoring frequency become available.
	7.	Exceedance of an IOC MCL. Public water supply systems which exceed the maximum contaminant levels as calculated in 41.3(1)“b” shall monitor quarterly beginning in the next quarter after the violation occurred.
	8.	IOCs reliably and consistently below the MCL. The department may decrease the quarterly monitoring requirement to the frequencies specified in 41.3(1)“c”(4)“1” and “3” provided it has determined that the public water supply system is reliably and consistently below the maximum contaminant level. In no case can the department make this determination unless a groundwater system takes a minimum of two quarterly samples and a surface water system takes a minimum of four quarterly samples.
	(5)	Routine and repeat monitoring frequency for nitrates. All public water supply systems (community; nontransient noncommunity; and transient noncommunity systems) shall monitor to determine compliance with the maximum contaminant level for nitrate in 41.3(1)“b.”
	1.	Initial nitrate sampling. Community and nontransient noncommunity water systems served by groundwater systems shall monitor annually beginning January 1, 1993; systems served by surface water shall monitor quarterly beginning January 1, 1993. Transient noncommunity water systems shall monitor annually beginning January 1, 1993.
	2.	Groundwater repeat nitrate sampling frequency. For community and noncommunity water systems, the repeat monitoring frequency for groundwater systems shall be:
	●	Quarterly for at least one year following any one sample in which the concentration is greater than or equal to 5.0 mg/L as N. The department may allow a groundwater system to reduce the sampling frequency to annually after four consecutive quarterly samples are reliably and consistently less than 5.0 mg/L as N.
	●	Monthly for at least one year following any one sample in which the concentration is greater than or equal to 10.0 mg/L as N.
3. Surface water repeat nitrate sampling frequency. For community and noncommunity water systems, the department may allow a surface water system to reduce the sampling frequency to:
	●	Annually if all analytical results from four consecutive quarters are less than 5.0 mg/L as N.
	●	Quarterly for at least one year following any one sample in which the concentration is greater than or equal to 5.0 mg/L as N. The department may allow a surface water system to reduce the sampling frequency to annually after four consecutive quarterly samples are reliably and consistently less than 5.0 mg/L as N.
	●	Monthly for at least one year following any nitrate MCL exceedance.
4. Scheduling annual nitrate repeat samples. After the initial round of quarterly sampling is completed, each community and nontransient noncommunity system which is monitoring annually shall take subsequent samples during the quarter(s) which previously resulted in the highest analytical result.
	(6)	Routine and repeat monitoring frequency for nitrite. All public water supply systems (community; nontransient noncommunity; and transient noncommunity systems) shall monitor to determine compliance with the maximum contaminant level for nitrite in 41.3(1)“b.”
	1.	Initial nitrite sampling. All public water systems shall take one sample at each sampling point in the compliance period beginning January 1, 1993, and ending December 31, 1995.
	2.	Nitrite repeat monitoring. After the initial sample, systems where an analytical result for nitrite is less than 0.50 mg/L as N shall monitor at the frequency specified by the department.
	3.	Nitrite increased monitoring. For community, nontransient noncommunity, and transient noncommunity water systems, the repeat monitoring frequency for any water system shall be:
	●	Quarterly for at least one year following any one sample in which the concentration is greater than or equal to 0.50 mg/L as N. The department may allow a system to reduce the sampling frequency to annually after determining the system is reliably and consistently less than 0.50 mg/L.
	●	Monthly for at least one year following any nitrite MCL exceedance.
4. Scheduling of annual nitrite repeat samples. Systems which are monitoring annually shall take each subsequent sample during the quarter(s) which previously resulted in the highest analytical result.
	(7)	Confirmation sampling.
	1.	Deadline for IOCs confirmation samples. Where the results of an analysis for antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium, or thallium indicate an exceedance of the maximum contaminant level, the department may require that one additional sample be collected as soon as possible after the initial sample was taken (but not to exceed two weeks) at the same sampling point.
	2.	Deadline for nitrate and nitrite confirmation samples. Where nitrate or nitrite sampling results indicate an exceedance of the maximum contaminant level and the sampling frequency is quarterly or annual, the system shall take a confirmation sample within 24 hours of the system’s receipt of notification of the analytical results of the first sample. Public water supply systems unable to comply with the 24-hour sampling requirement must immediately notify the consumers served by the area served by the public water system in accordance with 567—42.1(455B) Tier 1 public notice and complete an analysis of a confirmation sample within two weeks of notification of the analytical results of the first sample. Where the sampling frequency is monthly, a confirmation sample will not be used to determine compliance with the MCL.
	3.	Rescinded IAB 1/7/04, effective 2/11/04.
	4.	Compliance calculations and confirmation samples. If a required confirmation sample as collected within the time specified in 41.3(1)“c”(7)“1” is taken for any contaminant, then the results of the initial and confirmation sample shall be averaged. The resulting average shall be used to determine the system’s compliance in accordance with 41.3(1)“b.” The department has the discretion to invalidate results of obvious sampling errors.
	(8)	Designation of increased sampling frequency. The department may require more frequent monitoring than specified in 41.3(1)“c”(3) through (6) or may require confirmation samples for positive and negative results at its discretion. Public water supply systems may apply to conduct more frequent monitoring than the minimum monitoring frequencies specified in this subrule. Any increase or decrease in monitoring under this subparagraph will be designated in an operation permit or administrative order. To increase or decrease such frequency, the department shall consider the following factors:
	1.	Reported concentrations from previously required monitoring,
	2.	The degree of variation in reported concentrations,
	3.	Blending or treatment processes conducted for the purpose of complying with a maximum contaminant level, treatment technique, or action level, and
	4.	Other factors include changes in pumping rates in groundwater supplies or significant changes in the system’s configuration, operating procedures, source of water and changes in streamflows.
	(9)	Grandfathered data. For the initial analysis required by 41.3(1)“c,” data for surface waters acquired within one year prior to the effective date and data for groundwaters acquired within three years prior to the effective date of 41.3(1)“c” may be substituted at the discretion of the department.
	d. 	Best available treatment technologies (BATs) for IOCs. Rescinded IAB 8/11/99, effective 9/15/99.
	e. 	Analytical methodology.
	(1)	Analytical methods for IOCs. Analysis for the listed inorganic contaminants shall be conducted using the following methods, or their equivalent as determined by EPA. Criteria for analyzing arsenic, barium, beryllium, cadmium, chromium, copper, lead, nickel, selenium, sodium, and thallium with digestion or directly without digestion, and other analytical test procedures are contained in Technical Notes on Drinking Water Methods, EPA-600/R-94-173, October, 1994. This document is available from the National Technical Information Service, NTIS PB95-104766, U.S. Department of Commerce, 5285 Port Royal Road, Springfield, VA 22161. The toll-free number is (800)553-6847.
INORGANIC CONTAMINANTS ANALYTICAL METHODS

Contaminant	Methodology15	EPA	ASTM3	SM	SM Online26	Other	Detection Limit,
mg/L	
Antimony	Atomic absorption; furnace	 	 	3113B4, 27, 33	3113 B-04, B-10	 	0.003	
 	Atomic absorption; platform	200.92	 	 	 	 	0.000812	
 	ICP-Mass spectrometry	200.82	 	 	 	 	0.0004	
 	Atomic absorption; hydride	 	D3697-92, 02, 07, 12	 	 	 	0.001	
 	Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)	200.5, Revision 4.228	 	 	 	 	 	
Arsenic16	ICP-Mass spectrometry	200.82	 	 	 	 	0.0014	
 	Atomic absorption; platform	200.92	 	 	 	 	0.000515	
 	Atomic absorption; furnace	 	D2972-97C, 03C, 08C	3113B4, 27, 33	3113 B-04, B-10	 	0.001	
 	Atomic absorption; hydride	 	D2972-97B, 03B, 08B	3114B4, 27, 33	3114 B-09	 	0.001	
 	Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)	200.5, Revision 4.228	 	 	 	 	 	
Asbestos	Transmission electron microscopy	100.19	 	 	 	 	0.01 MFL	
 	Transmission electron microscopy	100.210	 	 	 	 	 	
Barium	Inductively coupled plasma	200.72	 	3120B18, 27, 33	3120 B-99	 	0.002	
 	ICP-Mass spectrometry	200.82	 	 	 	 	 	
 	Atomic absorption; direct	 	 	3111D4, 27, 33	3111 D-99	 	0.1	
 	Atomic absorption; furnace	 	 	3113B4, 27, 33	3113 B-04, B-10	 	0.002	
 	Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)	200.5, Revision 4.228	 	 	 	 	 	
Beryllium	Inductively coupled plasma	200.72	 	3120B18, 27, 33	3120 B-99	 	0.0003	
 	ICP-Mass spectrometry	200.82	 	 	 	 	0.0003	
 	Atomic absorption; platform	200.92	 	 	 	 	0.0000212	
 	Atomic absorption; furnace	 	D3645-97B, 03B, 08B	3113B4, 27, 33	3113 B-04, B-10	 	0.0002	
 	Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)	200.5, Revision 4.228	 	 	 	 	 	
Cadmium	Inductively coupled plasma	200.72	 	 	 	 	0.001	
 	ICP-Mass spectrometry	200.82	 	 	 	 	 	
 	Atomic absorption; platform	200.92	 	 	 	 	 	
 	Atomic absorption; furnace	 	 	3113B4, 27, 33	3113 B-04, B-10	 	0.0001	
 	Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)	200.5, Revision 4.228	 	 	 	 	 	
Chromium	Inductively coupled plasma	200.72	 	3120B18, 27, 33	3120 B-99	 	0.007	
 	ICP-Mass spectrometry	200.82	 	 	 	 	 	
 	Atomic absorption; platform	200.92	 	 	 	 	 	
 	Atomic absorption; furnace	 	 	3113B4, 27, 33	3113 B-04, B-10	 	0.001	
 	Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)	200.5, Revision 4.228	 	 	 	 	 	
Cyanide	Manual distillation (followed by one of the following four analytical methods:)	 	D2036-98A, D2036-06A	4500-CN-C18,27, 33	 	 	 	
 	Spectrophotometric; amenable14	 	D2036-98B, D2036-06B	4500-CN-G18,27, 33	4500-CN-G-99	 	0.02	
 	Spectrophotometric; manual13	 	D2036-98A, D2036-06A	4500-CN-E18,27, 33	4500-CN-E-99	I-3300-855	0.02	
 	Spectrophotometric; semi-automated13	335.46	 	 	 	 	0.005	
 	Selective electrode13	 	 	4500-CN-F18, 27, 33	4500-CN-F-99	 	0.05	
 	UV, distillation, spectrophotometric22	 	 	 	 	Kelada 0120	0.0005	
 	Micro distillation, flow injection, spectrophotometric13	 	 	 	 	QuikChem
10-204-00-1
-X21	0.0006	
 	Ligand exchange with amperometry14	 	D6888-04	 	 	OIA-1677, DW25	0.0005	
 	Gas chromatography/mass spectrometry headspace	 	 	 	 	ME355.0129	 	
Fluoride	Ion chromatography	300.06, 300.123	D4327-97, 03, 11	4110B18, 27, 33	4110 B-00	 	 	
 	Manual distillation; colorimetric; SPADNS	 	 	4500F-B,D18,27, 33	4500 F-B,D-97	 	 	
 	Manual electrode	 	D1179-93B, 99B, D1179-04B, 10B	4500F-C18, 27, 33	4500 F-C-97	 	 	
 	Automated electrode	 	 	 	 	380-75WE11	 	
 	Automated alizarin	 	 	4500F-E18, 27, 33	4500 F-E-97	129-71W11	 	
 	Capillary ion electrophoresis	 	 	 	 	D6508, Rev.224	 	
 	Arsenite-free colorimetric; SPADNS	 	 	 	 	Hach SPADNS 2 Method 1022531	 	
Magnesium	Atomic absorption; direct	 	D511-93, 03B, 09B, 14B	3111B4, 27, 33	3111 B-99	 	 	
 	ICP	200.71	 	3120B18, 27, 33	3120 B-99	 	 	
 	Complexation Titrimetric Methods	 	D511-93, 03A, 09A, 14B	3500-Mg E4	 	 	 	
 	 	 	 	3500-Mg B19, 27, 33	3500-Mg B-97	 	 	
 	Ion chromatography	 	D6919-03, 09	 	 	 	 	
 	Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)	200.5, Revision 4.228	 	 	 	 	 	
Mercury	Manual, cold vapor	245.12	D3223-97, 02, 12	3112B4, 27, 33	3112 B-09	 	0.0002	
 	Automated, cold vapor	245.21	 	 	 	 	0.0002	
 	ICP-Mass spectrometry	200.82	 	 	 	 	 	
Nickel	Inductively coupled plasma	200.72	 	3120B18, 27, 33	3120 B-99	 	0.005	
 	ICP-Mass spectrometry	200.82	 	 	 	 	0.0005	
 	Atomic absorption; platform	200.92	 	 	 	 	0.000612	
 	Atomic absorption; direct	 	 	3111B4, 27, 33	3111 B-99	 	 	
 	Atomic absorption; furnace	 	 	3113B4, 27, 33	3113 B-04, 10	 	0.001	
 	Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)	200.5, Revision 4.228	 	 	 	 	 	
Nitrate	Ion chromatography	300.06, 300.123	D4327-97, 03, 11	4110B18, 27, 33	4110 B-00	B-10118	0.01	
 	Automated cadmium reduction	353.26	D3867-90A	4500-NO3-F18, 27, 33	4500-NO3-F-00	 	0.05	
 	Ion selective electrode	 	 	4500-NO3-D18, 27, 33	4500-NO3-D-00	6017	1	
 	Manual cadmium reduction	 	D3867-90B	4500-NO3-E18, 27, 33	4500-NO3-E-00	 	0.01	
 	Capillary ion electrophoresis	 	 	 	 	D6508, Rev.224	0.076	
 	Reduction/colorimetric	 	 	 	 	Systea Easy (1-Reagent)30 NECi Nitrate-
Reductase34	 	
 	Colorimetric; direct	 	 	 	 	Hach TNTplusTM 835/836 Method 1020632	 	
Nitrite	Ion chromatography	300.06, 300.123	D4327-97, 03, 11	4110B18, 27, 33	4110 B-00	B-10118	0.004	
 	Automated cadmium reduction	353.26	D3867-90A	4500-NO3-F18, 27, 33	4500-NO3-F-00	 	0.05	
 	Manual cadmium reduction	 	D3867-90B	4500-NO3-E18, 27, 33	4500-NO3-E-00	 	0.01	
 	Spectrophotometric	 	 	4500-NO2-B18, 27, 33	4500-NO2-B-00	 	0.01	
 	Capillary ion electrophoresis	 	 	 	 	D6508, Rev.	224	0.103	
 	Reduction/colorimetric	 	 	 	 	Systea Easy (1-Reagent)30
NECi Nitrate-
Reductase34	 	
Selenium	Atomic absorption; hydride	 	D3859-98, 03A, 08A	3114B4, 27, 33	3114 B-09	 	0.002	
 	ICP-Mass spectrometry	200.82	 	 	 	 	 	
 	Atomic absorption; platform	200.92	 	 	 	 	 	
 	Atomic absorption; furnace	 	D3859-98, 03B, 08B	3113B4, 27, 33	3113 B-04, 10	 	0.002	
 	Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)	200.5, Revision 4.228	 	 	 	 	 	
Sodium	Inductively coupled plasma	200.72	 	 	 	 	 	
 	Atomic absorption; direct	 	 	3111B4, 27, 33	3111 B-99	 	 	
 	Ion chromatography	 	D6919-03, 09	 	 	 	 	
 	Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)	200.5, Revision 4.228	 	 	 	 	 	
Thallium	ICP-Mass spectrometry	200.82	 	 	 	 	 	
 	Atomic absorption; platform	200.92	 	 	 	 	0.000712	

<fo:wrapper font-size="8pt">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 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, EPA West, 1301 Constitution Avenue, NW, Room B102, Washington, DC 20460 (telephone: (202)566-2426); or at the Office of Federal Register, 800 North Capitol Street, NW, Suite 700, Washington, DC.</fo:wrapper>	
1“Methods for Chemical Analysis of Water and Wastes,” EPA-600/4-79-020, March 1983. Available at NTIS, PB84-128677.
2“Methods for the Determination of Metals in Environmental Samples—Supplement I,” EPA-600/R-94-111, May 1994. Available at NTIS, PB95-125472.
3Annual Book of ASTM Standards, 1994, 1996, 1999 or 2003, Vols. 11.01 and 11.02, American Society for Testing and Materials (ASTM) International; the methods listed are the only versions that may be used. Copies may be obtained from ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428.
418th and 19th editions of Standard Methods for the Examination of Water and Wastewater, 1992 and 1995, respectively, American Public Health Association; either edition may be used. Copies may be obtained from the American Public Health Association, 800 I Street, NW, Washington, DC 20001-3710.
5Techniques of Water Resources Investigation of the U.S. Geological Survey, Book 5, Chapter A-1, 3rd edition, 1989, Method I-3300-85. Available from Information Services, U.S. Geological Survey, Federal Center, Box 25286, Denver, CO 80225-0425.
6“Methods for the Determination of Inorganic Substances in Environmental Samples,” EPA-600-R-93-100, August 1993. Available at NTIS, PB94-120821.
7The procedure shall be done in accordance with the Technical Bulletin 601, “Standard Method of Test for Nitrate in Drinking Water,” July 1994, PN221890-001, Analytical Technology, Inc.	Copies may be obtained from ATI Orion, 529 Main Street, Boston, MA 02129.
8Method B-1011, “Waters Test Method for Determination of Nitrite/Nitrate in Water Using Single Column Ion Chromatography,” August 1987. Copies may be obtained from Waters Corporation, Technical Services Division, 34 Maple Street, Milford, MA 01757; telephone: (508)482-2131.
9Method 100.1, “Analytical Method for Determination of Asbestos Fibers in Water,” EPA-600/4-83-043, EPA, September 1983. Available at NTIS, PB83-260471.
10Method 100.2, “Determination of Asbestos Structure Over 10 Microns in Length in Drinking Water,” EPA-600/R-94-134, June 1994. Available at NTIS, PB94-201902.
11Industrial Method No.	129-71W, “Fluoride in Water and Wastewater,” December 1972, and Method No.	380-75WE, “Fluoride in Water and Wastewater,” February 1976, Technicon Industrial Systems. Copies may be obtained from Bran & Luebbe, 1025 Busch Parkway, Buffalo Grove, IL 60089.
12Lower MDLs are reported using stabilized temperature graphite furnace atomic absorption.
13Screening method for total cyanides.
14Measures “free” cyanides when distillation, digestion, or ligand exchange is omitted.
15Because MDLs reported in EPA Methods 200.7 and 200.9 were determined using a 2X preconcentration step during sample digestion, MDLs determined when samples are analyzed by direct analysis (i.e., no sample digestion) will be higher. For direct analysis of cadmium by Method 200.7, sample preconcentration using pneumatic nebulization may be required to achieve lower detection limits. Preconcentration may also be required for direct analysis of antimony and thallium by Method 200.9, and antimony by Method 3113B, unless multiple in-furnace depositions are made.
16If ultrasonic nebulization is used in the determination of arsenic by Method 200.8, the arsenic must be in the pentavalent state to provide uniform signal response. For direct analysis of arsenic with Method 200.8 using ultrasonic nebulization, samples and standards must contain 1 mg/L of sodium hypochlorite.
17Reserved.
18The 18th, 19th, and 20th editions of Standard Methods for the Examination of Water and Wastewater, 1992, 1995, and 1998, respectively, American Public Health Association; any edition may be used, except that the versions of 3111B, 3111D, 3113B, and 3114B in the 20th edition may not be used. Copies may be obtained from the American Public Health Association, 800 I Street, NW, Washington, DC 20001-3710.
19The 20th edition of Standard Methods for the Examination of Water and Wastewater, 1998, American Public Health Association. Copies may be obtaining from the American Public Health Association, 800 I Street, NW, Washington, DC 20001-3710.
20The description for the Kelada 01 Method, “Kelada Automated Test Methods for Total Cyanide, Acid Dissociable Cyanide, and Thiocyanate,” Revision 1.2, August 2001, EPA #821-B-01-009 for cyanide is available from NTIS PB 2001-108275. Note: A 450W UV lamp may be used in this method instead of the 550W lamp specified if it provides performance within the quality control acceptance criteria of the method in a given instrument. Similarly, modified flow cell configurations and flow conditions may be used in the method, provided that the quality control acceptance criteria are met.
21The description for the QuikChem Method 10-204-00-1-X, “Digestion and distillation of total cyanide in drinking water and wastewaters using MICRO DIST and determination of cyanide by flow injection analysis,” Revision 2.1, November 30, 2000, for cyanide is available from Lachat Instruments, 6645 W. Mill Road, Milwaukee, WI 53218, telephone (414)358-4200.
22Measures total cyanides when UV-digestor is used, and “free” cyanides when UV-digestor is bypassed.
23“Methods for the Determination of Organic and Inorganic Compounds in Drinking Water,” Volume 1, EPA 815-R-00-014, August 2000. Available at NTIC, PB2000-106981.
24Method D6508, Rev.	2, “Test Method for Determination of Dissolved Inorganic Anions in Aqueous Matrices Using Capillary Ion Electrophoresis and Chromate Electrolyte,” available from Waters Corp., 34 Maple Street, Milford, MA 01757; telephone: (508)482-2131; fax: (508)482-3625.
25Method OIA-1677, DW “Available Cyanide by Flow Injection, Ligand Exchange, and Amperometry,” January 2004. EPA-821-R-04-001. Available from ALPKEM, a division of OI Analytical, P.O. Box 9010, College Station, TX 77542-9010.
26Standard 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.
27Standard Methods for the Examination of Water and Wastewater, 21st edition (2005). Available from American Public Health Association, 800 I Street, NW, Washington, DC 20001-3710.
28EPA Method 200.5, Revision 4.2: “Determination of Trace Elements in Drinking Water by Axially Viewed Inductively Coupled Plasma-Atomic Emission Spectrometry,” 2003. EPA/600/R-06/115. Available at www.nemi.gov.
29Method ME355.01, Revision 1.0, “Determination of Cyanide in Drinking Water by GC/MS Headspace,” May 26, 2009. Available at www.nemi.gov or from H & E Testing Laboratory, 221 State Street, Augusta, ME 04333; telephone: (207)287-2727.
30Systea Easy (1-Reagent), “Systea Easy (1-Reagent) Nitrate Method,” February 4, 2009. Available at www.nemi.gov or from Systea Scientific, LLC, 900 Jorie Blvd., Suite 35, Oak Brook, IL 60523.
31Hach Company Method, “Hach Company SPADNS 2 (Arsenic-free) Fluoride Method 10225 – Spectrophotometric Measurement of Fluoride in Water and Wastewater,” January 2011. 5600 Lindbergh Drive, P.O. Box 389, Loveland, CO 80539. Available at www.hach.com.
32Hach Company Method, “Hach Company TNTplusTM 835/836 Nitrate Method 10206 – Spectrophotometric Measurement of Nitrate in Water and Wastewater,” January 2011. 5600 Lindbergh Drive, P.O. Box 389, Loveland, CO 80539. Available at www.hach.com.
33Standard Methods for the Examination of Water and Wastewater, 22nd edition (2012), American Public Health Association. Available from the American Public Health Association, 800 I Street, NW, Washington, DC 20001-3710.
34Nitrate Elimination Company, Inc.	(NECi). “Method for Nitrate Reductase Nitrate-Nitrogen Analysis of Drinking Water,” February 2016. Superior Enzymes, Inc., 334 Hecla Street, Lake Linden, MI 49945.
	(2)	Sampling methods for IOCs. Sample collection for antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, nitrate, nitrite, selenium, and thallium under this subparagraph shall be conducted using the sample preservation, container, and maximum holding time procedures specified in the table below:
SAMPLING METHODS FOR IOCs

Contaminant	Preservative1	Container2	Time3	
Antimony	HNO3	P or G	6 months	
Arsenic	HNO3	P or G	6 months	
Asbestos	4 degrees C	P or G	48 hours for filtration5	
Barium	HNO3	P or G	6 months	
Beryllium	HNO3	P or G	6 months	
Cadmium	HNO3	P or G	6 months	
Chromium	HNO3	P or G	6 months	
Cyanide	4 degrees C, NaOH	P or G	14 days	
Fluoride	None	P or G	1 month	
Mercury	HNO3	P or G	28 days	
Nickel	HNO3	P or G	6 months	
Nitrate4	4 degrees C	P or G	48 hours	
Nitrate-Nitrite4	H2SO4	P or G	28 days	
Nitrite4	4 degrees C	P or G	48 hours	
Selenium	HNO3	P or G	6 months	
Thallium	HNO3	P or G	6 months	
1When indicated, samples must be acidified at the time of collection to pH < 2 with concentrated acid, or adjusted with sodium hydroxide to pH > 12. Samples collected for metals analysis may be preserved by acidification at the laboratory, using a 1:1 nitric acid solution (50 percent by volume), provided the shipping time and other instructions in Section 8.3 of EPA Methods 200.7, 200.8, and 200.9 are followed. When chilling is indicated, the sample must be shipped and stored at 4 degrees C or less.
2P: plastic, hard or soft; G: glass, hard or soft.
3In all cases, samples should be analyzed as soon after collection as possible. Follow additional (if any) information on preservation, containers, or holding times that is specified in the method.
4Nitrate may only be measured separate from nitrite in samples that have not been acidified. Measurement of acidified samples provides a total nitrate (sum of nitrate plus nitrite) concentration. Acidification of total nitrate (nitrate plus nitrite) samples must be done in the field at the time of sample collection.
5Instructions for containers, preservation procedures, and holding times as specified in Method 100.2 must be adhered to for all compliance analyses, including those conducted with Method 100.1.
	f. 	Unregulated inorganic chemicals. Rescinded IAB 1/7/04, effective 2/11/04.
	41.3(2) Other inorganic chemical contaminants. Reserved.
[ARC 9915B, IAB 12/14/11, effective 1/18/12; ARC 3735C, IAB 4/11/18, effective 5/16/18]