NR 809.115(2)(g)(g) Sample frequency for public water systems with vulnerable source water. A public water system vulnerable to asbestos contamination due solely to source water shall be monitored in accordance with the provisions in par. (a). NR 809.115(2)(h)(h) Monitoring when an MCL is exceeded. A public water system which exceeds the MCL as determined in s. NR 809.117 shall be monitored quarterly beginning in the next quarter after the violation occurred. The department may decrease the quarterly monitoring requirement to one sample as specified in par. (a) if the department has determined that the public water system is reliably and consistently below the maximum contaminant level. In no case may the department make this determination unless a groundwater system takes a minimum of 2 quarterly samples and a surface water system or a combined surface water and groundwater system takes a minimum of 4 quarterly samples. NR 809.115(2)(i)(i) Grandfathered data. If monitoring data collected after January 1, 1990 is generally consistent with the requirements of this subsection, then the department may allow water suppliers for public water systems to use that data to satisfy the monitoring requirement for the initial compliance period beginning January 1, 1993. NR 809.115(3)(3) Monitoring frequency for MCLs other than asbestos, nitrate, and nitrite. The water supplier shall conduct monitoring for each community and non-transient, non-community water system to determine compliance with the MCLs specified in s. NR 809.11 (2) for antimony, arsenic, barium, beryllium, cadmium, chromium, cyanide, mercury, nickel, selenium and thallium at the frequencies specified in this subsection. The water supplier shall conduct monitoring for each community water system to determine compliance with the MCL in s. NR 809.11 (2) for fluoride at the frequencies specified in this subsection: NR 809.115(3)(a)(a) Initial monitoring. New community public water systems or community public water systems with new sources shall demonstrate compliance with the MCLs listed under s. NR 809.11 (2) for antimony, arsenic, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium and thallium prior to initiating water service. New non-transient non-community public water systems or non-transient non-community public water systems with new sources shall take one sample for each contaminant listed in s. NR 809.11 (2) beginning with the year the public water system initiates service or the new water source is put into service. If a waiver from cyanide monitoring has been granted under par. (c) cyanide is not required to be sampled for in the initial monitoring. NR 809.115(3)(b)(b) Routine monitoring. Groundwater sources shall be sampled at each sampling point during each compliance period as determined by the department. Water suppliers for public water systems having surface water sources or combined surface water and groundwater sources shall take one sample annually at each sampling point. If a waiver from cyanide monitoring has been granted under par. (c), cyanide is not required to be sampled for routine monitoring. NR 809.115(3)(c)(c) Waiver request. The water supplier may apply to the department for a waiver from the monitoring frequencies specified in par. (b). Public water systems that use a new water source are not eligible for a waiver until monitoring from the new source has been conducted in at least three compliance periods except that the department may grant a waiver for monitoring of cyanide beginning with initial monitoring, provided the public water system is not vulnerable to contamination because there is no industrial source of cyanide present. NR 809.115(3)(d)(d) Waiver evaluation. In determining the appropriate reduced monitoring frequency, the department shall consider all of the following: NR 809.115(3)(d)3.3. Other factors which may affect contaminant concentrations such as changes in groundwater pumping rates, changes in the public water system’s configuration, changes in the public water system’s operating procedures, or changes in stream flows or characteristics. NR 809.115(3)(e)(e) Waiver conditions. The department may grant a waiver if surface water systems have been monitored annually for at least 3 years and groundwater systems have been monitored in at least three compliance periods. At least one of the 3 samples shall have been taken since January 1, 1990. Water suppliers for both surface and groundwater systems shall demonstrate that all previous analytical results were less than the maximum contaminant level. Public water systems that use a new water source are not eligible for a waiver until monitoring from the new source has been conducted in at least three compliance periods. A condition of the waiver shall be the collection of a minimum of one sample while the waiver is effective. The term during which the waiver is effective may not exceed 9 years. NR 809.115(3)(f)(f) Monitoring frequency when an MCL has been exceeded. Public water systems which exceed the MCLs in s. NR 809.11 (2) shall be monitored quarterly beginning in the next quarter after the violation occurred. The department may decrease the quarterly monitoring requirement to the frequencies specified in pars. (a) and (b) if the department has determined that the public water system is reliably and consistently below the maximum contaminant level. In no case may the department make this determination unless a groundwater system takes a minimum of 2 quarterly samples and a surface water system takes a minimum of 4 quarterly samples. NR 809.115(4)(4) Monitoring frequency for nitrate. The water supplier for public water systems shall conduct monitoring for the public water systems to determine compliance with the MCL for nitrate specified in s. NR 809.11 (2) at the following frequencies: NR 809.115(4)(a)(a) Initial monitoring. Water suppliers for new public water systems or public water systems with new sources shall demonstrate compliance with the MCLs listed under s. NR 809.11 (2) for nitrate prior to initiating water service. NR 809.115(4)(b)(b) Routine monitoring. Each community water system and non-community water system shall be monitored according to the following frequencies: NR 809.115(4)(b)1.1. Community water systems and non-transient non-community water systems served by groundwater shall be monitored annually. NR 809.115(4)(b)2.2. Community water systems and non-transient non-community water systems served by surface water shall be monitored quarterly. NR 809.115(4)(c)(c) Increased monitoring due to detection at one-half the MCL and greater. For community and non-transient non-community 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 mg/L nitrate as nitrogen. The department may reduce a groundwater system’s sampling frequency to annual after 4 consecutive quarterly samples are reliably and consistently less than the MCL. NR 809.115(4)(d)(d) Timing of samples after increased monitoring is ended. After quarterly sampling is completed, any community or non-transient non- community water system which is allowed to resume routine monitoring, under par. (b), shall be monitored during the quarter which previously resulted in the highest analytical result. NR 809.115(4)(e)(e) Reduction of quarterly monitoring for surface water systems. The department may reduce a surface water system’s sampling frequency to annual if all analytical results from 4 consecutive quarters are less than 5 mg/L nitrate as nitrogen. A surface water system shall return to quarterly monitoring if any one sample is greater than or equal to 5 mg/L nitrate. NR 809.115(4)(f)(f) Monitoring if an MCL is exceeded. Where nitrate sampling results indicate an exceedance of the MCL, the water supplier shall take a confirmation sample as required under sub. (6) (b) NR 809.115(5)(5) Monitoring frequency for nitrite. The water supplier shall conduct monitoring for the public water system to determine compliance with the MCL for nitrite specified in s. NR 809.11 (2) at the following frequencies: NR 809.115(5)(a)(a) Initial monitoring. Water suppliers for new public water systems or public water systems with new sources shall demonstrate compliance with the MCLs listed under s. NR 809.11 (2) for nitrite prior to initiating water service. NR 809.115(5)(b)(b) Routine monitoring. After the initial sample, water suppliers for public water systems where an analytical result for nitrite is less than 0.5 mg/L nitrite as nitrogen shall monitor at the frequency specified by the department. Community and non-transient non-community water systems shall be sampled at the same frequency as the monitoring required under sub. (3). NR 809.115(5)(c)(c) Increased monitoring due to detection at one-half the MCL and greater. The repeat monitoring frequency shall be quarterly for at least one year following any one sample in which the concentration of nitrite is greater than or equal to 0.5 mg/L nitrite as nitrogen. The department may reduce the sampling frequency to annual after determining the concentration is reliably and consistently less than the MCL. Each subsequent annual sample shall be taken during the quarter which previously resulted in the highest analytical result. NR 809.115(5)(d)(d) Monitoring if an MCL is exceeded. If nitrite sampling results indicate an exceedance of the MCL, the water supplier shall take a confirmation sample as required under sub. (6) (b). NR 809.115(6)(6) Confirmation samples. The collection of confirmation samples shall comply with the following requirements: NR 809.115(6)(a)(a) Department required confirmation samples. The department may require the collection of a confirmation sample where sample results indicate an exceedance of the MCL for antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium or thallium. The confirmation sample shall be collected as soon as possible after the initial sample results were received, but not exceeding 2 weeks, at the same entry point. NR 809.115(6)(b)(b) Mandatory confirmation samples. If nitrate or nitrite sampling results indicate an exceedance of the MCL, the water supplier shall take a confirmation sample within 24 hours of the water supplier’s receipt of notification of the analytical results of the first sample. Water suppliers unable to comply with the 24-hour sampling requirement shall immediately notify the consumers served by the public water system in accordance with subch. VII and meet other Tier 1 public notification requirements under subch. VII. Water suppliers exercising this option shall take and analyze a confirmation sample within 2 weeks of notification of the analytical results of the first sample. NR 809.115(6)(c)(c) Averaging of confirmation samples. If a confirmation sample is required for any contaminant, the results of the original and the confirmation sample shall be averaged. The resultant average shall be used to determine the public water system’s compliance in accordance with s. NR 809.117 (1). NR 809.115(7)(7) Sampling frequency. The department may require more frequent monitoring than specified in subs. (2), (3), (4) and (5) and may require confirmation samples for positive and negative results at its discretion. NR 809.115(8)(8) Increased monitoring. Water suppliers may apply to the department to conduct more frequent monitoring than the minimum monitoring frequencies specified in this section. NR 809.115(9)(9) Designated sampling time. Each public water system shall be monitored during the month, quarter or year designated by the department during each compliance period for all monitoring required under subs. (2), (3), (4) and (5). NR 809.115(10)(10) Sampling errors. The department may delete results of obvious sampling errors, or may require the collection of additional samples to determine whether the result is or is not in error. NR 809.115 HistoryHistory: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10; CR 15-049: am. (1) (d), (2) (f) 2., (3) (intro.), (a), (b) Register March 2016 No. 723, eff. 4-1-16. NR 809.117NR 809.117 Compliance requirements for inorganic contaminants. NR 809.117(1)(1) Compliance determinations. Compliance for inorganic contaminants shall be determined based on all of the following: NR 809.117(1)(a)(a) Compliance with s. NR 809.11 shall be determined based on the analytical results obtained at each entry point. Any contaminant listed in s. NR 809.11 which is detected shall be quantified. NR 809.117(1)(b)(b) For public water systems which are monitored more frequently than annually, compliance with the MCLs for antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium or thallium is determined by a running annual average at each entry point. If the average at any sampling point is greater than the MCL, then the public water system is out of compliance. If any one or more samples would cause the annual average to exceed an MCL, then the public water system is out of compliance immediately. Any sample below the reported method detection limit shall be calculated at zero for the purpose of determining the annual average. If a water supplier fails to collect the required number of samples, compliance shall be based on the total number of samples collected. NR 809.117(1)(c)(c) For public water systems which are monitored annually, or less frequently, the public water system is out of compliance with the MCL for antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium or thallium if the level of a contaminant at any entry point is greater than the MCL. If a confirmation sample is required by the department, compliance shall be based on the average of the 2 samples. If a water supplier fails to collect the required number of samples, compliance shall be based on the total number of samples collected. NR 809.117(1)(d)(d) Compliance with the MCLs for nitrate, nitrite or combined nitrate and nitrite is determined based on one sample if the levels of these contaminants are below the MCLs. If the levels exceed a MCL in the initial sample, a confirmation sample is required in accordance with s. NR 809.115 (6) (b). Compliance shall be determined based on the average of the initial and confirmation samples. NR 809.117(1)(e)(e) Arsenic sampling results shall be reported to the nearest 0.001 mg/L. NR 809.117(1)(f)(f) Public water systems remain out of compliance with the MCLs for nitrate, nitrite, or combined nitrate and nitrite until the results of 4 consecutive quarterly samples do not exceed the MCL. The department may specify alternate means for returning to compliance with the MCLs for nitrate, nitrite, or combined nitrate and nitrite. Alternate compliance agreements shall be in writing. NR 809.117(2)(2) Monitoring and reporting violations. Failure to monitor shall result in a monitoring and reporting violation. NR 809.117(3)(3) Use of analytical results. The department may determine compliance or initiate enforcement action based upon analytical results and other information compiled by their sanctioned representatives and agencies. NR 809.117 HistoryHistory: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10; CR 15-049: am. (1) (f) Register March 2016 No. 723, eff. 4-1-16. NR 809.118NR 809.118 Sodium monitoring, reporting and notification requirements. NR 809.118(1)(1) General. The water supplier for a community water system shall collect and analyze one sample per plant at the entry point to the distribution system for the determination of sodium concentration. Samples shall be collected and analyzed annually for public water systems utilizing surface water sources in whole or in part, and at least every 3 years for public water systems utilizing solely groundwater sources. The minimum number of samples required to be taken by the public water system shall be based on the number of plants used by the public water system, except that multiple wells drawing raw water from a single aquifer may, with department approval, be considered one plant for determining the minimum number of samples. The water supplier may be required by the department to collect and analyze water samples for sodium more frequently in locations where the sodium content is variable. NR 809.118(2)(2) Department notification. The water supplier shall report to the department the results of the analyses for sodium concentration within the first 10 days of the month following the month in which the sample results were received or within the first 10 days following the end of the required monitoring period as stipulated by the department, whichever is first. If more than annual sampling is required, the water supplier shall report the average sodium concentration within 10 days of the month following the month in which the analytical results of the last sample used for the annual average was received. NR 809.118(3)(3) Health officials notification. The water supplier shall notify appropriate local health officials of the sodium concentration by written notice by direct mail within 3 months of receipt of sample results. A copy of each notice required to be provided by this subsection and a list of health officials notified shall be sent to the department within 10 days of its issuance. NR 809.118 NoteNote: A primary maximum contaminant level has not been established for sodium.
NR 809.118 HistoryHistory: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10. NR 809.119NR 809.119 Materials identification for corrosivity characteristics. Suppliers of water for community water systems shall identify whether the following construction materials are present in their distribution system and report their findings to the department: NR 809.119(1)(1) Lead from piping, solder, caulking, interior lining of distribution mains, alloys and home plumbing. NR 809.119(2)(2) Copper from piping and alloys, service lines and home plumbing. NR 809.119(3)(3) Galvanized piping, service lines and home plumbing. NR 809.119(4)(4) Ferrous piping materials such as cast iron and steel. NR 809.119 HistoryHistory: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10. NR 809.20NR 809.20 Synthetic organic contaminant maximum contaminant levels and BATS. NR 809.20(1)(1) Applicability. The following maximum contaminant levels for synthetic organic contaminants apply to community water systems and non-transient non-community water systems. NR 809.20(2)(2) Best available treatment. The following are the BATs available for achieving compliance with the maximum contaminant levels for the organic contaminants listed in sub. (1): NR 809.20(2)(a)(a) Central treatment using granular activated carbon, except for glyphosate. NR 809.20(2)(b)(b) Packed tower aeration for dibromochloropropane, di(2-ethylhexyl)adipate, ethylene dibromide, and hexachlorocyclopentadiene. NR 809.20(2)(d)(d) Granular activated carbon, powdered activated carbon, ion exchange resins, nanofiltration, and reverse osmosis for PFOS and PFOA. NR 809.20(3)(3) Alternative treatment. A water supplier may use an alternative treatment not listed in sub. (2) if it is demonstrated to the department, using pilot studies or other means, that the alternative treatment is sufficient to achieve compliance with the MCLs in sub. (1). NR 809.20 HistoryHistory: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10; CR 21-088: am. (1) Table, cr. (2) (d) Register July 2022 No. 799, eff. 8-1-22. NR 809.203NR 809.203 Analytical requirements for synthetic organic contaminants. NR 809.203(1)(1) Detection limits. Detection as used in this section shall be defined as greater than or equal to the following concentrations for each contaminant: NR 809.203(2)(2) Analytical methods. Analysis for the synthetic organic contaminants listed in s. NR 809.20 shall be conducted using the methods prescribed in Table CM. 2 Accurate determination of the chlorinated esters requires hydrolysis of the sample as described in EPA Methods 515.1, 515.2, 515.3, 515.4 and 555 and ASTM Method D 5317-93, 98 (Reapproved 2003).
3 Substitution of the detector specified in Method 505, 507, 508, or 508.1 for the purpose of achieving lower detection limits is allowed as follows: Either an electron capture or nitrogen phosphorus detector may be used provided all regulatory requirements and quality control criteria are met.
4 This method may not be used for the analysis of atrazine in any system where chlorine dioxide is used for drinking water treatment. In samples from all other systems, any result generated by Method AG-625 that is greater than one-half the maximum contaminant level (MCL) (in other words, greater than 0.0015 mg/L or 1.5 ìg/L) must be confirmed using another approved method for this contaminant and should use additional volume of the original sample collected for compliance monitoring. In instances where a result from Method AG-625 triggers such confirmatory testing, the confirmatory result is to be used to determine compliance.
5 Method 6610 shall be followed in accordance with the “Supplement to the 18th edition of Standard Methods for the Examination of Water and Wastewater”, 1994, or with the 19th edition of Standard Methods for the Examination of Water and Wastewater, 1995, APHA; either publication may be used. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 USC 552 (a) and 1 CFR Part 51. Copies may be obtained from the American Public Health Association, 1015 Fifteenth Street, N.W., Washington, D.C., 2005. Other required analytical test procedures germane to conducting these analyses are contained in Technical Notes on Drinking Water Methods, EPA/600/R-94-173, October 1994, NTIS PB95-104766. 6 Method 6651 shall be followed in accordance with the “Standard Methods for the Examination of Water and Wastewater”, 18th Edition, 1992, and 19th edition, 1995, American Public Health Association. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552 (a) and 1 CFR Part 51. Copies may be obtained from the American Public Health Association, 1015 Fifteenth Street, N.W., Washington, D.C., 20005. 7 Method 505 or 508 can be used as a screen for PCBs. Method 508A shall be used to quantitate PCBs as decachlorobiphenyl if detected in Method 505 or 508. PCBs are qualitatively identified as Aroclors and measured for compliance purposes as decachlorobiphenyl.
8 A nitrogen-phosphorus detector should be substituted for the electron capture detector in Method 505 (or a different approved method should be used) to determine alachlor, atrazine and simizine, if lower detection limits are required.
9 Standard Methods for the Examination of Water and Wastewater, 18th edition (1992), 19th edition (1995), 20th edition (1998), 21st edition (2005), 22nd edition (2012). Available from American Public Health Association, 800 I Street, NW., Washington, DC, 20001-3710.
