NR 809.205(1)(b)(b) Surface water sources or combined surface water and groundwater sources shall be sampled at each entry point to the distribution system after treatment, or at locations in the distribution system that are representative of each source after treatment. Each sample shall be taken at the same sampling location unless, if approved by the department, conditions make another sampling location more representative of each source or treatment plant.

NR 809.205(1)(c)(c) If the public water system draws water from more than one source and the sources are combined before distribution, the public water system shall be sampled at an entry point to the distribution system during periods of normal operating conditions when water representative of all sources is being used.

NR 809.205(1)(d)(d) The water supplier for all new public water systems or for public water systems that use a new source of water that begin operation after January 22, 2004 shall demonstrate compliance with the MCLs specified in s. NR 809.20 in accordance with the requirements in this section. The water supplier shall also comply with the initial sampling frequencies specified by the department to ensure the public water system can demonstrate compliance with the MCLs. Routine and increased monitoring frequencies shall be conducted in accordance with the requirements of this section.

NR 809.205(1g)(a)(a) Community and non-transient non-community public water systems serving a population of 50,000 or more shall comply with initial monitoring requirements under sub. (1r) (a) for perfluorooctane sulfonic acid and perfluorooctanoic acid beginning on November 1, 2022.

NR 809.205(1g)(b)(b) Community and non-transient non-community public water systems serving a population of 10,000 to 49,999 shall comply with initial monitoring requirements under sub. (1r) (a) for perfluorooctane sulfonic acid and perfluorooctanoic acid beginning on February 1, 2023.

NR 809.205(1g)(c)(c) Community and non-transient non-community public water systems serving a population of less than 10,000 shall comply with initial monitoring requirements under sub. (1r) (a) for perfluorooctane sulfonic acid and perfluorooctanoic acid beginning on May 1, 2023.

NR 809.205(1r)(1r) Monitoring frequency for perfluorooctane sulfonic acid and perfluorooctanoic acid. Water suppliers shall monitor to determine compliance with the maximum contaminant level for perfluorooctane sulfonic acid and perfluorooctanoic acid at the following frequencies:

NR 809.205(1r)(a)(a) Initial monitoring. Water suppliers for new community public water systems or for community public water systems with new sources shall demonstrate compliance with the MCLs prior to initiating water service. Water suppliers for each community and non-transient, non-community water system shall take 4 consecutive quarterly samples for perfluorooctane sulfonic acid and perfluorooctanoic acid beginning on the dates specified under sub. (1g) or beginning with the year the public water system initiates water service, or a new source is put into service, and every compliance period thereafter unless the requirements of pars. (b) and (c) are met.

NR 809.205(1r)(b)(b) Initial waiver evaluation. For perfluorooctane sulfonic acid and perfluorooctanoic acid the department may waive the final 2 quarters of initial monitoring for a sampling point if the results of the samples from the previous 2 quarters are below the detection limit.

NR 809.205(1r)(c)(c) Routine monitoring. Sampling may be reduced to routine monitoring after the initial monitoring period as follows:

NR 809.205(1r)(c)1.1. ‘Public water systems serving greater than 3,300.’ Public water systems serving more than 3,300 persons that do not detect a contaminant in the initial compliance period or during 3 consecutive years of annual monitoring may reduce the sampling frequency to a minimum of 2 quarterly samples in one year during each repeat compliance period.

NR 809.205(1r)(c)2.2. ‘Public water systems serving 3,300 or less.’ Public water systems serving 3,300 persons or less that do not detect a contaminant in the initial compliance period or during 3 consecutive years of annual monitoring may reduce the sampling frequency to a minimum of one sample during each repeat compliance period.

NR 809.205(1r)(d)(d) Waiver request. Water suppliers for community and non-transient non-community systems may apply to the department for a waiver from the requirements under pars. (a) and (c) for perfluorooctane sulfonic acid and perfluorooctanoic acid. A water supplier shall reapply for a waiver for each compliance period. The waiver period shall not exceed 2 compliance periods.

NR 809.205(1r)(e)(e) Waiver evaluation. The department may grant a waiver from the requirements under pars. (a) and (c) after evaluating all of the following factors:

NR 809.205(1r)(e)1.1. ‘Waiver evaluation when the department determines a contaminant has not been used.’ The department may grant a waiver when the department determines a contaminant has not been used based on a system’s previous use information, including transport, storage, or disposal of the contaminant within the watershed or zone of influence of the public water system, or the results of analysis of a system’s water source.

NR 809.205(1r)(e)2.2. ‘Waiver evaluation when a contaminant has been used or its use is unknown.’ If previous use of the contaminant is unknown or it has been used previously, all of the following factors shall be used to determine whether a waiver is granted:

NR 809.205(1r)(e)2.b.b. The proximity of the public water system to a potential point source of contamination. Point sources include spills and leaks of chemicals at or near a water treatment facility or at manufacturing, distribution, or storage facilities, or from hazardous and municipal waste landfills and other waste handling or treatment facilities; or at airports, military bases, and fire training facilities.

NR 809.205(1r)(f)(f) Waiver conditions and monitoring assessments. As a condition of the waiver under par. (e), the water supplier for a groundwater system shall update the monitoring assessment considering the factors listed under par. (e). Based on this updated monitoring assessment, the department shall reconfirm that the public water system is non-vulnerable. If the department does not make this reconfirmation within 3 years of the initial determination or each subsequent determination, then the waiver is invalidated, and the public water system is required to sample during each compliance period as specified under par. (c).

NR 809.205(2)(2) Monitoring frequency for synthetic organic contaminants other than perfluorooctane sulfonic acid and perfluorooctanoic acid. Water suppliers shall monitor to determine compliance with the maximum contaminant level for synthetic organic contaminants other than perfluorooctane sulfonic acid and perfluorooctanoic acid listed under s. NR 809.20 at the following frequencies:

NR 809.205(2)(a)(a) Initial monitoring. Water suppliers for new community public water systems or for community public water systems with new sources shall demonstrate compliance with the MCLs listed under s. NR 809.20 for synthetic organic contaminants other than perfluorooctane sulfonic acid and perfluorooctanoic acid prior to initiating water service. Water suppliers for each community and non-transient, non-community water system shall take 4 consecutive quarterly samples for each contaminant listed under s. NR 809.20, other than perfluorooctane sulfonic acid and perfluorooctanoic acid, beginning with the year the public water system initiates water service, or a new source is put into service, and every compliance period after that unless they meet the requirements under par. (b).

NR 809.205(2)(b)(b) Routine monitoring. Initial quarterly sampling under sub. (2) (a) may be reduced to routine monitoring after the initial monitoring period as follows:

NR 809.205(2)(b)1.1. ‘Public water systems serving greater than 3,330.’ Public water systems serving more than 3,300 persons that do not detect a contaminant in the initial compliance period or during 3 consecutive years of annual monitoring may reduce the sampling frequency to a minimum of 2 quarterly samples in one year during each repeat compliance period.

NR 809.205(2)(b)2.2. ‘Public water systems serving 3,300 or less.’ Public water systems serving 3,300 persons or less that do not detect a contaminant in the initial compliance period or during 3 consecutive years of annual monitoring may reduce the sampling frequency to a minimum of one sample during each repeat compliance period.

NR 809.205(2)(c)(c) Waiver request. Water suppliers for community and non-transient non-community systems or groundwater systems with new sources may apply to the department for a waiver from the requirements of pars. (a) and (b) for the synthetic organic contaminants other than perfluorooctane sulfonic acid and perfluorooctanoic acid listed under s. NR 809.20. A water supplier shall reapply for a waiver for each compliance period.

NR 809.205(2)(d)(d) Waiver evaluation. The department may grant a waiver from the requirements of this subsection after evaluating all of the following factors:

NR 809.205(2)(d)1.1. ‘Waiver evaluation when the department determines a contaminant has not been used.’ The department may grant a waiver as described in this subdivision and subd. 2. of this paragraph under the following circumstances when the department determines a contaminant has not been used based on a system’s previous use information, including transport, storage, or disposal of the contaminant within the watershed or zone of influence of the public water system, or the results of analysis of a system’s water source:

NR 809.205(2)(d)1.a.a. When a groundwater system can demonstrate that a synthetic organic contaminant has not been used, the department may grant waivers for the contaminant based on results of the analysis of a minimum of one sample at the water source, except as noted under subd. 1. b.