NR 809.547(4)(d)7.7. A water supplier for a public water system under subd. 6. b. may resume reduced monitoring for lead and copper at the tap and for water quality parameters within the distribution system under the following conditions:

NR 809.547(4)(d)7.a.a. The water supplier may resume annual monitoring for lead and copper at the tap at the reduced number of sites specified in sub. (3) after they have completed two subsequent six-month rounds of monitoring that meet the criteria of par. (d) 2. and the public water system has received written approval from the department that it is appropriate to resume reduced monitoring on an annual frequency. This sampling shall begin during the calendar year immediately following the end of the second consecutive six-month monitoring period.

NR 809.547(4)(d)7.b.b. The water supplier may resume triennial monitoring for lead and copper at the tap at the reduced number of sites after they demonstrate through subsequent rounds of monitoring that the public water system meets the criteria of either par. (d) 3. or 5. and the water supplier has received written approval from the department that it is appropriate to resume triennial monitoring.

NR 809.547(4)(d)7.c.c. The water supplier may reduce the number of water quality parameter tap water samples required in accordance with s. NR 809.548 (5) (a) and the frequency with which they collect such samples in accordance with s. NR 809.548 (5) (b). The water supplier may not resume triennial monitoring for water quality parameters at the tap until they demonstrate, in accordance with the requirements of s. NR 809.548 (5) (b) that the public water system has re-qualified for triennial monitoring.

NR 809.547(4)(d)8.8. A water supplier for a public water system subject to a reduced monitoring frequency under par. (d) shall notify the department in writing in accordance with s. NR 809.55 (1) (c) 3. of any upcoming long-term change in treatment or addition of a new source as described in that section. The department must review and approve the addition of a new source or long-term change in water treatment before it is implemented by the water supplier. After approved modifications are completed the water supplier may resume reduced monitoring for lead and copper under the following conditions:

NR 809.547(4)(d)8.a.a. The water supplier may resume annual monitoring for lead and copper at the tap at the reduced number of sites specified in sub. (3) after they have completed 2 subsequent 6-month rounds of monitoring that meet the criteria in subd. 2. and the water supplier has received written approval from the department that it is appropriate to resume reduced monitoring on an annual frequency.

NR 809.547(4)(d)8.b.b. The water supplier may resume triennial monitoring for lead and copper at the tap at the reduced number of sites after they demonstrate through subsequent rounds of monitoring that the public water system meets the criteria of either subd. 3. or 5. and the water supplier has received written approval from the department that it is appropriate to resume triennial monitoring.

NR 809.547(4)(d)8.c.c. The water supplier for a public water system may reduce the number of water quality parameter tap water samples required in accordance with s. NR 809.548 (5) (a) and the frequency with which they collect such samples in accordance with s. NR 809.548 (5) (b). The water supplier may not resume triennial monitoring for water quality parameters at the tap until the public water system demonstrates, in accordance with the requirements of s. NR 809.548 (5) (b), that the public water system has re-qualified for triennial monitoring.

NR 809.547(4)(d)9.9. The water supplier for a public water system subject to a reduced monitoring frequency under this paragraph that either adds a new source of water or changes any water treatment shall inform the department in writing in accordance with s. NR 809.55 (1) (e). The department may require the water supplier to resume sampling in accordance with sub. (2) (c) and collect the number of samples specified for standard monitoring under sub. (3) or take other appropriate steps such as increased water quality parameter monitoring or re-evaluation of its corrosion control treatment given the potentially different water quality considerations.

NR 809.547(5)(5) Additional monitoring by water suppliers. The results of any monitoring conducted in addition to the minimum requirements of this section shall be considered by the water supplier and the department in making any determinations, i.e., calculating the 90th percentile lead or copper level, under this subchapter.

NR 809.547(6)(6) Invalidation of lead or copper tap water samples. A sample invalidated under this subsection does not count toward determining lead or copper 90th percentile levels under s. NR 809.54 (3) (c) or toward meeting the minimum monitoring requirements of sub. (3).

NR 809.547(6)(a)(a) The department may invalidate a lead or copper tap water sample if at least one of the following conditions is met:

NR 809.547(6)(b)(b) The water supplier shall report the results of all samples to the department and all supporting documentation for samples the water supplier believes should be invalidated.

NR 809.547(6)(c)(c) To invalidate a sample under par. (a), the decision and the rationale for the decision shall be documented in writing. The department may not invalidate a sample solely on the grounds that a follow-up sample result is higher or lower than that of the original sample.

NR 809.547(6)(d)(d) The water supplier shall collect replacement samples for any samples invalidated under this subsection if, after the invalidation of one or more samples, the public water system has too few samples to meet the minimum requirements of sub. (3). Any replacement samples shall be taken as soon as possible, but no later than 20 days after the date the department invalidates the sample or by the end of the applicable monitoring period, whichever occurs later. Replacement samples taken after the end of the applicable monitoring period may not also be used to meet the monitoring requirements of a subsequent monitoring period. The replacement samples shall be taken at the same locations as the invalidated samples or, if that is not possible, at locations other than those already used for sampling during the monitoring period.

NR 809.547(7)(7) Monitoring waivers for small water systems. The water supplier of any small water system that meets the criteria of this subsection may apply to the department to reduce the frequency of monitoring for lead and copper under this section to once every 9 years, also known as a “full waiver,” if the public water system meets all of the materials criteria specified in par. (a) and all of the monitoring criteria specified in par. (b). If department rules permit, the water supplier for any small water system that meets the criteria in pars. (a) and (b) only for lead, or only for copper, may apply to the department for a waiver to reduce the frequency of tap water monitoring to once every 9 years for that contaminant only, also known as a “partial waiver.”

NR 809.547(7)(a)(a) Materials criteria. The water supplier shall demonstrate that the distribution system of their public water supply system and service lines and all drinking water supply plumbing, including plumbing conveying drinking water within all residences and buildings connected to the public water system, are free of lead-containing materials or copper-containing materials, as those terms are defined in this paragraph, as follows:

NR 809.547(7)(a)1.1. ‘Lead waiver.’ To qualify for a full waiver, or a waiver of the tap water monitoring requirements for lead, known as a “lead waiver,” the water supplier shall provide certification and supporting documentation to the department that the public water system is free of all lead-containing materials, and complies with all of the following:

NR 809.547(7)(a)1.b.b. The public water system is free of lead service lines, lead pipes, lead soldered pipe joints, and leaded brass or bronze alloy fittings and fixtures, unless the fittings and fixtures meet the specifications of any standard established pursuant to 42 USC 300g-6(e).

NR 809.547(7)(a)2.2. ‘Copper waiver.’ To qualify for a full waiver, or a waiver of the tap water monitoring requirements for copper, hereafter known as a “copper waiver,” the water supplier shall provide certification and supporting documentation to the department that the public water system contains no copper pipes or copper service lines.

NR 809.547(7)(b)(b) Monitoring criteria for waiver issuance. The water supplier for the public water system shall have completed at least one 6-month round of standard tap water monitoring for lead and copper at sites approved by the department and from the number of sites required by sub. (3) and demonstrate that the 90th percentile levels for any and all rounds of monitoring conducted since the public water system became free of all lead-containing and copper-containing materials, as appropriate, meet the following criteria:

NR 809.547(7)(b)1.1. ‘Lead waiver.’ To qualify for a lead waiver, the water supplier shall demonstrate that the 90th percentile lead level does not exceed 0.005 mg/L.

NR 809.547(7)(b)2.2. ‘Copper waiver.’ To qualify for a copper waiver, the water supplier shall demonstrate that the 90th percentile copper level does not exceed 0.65 mg/L.