NR 809.547(2)(a)(a) All tap samples for lead and copper collected in accordance with this subchapter, with the exception of lead service line samples collected under s. NR 809.545 (3) and samples collected under par. (e), shall be first draw samples. NR 809.547(2)(b)(b) Each first-draw tap sample for lead and copper shall be one liter in volume and have stood motionless in the plumbing system of each sampling site for at least 6 hours. First-draw samples from residential housing shall be collected from the cold water kitchen tap or bathroom sink tap. First-draw samples from a nonresidential building shall be collected at an interior tap from which water is typically drawn for consumption. Non-first-draw samples collected in lieu of first-draw samples pursuant to par. (e) shall be one liter in volume and shall be collected at an interior tap from which water is typically drawn for consumption. First-draw samples may be collected by the water supplier or the water supplier may allow residents to collect first-draw samples after instructing the residents of the sampling procedures specified in this paragraph. To avoid problems of residents handling nitric acid, acidification of first-draw samples may be done up to 14 days after the sample is collected. After acidification to resolubilize the metals, the sample shall stand in the original container for the time specified in the approved EPA method before the sample can be analyzed. If a water supplier allows residents to perform sampling, the water supplier may not challenge, based on alleged errors in sample collection, the accuracy of sampling results. NR 809.547(2)(c)(c) Each service line sample shall be one liter in volume and have stood motionless in the lead service line for at least 6 hours. Lead service line samples shall be collected in one of the following 3 ways: NR 809.547(2)(c)1.1. At the tap after flushing the volume of water between the tap and the lead service line. The volume of water shall be calculated based on the interior diameter and length of the pipe between the tap and the lead service line. NR 809.547(2)(c)3.3. If the sampling site is a building constructed as a single-family residence, allowing the water to run until there is a significant change in temperature which would be indicative of water that has been standing in the lead service line. NR 809.547(2)(d)(d) A water supplier shall collect each first-draw tap sample from the same sampling site from which they collected a previous sample. If for any reason the water supplier cannot gain entry to a sampling site in order to collect a follow-up tap sample, the water supplier may collect the follow-up tap sample from another sampling site in their sampling pool as long as the new site meets the same targeting criteria, and is within reasonable proximity of the original site. NR 809.547(2)(e)(e) The water supplier for a non-transient non-community water system or a community water system that meets the criteria of s. NR 809.546 (2) (g) that does not have enough taps that can supply first-draw samples, may apply to the department in writing to substitute non-first-draw samples. Water suppliers for these public water systems shall collect as many first-draw samples from appropriate taps as possible and identify sampling times and locations that would likely result in the longest standing time for the remaining sites. The department may waive the requirement for prior departmental approval of non-first-draw sample sites selected by the water supplier, either through department rule or written notification to the water supplier. NR 809.547(3)(3) Number of samples. Water suppliers shall collect at least one sample during each monitoring period specified in sub. (4) from the number of sites listed in the following column titled “standard monitoring.” A water supplier conducting reduced monitoring under sub. (4) (d) may collect one sample from the number of sites specified in the second following column during each monitoring period specified in sub. (4) (d). The department may specify sampling locations when a water supplier is conducting reduced monitoring. Such reduced monitoring sites shall be representative of the sites required for standard monitoring. A water supplier for a public water system that has fewer than five drinking water taps that can be used for human consumption meeting the sample site criteria of sub. (1) of this section to reach the required number of sample sites listed in this subsection, shall collect at least one sample from each tap and then shall collect additional samples from those taps on different days during the monitoring period to meet the required number of sites. Alternatively the department may allow water suppliers of these public water systems to collect a number of samples less than the number of sites specified in this subsection, provided that 100 percent of all taps that can be used for human consumption are sampled. The department may approve this reduction of the minimum number of samples in writing based on a request from the water supplier or onsite verification by the department. NR 809.547(4)(a)(a) Initial tap sampling. The first 6-month monitoring period for small, medium and large-size systems shall begin on the following dates: NR 809.547(4)(a)1.1. The water suppliers of all large systems shall monitor during 2 consecutive 6-month periods. NR 809.547(4)(a)2.2. The water suppliers of all small and medium-size systems shall monitor during each 6-month monitoring period until one of the following occurs: NR 809.547(4)(a)2.a.a. The public water system exceeds the lead or copper action level and is therefore required to implement the corrosion control treatment requirements under s. NR 809.542, in which case the water supplier shall continue monitoring in accordance with par. (b). NR 809.547(4)(a)2.b.b. The public water system meets the lead or copper action levels during 2 consecutive 6-month monitoring periods, in which case the water supplier may reduce monitoring in accordance with par. (d). NR 809.547(4)(b)(b) Monitoring after installation of corrosion control and source water treatment. NR 809.547(4)(c)(c) Monitoring after the department specifies water quality parameter values for optimal corrosion control. After the department approves the values for water quality control parameters under s. NR 809.543 (6), the water supplier shall monitor during each subsequent 6-month monitoring period, with the first monitoring period to begin on the date the department specifies the optimal values under s. NR 809.543 (6). NR 809.547(4)(d)1.1. The water supplier for a small or medium-size water system that meets the lead and copper action levels during each of 2 consecutive 6-month monitoring periods may reduce the number of samples in accordance with sub. (3), and reduce the frequency of sampling to once per year. The water supplier for a small or medium water system collecting fewer than five samples as specified in sub. (3) of this section, that meets the lead and copper action levels during each of two consecutive six-month monitoring periods may reduce the frequency of sampling to once per year. In no case may the water supplier reduce the number of samples required below the minimum of one sample per available tap. The water supplier shall begin this sampling during the calendar year immediately following the end of the second consecutive six-month monitoring period. NR 809.547(4)(d)2.2. The water supplier for a public water system that meets the lead action level and maintains the range of values for the water quality control parameters reflecting optimal corrosion control treatment specified by the department under s. NR 809.543 (6) and (7) during each of two consecutive six-month monitoring periods may reduce the frequency of monitoring to once per year and reduce the number of lead and copper samples in accordance with sub. (3) of this section if they receive written approval from the department. This sampling shall begin during the calendar year immediately following the end of the second consecutive six-month monitoring period. The department shall review monitoring, treatment, and other relevant information submitted by the water supplier in accordance with s. NR 809.55, and shall notify the water supplier in writing when it determines the public water system is eligible to commence reduced monitoring pursuant to this paragraph. The department shall review, and where appropriate, revise its determination when the water supplier submits new monitoring or treatment data, or when other data relevant to the number and frequency of tap sampling becomes available. NR 809.547(4)(d)3.3. The water supplier for a small or medium-size water system that meets the lead and copper action levels during three consecutive years of monitoring may reduce the frequency of monitoring for lead and copper from annually to once every three years. The water supplier for a public water system that meets the lead action level and maintains the range of values for the water quality control parameters reflecting optimal corrosion control treatment specified by the department under s. NR 809.543 (6) during three consecutive years of monitoring may reduce the frequency of monitoring from annually to once every three years if they receives written approval from the department. Samples collected once every three years shall be collected no later than every third calendar year. The department shall review monitoring, treatment, and other relevant information submitted by the water supplier in accordance with s. NR 809.55, and shall notify the water supplier in writing when it determines the public water system is eligible to reduce the frequency of monitoring to once every three years. The department shall review, and where appropriate, revise its determination when the water supplier submits new monitoring or treatment data, or when other data relevant to the number and frequency of tap sampling becomes available. NR 809.547(4)(d)4.4. A water supplier that reduces the number and frequency of sampling shall collect these samples from representative sites included in the pool of targeted sampling sites identified in sub. (1). A water supplier sampling annually or less frequently shall conduct the lead and copper tap sampling during the months of June, July, August or September unless the department has approved a different sampling month. NR 809.547(4)(d)4.a.a. The department, at its discretion, may approve a different period for conducting the lead and copper tap sampling for water suppliers collecting a reduced number of samples. Such a period shall be no longer than four consecutive months and must represent a time of normal operation where the highest levels of lead are most likely to occur. For a non-transient noncommunity water system that does not operate during the months of June through September, and for which the period of normal operation where the highest levels of lead are most likely to occur is not known, the department shall designate a period that represents a time of normal operation for the public water system. This sampling shall begin during the period approved or designated by the department in the calendar year immediately following the end of the second consecutive six-month monitoring period for water suppliers initiating annual monitoring and during the three-year period following the end of the third consecutive calendar year of annual monitoring for public water systems initiating triennial monitoring. NR 809.547(4)(d)4.b.b. Water suppliers monitoring annually, that have been collecting samples during the months of June through September and that receive department approval to alter their sample collection period under this subd. 4. a. shall collect their next round of samples during a time period that ends no later than 21 months after the previous round of sampling. Water suppliers monitoring triennially that have been collecting samples during the months of June through September, and receive department approval to alter the sampling collection period as under this subd. 4. a. shall collect their next round of samples during a time period that ends no later than 45 months after the previous round of sampling. Subsequent rounds of sampling shall be collected annually or triennially, as required by this section. Water suppliers for small water systems with waivers, granted pursuant to sub. (7), that have been collecting samples during the months of June through September and receive department approval to alter their sample collection period under this subd. 4. a. shall collect their next round of samples before the end of the 9-year period. NR 809.547(4)(d)5.5. Any water supplier that demonstrates for 2 consecutive 6-month monitoring periods that the tap water lead level computed under s. NR 809.54 (3) (c) is less than or equal to 0.005 mg/L and the tap water copper level computed under s. NR 809.54 (3) (c) is less than or equal to 0.65 mg/L may reduce the number of samples in accordance with sub. (3) and reduce the frequency of sampling to once every 3 calendar years.