NR 809.547(1)(f)(f) Any water supplier for a community water system with insufficient tier 1 and tier 2 sampling sites shall complete the sampling pool with “tier 3 sampling sites”, consisting of single family structures that contain copper pipes with lead solder installed before 1983. A water supplier for a community water system with insufficient tier 1, tier 2 and tier 3 sampling sites shall complete its sampling pool with representative sites throughout the distribution system. For the purpose of this paragraph, a representative site is a site at which the plumbing materials used at that site would be commonly found at other sites served by the public water system.

NR 809.547(1)(h)(h) A water supplier for a non-transient, non-community water system with insufficient tier 1 sites that meet the targeting criteria in par. (g) shall complete their sampling pool with sampling sites that contain copper pipes with lead solder installed before 1983. If additional sites are needed to complete the sampling pool, the water supplier shall use representative sites throughout the distribution system. For the purpose of this paragraph, a representative site is a site at which the plumbing materials used at that site would be commonly found at other sites served by the public water system.

NR 809.547(1)(i)(i) Any water supplier whose distribution system contains lead service lines shall draw 50% of the samples collected during each monitoring period from sites that contain lead pipes, or copper pipes with lead solder, and 50% of those samples from sites served by a lead service line. A water supplier who cannot identify a sufficient number of sampling sites served by a lead service line shall collect first draw samples from all of the sites identified as being served by such lines.

NR 809.547(2)(2) Sample collection methods.

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)(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.