NR 809.546(2)(b)7.
7. For public water systems that are required to conduct monitoring annually or less frequently, the end of the monitoring period is September 30 of the calendar year in which the sampling occurs, or, if the department has established an alternate monitoring period, the last day of that period.
NR 809.546(2)(c)
(c) Requirements for continuing community water system exceedances. As long as a community water system exceeds the action level, the water supplier shall repeat the activities pursuant to par.
(b) as described in this paragraph.
NR 809.546(2)(c)1.
1. A water supplier for a community water system shall repeat the tasks contained in par.
(b) 1.,
2., and
6. every 12 months.
NR 809.546(2)(c)2.
2. A water supplier for a community water system shall repeat the tasks contained in par.
(b) 3. with each billing cycle.
NR 809.546(2)(c)3.
3. A water supplier for a community water system serving a population greater than 100,000 shall post and retain material on a publicly accessible Web site pursuant to par.
(b) 4. NR 809.546(2)(c)4.
4. A water supplier for a community water system shall repeat the task in par.
(b) 5., twice every 12 months on a schedule agreed upon with the department. The department may allow activities in par.
(b) to extend beyond the 60-day requirement if needed for implementation purposes on a case-by-case basis. However, this extension must be approved in writing by the department in advance of the 60-day deadline.
NR 809.546(2)(d)
(d) Non-transient non-community water system public education tasks. No later than 60 days after the end of the monitoring period in which the exceedance occurred, unless it already is repeating public education tasks pursuant to par.
(e), the water supplier for a non-transient non-community water system shall deliver the public education materials specified in sub.
(1), by posting informational posters regarding lead in drinking water in a public place or common area in each of the buildings served by the public water system; and distributing informational pamphlets or brochures, or both, regarding lead in drinking water to each person served by the non-transient non-community water system. The department may allow the water supplier to utilize electronic transmission in lieu of, or combined with, printed materials as long as the same coverage is achieved. For public water systems that are required to be monitored annually or less frequently, the end of the monitoring period is September 30 of the calendar year in which the sampling occurs, or, if the department has established an alternate monitoring period, the last day of that period.
NR 809.546(2)(e)
(e) Requirements for continuing non-transient non-community water system exceedances. A water supplier for a non-transient non-community water system shall repeat the tasks contained in par.
(d) at least once during each calendar year in which the public water system exceeds the lead action level. The department may, on a case-by-case basis, allow activities in par.
(d) to extend beyond the 60-day requirement if needed for implementation purposes. However, this extension is required to be approved in writing by the department in advance of the 60-day deadline.
NR 809.546(2)(f)
(f) Requirements for discontinuing public education materials. A water supplier may discontinue delivery of public education materials if the public water system has met the lead action level during the most recent six-month monitoring period conducted pursuant to s.
NR 809.547. The water supplier shall recommence public education in accordance with this section if the public water system subsequently exceeds the lead action level during any monitoring period.
NR 809.546(2)(g)
(g) Community water system text waiver. A water supplier for a community water system may apply to the department in writing unless the department has waived the requirement for prior approval, to use only the text specified in sub.
(1) (a) in lieu of the text in sub.
(1) (a) and
(b) and to perform the tasks listed in pars.
(d) and
(e) in lieu of the tasks in pars.
(b) and
(c) if all of the following are met:
NR 809.546(2)(g)1.
1. The public water system is a facility, such as a prison or a hospital, where the population served is not capable of or is prevented from making improvements to plumbing or installing point of use treatment devices.
NR 809.546(2)(g)2.
2. The public water system provides water as part of the cost of services provided and does not separately charge for water consumption.
NR 809.546(2)(h)
(h) Reduction in public education requirements for public water systems serving 3300 or fewer people. A water supplier for a community water system serving 3,300 or fewer people may limit certain aspects of the public education programs as follows:
NR 809.546(2)(h)1.
1. With respect to the requirements of par.
(b) 6., a water supplier for a public water system serving 3,300 or fewer shall implement at least one of the activities listed in that paragraph.
NR 809.546(2)(h)2.
2. With respect to the requirements of par.
(b) 2., a water supplier for a public water system serving 3,300 or fewer people may limit the distribution of the public education materials required under that paragraph to facilities and organizations served by the public water system that are most likely to be visited regularly by pregnant women and children.
NR 809.546(2)(h)3.
3. With respect to the requirements of par.
(b) 5., the department may waive this requirement for public water systems serving 3,300 or fewer persons as long as the water supplier distributes notices to every household served by the public water system.
NR 809.546(3)
(3)
Supplemental monitoring for lead. A water supplier for a public water system that fails to meet the lead action level on the basis of tap samples collected in accordance with s.
NR 809.547 shall offer to sample the tap water of any customer who requests it. The water supplier is not required to pay for collecting or analyzing the sample, nor is the water supplier required to collect and analyze the sample.
NR 809.546(4)(a)
(a)
Reporting requirement. All water suppliers for public water systems shall provide a notice of the individual tap results from lead tap water monitoring carried out under the requirements of s.
NR 809.547 to the persons served by the public water system at the specific sampling site from which the sample was taken, for example, the occupants of the residence where the tap was tested.
NR 809.546(4)(b)
(b) Timing of notification. A water supplier shall provide the consumer notice as soon as practical, but no later than 30 days after the water supplier learns of the tap monitoring results.
NR 809.546(4)(c)
(c) Content. The consumer notice shall include the results of lead tap water monitoring for the tap that was tested, an explanation of the health effects of lead, steps consumers can take to reduce exposure to lead in drinking water and contact information for the water utility. The notice shall also provide the maximum contaminant level goal and the action level for lead and the definitions for these two terms from s.
NR 809.833 (2).
NR 809.546(4)(d)
(d) Delivery. The consumer notice shall be provided to persons served at the tap that was tested, either by mail or by another method approved by the department. For example, upon approval by the department, a non-transient noncommunity water system could post the results on a bulletin board in the facility to allow users to review the information. The water supplier shall provide the notice to customers at sample taps tested, including consumers who do not receive water bills.
NR 809.546 History
History: CR 09-073: cr.
Register November 2010 No. 659, eff. 12-1-10; correction in (intro.) made under s.
13.92 (4) (b) 7., Stats.,
Register November 2010 No. 659;
CR 15-049: am. (intro.), (1) (a) 1., (2) (b) 1., 2., (c) 1., (d)
Register March 2016 No. 723, eff. 4-1-16.
NR 809.547
NR 809.547 Monitoring requirements for lead and copper in tap water. NR 809.547(1)(a)
(a) By the applicable date for commencement of monitoring under sub.
(4) (a), each water supplier shall complete a materials evaluation of the distribution system of this public water system in order to identify a pool of targeted sampling sites that meet the requirements as specified in pars.
(c) to
(f), and which is sufficiently large to ensure that the water supplier can collect the number of lead and copper tap samples required in sub.
(3). All sites from which first draw samples are collected shall be selected from this pool of targeted sampling sites. Sampling sites may not include faucets that have point-of-use or point-of-entry treatment devices designed to remove inorganic contaminants.
NR 809.547(1)(b)
(b) A water supplier shall use the information on lead, copper and galvanized steel that they are required to collect under s.
NR 809.119 when conducting a materials evaluation. When an evaluation of the information collected pursuant to s.
NR 809.119 (4) is insufficient to locate the requisite number of lead and copper sampling sites that meet the targeting criteria in this subsection, the water supplier shall review the following sources of information in order to identify a sufficient number of sampling sites. In addition, the water supplier shall seek to collect such information where possible in the course of its normal operations, including, checking service line materials when reading water meters or performing maintenance activities:
NR 809.547(1)(b)1.
1. All plumbing codes, permits and records in the files of the building department which indicate the plumbing materials that are installed within publicly and privately owned structures connected to the distribution system.
NR 809.547(1)(b)2.
2. All inspections and records of the distribution system that indicate the material composition of the service connections that connect a structure to the distribution system.
NR 809.547(1)(b)3.
3. All existing water quality information, which includes the results of all prior analyses of the public water system or individual structures connected to the public water system, indicating locations that may be particularly susceptible to high lead or copper concentrations.
NR 809.547(1)(c)
(c) The “tier 1 sampling sites" selected for a community water system's sampling pool shall consist of single family structures that meet at least one of the following requirements:
NR 809.547(1)(c)1.
1. Contain copper pipes with lead solder installed after 1982 or contain lead pipes.
NR 809.547(1)(d)
(d) When multiple-family residences comprise at least 20% of the structures served by a public water system, the water supplier may include the types of structures described in par.
(c) in its sampling pool.
NR 809.547(1)(e)
(e) Any water supplier for a community water system with insufficient tier 1 sampling sites shall complete the sampling pool with “tier 2 sampling sites," consisting of buildings, including multiple-family residences that meet at least one of the following requirements:
NR 809.547(1)(e)1.
1. Contain copper pipes with lead solder installed after 1982 or contain lead pipes.
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)(g)
(g) The “tier one sampling sites" selected for a non-transient non-community water system shall consist of buildings that meet at least one of the following requirements:
NR 809.547(1)(g)1.
1. Contain copper pipes with lead solder installed after 1982 or contain lead pipes.
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)(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.
-
See PDF for table 
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:
-
See PDF for table 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.
NR 809.547(4)(d)6.a.a. Water suppliers for public water systems that are on reduced monitoring shall increase monitoring by the following: Water suppliers for a small or medium-sized water system subject to reduced monitoring that exceeds the lead or copper action level shall resume sampling in accordance with par.
(c) and collect the number of samples specified for standard monitoring under sub.
(3). A water supplier shall also conduct water quality parameter monitoring in accordance with s.
NR 809.548 (2),
(3) or
(4) during the monitoring period in which the action level was exceeded. A water supplier for any public water system subject to reduced monitoring frequency that fails to operate within the range of values for the water quality control parameters specified by the department under s.
NR 809.543 (6) shall resume tap water sampling in accordance with par.
(c) and collect the number of samples specified for standard monitoring under sub.
(3).
NR 809.547(4)(d)6.b.
b. A water supplier for any public water system subject to the reduced monitoring frequency that fails to meet the lead action level during any four-month monitoring period or that fails to operate at or above the minimum value or within the range of values for the water quality parameters specified by the department under s.
NR 809.543 (6) for more than 9 days in any 6-month period specified in s.
NR 809.548 (4) shall conduct tap water sampling for lead and copper at the frequency specified in par.
(c), collect the number of samples specified for standard monitoring under sub.
(3), and shall resume monitoring for water quality parameters within the distribution system in accordance with s.
NR 809.548 (4). This standard tap water sampling shall begin no later than the six-month period beginning January 1 of the calendar year following the lead action level exceedance or water quality parameter excursion.
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)(a)1.
1. The laboratory establishes that improper sample analysis caused erroneous results.
