NR 809.547(7)(f)1.1. If the public water system exceeds the lead or copper action level, or both, the water supplier shall implement corrosion control treatment in accordance with the deadlines specified in s. NR 809.542 (5), and any other applicable requirements of this paragraph. NR 809.547(7)(f)2.2. If the public water system meets both the lead and the copper action level, the water supplier shall monitor for lead and copper at the tap no less frequently than once every 3 years using the reduced number of sample sites specified in sub. (3). NR 809.547(7)(g)(g) Pre-existing waivers. Small water system waivers approved by the department in writing prior to April 11, 2000 shall remain in effect under the following conditions: NR 809.547(7)(g)1.1. If the water supplier for a public water system has demonstrated that the public water system is free of both lead-containing and copper-containing materials, as required by par. (a) and that its 90th percentile lead levels and 90th percentile copper levels meet the criteria of par. (b), the waiver remains in effect so long as the public water system continues to meet the waiver eligibility criteria of par. (e). The first round of tap water monitoring conducted pursuant to par. (d) shall be completed no later than 9 years after the last time the water supplier has monitored for lead and copper at the tap. Samples collected every nine years shall be collected no later than every ninth calendar year. NR 809.547(7)(g)2.2. If the public water system has met the materials criteria of par. (a) but has not met the monitoring criteria of par. (b), the water supplier shall conduct a round of monitoring for lead and copper at the tap demonstrating that the public water system meets the criteria of par. (b) to meet initial monitoring requirements. Thereafter, the waiver shall remain in effect as long as the public water system meets the continued eligibility criteria of par. (e). The first round of tap water monitoring conducted pursuant to par. (d) shall be completed no later than 9 years after the round of monitoring conducted pursuant to par. (b). NR 809.547 HistoryHistory: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10; corrections in (4) (d) 5. and (6) (intro.) made under s. 13.92 (4) (b) 7., Stats., Register November 2010 No. 659; CR 15-049: am. (3), (4) (d) 2. Register March 2016 No. 723, eff. 4-1-16. NR 809.548NR 809.548 Monitoring requirements for water quality parameters. Water suppliers for all large systems, and for all small and medium-size systems that exceed the lead or copper action level, shall monitor water quality parameters in addition to lead and copper in accordance with this section. The requirements of this section are summarized in the table at the end of this section. NR 809.548(1)(a)1.1. Tap samples shall be representative of water quality throughout the distribution system taking into account the number of persons served, the different sources of water, the different treatment methods employed by the water supplier, and seasonal variability. Tap sampling under this section is not required to be conducted at taps targeted for lead and copper sampling under s. NR 809.547 (1). NR 809.548(1)(a)2.2. Samples collected at the entry points to the distribution system shall be from locations representative of each source after treatment. If a public water system draws water from more than one source and the sources are combined before distribution, the water supplier shall sample at an entry point to the distribution system during periods of normal operating conditions, i.e., when water is representative of all sources being used. NR 809.548(1)(b)1.1. The water supplier shall collect 2 tap samples for applicable water quality parameters during each monitoring period specified under subs. (2) to (5) from the following number of sites: NR 809.548(1)(b)2.2. Except as provided in sub. (3) (c), water suppliers shall collect 2 samples for each applicable water quality parameter at each entry point to the distribution system during each monitoring period specified in sub. (2). NR 809.548(2)(2) Initial sampling. Water suppliers of all large water systems shall measure the applicable water quality parameters as specified below at taps and at each entry point to the distribution system during each 6-month monitoring period specified in s. NR 809.547 (4) (a). Water suppliers of all small and medium-size systems shall measure the applicable water quality parameters at the locations specified below during each 6-month monitoring period specified in s. NR 809.547 (4) (a) during which the public water system exceeds the lead or copper action level. NR 809.548(2)(a)3.3. Orthophosphate, when an inhibitor containing a phosphate compound is used; NR 809.548(2)(b)(b) At each entry point to the distribution system: all of the applicable parameters listed in par. (a). NR 809.548(3)(3) Monitoring after installation of corrosion control. The water supplier of any large system which installs optimal corrosion control treatment pursuant to s. NR 809.542 (4) (d) shall measure the water quality parameters at the following locations and frequencies during each 6-month monitoring period specified in s. NR 809.547 (4) (b) 1. The water supplier of any small or medium-size system which installs optimal corrosion control treatment shall conduct such monitoring during each 6-month monitoring period specified in s. NR 809.547 (4) (b) 2. in which the public water system exceeds the lead or copper action level. NR 809.548(3)(a)3.3. Orthophosphate, when an inhibitor containing a phosphate compound is used;