NR 809.331(1)(f)(f) Water suppliers for unfiltered public water systems serving fewer than 10,000 people shall sample their source water for Cryptosporidium at least twice per month for 12 months or at least monthly for 24 months.

NR 809.331(1)(g)(g) Water suppliers may sample more frequently than required under this section if the sampling frequency is evenly spaced throughout the monitoring period.

NR 809.331(2)(2) Second round of source water monitoring. Water supplier shall conduct a second round of source water monitoring that meets the requirements for monitoring parameters, frequency, and duration described in sub. (1), unless they meet the monitoring exemption criteria in sub. (4). Water suppliers shall conduct this monitoring on the schedule in sub. (3).

NR 809.331(3)(3) Monitoring schedule. According to EPA requirements, water supplier shall begin the monitoring required in subs. (1) and (2) no later than the month beginning with the date listed in Table H:

NR 809.331(4)(a)(a) Water suppliers for filtered public water systems are not required to conduct source water monitoring under this section if the public water system will provide a total of at least 5.5-log of treatment for Cryptosporidium, equivalent to meeting the treatment requirements of Bin 4 in s. NR 810.35.

NR 809.331(4)(b)(b) Water supplier for unfiltered public water systems are not required to conduct source water monitoring under this section if the public water system will provide a total of at least 3-log Cryptosporidium inactivation, equivalent to meeting the treatment requirements for unfiltered public water systems with a mean Cryptosporidium concentration of greater than 0.01 oocysts/L in s. NR 810.36.

NR 809.331(4)(c)(c) If a water supplier chooses to provide the level of treatment in par. (a) or (b), as applicable, rather than start source water monitoring, the water supplier shall notify the department in writing no later than the date the public water system is otherwise required to submit a sampling schedule for monitoring under s. NR 809.332. Alternatively, a water supplier may choose to stop sampling at any point after the public water system has initiated monitoring if the water supplier notifies the department in writing that the public water system will provide this level of treatment. Water supplier shall install and operate technologies to provide this level of treatment by the applicable treatment compliance date in s. NR 810.37.

NR 809.331(5)(5) Plants operating only part of the year. Water suppliers for public water systems with surface water treatment plants that operate for only part of the year shall conduct source water monitoring in accordance with this section, but with the following modifications:

NR 809.331(5)(a)(a) Water supplier shall sample their source water only during the months that the plant operates unless the department specifies another monitoring period based on plant operating practices.

NR 809.331(5)(b)(b) Water supplier for public water systems with plants that operate less than six months per year and that monitor for Cryptosporidium shall collect at least six Cryptosporidium samples per year during each of two years of monitoring. Samples shall be evenly spaced throughout the period the plant operates.

NR 809.331(6)(a)(a) A water supplier for a public water system that begins using a new source of surface water or GWUDI after the public water system is required to begin monitoring under sub. (3) shall monitor the new source on a schedule the department approves. Source water monitoring shall meet the requirements of this section. The public water system shall also meet the bin classification and Cryptosporidium treatment requirements of ss. NR 810.34 and 810.35 or s. NR 810.36, as applicable, for the new source on a schedule the department approves.

NR 809.331(6)(b)(b) The requirements of this section apply to public water systems with surface water treatment plants that begin operation after the monitoring start date applicable to the public water system’s size under sub. (3).

NR 809.331(6)(c)(c) The water supplier shall begin a second round of source water monitoring no later than 6 years following initial bin classification under s. NR 810.34 or determination of the mean Cryptosporidium level under s. NR 810.36, as applicable.

NR 809.331(7)(7) Monitoring violation. Failure to collect any source water sample required under this section in accordance with the sampling schedule, sampling location, analytical method, approved laboratory, and reporting requirements of s. NR 809.332 to s. NR 809.336 is a monitoring violation.

NR 809.331(8)(8) Grandfathering monitoring data. The water supplier may use monitoring data collected prior to the applicable monitoring start date in sub. (3) to meet the initial source water monitoring requirements in sub. (1). This data, referred to as grandfathered data, may substitute for an equivalent number of months of data at the end of the monitoring period. All data submitted under this section shall meet the requirements in s. NR 809.334.

NR 809.331 HistoryHistory: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10; correction in (8) made under s. 13.92 (4) (b) 7., Stats., Register November 2010 No. 659.

NR 809.332(1)(1) Sampling schedules. Water suppliers for public water systems required to conduct source water monitoring under s. NR 809.331 shall submit a sampling schedule that specifies the calendar dates when the water supplier will collect each required sample.

NR 809.332(1)(a)(a) Water suppliers shall submit sampling schedules no later than 3 months prior to the applicable date listed in s. NR 809.331 (3), Table H, for each round of required monitoring.

NR 809.332(1)(b)(b) Water suppliers for public water systems serving at least 10,000 people shall submit their sampling schedule for the initial round of source water monitoring under s. NR 809.331 (1) to EPA. If a water supplier is unable to submit the sampling schedule electronically, the water supplier may use an alternative approach for submitting the sampling schedule subject to EPA approval.

NR 809.332(1)(c)(c) Water suppliers for public water systems serving fewer than 10,000 people shall submit their sampling schedules for the initial round of source water monitoring under s. NR 809.331 (1) to the EPA or the department.

NR 809.332(1)(d)(d) Water suppliers shall submit sampling schedules for the second round of source water monitoring under s. NR 809.331 (2) to the department.

NR 809.332(1)(e)(e) If EPA or the department does not respond to a water supplier regarding its sampling schedule, the water supplier shall sample at the reported schedule.