Chapter NR 809

NR 809.325(2) (2) Triggered source water monitoring.

NR 809.325(2)(a) (a) Water suppliers for groundwater systems shall conduct triggered source water monitoring if all of the following conditions exist:

NR 809.325(2)(a)1. 1. The public water system does not provide at least 4-log treatment of viruses before or at the first customer for each groundwater source.

NR 809.325(2)(a)2. 2. The public water system is notified that a sample collected under s. NR 809.31 (1) is total coliform-positive and the sample is not invalidated under s. NR 809.31 (3).

NR 809.325(2)(b) (b) The following sampling requirements apply:

NR 809.325(2)(b)1. 1. No later than 24 hours after notification of a total coliform-positive distribution system sample, a water supplier for a groundwater system shall collect at least one groundwater source sample, for each total coliform-positive sample, from each groundwater source in use at the time the total coliform-positive sample was collected, except as provided in par. (c).

NR 809.325(2)(b)2. 2. The department may extend the 24-hour time limit on a case-by-case basis if the water supplier cannot collect the groundwater source water sample within the 24-hour time limit due to circumstances beyond the water supplier’s control. In the case of an extension, the department shall specify, in writing, how much time the water supplier has to collect the sample.

NR 809.325(2)(b)3. 3. If approved by the department, water suppliers for groundwater systems with more than one groundwater source may meet the requirements of this paragraph by sampling a representative groundwater source or sources if they have an approved triggered source water monitoring plan.

NR 809.325(2)(c) (c) A triggered source water monitoring plan shall evaluate each sample site in the sample siting plan for the public water system under s. NR 809.31 (1) (a) and identify the sources that are representative of each monitoring site. If directed by the department, a water supplier for a public water system shall submit for department approval a triggered source water monitoring plan that identifies one or more groundwater sources that are representative of each monitoring site in the sample siting plan for the public water system and that the water supplier intends to use for representative sampling under par. (b).

NR 809.325(2)(d) (d) A water supplier for a groundwater system serving 1,000 people or fewer may use a repeat sample collected from a groundwater source to meet both the requirements of s. NR 809.31 (2) and to satisfy the monitoring requirements of par. (b) for that groundwater source. If the repeat samples collected from the groundwater source are E. coli positive, the water supplier shall comply with the requirements of par. (e) unless the department requires immediate corrective action under s. NR 809.327 (2) (b).

NR 809.325(2)(e) (e) If the department does not require corrective action under s. NR 809.327 (2) (b) for an E. coli-positive source water sample collected under par. (b), the water supplier shall collect five additional source water samples from the same source no later than 24 hours after being notified of the E. coli positive sample. If any of the 5 samples collected under this paragraph is E. coli-positive, the water supplier shall conduct a corrective action as outlined in s. NR 809.327 (2).

NR 809.325(3) (3) Consecutive and wholesale systems.

NR 809.325(3)(a) (a) In addition to the other requirements of this section, a water supplier for a consecutive groundwater system that has a total coliform-positive sample collected under s. NR 809.31 (1) shall notify any wholesale system from which it receives water no later than 24 hours after being notified of the total coliform-positive sample.

NR 809.325(3)(b) (b) A water supplier for a wholesale groundwater system that receives notice from a water supplier for a consecutive system served by the wholesale system that a sample collected under s. NR 809.31 (1) was total coliform-positive shall, no later than 24 hours after being notified, collect samples from its groundwater sources under sub. (2) and analyze them for E. coli under s. NR 809.323 (1) (b) Table G. The department may extend the 24-hour time limit on a case-by-case basis if the public water system cannot collect the groundwater source water sample within the 24-hour time limit due to circumstances beyond the water supplier’s control. In the case of an extension, the department shall specify, in writing, how much time the water supplier has to collect the sample.

NR 809.325(3)(c) (c) If the sample collected under par. (b) is E. coli-positive, the water supplier for the wholesale groundwater system shall notify all water suppliers for the consecutive systems served by that groundwater source no later than 24 hours after being notified of the groundwater source sample monitoring result and shall meet the requirements of sub. (2) (e) unless the department requires immediate corrective action under s. NR 809.327 (2) (b).

NR 809.325(4) (4) Exception to the triggered source water monitoring requirements. A water supplier for a groundwater system is not required to comply with the triggered source water monitoring requirements of sub. (2) if the department determines, and documents in writing, that the total coliform-positive sample collected under s. NR 809.31 (1) was caused by a distribution system deficiency.

NR 809.325(5) (5) Failure to meet monitoring requirements. If a water supplier fails to meet any of the monitoring requirements of subs. (1) to (3), the public water system is in violation and is required to complete public notification requirements under s. NR 809.953.

NR 809.325(6) (6) Public notification. A water supplier for a groundwater system with a groundwater source sample collected under subs. (2) or (3) that is fecal indicator-positive and that is not invalidated under s. NR 809.323, including consecutive systems served by the groundwater source, shall conduct public notification under s. NR 809.951 (1) (b) 9.

NR 809.325 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10; correction in (5) made under s. 13.92 (4) (b) 7., Stats., Register November 2010 No. 659; CR 15-049: am. (1) (b), (2) (b) 1., (d), (e), (3) (b), (c), renum. (4) (a) to (4) and am. Register March 2016 No. 723, eff. 4-1-16; correction in (3) (a), (b) made under s. 13.92 (4) (b) 7., Stats., Register July 2022 No. 799.

NR 809.327 NR 809.327 Compliance requirements for groundwater source microbiological monitoring.

NR 809.327(1) (1) Compliance requirements. Treatment technique submittal requirements for water suppliers for public water systems with significant deficiencies or confirmed source water fecal contamination are as follows:

NR 809.327(1)(a) (a) No later than 30 days after receiving written notice from the department of significant deficiencies, or notified by a laboratory of source water fecal contamination, water suppliers for groundwater systems shall consult with the department regarding appropriate corrective action, unless the department directs the water supplier to implement a specific corrective action.

NR 809.327(1)(b) (b) If the department specifies interim measures for protection of the public health, pending department approval of the corrective action plan and schedule or pending completion of the corrective action plan, the water supplier shall comply with these interim measures in addition to the other requirements of this section.

NR 809.327(1)(c) (c) No later than 120 days after receiving written notification from the department of a significant deficiency, or notified by a laboratory of confirmed source water fecal contamination, the water supplier for a groundwater system shall have one of the following:

NR 809.327(1)(c)1. 1. A completed corrective action in accordance with the applicable department plan review processes contained in ch. NR 811 for community systems or ch. NR 812 for noncommunity systems.

NR 809.327(1)(c)2. 2. A written and approved department corrective action plan and schedule.

NR 809.327(2) (2) Corrective action alternatives. A water supplier for a groundwater systems receiving written notice from the department of significant deficiencies under s. NR 809.35 or confirmed source water fecal contamination under s. NR 809.325 shall implement one or more of the following corrective action alternatives:

NR 809.327(2)(a) (a) Correct all significant deficiencies.

NR 809.327(2)(b) (b) Provide an alternate source of water.

NR 809.327(2)(c) (c) Eliminate the source of contamination.

NR 809.327(2)(d) (d) Provide treatment that reliably achieves at least 4-log treatment of viruses before or at the first customer for the groundwater source.

NR 809.327(3) (3) Notification and submittal requirements for systems providing 4 log treatment of viruses.

NR 809.327(3)(a) (a) A public water system that has an existing or new groundwater source and serves customers on or after November 30, 2009 and provides department-approved treatment that achieves 4 log inactivation or removal of viruses before the first customer, is not required to meet the triggered source water monitoring requirements of s. NR 809.325 (2) if all of the following conditions are met:

NR 809.327(3)(a)1. 1. The water supplier notifies the department in writing that the public water system provides at least 4-log treatment of viruses.

NR 809.327(3)(a)2. 2. The notification from the water supplier to the department shall include a submittal for review that includes the engineering and operational information that the department will need to evaluate the adequacy of the treatment.

NR 809.327(3)(a)3. 3. The water supplier provides any other information that the department requests to aid in its evaluation of the sufficiency of the public water system’s treatment process for viruses.

NR 809.327(3)(b) (b) A water supplier for a public water system that provides at least 4-log treatment of viruses before or at the first customer and places a new groundwater source into service after November 30, 2009, is not required to meet the triggered source water monitoring requirements of s. NR 809.325 if the water supplier complies with all of the following requirements:

NR 809.327(3)(b)1. 1. The water supplier notifies the department in writing that it provides at least 4-log treatment of viruses before or at the first customer for the groundwater source.

NR 809.327(3)(b)2. 2. The notification the water supplier provides to the department shall include an engineering, operational, or other information that the department requests to evaluate the submission.

NR 809.327(3)(b)3. 3. The water supplier conducts compliance monitoring as required under sub. (4) within 30 days of placing the source in service.

NR 809.327(3)(c) (c) If a water supplier for a public water system subsequently discontinues 4-log treatment of viruses before or at the first customer for a groundwater source, the water supplier shall conduct triggered source water monitoring in accordance with the requirements of s. NR 809.325 (2).

NR 809.327(4) (4) Treatment compliance monitoring. A groundwater system that provides 4 log treatment of viruses shall monitor the effectiveness and reliability of treatment for that groundwater source before or at the first customer as follows:

NR 809.327(4)(a) (a) Chemical disinfection.

NR 809.327(4)(a)1. 1. All water suppliers for community water systems shall continuously monitor the residual disinfectant concentration using analytical methods and requirements specified in s. NR 809.563 at a location approved by the department and shall record the lowest residual disinfectant concentration each day that water from the groundwater source is served to the public, unless the department allows less frequent monitoring as outlined in subd. 2.

NR 809.327(4)(a)1.a. a. The groundwater system shall maintain the department determined residual disinfectant concentration every day the public water system serves water from the groundwater source to the public.

NR 809.327(4)(a)1.b. b. If there is a failure in the continuous monitoring equipment, the water supplier shall conduct grab sampling every four hours until the continuous monitoring equipment is returned to service.

NR 809.327(4)(a)1.c. c. The water supplier for the public water system shall resume continuous residual disinfectant monitoring, as soon as possible, but no later than 14 days after the failure.

NR 809.327(4)(a)2. 2. The water supplier for a community water systems serving 3,300 or fewer people shall be allowed to monitor the residual disinfectant concentration less than continuously, if the water supplier receives approval under s. NR 811.48 (3) (b) to monitor less than continuously. The monitoring shall be done using analytical methods and requirements specified in s. NR 809.563 at a location approved by the department and the residual disinfection concentration shall be recorded from that water every day the groundwater source is served to the public.

NR 809.327(4)(a)2.a. a. The groundwater system shall maintain the department determined residual disinfectant concentration every day the groundwater system serves water from the groundwater source to the public. The water supplier for a groundwater system shall take a daily grab sample during the hour of peak flow or at another time specified by the department.

NR 809.327(4)(a)2.b. b. If any daily grab sample measurement falls below the department determined residual disinfectant concentration, the water supplier shall take follow-up samples at the frequency determined by the department under s. NR 811.48 (3) (b) but no less than four hours until the residual disinfectant concentration is restored to the department determined level.

NR 809.327(4)(a)3. 3. Water suppliers for non-community systems serving 3,300 or fewer people, unless otherwise required by the department under s. NR 812.37, shall monitor the residual disinfectant concentration using analytical methods and requirements specified in s. NR 809.563 at a location approved by the department and record the residual disinfection concentration once each day that water from the groundwater source is served to the public.

NR 809.327(4)(a)3.a. a. The water supplier for a groundwater system shall maintain the department determined residual disinfectant concentration every day the groundwater system serves water from the groundwater source to the public. The water supplier for a groundwater system shall take a daily grab sample during the hour of peak flow or at another time specified by the department.

NR 809.327(4)(a)3.b. b. If any daily grab sample measurement falls below the department determined residual disinfectant concentration, the water supplier shall take follow-up samples every four hours until the residual disinfectant concentration is restored to the department determined level.

NR 809.327(4)(a)3.c. c. Alternatively, water suppliers for non-community groundwater systems that serve 3,300 or fewer people may monitor continuously in order to meet the requirements of subd. 1.

NR 809.327(4)(b) (b) Membrane filtration. A water supplier for a groundwater system that uses membrane filtration to meet the requirements of sub. (2) shall monitor the membrane filtration process in accordance with all department specified monitoring requirements and shall operate the membrane filtration in accordance with all department specified compliance requirements. To be in compliance with the requirement to achieve at least 4-log treatment of viruses when a public water system uses membrane filtration exclusively, the public water system shall meet all of the following:

NR 809.327(4)(b)1. 1. The membrane shall have an absolute molecular weight cut-off (MWCO), or an alternate parameter that describes the exclusion characteristics of the membrane, that can reliably achieve at least 4-log removal of viruses.

NR 809.327(4)(b)2. 2. The membrane process shall be operated in accordance with department-specified compliance requirements.

NR 809.327(4)(b)3. 3. The integrity of the membrane is intact.

NR 809.327(4)(b)4. 4. The public water system shall be provided with at least 2 log of additional treatment of viruses using a chemical disinfectant.

NR 809.327(4)(c) (c) Alternative treatment. A water supplier for a groundwater system that uses a department-approved alternative treatment to meet the requirements of sub. (2) (d) for providing at least 4-log treatment of viruses before or at the first customer shall do all of the following:

NR 809.327(4)(c)1. 1. Monitor the alternative treatment in accordance with all department specified monitoring requirements.

NR 809.327(4)(c)2. 2. Operate the alternative treatment in accordance with all compliance requirements that the department determines to be necessary to achieve at least 4-log treatment of viruses.

NR 809.327(5) (5) Discontinuing treatment. A water supplier for a groundwater system may discontinue 4-log treatment of viruses before or at the first customer for a groundwater source if the department determines and documents in writing that 4-log treatment of viruses is no longer necessary for that water source. A public water system where 4-log treatment of viruses is discontinued is subject to the source water monitoring requirements of s. NR 809.325.

NR 809.327(6) (6) Failure to meet monitoring requirements. If a water supplier fails to meet any of the monitoring requirements of sub. (4), the public water system is in violation and the water supplier shall complete public notification requirements under s. NR 809.953.

NR 809.327 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10; correction in (4) (a) 2. b. made under s. 13.92 (4) (b) 7., Stats., Register November 2010 No. 659; CR 15-049: am. (1) (a), (c) (intro.), (3) (a) 2., (4) (a) 3., (6) Register March 2016 No. 723, eff. 4-1-16.

NR 809.328 NR 809.328 Treatment technique compliance for groundwater source microbiological contaminants.

NR 809.328(1) (1) Treatment technique violations for groundwater systems.

NR 809.328(1)(a) (a) A groundwater system with a significant deficiency is in violation of the treatment technique requirement if, within 120 days of the water supplier receiving written notice from the department of the significant deficiency or earlier if directed by the department, subd. 1. or 2. are not met.

NR 809.328(1)(a)1. 1. The water supplier has not completed a corrective action in accordance with any applicable department plan approval processes under chs. NR 811 and 812, including any department specified interim actions.

NR 809.328(1)(a)2. 2. The public water system is not in compliance with a department-approved corrective action plan and schedule.

NR 809.328(1)(b) (b) Unless the department invalidates an E. coli-positive groundwater source sample collected under s. NR 809.325, a public water system is in violation of the treatment technique requirement under s. NR 809.327 if within 120 days or earlier if directed by the department, the conditions of subd. 1. or 2 are not met.

NR 809.328(1)(b)1. 1. The water supplier does not complete corrective action in accordance with any applicable department plan review processes under chs. NR 811 and 812, including department specified interim measures.

NR 809.328(1)(b)2. 2. The public water system is not in compliance with a department-approved corrective action plan and schedule.

NR 809.328(1)(c) (c) A water supplier for a groundwater system subject to the requirements of s. NR 809.327 (4) that fails to maintain at least 4-log treatment of viruses before or at the first customer for a groundwater source is in violation of the treatment technique requirement if the failure is not corrected within 4 hours of determining the public water system is not maintaining at least 4-log treatment of viruses before or at the first customer.

NR 809.328(2) (2) public notification for treatment technique violations. Water suppliers for groundwater systems shall give public notification under s. NR 809.952 for the treatment technique violations specified under this section.

NR 809.328 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10; CR 15-049: am. (1) (b) (intro.) Register March 2016 No. 723, eff. 4-1-16.

NR 809.329 NR 809.329 Reporting and recordkeeping requirements for groundwater systems.

NR 809.329(1) (1) Reporting. In addition to the requirements of ss. NR 809.31 and 809.80, a water supplier for a groundwater system regulated under s. NR 809.32 shall provide the following information to the department:

NR 809.329(1)(a) (a) A water supplier for a groundwater system conducting compliance monitoring under s. NR 809.327 (3) shall notify the department any time the public water system fails to meet any department-specified requirements including, but not limited to, minimum residual disinfectant concentration, membrane operating criteria or membrane integrity, and alternative treatment operating criteria, if the operation is not restored in accordance with the criteria or requirements within four hours. The water supplier shall notify the department as soon as possible, but in no case later than the end of the next business day after the failure.

NR 809.329(1)(b) (b) After completing any corrective action under s. NR 809.327 (2), a water supplier shall notify the department within 30 days of completion of the corrective action.

NR 809.329(2) (2) Recordkeeping. In addition to the requirements of s. NR 809.80, a water supplier for a public water system regulated under s. NR 809.32 shall maintain the following information in its records:

NR 809.329(2)(a) (a) Documentation of corrective actions. Documentation shall be kept for a period of not less than ten years.

NR 809.329(2)(b) (b) Documentation of notice to the public as required under s. NR 809.80. Documentation shall be kept for a period of not less than three years.

NR 809.329(2)(c) (c) Records of decisions under s. NR 809.325 (4) and records of invalidation of an E. coli-positive groundwater source sample under s. NR 809.323 (2). Documentation shall be kept for a period of not less than five years.

NR 809.329(2)(d) (d) For consecutive systems, documentation of notification to its wholesale systems of total-coliform positive samples that are not invalidated under s. NR 809.31 (3). Documentation shall be kept for a period of not less than five years.

NR 809.329(2)(e) (e) For public water systems, including wholesale systems, which are required to perform compliance monitoring under s. NR 809.327 (4) all of the following apply:

NR 809.329(2)(e)1. 1. Records of the department specified minimum disinfectant residual. Documentation shall be kept for a period of not less than ten years.

NR 809.329(2)(e)2. 2. Records of the lowest daily residual disinfectant concentration and records of the date and duration of any failure to maintain the department prescribed minimum residual disinfectant concentration for a period of more than four hours. Documentation shall be kept for a period of not less than five years.

NR 809.329(2)(e)3. 3. Records of department-specified compliance requirements for membrane filtration and of parameters specified by the department for department-approved alternative treatment and records of the date and duration of any failure to meet the membrane operating, membrane integrity, or alternative treatment operating requirements for more than 4 hours. Documentation shall be kept for a period of not less than five years.