Section NR 809.313 - Coliform treatment technique triggers and assessment requirements for protection against potential fecal contamination(1) TREATMENT TECHNIQUE TRIGGERS. Water suppliers of public water systems shall conduct assessments in accordance with sub. (2) after public water systems exceed treatment technique triggers in par. (a) or (b). (a)Level 1 treatment technique triggers.1. For public water systems taking 40 or more samples per month, the public water system exceeds 5.0% total coliform-positive samples for the month.2. For public water systems taking fewer than 40 samples per month, the public water system has two or more total coliform-positive samples in the same month.3. The water supplier fails to take every required repeat sample after any single total coliform-positive sample.(b)Level 2 treatment technique triggers.1. An E. coli MCL violation, as specified in s. NR 809.30.2. A second Level 1 trigger as defined in par. (a) within a rolling 12-month period, unless the department has determined a likely reason that the samples that caused the first Level 1 treatment technique trigger were total coliform-positive and has established that the water supplier has corrected the problem. 3. For public water systems with approved annual monitoring, a Level 1 trigger in two consecutive years.(2) REQUIREMENTS FOR ASSESSMENTS.(a)General requirements.1. Water suppliers shall ensure that Level 1 and 2 assessments are conducted in order to identify the possible presence of sanitary defects, and defects in distribution system coliform monitoring practices. Level 2 assessments shall be conducted by parties approved by the department.2. When conducting assessments, water suppliers shall ensure that the assessor evaluates minimum elements that include review and identification of inadequacies in sample sites; sampling protocol; sample processing; atypical events that could affect distributed water quality or indicate that distributed water quality was impaired; changes in distribution system maintenance and operation that could affect distributed water quality, including water storage; source and treatment considerations that bear on distributed water quality, where appropriate, as for example, small ground water systems; and existing water quality monitoring data. The water supplier shall conduct the assessment consistent with any department directives that tailor specific assessment elements with respect to the size and type of the public water system and the size, type, and characteristics of the distribution system.(b)Level 1 assessments. A water supplier shall conduct a Level 1 assessment consistent with department requirements if the public water system exceeds one of the treatment technique triggers in sub. (1) (a). The department may conduct a Level 2 assessment in response to a Level 1 treatment technique trigger at a non-community water system, which may include the collection of a large-volume sample. 1. The water supplier shall complete a Level 1 assessment as soon as practical after any trigger in sub. (1) (a). In the completed assessment form, the water supplier shall describe sanitary defects detected, corrective actions completed, and a proposed timetable for any corrective actions not already completed. The assessment form may also note that no sanitary defects were identified. The water supplier shall submit the completed Level 1 assessment form to the department within 30 days after the water supplier learns that the public water system has exceeded a trigger. 2. If the department reviews the completed Level 1 assessment and determines that the assessment is not sufficient, including any proposed timetable for any corrective actions not already completed, the department shall consult with the water supplier. If the department requires revisions after consultation, the water supplier shall submit a revised assessment form to the department on an agreed-upon schedule not to exceed 30 days from the date of the consultation.3. Upon completion and submission of the assessment form by the water supplier, the department shall determine if the water supplier has identified a likely cause for the Level 1 trigger and, if so, establish that the water supplier has corrected the problem, or has included a schedule acceptable to the department for correcting the problem.(c)Level 2 assessments. A water supplier shall ensure that a Level 2 assessment consistent with department requirements is conducted if the public water system exceeds one of the treatment technique triggers in sub. (1) (b). The water supplier shall comply with any expedited actions or additional actions required by the department in the case of an E. coli MCL violation. 1. The water supplier shall ensure that a Level 2 assessment is completed by the department or by a party approved by the department as soon as practical after any trigger in sub. (1) (b). The water supplier shall submit a completed Level 2 assessment form to the department within 30 days after the water supplier learns that it has exceeded a trigger. The assessment form shall describe sanitary defects detected, corrective actions completed, and a proposed timetable for any corrective actions not already completed. The assessment form may also note that no sanitary defects were identified. 2. The water supplier may conduct Level 2 assessments if the water supplier has staff or management with the certification or qualifications specified by the department unless otherwise directed by the department.3. If the department reviews the completed Level 2 assessment and determines that the assessment is not sufficient, including any proposed timetable for any corrective actions not already completed, the department shall consult with the water supplier. If the department requires revisions after consultation, the water supplier shall submit a revised assessment form to the department on an agreed-upon schedule not to exceed 30 days.4. Upon completion and submission of the assessment form by the water supplier, the department shall determine if the water supplier has identified a likely cause for the Level 2 trigger and determine whether the water supplier has corrected the problem, or has included a schedule acceptable to the department for correcting the problem.(3) CORRECTIVE ACTION. Water suppliers shall correct sanitary defects found through Level 1 or Level 2 assessments conducted under sub. (2). For corrections not completed by the time of submission of the assessment form, the water supplier shall complete the corrective action in compliance with a timetable approved by the department in consultation with the water supplier. The water supplier shall notify the department when each scheduled corrective action is completed.(4) CONSULTATION. At any time during the assessment or corrective action phase, the water supplier or the department may request a consultation with the other party to determine the appropriate actions to be taken. The water supplier may consult with the department on all relevant information that may affect the ability to comply with a requirement of this subsection, including the method of accomplishment, an appropriate timeframe, and other relevant information.Wis. Admin. Code Department of Natural Resources NR 809.313
Adopted by, CR 15-049: cr. Register March 2016 No. 723, eff. 4-1-16; correction in (1) (intro.) made under s. 35.17, Stats., Register March 2016 No. 723, eff.4/1/2016Amended by, correction in (1) (b) 2. made under s. 13.92 (4) (b) 7, Stats, Register July 2022 No. 799, eff. 8/1/2022.