NR 809.31(2m)(a)4.4. The public water system has two coliform monitoring violations in a rolling 12-month period, or is a non-community public water system and has one coliform monitoring violation and one Level 1 assessment under the provisions of s. NR 809.313 in a rolling 12-month period for a public water system on quarterly monitoring.

NR 809.31(2m)(a)5.5. The public water system has one coliform monitoring violation for a public water system on annual monitoring. For transient non-community public water systems, the department may elect to not count monitoring violations under sub. (9) if the missed sample is collected no later than the end of the monitoring period following the monitoring period in which the sample was missed. The water supplier shall collect the make-up sample in a different week than the routine sample for that monitoring period and shall collect the sample as soon as possible during the monitoring period, except that this is not allowed under par. (c). This authority does not affect the provisions of sub. (9) and s. NR 809.312 (2).

NR 809.31(2m)(b)(b) Requirements for public water systems on increased monitoring to return to quarterly monitoring. The department may reduce the monitoring frequency for a public water system on monthly monitoring triggered under par. (a) to quarterly monitoring if the public water system meets the criteria in subds. 1. and 2.

NR 809.31(2m)(b)1.1. Within the last 12 months, the public water system shall have a completed sanitary survey or a site visit by the department or a voluntary Level 2 assessment by a party approved by the department, be free of sanitary defects, and have a protected water source.

NR 809.31(2m)(b)2.2. The public water system shall have a clean compliance history for a minimum of 12 months. For transient non-community public water systems, the department may elect to not count monitoring violations, as allowed under sub. (9), if the missed sample is collected no later than the end of the monitoring period following the monitoring period in which the sample was missed. The water supplier shall collect the make-up sample in a different week than the routine sample for that monitoring period and should collect the sample as soon as possible during the monitoring period, except that this is not allowed under par. (c). This authority does not affect the provisions of sub. (9) and s. NR 809.312 (2).

NR 809.31(2m)(c)(c) Requirements for systems on increased monitoring to qualify for annual monitoring. The department may reduce the monitoring frequency for a transient non-community public water system on increased monitoring under par. (a) if the transient non-community public water system meets the criteria in par. (d) and the criteria in subds. 1. and 2.

NR 809.31(2m)(c)1.1. The department shall conduct an annual site visit and the water supplier shall correct all identified sanitary defects. The water supplier may substitute a voluntary Level 2 assessment conducted by a party approved by the department in place of the department’s annual site visit in any given year.

NR 809.31(2m)(c)2.2. The water supplier shall have in place or adopt one or more additional enhancements to the water system barriers to contamination in subds. 2. a. to 2. e.

NR 809.31(2m)(d)(d) Allowance for transient non-community water systems to monitor annually. The department may allow water suppliers at transient non-community water systems to monitor annually for total coliform and E. coli following conditions that would require increased monitoring under par. (a), provided the water supplier meets the requirements of subd. 1. or 2.

NR 809.31(2m)(d)1.1. For water systems that began operation and conducted coliform monitoring prior to April 1, 2016, the water supplier shall have done all of the following:

NR 809.31(2m)(d)1.d.d. Received a level 2 assessment within 30 days of any level 1 assessment trigger identified after April 1, 2016, and corrected all sanitary defects or is following a department agreed upon schedule for correcting all sanitary defects.

NR 809.31(2m)(d)2.2. For public water systems that began operation or began coliform monitoring on or after April 1, 2016, the water supplier shall meet all of the requirements of subd. 1 and shall have completed at least one year of coliform monitoring at a frequency of no less than quarterly.

NR 809.31(2m)(e)(e) Allowance for non-transient non-community water systems to monitor quarterly. The department may allow a water supplier of a non-transient non-community water system to monitor quarterly for total coliform and E. coli following conditions that would require increased monitoring under par. (a), provided the water supplier meets the same requirements specified for transient non-community water systems in par. (d) 1. a. to f.

NR 809.31(3)(b)1.1. A certified laboratory establishes that improper sample analysis caused the total coliform-positive result.

NR 809.31(3)(b)2.2. The department, on the basis of the results of repeat samples collected as required by sub. (2) (a) to (e), determines that the total coliform-positive sample resulted from a domestic or other non-distribution system plumbing problem. A sample may not be invalidated by the department on the basis of repeat sample results alone, unless all repeat samples collected at the same tap as the original total coliform-positive sample are also total coliform-positive, and all repeat samples collected at a location other than the original tap are total coliform-negative. The department will not invalidate a total coliform-positive sample on the basis of repeat samples if all the repeat samples are total coliform-negative, or if the public water system has only one service connection.

NR 809.31(3)(b)3.3. The department has substantial grounds to believe that a total coliform-positive result is due to a circumstance or condition which does not reflect water quality in the distribution system. In this case, the water supplier shall still collect all repeat samples required, and shall use them to determine whether a coliform treatment technique trigger in s. NR 809.313 has been exceeded. To invalidate a total coliform-positive sample under this paragraph, the decision with the rationale for the decision shall be documented in writing, approved by a qualified department official and available to the public for inspection. The document shall state the specific cause of the total coliform-positive sample, and what action the water supplier has taken or will take, to correct this problem. The department may not invalidate a total coliform-positive sample solely on the grounds that all repeat samples are total coliform-negative.