NR 809.60(7)(a)
(a) Water suppliers for public water systems required to be monitored quarterly shall calculate LRAAs for TTHM and HAA5 to determine that each monitoring location LRAA does not exceed the MCL.
NR 809.60(7)(a)1.
1. If four consecutive quarters of monitoring are not completed, compliance with the MCL shall be based on the average of the available data from the most recent four quarters.
NR 809.60(7)(a)2.
2. If more than one sample per quarter is collected at a monitoring location, all samples taken in the quarter at that location shall be averaged to determine a quarterly average to be used in the LRAA calculation.
NR 809.60(7)(b)
(b) Water suppliers for public water systems required to be monitored yearly or less frequently shall establish compliance for TTHM and HAA5 by using each sample collected to determine if it is less than the MCL.
NR 809.60(7)(b)2.
2. If no sample exceeds the MCL, the sample result for each monitoring location is considered the LRAA for that monitoring location.
NR 809.60(7)(c)
(c) A public water system is in violation of the monitoring requirements for each quarter that a LRAA is calculated using a quarter in which the water supplier failed to monitor.
NR 809.60 History
History: CR 09-073: cr.
Register November 2010 No. 659, eff. 12-1-10;
CR 15-049: am. (3) Table X, (4) (b)
Register March 2016 No. 723, eff. 4-1-16.
NR 809.61
NR 809.61 Routine monitoring for Stage 2 DBP. NR 809.61(1)(a)(a) A water supplier that submitted an IDSE report to EPA under Subpart U of
40 CFR part 141 shall begin monitoring at the locations and months recommended in the IDSE report submitted to EPA under Subpart U of
40 CFR part 141.605 following the schedule in s.
NR 809.60 (3), unless the department requires other locations or additional locations after its review.
NR 809.61(1)(b)
(b) A water supplier that submitted a 40/30 certification from EPA under Subpart U of
40 CFR part 141.603 or the department under s.
NR 809.974 or for a public water system that qualified for a very small system waiver from EPA under Subpart U of
40 CFR 141.604 or the department under s.
NR 809.975 or for a public water system that is a nontransient noncommunity water system serving <10,000, shall monitor at the location or locations and dates identified in the public water system's monitoring plan in s.
NR 809.565 (6), updated as required by s.
NR 809.62.
NR 809.61 Note
Note: Sections NR 809.974 and 809.975 were repealed by
CR 15-049. Corrections will be made in future rulemaking.
NR 809.61(1)(d)
(d) All public water systems shall be monitored during the month of highest DBP concentrations.
NR 809.61(1)(e)
(e) Water suppliers for public water systems on quarterly monitoring shall take dual sample sets every 90 days at each monitoring location, except for water supplier for surface water systems or groundwater under the direct influence of surface water systems serving 500–3,300. Water suppliers for groundwater systems serving 500–9,999 on annual monitoring shall take dual sample sets at each monitoring location. All other public water systems on annual monitoring and surface water systems or groundwater under the direct influence of surface water systems serving 500–3,300 shall take individual TTHM and HAA5 samples, instead of a dual sample set, at the locations with the highest TTHM and HAA5 concentrations, respectively. For public water systems serving fewer than 500 people, only one location with a dual sample set per monitoring period is required if the highest TTHM and HAA5 concentrations occur at the same location and month.
NR 809.61(1)(f)
(f) Water suppliers for undisinfected systems that begin using a disinfectant other than UV light after the dates for complying with the Initial Distribution System Evaluation requirements shall consult with the department to identify compliance monitoring locations for s.
NR 809.60 and develop a monitoring plan under s.
NR 809.62 that includes those monitoring locations.
NR 809.61(2)(b)
(b) The analysis under par.
(a) shall be conducted by laboratories that are certified by EPA or the department under ch.
NR 149.
NR 809.61 History
History: CR 09-073: cr.
Register November 2010 No. 659, eff. 12-1-10;
CR 15-049: am. (1) (a), (c) Table Y, (2) (a)
Register March 2016 No. 723, eff. 4-1-16.
NR 809.62
NR 809.62 Monitoring plan for Stage 2 DBP. NR 809.62(1)(1)
General monitoring plan requirements. Monitoring plans shall be developed, implemented and kept up to date by water suppliers for all public water systems that are required to be monitored for TTHMs and HAA5s and shall be kept on file for department and public review.
NR 809.62(1)(a)
(a) Monitoring plans under this section shall be completed no later than the date the public water system is required to begin initial compliance monitoring under s.
NR 809.60 (3).
NR 809.62(1)(b)
(b) The monitoring plan shall contain the all of the following elements:
NR 809.62(1)(b)4.
4. Monitoring plans for any other public water systems in a combined distribution system.
NR 809.62(1)(c)
(c) If a public water system was not required to submit an IDSE report to the EPA under Subpart U of
40 CFR 141.601 or
141.602 and does not have sufficient monitoring locations to identify the required number of locations indicated in Subpart U of
40 CFR 141.605(b) or under s.
NR 809.61; the water supplier shall do all of the following:
NR 809.62(1)(c)1.
1. Identify additional locations by alternating selection of locations representing high TTHM levels and high HAA5 levels until the required number of compliance monitoring locations have been identified.
NR 809.62(1)(c)2.
2. Provide the rationale for identifying the locations as having high levels of TTHM or HAA5. Water suppliers should compare the number of monitoring locations required under s.
NR 809.565 with the number of monitoring locations under s.
NR 809.61 Table Y. If the public water system was required to have more monitoring locations under s.
NR 809.565 than under s.
NR 809.62 compliance monitoring, the water supplier shall identify which locations will be used by alternating selection of locations representing high TTHM levels and high HAA5 levels until the required number of compliance monitoring locations under s.
NR 809.61 Table Y have been identified.
NR 809.62(2)
(2) Submittal of monitoring plans. If a public water system serves > 3,300 people, the water supplier shall submit a copy of a monitoring plan to the department prior to the date the water supplier for the public water system is required to conduct initial monitoring under s.
NR 809.60 (3), unless the IDSE report submitted under Subpart U of
40 CFR part 141 of the Federal Regulation contains all the information required by this subsection.
NR 809.62(3)
(3) Revising monitoring plans. Water suppliers shall revise monitoring plans to reflect changes in treatment, distribution system operations and layout including new service areas, or other factors that may affect TTHM or HAA5 formation, or as approved by the department.
NR 809.62(3)(a)
(a) The department shall be consulted regarding the need for changes and the appropriateness of changes to a monitoring plan.
NR 809.62(3)(b)
(b) If monitoring locations are changed, existing compliance monitoring locations with the lowest LRAA shall be replaced with new locations that are expected have the highest TTHM or HAA5 levels in the distribution system.
NR 809.62(3)(c)
(c) The department may also require other modifications in the public water systems monitoring plan.
NR 809.62(3)(d)
(d) If the public water system serves > 3,300 people, the water supplier shall submit a copy of the modified monitoring plan to the department prior to the date the public water system is required to comply with the revised monitoring plan.
NR 809.62 History
History: CR 09-073: cr.
Register November 2010 No. 659, eff. 12-1-10; correction to numbering of (3) (a) to (d) made under s.
13.92 (4) (b) 1., Stats.,
Register November 2010 No. 659;
CR 15-049: am. (1) (a), (c) (intro.), 2., (2)
Register March 2016 No. 723, eff. 4-1-16; correction in (1) (c) made under s.
13.92 (4) (b) 7., Stats.,
Register December 2018 No. 756.
NR 809.63
NR 809.63 Requirements for reduced and increased monitoring for Stage 2 DBP. NR 809.63(1)(1)
Reduced monitoring. The department may reduce the monitoring frequency when the LRAA is less than or equal to 0.040 mg/L for TTHM and less than or equal to 0.030 mg/L for HAA5 at all compliance monitoring locations. Systems may only use data collected in compliance with s.
NR 809.565 and under this section to qualify for reduced monitoring. In addition, the source water annual average TOC level, before any treatment, must be
≤4.0 mg/L at each treatment plant treating surface water or GWUDI, based on monitoring conducted under s.
NR 809.565 (2) (c) 2m. The reduced sampling frequency and number of sample sites are given in Table Z:
-
See PDF for table 
NR 809.63(1)(a)
(a) Water suppliers for public water systems on quarterly monitoring shall take dual sample sets every 90 days.
NR 809.63(1)(b)
(b) Public water systems on annual monitoring and surface water or GWUDI systems serving 500 to 3,300 people may use a single site if the highest TTHM and HAA5 concentrations occur at the same time and place. Any such public water system may be required to take individual TTHM and HAA5 samples, instead of a dual sample set, at sites identified as the highest TTHM and HAA5 sites, respectively. If separate sites for individual TTHM and HAA5 samples are used, then the TTHM sample shall be collected during the quarter with highest historical TTHM levels and the HAA5 sample shall be collected during the quarter with the highest historical HAA5 level.
NR 809.63(1)(c)
(c) Only data collected under the provisions of s.
NR 809.565 and under this section may be used to qualify for reduced monitoring.
NR 809.63(1)(d)
(d) To remain on reduced monitoring, a public water system shall meet the following conditions:
NR 809.63(1)(d)1.
1. Public water systems on a quarterly reduced monitoring schedule may remain on that reduced schedule as long as the TTHM LRAA
<0.040 mg/L and the HAA5 LRAA
<0.030 mg/L at each monitoring location.
NR 809.63(1)(d)2.
2. Public water systems on an annual or less frequent reduced monitoring schedule may remain on that reduced schedule as long as each TTHM sample
<0.060 mg/L and each HAA5 sample
<0.045 mg/L.
NR 809.63(1)(d)3.
3. In addition to subds.
1. and
2., for a surface water or GWUDI system, the source water annual average TOC level, before any treatment, shall be
<4.0 mg/L, based on monitoring conducted under s.
NR 809.565 (2) (c) 2m. NR 809.63(1)(e)
(e) If the LRAA based on quarterly monitoring at any monitoring location exceeds either 0.040 mg/L for TTHM or 0.030 mg/L for HAA5 or if the annual (or less frequent) sample at any location exceeds either 0.060 mg/L for TTHM or 0.045 mg/L for HAA5, or if the source water annual average TOC level, before any treatment, is >4.0 mg/L at any treatment plant treating surface water or groundwater under the direct influence of surface water, the water supplier shall resume routine monitoring under s.
NR 809.61 or begin increased monitoring under sub.
(2).
NR 809.63(1)(f)
(f) The department may return a public water system to routine monitoring, at any time, at the department's discretion.
NR 809.63(2)(a)(a) A public water system that is required to monitor at a particular location annually or less frequently than annually under s.
NR 809.62 or
809.63 (1), shall increase monitoring to dual sample sets once per quarter at all locations if a TTHM sample is >0.080 mg/L or a HAA5 sample is >0.060 mg/L at any location.
NR 809.63(2)(am)
(am) Water suppliers shall conduct increased monitoring under this paragraph at the monitoring locations in the monitoring plan developed under s.
NR 809.62 beginning on the date identified in s.
NR 809.60 (3) for compliance with this subchapter. The public water system shall remain on increased monitoring until it qualifies to return to routine monitoring under s.
NR 809.61.
NR 809.63(2)(b)
(b) Samples shall be taken every 90 days plus or minus 5 days beginning from the date of collection of the original sample that exceeded the MCL for either TTHM or HAA5.
NR 809.63(3)
(3) MCL violation determination. A public water system is in violation of the MCL when the LRAA for TTHM or HAA5 exceeds the MCLs in s.
NR 809.561 (3), calculated based on four consecutive quarters of monitoring or the LRAA calculated based on fewer than four quarters of data if the MCL would be exceeded regardless of the monitoring results of subsequent quarters.
NR 809.63(4)
(4) Return to routine monitoring. The department may return a public water system to routine monitoring once the water supplier has completed increased monitoring for at least four consecutive quarters and the LRAA for every monitoring location is
<0.060 mg/L for TTHM and
<0.045 mg/L for HAA5.
NR 809.63(5)
(5) Violation of monitoring requirements. A public water system is in violation of the monitoring requirements if the water supplier fails to monitor during a quarter and for each subsequent quarter that the monitoring result would have been used in calculating a LRAA.
NR 809.63 History
History: CR 09-073: cr.
Register November 2010 No. 659, eff. 12-1-10;
CR 15-049: am. (1) (intro.), (d) 3., (e), cr. (2) (am), am. (4) (title)
Register March 2016 No. 723, eff. 4-1-16; s.
35.17 correction made in (1) (intro.) under s.
35.17, Stats.,
Register March 2016.
NR 809.64
NR 809.64 Additional disinfection byproducts requirements for consecutive systems under Stage 2 DBP. A consecutive system that does not add a disinfectant but receives and delivers water that has been treated with a primary or residual disinfectant other than ultraviolet light, shall comply with analytical and monitoring requirements for chlorine and chloramines in s.
NR 809.565 (4) (a) and the compliance requirements in s.
NR 809.566 (3) (a) beginning April 1, 2009, unless required to comply earlier by the department, and shall report monitoring results under s.
NR 809.567 (3) (a).
NR 809.64 History
History: CR 09-073: cr.
Register November 2010 No. 659, eff. 12-1-10.
NR 809.65
NR 809.65 Operational evaluation levels for disinfection byproducts under Stage 2 DBP. NR 809.65(1)(1)
Operational evaluation. An operational evaluation shall be conducted if any of the following occurs:
NR 809.65(1)(a)
(a) The sum of the two previous quarters' TTHM results plus twice the current quarter's TTHM result, divided by 4, exceeds 0.080 mg/L at any monitoring location.
NR 809.65(1)(b)
(b) The sum of the two previous quarters' HAA5 results plus twice the current quarter's HAA5 result, divided by 4, exceeds 0.060 mg/L at any monitoring location.
NR 809.65(2)
(2) Operational evaluation reporting. If an operational evaluation must be performed as required in sub.
(1), it shall be submitted as a written report to the department no later than 90 days after being notified of the analytical result that causes the public water system to exceed the operational evaluation level. The written report shall be made available to the public upon request.
NR 809.65(3)
(3) Contents of an operational report. An operational evaluation shall include an examination of the system treatment and distribution operational practices, including storage tank operations, excess storage capacity, distribution system flushing, changes in sources or source water quality, and treatment changes or problems that may contribute to TTHM and HAA5 formation and what steps could be considered to minimize future exceedances.
NR 809.65(4)
(4) Limiting the scope of an operational evaluation. A water supplier may request and the department may allow the water supplier to limit the scope of the operational evaluation if the water supplier is able to identify the cause of the operational evaluation level exceedance. The request to limit the scope of the evaluation does not extend the schedule required under sub.
(2) for submitting the written report. If the department approves this limited scope of evaluation, the approval shall be in writing and the water supplier shall keep the written approval with the completed report.
NR 809.65 History
History: CR 09-073: cr.
Register November 2010 No. 659, eff. 12-1-10;
CR 15-049: am. (1) (a), (b)
Register March 2016 No. 723, eff. 4-1-16.
NR 809.66
NR 809.66 Requirements for remaining on reduced TTHM and HAA5 monitoring based on Stage 1 DBP results. NR 809.66(1)(1)
Remaining on reduced monitoring. A public water system may remain on reduced monitoring after the dates identified in s.
NR 809.60 (3) for compliance with this subchapter only if the public water system qualified for a 40/30 certification by EPA under Subpart U of
40 CFR 141.603, or received a very small system waiver under Subpart U of
40 CFR 141.604, and if the public water system meets the reduced monitoring criteria in NR 809.63 (1) and all of the following criteria:
NR 809.66 History
History: CR 09-073: cr.
Register November 2010 No. 659, eff. 12-1-10; correction in (1) (intro.) made under s.
13.92 (4) (b) 7., Stats.,
Register January 2013 No. 685;
CR 15-049: am. (1) (intro.)
Register March 2016 No. 723, eff. 4-1-16.
NR 809.67
NR 809.67 Requirements for remaining on increased TTHM and HAA5 monitoring based on Stage 1 DBP results. A public water system that is on increased monitoring under ss.
NR 809.565 and
809.566 shall remain on increased monitoring until the public water system qualifies for a return to routine monitoring under s.
NR 809.61.
NR 809.67 History
History: CR 09-073: cr.
Register November 2010 No. 659, eff. 12-1-10;
CR 15-049: r. (1) (title), renum. (1) to 809.67, r. (2)
Register March 2016 No. 723, eff. 4-1-16.
NR 809.68
NR 809.68 Reporting and recordkeeping requirements for Stage 2 DBP. NR 809.68(1)(a)(a) Water suppliers shall report all of the following information for each monitoring location to the department no later than 10 days after the end of any quarter in which monitoring is required:
NR 809.68(1)(a)3.
3. Arithmetic average of quarterly results for the four quarters immediately previous for each monitoring location (LRAA), beginning at the end of the fourth calendar quarter that follows the compliance date and at the end of each subsequent quarter. If the LRAA calculated based on fewer than four quarters of data would cause the MCL to be exceeded regardless of the monitoring results of subsequent quarters, the water supplier shall report this information to the department as part of the first report due following the compliance date or anytime thereafter that this determination is made. If the public water system is required to conduct monitoring at a frequency that is less than quarterly, the water supplier shall make compliance calculations beginning with the first compliance sample taken after the compliance date, unless the public water system is required to conduct increased monitoring under s.
NR 809.63 (2).
NR 809.68(1)(a)4.
4. If the MCL for TTHM or HAA5s was violated at any monitoring location.
NR 809.68(1)(a)5.
5. Any operational evaluation levels that were exceeded during the quarter and, if so, the location and date, and the calculated TTHM and HAA5 levels.
NR 809.68(1)(b)
(b) Water suppliers for surface water or groundwater under the direct influence of surface water systems seeking to qualify for or remain on reduced TTHM or HAA5 monitoring, shall report the following source water TOC information for each treatment plant that treats surface water or groundwater under the direct influence of surface water to the department no later than 10 days after the end of any quarter in which monitoring is required:
NR 809.68(1)(b)1.
1. The number of source water TOC samples taken each month during the previous quarter.
NR 809.68(1)(b)2.
2. The date and result of each sample taken during the previous quarter.
NR 809.68(1)(b)3.
3. The quarterly average of monthly samples taken during the previous quarter or the result of the quarterly sample.
NR 809.68(1)(b)4.
4. The running annual average (RAA) of quarterly averages from the past four quarters.
