NR 809.332(2)(a)(a) If an extreme condition or situation exists that may pose danger to the sample collector, or that cannot be avoided and causes the water supplier to be unable to sample in the scheduled five-day period, the water supplier shall sample as close to the scheduled date as feasible unless the department approves an alternative sampling date. The water supplier shall submit an explanation for the delayed sampling date to the department concurrent with the shipment of the sample to the laboratory.

NR 809.332(2)(b)(b) If a water supplier is unable to report a valid analytical result for a scheduled sampling date due to equipment failure, loss of or damage to the sample, failure to comply with the analytical method requirements, including the quality control requirements in s. NR 809.334, or the failure of an approved laboratory to analyze the sample, then the water supplier shall collect a replacement sample. The water supplier shall collect the replacement sample no later than 21 days after receiving information that an analytical result cannot be reported for the scheduled date unless the water supplier demonstrates that collecting a replacement sample within this time frame is not feasible or the department approves an alternative resampling date. The water supplier shall submit an explanation for the delayed sampling date to the department concurrent with the shipment of the sample to the laboratory.

NR 809.332(3)(3) Revising sampling schedules. Water supplier for public water systems that fail to meet the criteria of sub. (2) for any source water sample required under s. NR 809.331 shall revise their sampling schedules to add dates for collecting all missed samples. The water supplier shall submit the revised schedule to the department for approval before the water supplier begins collecting the missed samples.

NR 809.333(1)(1) General requirements. Water suppliers for public water systems required to conduct source water monitoring under s. NR 809.331 shall collect samples for each plant that treats a surface water or GWUDI source. Where multiple plants draw water from the same influent, such as the same pipe or intake, the department may approve one set of monitoring results to be used to satisfy the requirements of s. NR 809.331 for all plants.

NR 809.333(2)(2) Sample collection location. The water supplier shall collect source water samples prior to chemical treatment, such as coagulants, oxidants and disinfectants, unless the public water system meets the condition of this subsection. The department may approve a water supplier to collect a source water sample after chemical treatment if the department determines that collecting a sample prior to chemical treatment is not feasible for the public water system and that the chemical treatment is unlikely to have a significant adverse effect on the analysis of the sample.

NR 809.333(3)(3) Recycled filter backwash. Water suppliers for public water systems that recycle filter backwash water shall collect source water samples prior to the point of filter backwash water. All public water systems that recycle filter backwash water shall comply with all of the requirements under ss. NR 810.295, 811.860, and 811.862.

NR 809.333(4)(a)(a) Water suppliers for public water systems that receive Cryptosporidium treatment credit for bank filtration under s. NR 810.29 (5) or 810.37 (2), as applicable, shall collect source water samples in the surface water prior to bank filtration.

NR 809.333(4)(b)(b) Water suppliers for public water systems that use bank filtration as pretreatment to a filtration plant shall collect source water samples from the collector well after bank filtration. Use of bank filtration during monitoring shall be consistent with routine operational practice. When samples are collected after a bank filtration process, public water systems may not receive treatment credit for the bank filtration under s. NR 810.43 (3).

NR 809.333(5)(5) Multiple sources. Water suppliers for public water systems with plants that use multiple water sources, including multiple surface water sources and blended surface water and groundwater sources, shall collect samples as specified in par. (a) or (b). The use of multiple sources during monitoring shall be consistent with routine operational practice.

NR 809.333(5)(a)(a) If a sampling tap where the sources are combined prior to treatment is available, the water supplier shall collect samples from that tap.

NR 809.333(5)(b)(b) If a sampling tap where the sources are combined prior to treatment is not available, the water supplier shall collect samples at each source near the intake on the same day and shall follow either subd. 1. or 2. for sample analysis.

NR 809.333(5)(b)1.1. Water suppliers may composite samples from each source into one sample prior to analysis. The volume of sample from each source shall be weighted according to the proportion of the source in the total plant flow at the time the sample is collected.

NR 809.333(5)(b)2.2. Water suppliers may analyze samples from each source separately and calculate a weighted average of the analysis results for each sampling date. The weighted average shall be calculated by multiplying the analysis result for each source by the fraction the source contributed to total plant flow at the time the sample was collected and then summing these values.

NR 809.333(6)(6) Additional requirements. Water suppliers shall submit a description of their sampling locations to the department at the same time as the sampling schedule required under s. NR 809.332. This description shall address the position of the sampling location in relation to the public water system’s water sources and treatment processes, including pretreatment, points of chemical treatment, and filter backwash recycle. If the department does not respond to a water supplier regarding sampling locations, the water supplier shall sample at the reported locations.

NR 809.334(1)(1) Cryptosporidium. Water suppliers shall analyze for Cryptosporidium using Method 1623: Cryptosporidium and Giardia in Water by Filtration/IMS/FA, 2005, United States Environmental Protection Agency, EPA–815-R–05–002 or Method 1622: Cryptosporidium in Water by Filtration/IMS/FA, 2005, United States Environmental Protection Agency, EPA–815–R–05–001. The water supplier may obtain a copy of these methods online from http://www.epa.gov/safewater/disinfection/lt2. Water suppliers may also use EPA Method 1623.1: Cryptosporidium and Giardia in Water by Filtration/IMS/FA, 2012. EPA-816-R-12-001. (Available at http://water.epa.gov/drink.)

NR 809.334(1)(a)(a) Water suppliers shall analyze at least a 10 L sample or a packed pellet volume of at least 2 mL as generated by the methods listed in this subsection. Water suppliers unable to process a 10 L sample shall analyze as much sample volume as can be filtered by two filters approved by EPA for the methods listed in this subsection, up to a packed pellet volume of at least 2 mL.

NR 809.334(1)(b)(b) Matrix spike (MS) samples, as required by the methods in this subsection, shall be spiked and filtered by a laboratory approved for Cryptosporidium analysis under s. NR 809.335. If the volume of the MS sample is greater than 10 L, the water supplier may filter all but 10 L of the MS sample in the field, and ship the filtered sample and the remaining 10 L of source water to the laboratory. In this case, the laboratory shall spike the remaining 10 L of water and filter it through the filter used to collect the balance of the sample in the field.

NR 809.334(1)(c)(c) Flow cytometer-counted spiking suspensions shall be used for MS samples and ongoing precision and recovery (OPR) samples.

NR 809.334(2)(a)(a) The time from sample collection to initiation of analysis may not exceed 30 hours unless the condition of par. (b) are met. In all cases, samples should be analyzed as soon after collection as possible.

NR 809.334(2)(b)(b) The department may approve on a case-by-case basis the holding of an E. coli sample for up to 48 hours between sample collection and initiation of analysis if the department determines that analyzing an E. coli sample within 30 hours is not feasible. E. coli samples held between 30 to 48 hours shall be analyzed by the Colilert reagent version of Standard Method 9223B as listed in sub. (2), Table I.