7 Samples must be preserved at the time of sampling with 50 mg ethylenediamine (EDA)/L of sample and must be analyzed within 28 days.

8 Amperometric titration or spectrophotometry may be used for routine daily monitoring of chlorite at the entrance to the distribution system, as prescribed in NR 809.565(3)(a)1. Ion chromatography must be used for routine monthly monitoring of chlorite and additional monitoring of chlorite in the distribution system, as prescribed in NR 809.565(30(a) 2. and. NR 809.565 (3) (a)3.

9 The Standard Methods Online version that is approved is indicated by the last two digits in the method number which is the year of approval by the Standard Method Committee. Standard Methods Online are available at http://www.standardmethods.org.

10 EPA methods are available at http://epa.gov/safewater/methods/analyticalmethods_ogwdw.html.

NR 809.563(4) (4) Laboratory certification for disinfectant byproducts. Laboratories that are certified by the department or EPA shall conduct the analysis under this section for disinfection byproducts.

NR 809.563(4)(a) (a) To receive certification to conduct analyses for the contaminants in this subchapter, a laboratory shall analyze performance evaluation samples approved by the department or EPA at least once during each consecutive 12-month period by each method for which a laboratory desires certification.

NR 809.563(4)(b) (b) When analyzing performance evaluation samples, the laboratory shall achieve quantitative results on the PE sample analyses that are within the acceptance limits in Table T.

NR 809.563(4)(c) (c) The acceptance limit shall be the 95% confidence interval calculated around the mean of the PE study data between a maximum and minimum acceptance limit of +/-50% and +/-15% of the study mean.

NR 809.563(4)(e) (e) Laboratories shall report quantitative data for concentrations as low as the ones listed in Table U for all DBP samples analyzed for compliance.

Table U
Minimum Reporting Levels for DBP Samples

1 The calibration curve must encompass the regulatory minimum reporting level (MRL) concentration. Data may be reported for concentrations lower than the regulatory MRL as long as the precision and accuracy criteria are met by analyzing an MRL check standard at the lowest reporting limit chosen by the laboratory. The laboratory must verify the accuracy of the calibration curve at the MRL concentration by analyzing an MRL check standard with a concentration less than or equal to 110% of the MRL with each batch of samples. The measured concentration for the MRL check standard must be ±50% of the expected value, if any field sample in the batch has a concentration less than 5 times the regulatory MRL. Method requirements to analyze higher concentration check standards and meet tighter acceptance criteria for them must be met in addition to the MRL check standard requirement.

2 When adding the individual trihalomethane or haloacetic acid concentrations to calculate the TTHM or HAA5 concentrations, respectively, a zero is used for any analytical result that is less than the MRL concentration for that DBP, unless otherwise specified by the department.

NR 809.563(5) (5) Approval of persons measuring disinfectant residual concentrations and chlorite. A person approved by the department or EPA shall measure residual disinfectant concentrations and daily chlorite samples at the entrance to the distribution system.

NR 809.563(6) (6) Analytical methods for additional required parameters. Water suppliers for public water systems required to analyze for additional parameters not included in sub. (3) shall have these parameters analyzed by a person approved by the department or EPA using the following methods:

NR 809.563(6)(a) (a) Alkalinity. For measuring alkalinity use the methods allowed in s. NR 809.113 Table A.

NR 809.563(6)(b) (b) Bromide. For measuring bromide use EPA Method 300.0 or EPA Method 300.1.

NR 809.563(6)(c) (c) Total organic carbon (TOC). For measuring total organic carbon, use Standard Method 5310 B (High-Temperature Combustion Method) or Standard Method 5310 C (Persulfate-Ultraviolet or Heated-Persulfate Oxidation Method) or Standard Method 5310 D (Wet-Oxidation Method).

NR 809.563(6)(c)1. 1. TOC samples may not be filtered prior to analysis.

NR 809.563(6)(c)2. 2. TOC samples shall either be analyzed or shall be acidified to achieve pH less than 2.0 by minimal addition of phosphoric or sulfuric acid as soon as practical after sampling, not to exceed 24 hours.

NR 809.563(6)(c)3. 3. Acidified TOC samples shall be analyzed within 28 days.

NR 809.563(6)(d) (d) Specific ultraviolet absorbance (SUVA). SUVA is equal to the UV absorption at 254nm (UV254) measured in m-1 divided by the dissolved organic carbon (DOC) concentration measured as mg/L.

NR 809.563(6)(d)1. 1. In order to determine SUVA, it is necessary to separately measure UV254 and DOC.

NR 809.563(6)(d)2. 2. When determining SUVA, water suppliers shall use the methods stipulated in par. (e) to measure DOC and the method stipulated in par. (f) to measure UV254 SUVA shall be determined on water prior to the addition of disinfectants or oxidants, or both, by the water supplier.

NR 809.563(6)(d)3. 3. DOC and UV254 samples used to determine a SUVA value shall be taken at the same time and at the same location.

NR 809.563(6)(e) (e) Dissolved organic carbon (DOC). For measuring dissolved organic carbon, use Standard Method 5310 B (High-Temperature Combustion Method) or Standard Method 5310 C (Persulfate-Ultraviolet or Heated-Persulfate Oxidation Method) or Standard Method 5310 D (Wet-Oxidation Method). Prior to analysis, DOC samples shall be filtered through a 0.45 mm pore-diameter filter. Water passed through the filter prior to filtration of the sample shall serve as the filtered blank. This filtered blank shall be analyzed using procedures identical to those used for analysis of the samples and shall meet the following criteria: DOC < 0.5 mg/L. DOC samples shall be filtered through the 0.45 mm pore-diameter filter prior to acidification. DOC samples shall either be analyzed or shall be acidified to achieve pH less than 2.0 by minimal addition of phosphoric or sulfuric acid as soon as practical after sampling, not to exceed 48 hours. Acidified DOC samples shall be analyzed within 28 days.

NR 809.563(6)(f) (f) Ultraviolet absorption at 254 nm (UV254). For measuring ultraviolet absorption at 254 nm, use Method 5910 B (Ultraviolet Absorption Method). UV absorption shall be measured at 253.7 nm (may be rounded off to 254 nm). Prior to analysis, UV254 samples shall be filtered through a 0.45 mm pore-diameter filter. The pH of UV254 samples may not be adjusted. Samples shall be analyzed as soon as practical after sampling, not to exceed 48 hours.

NR 809.563(6)(g) (g) pH. For measuring pH, use any method allowed in s. NR 809.113 (1) Table A.

NR 809.563(6)(h) (h) Magnesium. All methods allowed in s. NR 809.113 (1) Table A.

NR 809.563 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10; CR 15-049: am. (1), (2), r. and recr. (2) Table R, (3) Table S, am. (4) (a), (b), r. (4) (d), am. (4) (e), Table U, (5), (6) (intro.), cr. (6) (h) Register March 2016 No. 723, eff. 4-1-16.