Chapter NR 809

NR 809.50(3) (3) Best available technologies (BATs) for radionuclides.

NR 809.50(3)(a) (a) The department identifies, as indicated in the following table, the best available technology for achieving compliance with the maximum contaminant levels for combined radium-226 and radium-228, uranium, gross alpha particle activity and beta particle and photo radioactivity. A community water system that shall treat to reduce radionuclide levels below the MCLs specified in sub. (1) or s. NR 809.51 shall achieve compliance using one of the methods listed in Table J, Table K or Table L.

NR 809.50(4) (4) Small water systems compliance technologies for radionuclides.

NR 809.50(4)(a) (a) The department identifies, as indicated in the following table, the best available technology for achieving compliance with the maximum contaminant levels for combined radium-226 and radium-228, uranium, gross alpha particle activity and beta particle and photo radioactivity for small systems serving a population of 10,000 or less:

NR 809.50(4)(b) (b) Point of Use (POU) treatment may only be allowed if the department determines that treatment prior to entry is not feasible.

NR 809.50(5) (5) Alternative treatment. The department may approve the use of alternative treatment not listed in subs. (3) and (4), if a water supplier demonstrates to the department, using pilot studies or other means, that the alternative treatment is sufficient to achieve compliance with the MCLs in sub. (1).

Table J
BAT for Combined Radium-226 and Radium-228,
Uranium, Gross Alpha Particle Activity, and Beta Particle and Photon Radioactivity

1 National Research Council (NRC). Safe Water from Every Tap: Improving Water Service to Small Communities. National Academy Press, Washington, D.C. 1997.

2 POU devices are typically installed at the kitchen tap. See the April 21, 2000 NODA for more details.

Limitations Footnotes: Technologies for Radionuclides:

a The regeneration solution contains high concentrations of the contaminant ions. Disposal options should be carefully considered before choosing this technology.

b When POU devices are used for compliance, programs for long-term operation, maintenance, and monitoring shall be provided by water utility to ensure proper performance.

c Reject water disposal options should be carefully considered before choosing this technology. See other RO limitations described in the SWTR Compliance Technologies Table.

d The combination of variable source water quality and the complexity of the water chemistry involved may make this technology too complex for small surface water systems.

e Removal efficiencies can vary depending on water quality.

f This technology may be very limited in application to small water systems. Since the process requires static mixing, detention basins, and filtration, it is most applicable to small water systems with sufficiently high sulfate levels that already have a suitable filtration treatment train in place.

g This technology is most applicable to small water systems that already have filtration in place.

h Handling of chemicals required during regeneration and pH adjustment may be too difficult for small water systems without an adequately trained operator.

i Assumes modification to a coagulation/filtration process already in place.

1 Numbers correspond to those technologies found listed in the Table K of s. NR 809.50 (4).

NR 809.50 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10; CR 15-049: am. (4) Table K Register March 2016 No. 723, eff. 4-1-16.

NR 809.51 NR 809.51 Beta particle and photon radioactivity from man-made radionuclides maximum contaminant levels.

NR 809.51(1) (1) Allowable dose. The average annual concentration of beta particle and photon radioactivity from man-made radionuclides in drinking water shall not produce an annual dose equivalent to the total body or any internal organ greater than 4 millirem/year.

NR 809.51(2) (2) MCL calculation. Except for the radionuclides listed in Table M, the concentration of man–made radionuclides causing 4 mrem total body or organ dose equivalents shall be calculated on the basis of a 2 liter per day drinking water intake using the 168 hour data listed in “Maximum Permissible Body Burdens and Maximum Permissible Concentrations of Radionuclides in Air or Water for Occupational Exposure”, NBS Handbook 69 as amended August, 1963, U.S. Department of Commerce. Copies of this document are available for inspection at the office of the department of natural resources and the office of the legislative reference bureau, and may be obtained for personal use from the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402. If 2 or more radionuclides are present, the sum of their annual dose equivalent to the total body or to any organ may not exceed 4 millirem/year.

NR 809.51 Note Note: Sections ss. NR 809.50 to 809.52 are identical to the radioactivity standards of the department of health services in ch. DHS 157, Wis. Adm. Code, and to the National Interim Primary Drinking Water Regulations, 40 CFR part 141. These sections are adopted pursuant to s. 254.34, Stats.

NR 809.51 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10; correction in (2) made under s. 13.92 (4) (b) 6., Stats., Register April 2023 No. 808.

NR 809.52 NR 809.52 Analytical methods for radionuclides.

NR 809.52(1) (1) Analytical methods. Analyses conducted to determine compliance with ss. NR 809.50 and 809.51 shall be made in accordance with approved methods listed in Table N.

1 “Prescribed Procedures for Measurement of Radioactivity in Drinking Water”, EPA-600/4-80/032. August, 1980. Available from the EMSL, Office of Research and Development, U.S. EPA, 26 W. Martin Luther King Drive, Cincinnati, Ohio, 45268.

2 “Interim Radiochemical Methodology for Drinking Water”, EPA 600/4-75/008 (revised), March 1976, Available at NTIS, ibid PB 253258.

3 “Radiochemistry Procedures Manual”, EPA 520/5-84/006, December 1987, Available at NTIS, ibid, PB 84-215581

4 “Radiochemical Analytical Procedures for Analysis of Environmental Samples”, March 1979, Available at NTIS, ibid, EMSL LV 053917

5 “Standard Methods for the Examination of Water and Wastewater,” 13th, 17th, 18th, 19th, 20th, 21st, or 22nd, edition, 1971, 1989, 1992, 1995, 1998, 2005, 2012, available at American Public Health Association, 800 I Street NW., Washington, DC. 20001-3710. Methods 302, 303, 304, 305 and 306 are only in the 13th edition. Methods 7110B, 7500-Ra B, 7500-Ra C, 7500-Ra D, 7500-U B, 7500-Cs B, 7500-I B, 7500-I C, 7500-I D, 7500-Sr B, and 7500-3H B are in the 17th, 18th, 19th 20th, 21st, and 22nd editions. Method 7110 C and 7500-U C Alpha spectrometry is in the 18th, 19th, 20th, 21st, and 22nd editions. Method 7500-U C Fluorometric Uranium is only in the 17th edition, Method 7120 is only in the 19th and 20th editions. Method 3125 is only in the 20th edition. Standard Methods online are available at http://www.standardmethods.org. The year in which each method was approved by the Standard Methods Committee is designated by the last two digits in the method number. The methods listed are the only online versions that may be used.

6 Annual Book of ASTM Standards, Vol. 11.02, 1994. Available at American Society for Testing and Materials, 100 Barr Harbor Drive, West Conshohocken, PA 19428.

7 “Methods for Determination of Radioactive Substances in Water and Fluvial Sediments”, Chapter A 5 in Book 5 of Techniques of Water Resources Investigations of the United States Geological Survey, 1997. Available at U.S. Geological Survey (USGS) Information Services, Box 25286 Federal Center, Denver, CO 80225-0425.

8 “EML Procedures Manual”, 27th Edition, Volume 1, 1990. Available at the Environmental Measurements Laboratory, U.S. Department of Energy (DOE), 376 Hudson Street, New York, NY 10014-3621.

9 “Determination of Ra-226 and Ra-228 (Ra-02)”, January 1980, Revised June 1982. Available at Radiological Sciences Institute Center for Laboratories and Research, New York State Department of Health, Empire State Plaza, Albany, NY 12201.

10 “Determination of Radium 228 in Drinking Water”, August 1980. Available at State of New Jersey, Department of Environmental Protection, Division of Environmental Quality, Bureau of Radiation and Inorganic Analytical Services, 9 Ewing Street, Trenton, N.J. 08625.

11 Natural uranium and thorium-230 or approved as gross alpha calibration standards for gross alpha with co-precipitation and evaporation methods, americium-241 is approved with co-precipitation methods.

12 If uranium (U) is determined by mass a 0.67 pCi/g of uranium conversion factor shall be used. This conservative factor is based on the 1:1 activity ratio of U-234 to U-238 that is characteristic of naturally occurring uranium.

NR 809.52(2) (2) Detection limits. To determine compliance with s. NR 809.50 (1), the detection limit may not exceed the concentrations in Table O.

Table O
Detection Limits for Gross Alpha Particle Activity,
Radium 226, Radium 228, and Uranium

NR 809.52(3) (3) Results rounding. To judge compliance with the maximum contaminant levels listed in s. NR 809.50, averages of data shall be used and shall be rounded to the same number of significant figures as the maximum contaminant level for the substance in question.

NR 809.52(4) (4) Sensitivity limits. For the purpose of monitoring radionuclide concentrations in drinking water, the required sensitivity of the radioanalysis is defined in terms of a detection limit. The detection limit shall be that concentration which can be counted with a precision of plus or minus 100% at the 95% confidence level, 1.96 ó where ó is the standard deviation of the net counting rate of the sample.

NR 809.52(5) (5) Detection limits for man-made beta particle and photon emitters. To determine compliance with s. NR 809.51, the detection limits may not exceed the concentrations listed in Table P.

NR 809.52 Note Note: Sections NR 809.50 to 809.52 are identical to the radioactivity standards of the department of health services in ch. DHS 157, Wis. Adm. Code, and to the National Interim Primary Drinking Water Regulations, 40 CFR part 141. These sections are adopted pursuant to s. 254.34, Stats.

NR 809.52(6) (6) Sample collection methods. Sample collection for radionuclide contaminants under s. NR 809.50 shall be conducted using the sample preservation, containers and maximum holding time procedures specified in Table Q. If a composite sample is prepared, a holding time cannot exceed 12 months. In all cases, samples should be analyzed as soon after collection as possible.

1 It is recommended that the preservative be added to the sample at the time of collection unless suspended solids activity is to be measured. If the sample has to be shipped to a laboratory or storage area unpreserved, acidification of the sample (in its original container) may be delayed for a period not to exceed 5 days. A minimum of 16 hours shall elapse between acidification and analysis.

2 P = Plastic, hard or soft; G = Glass, hard or soft.

NR 809.52 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10; CR 15-049: am. (1) Table N Register March 2016 No. 723, eff. 4-1-16.

NR 809.53 NR 809.53 Radionuclide monitoring frequency and compliance requirements for community water systems.

NR 809.53(1) (1) Monitoring requirements for gross alpha particle activity, radium-226, radium-228 and uranium.

NR 809.53(1)(a) (a) Detection limits. For the purposes of monitoring for gross alpha particle activity, radium-226, radium-228, uranium and beta particle and photon radioactivity in drinking water, “detection limit” is defined in s. NR 809.52 (4).

NR 809.53(1)(b) (b) Applicability and sampling location. Community water system applicability and sampling location requirements shall be as follows:

NR 809.53(1)(b)1. 1. Applicability and sampling location for existing community water systems or sources. All water suppliers for existing community water systems shall sample at every entry point to the distribution system that is representative of all sources being used, under normal operating conditions. The water supplier shall take each sample at the same location unless conditions make another location more representative of each source or the department has designated a distribution system location, in accordance with par. (c) 2. c.

NR 809.53(1)(b)2. 2. Applicability and sampling location for new community water systems or sources. Water suppliers for all new community water systems or community water systems that use a new source of water shall begin to conduct initial monitoring for the new source within the first quarter after initiating use of the source. Water suppliers shall conduct more frequent monitoring when ordered by the department in the event of possible contamination or when changes in the distribution system or treatment processes occur which may increase the concentration of radionuclides in finished water.

NR 809.53(1)(c) (c) Initial monitoring. Water suppliers for community water systems shall conduct initial monitoring for gross alpha particle activity, radium-226, radium-228 and uranium as follows:

NR 809.53(1)(c)1. 1. Except as provided in subd. 2., water suppliers shall collect 4 consecutive quarterly samples at all sampling points before December 31, 2007.

NR 809.53(1)(c)2. 2. As an alternative to the requirement of subd. 1., water suppliers may use historical monitoring data collected at a sampling point to satisfy the initial monitoring requirements for that sampling point for the following situations:

NR 809.53(1)(c)2.a. a. To satisfy initial monitoring requirements, a water supplier for a community water system having only one entry point to the distribution system may use the monitoring data from the last compliance monitoring period that began between June 1, 2000 and December 8, 2003.

NR 809.53(1)(c)2.b. b. To satisfy initial monitoring requirements, a water supplier for a community water system with multiple entry points and having appropriate historical monitoring data for each entry point to the distribution system may use the monitoring data from the last compliance monitoring period that began between June 1, 2000 and December 8, 2003.

NR 809.53(1)(c)2.c. c. To satisfy initial monitoring requirements, a water supplier for a community water system with appropriate historical data for a representative point in the distribution system may use the monitoring data from the last compliance monitoring period that began between June 1, 2000 and December 8, 2003, provided that the department finds that the historical data satisfactorily demonstrate that each entry point to the distribution system is expected to be in compliance based upon the historical data and reasonable assumptions about the variability of contaminant levels between entry points. The department shall make a written finding indicating how the data conforms to these requirements.

NR 809.53(1)(c)3. 3. For gross alpha particle activity, uranium, radium-226 and radium-228 monitoring, the department may waive the final 2 quarters of initial monitoring for a sampling point if the results of the samples from the previous 2 quarters are below the detection limit.

NR 809.53(1)(c)4. 4. If the average of the initial monitoring results for a sampling point is above the MCL, the water supplier for a community water system shall collect and analyze quarterly samples at that sampling point until the water supplier has results from 4 consecutive quarters that are at or below the MCL, unless the water supplier enters into another schedule as part of a formal compliance agreement with the department.

NR 809.53(1)(d) (d) Reduced monitoring. Upon completion of initial monitoring the department may allow monitoring once every 3 years, once every 6 years, or once every 9 years, for each sampling point based on the following criteria:

NR 809.53(1)(d)1. 1. If the average of the initial monitoring results for each contaminant, i.e., gross alpha particle activity, uranium, radium-226 or radium-228, is below the detection limit specified in s. NR 809.52 (2), Table O, the water supplier for a community water system shall collect and analyze for that contaminant using at least one sample at that sampling point every 9 years.

NR 809.53(1)(d)2. 2. For gross alpha particle activity and uranium, if the average of the initial monitoring results for each contaminant is at or above the detection limit but at or below one-half the MCL, the water supplier for a community water system shall collect and analyze for that contaminant using at least one sample at that sampling point every 6 years. For combined radium-226 and radium-228, the analytical results shall be combined. If the average of the combined initial monitoring results for radium-226 and radium-228 is at or above the detection limit but at or below one-half the MCL, the water supplier for a community water system shall collect and analyze for that contaminant using at least one sample at that sampling point every 6 years.

NR 809.53(1)(d)3. 3. For gross alpha particle activity and uranium, if the average of the initial monitoring results for each contaminant is above one-half the MCL but at or below the MCL, the water supplier for a community water system shall collect and analyze at least one sample at that sampling point every 3 years. For combined radium-226 and radium-228, the analytical results shall be combined. If the average of the combined initial monitoring results for radium-226 and radium-228 is above one-half the MCL, but at or below the MCL, the water supplier for a community water system shall collect and analyze at least one sample at that sampling point every 3 years.

NR 809.53(1)(d)4. 4. Results of samples collected during a reduced monitoring period shall be used to determine the monitoring frequency for subsequent monitoring periods.

NR 809.53(1)(d)5. 5. If a community water system has a monitoring result that exceeds the MCL while on reduced monitoring, the water supplier for a community water system shall collect and analyze quarterly samples at that sampling point until the community water system has results from 4 consecutive quarters that are below the MCL, unless the water supplier for a community water system enters into another schedule as part of a formal compliance agreement with the department.

NR 809.53(1)(e) (e) Compositing. To fulfill quarterly monitoring requirements for gross alpha particle activity, radium-226, radium-228 or uranium, a water supplier for a community water system may composite up to 4 consecutive quarterly samples from a single entry point if analysis is done within a year of the first sample. The department will treat analytical results from the composited results as the average analytical result to determine compliance with the MCLs and the future monitoring frequency. If the analytical result from the composited sample is greater than one-half the MCL, the department may direct the water supplier to take additional quarterly samples before allowing the water supplier to sample under a reduced monitoring schedule.

NR 809.53(1)(f) (f) Gross alpha particle activity measurement substitutions. A gross alpha particle activity measurement may be substituted for the required radium-226 measurement provided that the measured gross alpha particle activity does not exceed 5 pCi/l. A gross alpha particle activity measurement may be substituted for the required uranium measurement provided that the measured gross alpha particle activity does not exceed 15 pCi/l. The gross alpha measurement shall have a confidence interval of 95% confidence level, 1.65 ó where ó is the standard deviation of the net counting rate of the sample for radium-226 and uranium. When a water supplier for a community water system uses a gross alpha particle activity measurement in lieu of a measurement for radium-226 or uranium, or both, the gross alpha particle activity analytical result shall be used to determine the future monitoring frequency for radium-226 or uranium, or both. If the gross alpha particle activity result is less than detection, one-half the detection limit shall be used to determine compliance and the future monitoring frequency.

NR 809.53(2) (2) Monitoring requirements for beta particle and photon radioactivity. To determine compliance with the maximum contaminant levels in s. NR 809.51 for beta particle and photon radioactivity, a water supplier for a community water system shall monitor at a frequency as follows:

NR 809.53(2)(a) (a) Community water systems designated by the department as vulnerable, shall be sampled for beta particle and photon radioactivity. Water suppliers for community water systems shall collect quarterly samples for beta emitters and annual samples for tritium and strontium-90 at each entry point to the distribution system, no later than one quarter after being notified by the department. Community water systems already designated by the department shall continue to be sampled until the department reviews and either reaffirms or removes the designation.

NR 809.53(2)(a)1. 1. If the gross beta particle activity minus the naturally occurring potassium-40 beta particle activity at an entry point has a running annual average, computed quarterly, less than or equal to 50 pCi/l, the department may reduce the frequency of monitoring at that entry point to once every 3 years. Water suppliers for community water systems shall collect all samples required in this subsection during the reduced monitoring period.

NR 809.53(2)(a)2. 2. For community water systems in the vicinity of a nuclear facility, the department may allow the water supplier for the community water system to utilize environmental surveillance data collected by the nuclear facility in lieu of monitoring at the community water system’s entry points, if the department determines that the data is applicable to a particular community water system. If there is a release from a nuclear facility, water suppliers for community water systems which are using surveillance data shall begin monitoring at the community water system’s entry points in accordance with this subsection.

NR 809.53(2)(a)3. 3. At the discretion of the department, water suppliers for the community water systems utilizing only groundwater may be required to monitor for manmade radioactivity.

NR 809.53(2)(b) (b) Water suppliers for community water systems designated by the department as utilizing waters contaminated by effluents from nuclear facilities shall sample for beta particle and photon radioactivity. Water suppliers shall collect quarterly samples for beta emitters and iodine-131 and annual samples for tritium and strontium-90 at each entry point to the distribution system, beginning no later than one quarter after being notified by the department. Water suppliers for community water systems already designated by the department as community water systems using water contaminated by effluents from nuclear facilities shall continue to sample until the department reviews and either reaffirms or removes the designation.

NR 809.53(2)(b)1. 1. Quarterly monitoring for gross beta particle activity shall be based on the analysis of monthly samples or the analysis of a composite of 3 monthly samples.

NR 809.53 Note Note: Quarterly monitoring for gross beta particle activity based on the analysis of monthly samples is recommended.

NR 809.53(2)(b)2. 2. For iodine-131, a composite of 5 consecutive daily samples shall be analyzed once each quarter. As ordered by the department, more frequent monitoring shall be conducted when iodine-131 is identified in the finished water.

NR 809.53(2)(b)3. 3. Annual monitoring for strontium-90 and tritium shall be conducted by means of the analysis of a composite of 4 consecutive quarterly samples or analysis of 4 quarterly samples.

NR 809.53 Note Note: Annual monitoring for strontium-90 and tritium by means of the analysis of a composite of 4 consecutive quarterly samples is recommended.

NR 809.53(2)(b)4. 4. If the gross beta particle activity minus the naturally occurring potassium-40 beta particle activity at a sampling point has a running annual average, computed quarterly, less than or equal to 15 pCi/l, the department may reduce the frequency of monitoring at that sampling point to once every 3 years. Water suppliers for community water systems shall collect all samples required in this paragraph during the reduced monitoring period.

NR 809.53(2)(b)5. 5. For community water systems in the vicinity of a nuclear facility, the department may allow the water supplier for community water system to utilize environmental surveillance data collected by the nuclear facility in lieu of monitoring at the community water system’s entry points, if the department determines that the data is applicable to a particular community water system. If there is a release from a nuclear facility, water suppliers for community water systems which are using surveillance data shall begin monitoring at the community water system’s entry points in accordance with this paragraph.

NR 809.53(2)(c) (c) Water suppliers for community water systems designated by the department to monitor for beta particle and photon radioactivity may not apply to the department for a waiver from the monitoring frequencies specified in either par. (a) or (b).

NR 809.53(2)(d) (d) Water suppliers for community water systems may analyze for naturally occurring potassium-40 beta particle activity from the same or equivalent sample used for the gross beta particle activity analysis. Water suppliers for community water systems may subtract the potassium-40 beta particle activity value from the total gross beta particle activity value to determine if 50 pCi/l is exceeded. The potassium-40 beta particle activity shall be calculated by multiplying elemental potassium concentrations, in mg/l, by a factor of 0.82.

NR 809.53(2)(e) (e) If the gross beta particle activity minus the naturally occurring potassium-40 beta particle activity exceeds 50 pCi/l, an analysis of the sample shall be performed to identify the major radioactive constituents present in the sample and the appropriate doses shall be calculated and summed to determine compliance with s. NR 809.51 (1) using the formula in s. NR 809.51 (2). Doses shall also be calculated and combined for measured levels of tritium and strontium to determine compliance.

NR 809.53(2)(f) (f) Water suppliers for community water systems shall monitor monthly at the sampling points that exceed the maximum contaminant level in s. NR 809.51 beginning the month after the exceedance occurs. Water suppliers shall continue monthly monitoring until the water supplier has established, by a rolling average of 3 monthly samples, that the MCL is being met. Water suppliers for community water systems that establish that the MCL is being met shall return to quarterly monitoring until the requirements in par. (a) 1. or (b) 4. are met.