Section 809.50. Maximum contaminant levels, compliance dates and BATs for radionuclides.

  The following are the maximum contaminant levels, compliance dates and best available technologies for radium-226, radium-228 and gross alpha particle radioactivity:

(1)   Maximum contaminant levels for radionuclides. The following are the maximum contaminant levels for radium-226, radium-228 and gross alpha particle radioactivity:

(a) MCL for combined radium-226 and radium-228. The maximum contaminant level for combined radium-226 and radium-228 is 5 pCi/l. The combined radium-226 and radium-228 value is determined by the addition of the results of the analysis for radium-226 and the analysis for radium-228.

(b) MCL for gross alpha particle activity, excluding radon and uranium. The maximum contaminant level for gross alpha particle activity, including radium-226 but excluding radon and uranium, is 15 pCi/l.

(c) MCL for uranium. The maximum contaminant level for uranium is 30 ug/l.

(2)   Compliance dates for combined radium-226 and radium-228, gross alpha particle activity, gross beta particle and photon radioactivity and uranium. Community water systems shall comply with the MCLs listed in sub. (1) and with s. NR 809.51 (1) beginning December 8, 2003 and compliance shall be determined in accordance with the requirements of ss. NR 809.50 and 809.51 . Compliance with reporting requirements for the radionuclides under Appendix A to subch. VII is required on and after December 8, 2003.

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

(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.

(4)   Small water systems compliance technologies for radionuclides.

(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:

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

(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 - See PDF for table - See PDF for table

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. - See PDF for table

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

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.