[Code of Federal Regulations]
[Title 40, Volume 22]
[Revised as of July 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR141.66]

[Page 443-445]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 141_NATIONAL PRIMARY DRINKING WATER REGULATIONS--Table of Contents
 
     Subpart G_National Primary Drinking Water Regulations: Maximum 
 
Sec. 141.66  Maximum contaminant levels for radionuclides.

    (a) [Reserved]
    (b) MCL for combined radium-226 and -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.
    (c) 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.
    (d) MCL for beta particle and photon radioactivity. (1) The average 
annual concentration of beta particle and photon radioactivity from man-
made radionuclides in drinking water must not produce an annual dose 
equivalent to the total body or any internal organ greater than 4 
millirem/year (mrem/year).
    (2) Except for the radionuclides listed in table A, the 
concentration of man-made radionuclides causing 4 mrem total body or 
organ dose equivalents must be calculated on the basis of 2 liter per 
day drinking water intake using the 168 hour data list in ``Maximum 
Permissible Body Burdens and Maximum Permissible Concentrations of 
Radionuclides in Air and in Water for Occupational Exposure,'' NBS 
(National Bureau of Standards) Handbook 69 as amended August 1963, U.S. 
Department of Commerce. This incorporation by reference was approved by 
the Director of the Federal Register in accordance with 5 U.S.C. 552(a) 
and 1 CFR part 51. Copies of this document are available from the 
National Technical Information Service, NTIS ADA 280 282, U.S. 
Department of Commerce, 5285 Port Royal Road, Springfield, Virginia 
22161. The toll-free number is 800-553-6847. Copies may be inspected at 
EPA's Drinking Water Docket, 401 M Street, SW., Washington, DC 20460; or 
at the National Archives and Records Administration (NARA). For 
information on the availability of this material at NARA, call 202-741-
6030, or go to: http://www.archives.gov/federal--register/code--of--
federal--regulations/ibr--locations.html. If two or more radionuclides 
are present, the sum of their annual dose equivalent to the total body 
or to any organ shall not exceed 4 mrem/year.

[[Page 444]]



 Table A--Average Annual Concentrations Assumed To Produce: a Total Body
                       or Organ Dose of 4 mrem/yr
1. Radionuclide.................  Critical organ....  pCi per liter
2. Tritium......................  Total body........  20,000
3. Strontium-90.................  Bone Marrow.......  8
------------------------------------------------------------------------

    (e) MCL for uranium. The maximum contaminant level for uranium is 30 
[micro]g/L.
    (f) Compliance dates. (1) Compliance dates for combined radium-226 
and -228, gross alpha particle activity, gross beta particle and photon 
radioactivity, and uranium: Community water systems must comply with the 
MCLs listed in paragraphs (b), (c), (d), and (e) of this section 
beginning December 8, 2003 and compliance shall be determined in 
accordance with the requirements of Sec. Sec. 141.25 and 141.26. 
Compliance with reporting requirements for the radionuclides under 
appendix A to subpart O and appendices A and B to subpart Q is required 
on December 8, 2003.
    (2) [Reserved]
    (g) Best available technologies (BATs) for radionuclides. The 
Administrator, pursuant to section 1412 of the Act, hereby identifies as 
indicated in the following table the best technology available for 
achieving compliance with the maximum contaminant levels for combined 
radium-226 and -228, uranium, gross alpha particle activity, and beta 
particle and photon radioactivity.

   Table B--BAT for Combined Radium-226 and Radium-228, Uranium, Gross
   Alpha Particle Activity, and Beta Particle and Photon Radioactivity
------------------------------------------------------------------------
              Contaminant                              BAT
------------------------------------------------------------------------
1. Combined radium-226 and radium-228..  Ion exchange, reverse osmosis,
                                          lime softening.
2. Uranium.............................  Ion exchange, reverse osmosis,
                                          lime softening, coagulation/
                                          filtration.
3. Gross alpha particle activity         Reverse osmosis.
 (excluding Radon and Uranium).
4. Beta particle and photon              Ion exchange, reverse osmosis.
 radioactivity.
------------------------------------------------------------------------

    (h) Small systems compliance technologies list for radionuclides.

         Table C--List of Small Systems Compliance Technologies for Radionuclides and Limitations to Use
----------------------------------------------------------------------------------------------------------------
                                           Limitations
            Unit technologies                 (see          Operator skill level     Raw water quality range and
                                           footnotes)           required \1\              considerations. \1\
----------------------------------------------------------------------------------------------------------------
1. Ion exchange (IE)....................        (\a\)   Intermediate...............  All ground waters.
2. Point of use (POU \2\) IE............        (\b\)   Basic......................  All ground waters.
3. Reverse osmosis (RO).................        (\c\)   Advanced...................  Surface waters usually
                                                                                      require pre-filtration.
4. POU \2\ RO...........................        (\b\)   Basic......................  Surface waters usually
                                                                                      require pre-filtration.
5. Lime softening.......................        (\d\)   Advanced...................  All waters.
6. Green sand filtration................        (\e\)   Basic.                       ...........................
7. Co-precipitation with Barium sulfate.        (\f\)   Intermediate to Advanced...  Ground waters with suitable
                                                                                      water quality.
8. Electrodialysis/electrodialysis        ............  Basic to Intermediate......  All ground waters.
 reversal.
9. Pre-formed hydrous Manganese oxide           (\g\)   Intermediate...............  All ground waters.
 filtration.
10. Activated alumina...................  (\a\), (\h\)  Advanced...................  All ground waters;
                                                                                      competing anion
                                                                                      concentrations may affect
                                                                                      regeneration frequency.
11. Enhanced coagulation/filtration.....        (\i\)   Advanced...................  Can treat a wide range of
                                                                                      water qualities.
----------------------------------------------------------------------------------------------------------------
\1\ National Research Council (NRC). Safe Water from Every Tap: Improving Water Service to Small Communities.
  National Academy Press. Washington, D.C. 1997.
\2\ A POU, or ``point-of-use'' technology is a treatment device installed at a single tap used for the purpose
  of reducing contaminants in drinking water at that one tap. 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 must
  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.

[[Page 445]]


\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 systems. Since the process requires static
  mixing, detention basins, and filtration, it is most applicable to systems with sufficiently high sulfate
  levels that already have a suitable filtration treatment train in place.
\g\ This technology is most applicable to small systems that already have filtration in place.
\h\ Handling of chemicals required during regeneration and pH adjustment may be too difficult for small systems
  without an adequately trained operator.
\i\ Assumes modification to a coagulation/filtration process already in place.


                Table D--Compliance Technologies by System Size Category for Radionuclide NPDWR's
----------------------------------------------------------------------------------------------------------------
                                          Compliance technologies \1\ for system size
                                                categories (population served)
             Contaminant              --------------------------------------------------       3,300-10,000
                                                25-500                 501-3,300
----------------------------------------------------------------------------------------------------------------
1. Combined radium-226 and radium-228  1, 2, 3, 4, 5, 6, 7, 8,  1, 2, 3, 4, 5, 6, 7, 8,  1, 2, 3, 4, 5, 6, 7. 8,
                                        9.                       9.                       9.
2. Gross alpha particle activity.....  3, 4...................  3, 4...................  3, 4.
3. Beta particle activity and photon   1, 2, 3, 4.............  1, 2, 3, 4.............  1, 2, 3, 4.
 activity.
4. Uranium...........................  1, 2, 4, 10, 11........  1, 2, 3, 4, 5, 10, 11..  1, 2, 3, 4, 5, 10, 11.
----------------------------------------------------------------------------------------------------------------
Note: \1\ Numbers correspond to those technologies found listed in the table C of 141.66(h).


[65 FR 76748, Dec. 7, 2000]