### Environmental Protection Agency

§ 141.65 Maximum residual disinfectant levels. (a) Maximum residual disinfectant levels (MRDLs) are as follows:

Disinfectant residual I MRDL (m911)

chbdne ................................................ a.o (as ci

~ ).
cMOramines ......................................... a.o (as ci,). chbrine d6oride ................................... 0.8 (as OiOx).

(b) Compliance dates—(1) CWSs and NTNCWSs. Subpart H systems serving 10,000 or more persons must comply with this section beginning January 1, 2002. Subpart H systems serving fewer than 10,000 persons and systems using oniy ground water not under the direct influence of surface water must comply with this subpart beginning January 1, 2004.(2) Transient NCWSs. Subpart H systems serving 10,000 or more persons and using chlorine dioxide as a disinfectantor oxidant must comply with the chlorine dioxide MRDL beginning January 1, 2002. Subpart H systems serving fewer than 10,000 persons and using chlorine dioxide as a disinfectant or oxidant and systems using only ground water not under the direct influence ofsurface water and using chlorine dioxide as a disinfectant or oxidant must comply with the chlorine dioxide MRDL beginning January 1, 2004. (c) The Administrator, pursuant toSection 1412 of the Act, hereby identifies the following as the best technology, treatment techniques, or othermeans available for achieving compliance with the maximum residual disinfectant levels identified in paragraph (a) of this section: control of treatment

### processes to reduce disinfectant demand and control of disinfection treat

### ment processes to reduce disinfectant levels.
[63 FR 69465, Dec. 16, 1998, as amended at 66 FR 3776, Jan. 16, 2001]

§ 141.66 Maximum contaminant levels for radionuclides. (a) [Reserved] (b) MCL J'or combined radium-226 and
-228. The maximum contaminant levelfor combined radium-226 and radium228 is 5 pCi/L. The combined radium-226 and radium-228 value is determined by the addition of the results of the anal- 

### § 141.66

ysis for radium-226 and the analysis for radium-228. (c) MCL Jor gross alpha particle activity (ercluding radon and uranium). The maximum contaminant level for grossalpha particle activity (including ra### dium-226 but excluding radon and uranium) is 15 pCi/L. (d) MCL jor beta partfcle and photon radioactivity. (1) The average annualconcentration 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 (mreml 

### year). (2) Except for the radionuclides listed

### in table A, the concentration of manmade radionuclides causing 4 mrem total body or organ dose equivalents 

### must be calculated on the basis of 2 liter per day drinking water intakeusing the 168 hour data list in "Maximum Permissible Body Burdens and Maximum Permissible Concentrations of Radionuclides in Air and in Waterfor Occupational Exposure," NBS (National Bureau of Standards) Handbook69 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 documentare 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 pocket, 401 M Street, SW., Washington, DC 20460; or 

### at the National Archives and RecordsAdministration (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

— o} federal

— regulations/ ibr locations.html. If two or more radionuclides are present, the sum of their annual dose equivalent to thetotal body or to any organ shall not exceed 4 mrem/year.

455§ 141.66

TABLE A—AVERAGE ANNUAL CONCENTRATIONS ASSUMED TO PRODUCE: A TOTAL BODY OR

ORGAN DOSE OF 4 MREM/YR

1. Radionudide ..... I CAtiCaI organ ........ I pCi per Iiter 2. Tritlum .............. Total body ............ 20.000 3. Strontium-90 ..... Bone Marrow ........ 8



### (e) MCL for uranium. The maximum contaminant level for nranium is 30 

### μgl
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 40 CFR Ch. 1(7

- 1

- 09 EdiHon)

and compliance shall be determined in accordance with the requirements of§§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 technologfes (BATs) Ior 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 levelsfor 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 I BAT

1. Combined radium-226 and radium-228 .................................. lon exchange, reverse osmosis, lime softening.
2. Uranium ................................................................................... lon exchange, reverse osmosis, lime softening, coagulatlonlfdtration.
3. Gross alpha partlde activiry (exduding Radon and Uranium) Reverse osmosls.
4. Beta partide and photon radioactivlty ..................................... lon exchange, reverse Osmosis.


### (h) 3Sma11 systems compliance technologies Zfst 

### for radionuclides.

TABLE C—LIST OF SMALL SYSTEMS COMPLIANCE TECHNOLOGIES FOR RADIONUCLIDES AND

LIMITATIONS TO USE

Unit technologies Umitatlons(see footnotes) Operator skll level required

~ Raw water q uality ran and oonsiderations.

~

1. lon exchar.ge (IE) ............................. (•) Intennediate

................................... AII ground waters.
2. Point of use (POU 2 ) IE .................... (") Basie

.............................................. AII ground waters.
3. Reverse osmosis (RO) ..................... Advanced

....................................... Surface waters usually require prefiltration.
4. POUz RO ......................................... (") Bas7o

.............................................. Surface waters usually require prefiltraGon. S. Lime softening .................................. (a) Advanced

....................................... AII waters.
6. Green sand fihration ......................... (•) Basic.
7. Co-preapita6on with Barium sulfate 0 Intennediate to Advanoed .............. Ground waters with suitable water quality.
8. Elearodlaysis/electrodialysis rever .

.................... Basic to Intermediate ..................... AII grourid waters. sal.
9. Pre•for(ned hydr0us Manganese (a) Intermediate

................................... AII ground waters.
oxltle filtration. 10. Activated alum na ........................... (°), (h) Advanoed

....................................... AII ground waters: oompeting anion concentrations may affect regenerat;on trequency.
11. Enhanced ooaguiatioNfiltration ...... () Advanoed

....................................... Can treat a wide range of water qualioes.
I National Research Coundl (NRC ) . Safe Water from Every Tap: Improving Water Servioe to Small Communifies. National Aoadem y Press. Washngton, D.C. 1997. 2A POU, or "pofntof-use" technology is a treatment device installed at a sin ry e tap used for the purpose of redud ng Contaminants in drinldng water at that one tap. POU devioes are typically installed at the tdtchen tap. See the April 21, 2006NODA for more details. Limitauons Footnotea: Techndogies for Radionudides:.The regeneratlon soluUon oontains Irgh oorxcentraUons of the oontaminant ions. Disposal options should be carefully ooiuidered before choosing this technology. b When POU devioes are used for oom p lianoe, programs for long-term operafion, maintenance, and morrtonng must be provided by water uullty to ensure proper pertormance.

~ Reject water di sposa I op nons shoWd be carefully considered before choosing this technology. See ofher RO limitations desafbed in the SWTR Compliance Technologies Table.

456Environrnental Protection Agency § 141.70

aThe oombinaUon of variable source water quality and the complexity of the water dlemistry irrvoNed may make this technology too oomWex for small surface water systems. Removal effidencies can vary depending on water quality. 'This technology may be very limited in applicabon to small s y5 tems. Since the p rocess requtres staoc mixing, deten5on basins, and filtration, it Is most applicable to systeme with sufficdendy high suHate levels that already have a suitable filtration treatment train in place. 9ThiS technol og y is most applicable to small systems fhat already have fiRration in place."Handiing of chemicals required dunng regenerabon and pH adjustment may be too ditficWt for small systems without an adequately trained o pe rator.

~ Assumes modification to a ooagulatiorVfittration process already in place.

TABLE D-COMPLIANCE TECHNOLOGIES BY SYSTEM SIZE CATEGORY FOR RADIONUCLIDE NPDWR'S

Compliance techndogies+ for system size categories

Contaminant 

# I (p oWlabon served) 3,300-10,000

25

- M 1 501-3.300

1. Combined radium-226 and radlum-228 I 1, 2,1 4, 5, 6, 7, 8, 9..... I 1, 2, 3, 4, 5, 6, 7, 8, 9..... ( 1, 2, 3, 4, 5, 6, 7. 8, 9.
2. Gross alpha par6de adivity ................... 3, 4................................... 3, 4................................... 3. 4. 3. Beta partlde acGviry and photon activity 1, 2, 3, 4 .......................... 1, 2, 3, 4.......................... 1, 2 1 3.4 4. Uranium .................................................. 1. 2, 4, 10, 11 .................. 1, 2, 3, 4, 5, 10, 11 .......... 1, 2, 3, 4. 5, 10. 11.
No7E: ' Numbers correspond to those tedmologies fourkl listed in th9 table C of 141.86(h).

[65 FR 76748, Dec. 7, 20001

Subpart H-Filtration and Disinfection

SOURCE: 54 FR 27527, June 29, 1989, unless otherwise noted.

11141.70 General requirements. 

### (a) The requirements of this subpart H constitute national primary drinking water regulations. These regulationsestablish criteria under which filtration is required as a treatment technique for public water systems supplied by a surface water source and public water systems supplied by a ground water source under the direct iniluenceof surface water. In addition, these regulations establish treatment techniquerequirements in lieu of mazimum contaminant levels for the following contaminants: Giard4a lamblia, viruses, 

### heterotrophic plate count bacteria, Legtonella, and turbidity. Eaeh public water system with a surface water 

### source or a ground water source under the direct influence of surface water must provide treatment of that sourcewater that complies with these treatment technique requirements. Thetreatment technique requirements consist of installing and properly operating water treatment processes which 

### reliably achieve:(1) At least 99.9 percent (3-log) removal and/or inactivation of Giardia Iambtia cysts between a point where theraw water is not subject to recontamination by surface water runoff and a point downstream before or at the first customer; and(2) At least 99.99 percent (4-log) removal and/or inactivation of viruses between a point where the raw water isnot subject to reeontamination by surface water runoff and a point downstream before or at the first eustomer. (b) A public water system using a surface water source or a ground water source under the direct influence of surface water is considered to be in compliance with the reqnirements of paragraph (a) of this section if: (1) It meets the requirements for avoiding filtration in § 141.71 and the disinfection requirements in § 141.72(a);



### or (2) It meets the filtration requirements in § 141.73 and the disinfection requirements in § 141.72(b). (c) Each public water system using a surface water source or a ground water 

### source under the direct influence of surface water must be operated byqualified personnel who meet the requirements specified by the State. (d) Addittonal requirements jor systems serving at least 10,000 people. In addition to complying with requirements in this subpart, systems serving a.t least 10,000people must also comply with the requirements in subpart P of this part. (e) Additional requirements for systems Serving jewer than 10,000 people. In addition to complying with requirements in this subpart, systems serving fewer than 10,000 people must also comply



### 457