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 disinfectant 

or 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 of 

surface 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 to 

Section 1412 of the Act, hereby identifies the following as the best technology, treatment techniques, or other 

means 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 treatment 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 level 

for 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 gross 

alpha particle activity (including radium-226 but excluding radon and uranium) is 15 pCi/L. 

(d) MCL jor beta partfcle 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 (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 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 pocket, 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—o} 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. 

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 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 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 quality 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 

Aoademy Press. Washngton, D.C. 1997. 

2A POU, or "pofntof-use" technology is a treatment device installed at a sin rye 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 plianoe, programs for long-term operafion, maintenance, and morrtonng must be provided by water uullty to ensure proper pertormance. 

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

456 
Environrnental 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 y5tems. Since the process 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 technology 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 operator. 

~ 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 (poWlabon 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, 21 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 regulations 

establish 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 iniluence 

of surface water. In addition, these regulations establish treatment technique 

requirements 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 source 

water that complies with these treatment technique requirements. The 

treatment 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 the 

raw 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 is 

not 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 by 

qualified 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 10,000 

people 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