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Title 40Chapter ISubchapter DPart 141 → Subpart F


Title 40: Protection of Environment
PART 141—NATIONAL PRIMARY DRINKING WATER REGULATIONS


Subpart F—Maximum Contaminant Level Goals and Maximum Residual Disinfectant Level Goals


Contents
§141.50   Maximum contaminant level goals for organic contaminants.
§141.51   Maximum contaminant level goals for inorganic contaminants.
§141.52   Maximum contaminant level goals for microbiological contaminants.
§141.53   Maximum contaminant level goals for disinfection byproducts.
§141.54   Maximum residual disinfectant level goals for disinfectants.
§141.55   Maximum contaminant level goals for radionuclides.

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§141.50   Maximum contaminant level goals for organic contaminants.

(a) MCLGs are zero for the following contaminants:

(1) Benzene

(2) Vinyl chloride

(3) Carbon tetrachloride

(4) 1,2-dichloroethane

(5) Trichloroethylene

(6) Acrylamide

(7) Alachlor

(8) Chlordane

(9) Dibromochloropropane

(10) 1,2-Dichloropropane

(11) Epichlorohydrin

(12) Ethylene dibromide

(13) Heptachlor

(14) Heptachlor epoxide

(15) Pentachlorophenol

(16) Polychlorinated biphenyls (PCBs)

(17) Tetrachloroethylene

(18) Toxaphene

(19) Benzo[a]pyrene

(20) Dichloromethane (methylene chloride)

(21) Di(2-ethylhexyl)phthalate

(22) Hexachlorobenzene

(23) 2,3,7,8-TCDD (Dioxin)

(b) MCLGs for the following contaminants are as indicated:

ContaminantMCLG in mg/l
(1) 1,1-Dichloroethylene0.007
(2) 1,1,1-Trichloroethane0.20
(3) para-Dichlorobenzene0.075
(4) Aldicarb0.001
(5) Aldicarb sulfoxide0.001
(6) Aldicarb sulfone0.001
(7) Atrazine0.003
(8) Carbofuran0.04
(9) o-Dichlorobenzene0.6
(10) cis-1,2-Dichloroethylene0.07
(11) trans-1,2-Dichloroethylene0.1
(12) 2,4-D0.07
(13) Ethylbenzene0.7
(14) Lindane0.0002
(15) Methoxychlor0.04
(16) Monochlorobenzene0.1
(17) Styrene0.1
(18) Toluene1
(19) 2,4,5-TP0.05
(20) Xylenes (total)10
(21) Dalapon0.2
(22) Di(2-ethylhexyl)adipate.4
(23) Dinoseb.007
(24) Diquat.02
(25) Endothall.1
(26) Endrin.002
(27) Glyphosate.7
(28) Hexachlorocyclopentadiene.05
(29) Oxamyl (Vydate).2
(30) Picloram.5
(31) Simazine.004
(32) 1,2,4-Trichlorobenzene.07
(33) 1,1,2-Trichloroethane.003

[50 FR 46901, Nov. 13, 1985, as amended at 52 FR 20674, June 2, 1987; 52 FR 25716, July 8, 1987; 56 FR 3592, Jan. 30, 1991; 56 FR 30280, July 1, 1991; 57 FR 31846, July 17, 1992]

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§141.51   Maximum contaminant level goals for inorganic contaminants.

(a) [Reserved]

(b) MCLGs for the following contaminants are as indicated:

ContaminantMCLG (mg/l)
Antimony0.006
Arseniczero1
Asbestos7 Million fibers/liter (longer than 10 µm).
Barium2
Beryllium.004
Cadmium0.005
Chromium0.1
Copper1.3
Cyanide (as free Cyanide).2
Fluoride4.0
Leadzero
Mercury0.002
Nitrate10 (as Nitrogen).
Nitrite1 (as Nitrogen).
Total Nitrate + Nitrite10 (as Nitrogen).
Selenium0.05
Thallium.0005

1This value for arsenic is effective January 23, 2006. Until then, there is no MCLG.

[50 FR 47155, Nov. 14, 1985, as amended at 52 FR 20674, June 2, 1987; 56 FR 3593, Jan. 30, 1991; 56 FR 26548, June 7, 1991; 56 FR 30280, July 1, 1991; 57 FR 31846, July 17, 1992; 60 FR 33932, June 29, 1995; 66 FR 7063, Jan. 22, 2001]

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§141.52   Maximum contaminant level goals for microbiological contaminants.

(a) MCLGs for the following contaminants are as indicated:

ContaminantMCLG
(1) Giardia lambliazero
(2) Viruseszero
(3) Legionellazero
(4) Total coliforms (including fecal)zero
coliforms and Escherichia coli
(5) Cryptosporidiumzero
(6) Escherichia coli (E. coli)zero

(b) The MCLG identified in paragraph (a)(4) of this section is applicable until March 31, 2016. The MCLG identified in paragraph (a)(6) of this section is applicable beginning April 1, 2016.

[78 FR 10347, Feb. 13, 2013]

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§141.53   Maximum contaminant level goals for disinfection byproducts.

MCLGs for the following disinfection byproducts are as indicated:

Disinfection byproductMCLG
(mg/L)
Bromodichloromethanezero
Bromoformzero
Bromatezero
Chlorite0.8
Chloroform0.07
Dibromochloromethane0.06
Dichloroacetic acidzero
Monochloroacetic acid0.07
Trichloroacetic acid0.02

[63 FR 69465, Dec. 16, 1998, as amended at 65 FR 34405, May 30, 2000; 71 FR 478, Jan. 4, 2006]

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§141.54   Maximum residual disinfectant level goals for disinfectants.

MRDLGs for disinfectants are as follows:

Disinfectant residualMRDLG(mg/L)
Chlorine4 (as Cl2).
Chloramines4 (as Cl2).
Chlorine dioxide0.8 (as ClO2)

[63 FR 69465, Dec. 16, 1998]

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§141.55   Maximum contaminant level goals for radionuclides.

MCLGs for radionuclides are as indicated in the following table:

Contaminant MCLG
1. Combined radium-226 and radium-228Zero.
2. Gross alpha particle activity (excluding radon and uranium)Zero.
3. Beta particle and photon radioactivityZero.
4. UraniumZero.

[65 FR 76748, Dec. 7, 2000]

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