## APPENDIX A-2

NATIONAL PRIMARY DRINKING WATER STANDARDS

## NATIONAL PRIMARY DRINKING WATER STANDARDS

Contaminants MCLG (mg/L) 1 4 

### MCL or TT (mg/L) 2 3 4 Inorganic Chemicals Antimony 0.006 0.006 Arsenic none5 0.01 Asbestos (fiber > 10 micrometers) 7 million fibers per Liter 7 MFL Barium 2 2 Beryllium 0.004 0.004 Cadmium 0.005 0.005 Chromium (total) 0.1 0.1 Copper 1.3 Action Level= 1.3; TT 6 Cyanide (as free cyanide) 0.2 0.2 Fluoride 4.0 4.0 Lead zero Action Level= 0.015; TT 6 Inorganic Mercury 0.002 0.002 Nitrate (measured as Nitrogen) 10 10 Nitrite (measured as Nitrogen) 1 1 Selenium 0.05 0.05 Thallium 0.0005 0.002 Organic Chemicals Acrylamide zero 1 mg/L equivalent TT7 Alachlor zero 0.002
Atrazine 0.003 0.003 Benzene zero 0.005 Benzo[a]pyrene zero 0.0002 Carbofuran 0.04 0.04 Carbon Tetrachloride zero 0.005 Chlordane zero 0.002 Chlorobenzene 0.1 0.1 Chlorine 4.0 MRDLG8 4.0 MRDL8 2,4-D 0.07 0.07 Dalapon 0.2 0.2 1,2-Dibromo-3-chloropropane (DBCP) zero 0.0002 o-Dichlorobenzene 0.6 0.6 p-Dichlorobenzene 0.075 0.075 1,2-Dichloroethane zero 0.005 1-1-Dichloroethylene 0.007 0.007 cis-1, 2-Dichloroethylene 0.07 0.07
trans-1,2-Dichloroethylene 0.1 0.1 Dichloromethane zero 0.005 1-2-Dichloropropane zero 0.005 Di(2-ethylhexyl)adipate 0.4 0.4 Di(2-ethylhexyl)phthalate zero 0.006 Dinoseb 0.007 0.007 Dioxin (2,3,7,8-TCDD) zero 0.00000003 Diquat 0.02 0.02 Endothall 0.1 0.1 Endrin 0.002 0.002

A-2-1

## NATIONAL PRIMARY DRINKING WATER STANDARDS (CONTINUED)

Contaminants MCLG (mg/L) 1 4 

### MCL or TT (mg/L) 2 3 4 Epichlorohydrin zero 20 mg/L equivalent TT7 Ethylbenzene 0.7 0.7 Ethylene Dibromide zero 0.00005 Glyphosate 0.7 0.7 Heptachlor zero 0.0004 Heptachlor Epoxide zero 0.0002 Hexachlorobenzene zero 0.001 Hexachlorocyclopentadiene 0.05 0.05 Lindane 0.0002 0.0002 Methoxychlor 0.04 0.04 Oxamyl (Vydate) 0.2 0.2 Polychlorinated biphenyls (PCBs) zero 0.0005 Pentachlorophenol zero 0.001 Picloram 0.5 0.5 Simazine 0.004 0.004 Styrene 0.1 0.1 Tetrachloroethylene zero 0.005 Toluene 1 1 Total Trihalomethanes (TTHMs) including: Bromodichloromethane Bromoform Chloroform Dibromochloromethane none 5 0.08

Toxaphene zero 0.003 2,4,5-TP (Silvex) 0.05 0.05 1,2,4-Trichlorobenzene 0.07 0.07 1,1,1-Trichloroethane 0.20 0.2 1,1,2-Trichloroethane 0.003 0.005 Trichloroethylene zero 0.005 Vinyl Chloride zero 0.002 Xylenes (total) 10 10

Notes
1 M aximum Contaminant Level Goal (MCLG) - The maximum level of a contaminant in drinking water at which no known or anticipated adverse

effect on the health effect of persons would occur, and which allows for an adequate margin of safety. MCLGs are non-enforceable public health goals.
2 Maximum Contaminant Level (MCL) - The maximum permissible level of a contaminant in water which is delivered to any user of a public

water system. MCLs are enforceable standards. The margins of safety in MCLGs ensure that exceeding the MCL slightly does not pose significant risk to public health.
3 Treatment Technique - An enforceable procedure or level of technical performance which public water systems must follow to ensure control

of a contaminant.
4 Units are in milligrams per Liter (mg/L) unless otherwise noted.
5 MCLGs were not established before the 1986 Amendments to the Safe Drinking Water Act. Therefore, there is no MCLG for this contaminant.
6 Lead and copper are regulated in a Treatment Technique which requires systems to take tap water samples at sites with lead pipes or copper pipes

that have lead solder and/or are served by lead service lines. The action level, which triggers water systems into taking treatment steps if exceeded in more than 10% of tap water samples, for copper is 1.3 mg/L, and for lead is 0.015mg/L.
7 Each water system must certify, in writing, to the state (using third-party or manufacturer' s certification) that when acrylamide and

epichlorohydrin are used in drinking water systems, the combination (or product) of dose and monomer level does not exceed the levels specified, as follows:

• Acrylamide= 0.05% dosed at 1 mg/L (or equivalent) 0.01% dosed at 20 mg/L (or equivalent) = Epichlorohydrin • 8 Maximum Residual Disinfectant Level Goals and Levels (MRDLG and MRDL).

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