Code of Federal Regulations > Title 40 > Chapter I > Part 192 > Subpart A > Appendix - Table 1 to Subpart A of Part 192—Maximum Concentration of Constituents for Groundwater Protection

Regulations last checked for updates: May 18, 2024

Title 40 - Protection of Environment last revised: May 16, 2024

Appendix - Table 1 to Subpart A of Part 192—Maximum Concentration of Constituents for Groundwater Protection

Constituent concentration ¹	Maximum
Arsenic	0.05
Barium	1.0
Cadmium	0.01
Chromium	0.05
Lead	0.05
Mercury	0.002
Selenium	0.01
Silver	0.05
Nitrate (as N)	10.
Molybdenum	0.1
Combined radium-226 and radium-228	5 pCi/liter
Combined uranium-234 and uranium-238 ²	30 pCi/liter
Gross alpha-particle activity (excluding radon and uranium)	15 pCi/liter
Endrin (1,2,3,4,10,10-hexachloro-6,7-exposy-1,4,4a,5,6,7,8,8a-octahydro-1,4-endo,endo-5,8-dimethanonaphthalene)	0.0002
Lindane (1,2,3,4,5,6-hexachlorocyclohexane, gamma insomer)	0.004
Methoxychlor (1,1,1-trichloro-2,2′-bis(p-methoxyphenylethane))	0.1
Toxaphene (C10 H10 Cl6, technical chlorinated camphene, 67-69 percent chlorine)	0.005
2,4-D (2,4-dichlorophenoxyacetic acid)	0.1
2,4,5-TP Silvex (2,4,5-trichlorophenoxypropionic acid)	0.01

¹ Milligrams per liter, unless stated otherwise.

² Where secular equilibrium obtains, this criterion will be satisfied by a concentration of 0.044 milligrams per liter (0.044 mg/l). For conditions of other than secular equilibrium, a corresponding value may be derived and applied, based on the measured site-specific ratio of the two isotopes of uranium.

[60 FR 2866, Jan. 11, 1995]

authority: Sec. 275 of the Atomic Energy Act of 1954, 42 U.S.C. 2022,as,Pub. L. 95-604, as amended

source: 48 FR 602, Jan. 5, 1983, unless otherwise noted.