(a) [Reserved]

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

Open Table
Contaminant MCLG (mg/l)
Antimony 0.006
Arsenic zero1
Asbestos 7 Million fibers/liter (longer than 10 µm).
Barium 2
Beryllium .004
Cadmium 0.005
Chromium 0.1
Copper 1.3
Cyanide (as free Cyanide) .2
Fluoride 4.0
Lead zero
Mercury 0.002
Nitrate 10 (as Nitrogen).
Nitrite 1 (as Nitrogen).
Total Nitrate + Nitrite 10 (as Nitrogen).
Selenium 0.05
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]


Tried the LawStack mobile app?

Join thousands and try LawStack mobile for FREE today.

  • Carry the law offline, wherever you go.
  • Download CFR, USC, rules, and state law to your mobile device.