26.04.01.06

.06 Maximum Contaminant Level for Inorganic Chemicals in Drinking Water.

A. With the exception of nitrate, nitrite, and total nitrate plus nitrite, all inorganic chemical contaminant levels are based on potential adverse health effects resulting from long term exposure to the contaminant in drinking water. All suppliers of water to community water systems shall comply with the MCL for fluoride. All suppliers of water to community water systems and nontransient noncommunity water systems shall comply with the MCLs for arsenic, asbestos, barium, cadmium, chromium, mercury, selenium, antimony, beryllium, cyanide, and thallium. All suppliers of water to community water systems, nontransient noncommunity water systems, and transient noncommunity water systems shall comply with the MCLs for nitrate, nitrite, and total nitrate plus nitrite. Compliance with MCLs for inorganic chemicals is determined under Regulation .14 of this chapter. The following are maximum contaminant levels for inorganic chemicals:

Contaminant

Maximum Contaminant
Level (mg/l)1
(1) Antimony 0.006
(2) Arsenic 0.010
(3) Asbestos 7 million fibers per liter
(longer than 10 Ám)
(4) Barium 2
(5) Beryllium 0.004
(6) Cadmium 0.005
(7) Chromium 0.1
(8) Cyanide (as free cyanide) 0.2
(9) Flouride 4.0
(10) Mercury 0.002
(11) Nitrate as nitrogen 10
(12) Nitrite as nitrogen 1
(13) Total nitrate plus nitrite 10
(14) Selenium 0.05
(15) Thallium 0.002
1Unless otherwise specified.

B. Notwithstanding §A(2) of this regulation, the MCL value of 0.05 milligrams per liter (mg/l) for arsenic applies to community water systems until January 22, 2006. Beginning January 23, 2006, this section is no longer applicable.

C. At the discretion of the Approving Authority, levels of nitrate and total nitrate plus nitrite not to exceed 20 milligrams/liter may be allowed in a noncommunity water system if the supplier of water demonstrates to the satisfaction of the Approving Authority that:

(1) The water is not available to children under 6 months old;

(2) The supplier will post a warning which indicates that levels of nitrate or total nitrate plus nitrite exceed 10 milligrams/liter and the potential health effects of exposure;

(3) Adverse health effects do not result; and

(4) The supplier notified county health officers and the Approving Authority annually of all nitrate or total nitrate plus nitrite levels that exceed 10 milligrams/liter.