Definitions for "Maximum contaminant levels"
enforceable drinking water standards that are protective of public health to the extent feasible with current technology.
(MCLs). Under the authority of the Safe Drinking Water Act, the U.S. EPA sets MCLs for groundwater. The National Primary Drinking Water Regulations (40 CFR 141) specify MCLs for radionuclide contaminants in drinking water. For all radionuclides, the combined dose to an individual from water consumption should not exceed 4 mrem/yr to the whole body or any internal organ.
The maximum permissible level of a contaminant in water that is delivered to a user of a public water system.