MCL = Maximum Contaminant Limit

Maximum Contaminant Level the highest level of a contaminant that is allowed in drinking water. MCLs are set as close to PHGs and MCLGs as is economically an technologically feasible.

Primary Drinking Water Standards: primary MCLs, specific treatment techniques adopted in lieu of primary MCLs, and monitoring and reporting requirements for MCLs that are specified in regulations. Secondary MCLs are set to protect the odor, taste and appearance of the drinking water.