Contaminant Level Occurrence Above the MCLG

The US Environmental Protection Agency (USEPA) sets a regulatory maximum contaminant level (MCL) or action level and a maximum contaminant level goal (MCLG) for all drinking water contaminants included in the National Primary Drinking Water Regulations (NPDWR). The MCLG is the maximum level of a contaminant in drinking water at which no known or anticipated health effect would occur. MCLGs are set based solely on the toxicity of the contaminant and represent an ideal for drinking water standards. The MCL is set as close as possible to the MCLG to protect public health, while considering available technologies and their costs to achieve contaminant removal.