Definitions for "MCLG"
a nonenforceable health goal established by the EPA, and implies the optimal level of the substance in drinking water at which no adverse health effects are anticipated to occur
a suggested level set by EPA as a guideline for water utilities
Maximum Contaminant Level Goal. Compare? The maximum level of a contaminant that is associated with no adverse health effects from drinking water containing that contaminant over a lifetime. For chemicals believed to cause cancer, the MCLGs are set at zero. MCLGs are not enforceable, but are ideal, health-based goals which are set in the National Primary Drinking Water Standards developed by EPA. MCLs are set as close to MCLGs as possible, considering costs and technology.