What is the role of MCLG in water quality regulations?

The role of MCLG, or Maximum Contaminant Level Goal, in water quality regulations is to establish a non-enforceable health goal for contaminants in drinking water. MCLGs are set by the Environmental Protection Agency (EPA) and represent the level of a contaminant in drinking water at which no known or anticipated adverse effects on health would occur, allowing for a margin of safety.

MCLGs are essential because they act as a benchmark for public health protection, guiding efforts to ensure safe drinking water. Unlike Maximum Contaminant Levels (MCLs), which are enforceable standards that take feasibility and cost into account, MCLGs are purely based on health considerations and aim to reflect a safe exposure level.

This distinction highlights why the correct response is the Maximum Contaminant Level Goal, as it directly relates to the goals of drinking water safety and public health, rather than operational lower limits or liability grades associated with chemical levels.