What are drinking water standards?

Drinking water standards set the highest level of a contaminant allowed for drinking water. There are two types of standards set by the Environmental Protection Agency (EPA): primary and secondary standards. These drinking water standards were developed to regulate public drinking water. DHSS also follows these standards when sampling unregulated private drinking water to make health-based recommendations.>

Primary standards, set as Maximum Containment Levels (MCLs) are the maximum allowable amount of a contaminant in drinking water. EPA’s MCLs can be found at: https://www.epa.gov/ground-water-and-drinking-water/table-regulated-drinking-water-contaminants.

Secondary Drinking Water Regulations (SDWRs) are non-enforceable guidelines for contaminants in drinking water that may cause cosmetic or aesthetic effects (stains, odors, tastes) such as iron, manganese, or chloride. EPA’s SDWRs can be found at: https://www.epa.gov/dwstandardsregulations/secondary-drinking-water-standards-guidance-nuisance-chemicals.

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