National Primary Drinking Water Regulations (NPDWR)

National Primary Drinking Water Regulations (NPDWR) are legally enforceable standards that apply to Public Water Systems (PWSs) in the United States. These regulations are intended to protect public health by limiting the levels of harmful contaminants in drinking water. Download our Spotlight on NPDWR to learn more about the regulations as well as recent changes to sampling rules and limits on common contaminants.