NATIONAL SECONDARY DRINKING WATER REGULATIONS (NSDWR)

Regulations governing the operation of public water supply systems under the Safe Drinking Water Act (SDWA). The regulations define secondary maximum contaminant levels, the maximum concentrations of certain substances in drinking water that affect its aesthetic quality. While the NSDWR set aesthetic standards for drinking water, i.e., color, odor, taste, etc., the National Primary Drinking Water Regulations (NPDWR) set standards protective of the public health.