The EPA also sets National Secondary Drinking Water Regulations (NSDWR). Secondary drinking water standards are not Federally enforceable but serve as a guideline for the States to follow. At present, there are 15 NSDWR contaminants.
- Aluminum
- Chloride
- Color
- Copper
- Corrosivity
- Fluoride
- Foaming agents
- Iron
- Manganese
- Odor
- pH
- Silver
- Sulfate
- Total dissolved solids
- Zinc
