Environmental Regulations

EPA Drinking Water Standards: Key Contaminants in PPB and PPM

Review primary EPA National Drinking Water Regulations (NPDWR), Maximum Contaminant Levels (MCLs), and action levels expressed in PPB and PPM.

S
Sarah Jenkins, MS
Environmental Science Specialist

EPA Drinking Water Standards: Key Contaminants in PPB and PPM

The United States Environmental Protection Agency (EPA) sets Maximum Contaminant Levels (MCLs) for public water systems to protect human health.

Key Contaminant Benchmarks:

  1. Arsenic: MCL is 10 PPB (0.010 PPM / 0.010 mg/L).
  2. Lead: Action level is 15 PPB (0.015 PPM / 15 µg/L).
  3. Copper: Action level is 1.3 PPM (1300 PPB).
  4. Nitrate: MCL is 10 PPM (10,000 PPB).
  5. Benzene: MCL is 5 PPB (0.005 PPM).