Primary Inorganic Chemicals

Fact Sheet

• Antimony
• Barium
• Beryllium
• Cadmium
• Chromium
• Cyanide
• Fluoride
• Mercury
• Nickel
• Selenium
• Thallium

FAQ

• What are inorganic chemicals?
  • Inorganic chemicals are metals, salts, and other compounds that do not contain carbon. These chemicals sometimes contaminate water supplies because of human activity; however, many are naturally occurring in certain geographic areas.
• What are the maximum contaminant levels (MCL), maximum contaminant level goals (MCLG), possible health effects and sources for the PIOCs?
  • National Primary Drinking Water Regulations Inorganic Chemicals Table
• Where and how often do samples for PIOCs need to be collected?
  • Sampling for PIOCs must be taken at the entry point to the distribution system after all treatment. The Standardized Monitoring Framework established by the U.S. EPA is followed for compliance cycles. Sampling for ground water systems is required once every three years and for surface water systems once every year. Sampling requirements will increase for any water system with a result at or above the MCL. Waivers may be issued to reduce the frequency of sampling to once every nine years.

Publications

• Standardized Monitoring Framework: A Quick Reference Guide