Chemicals and Contaminants in Drinking Water

Regulated Contaminants

• Drinking water standards are called maximum contaminant levels (MCLs). MCLs are found in Title 22 of the California Code of Regulations. (Go to Drinking Water Regulations and Statutes).
• Primary MCLs address health concerns — here is a comparison of federal and California MCLs (PDF).
• Esthetics such as taste and odor are addressed by secondary MCLs (PDF).
• Learn about MCLs and public health goals (PHGs).
• Standards also include detection limits for purposes of reporting (DLRs), included in this list of chemicals and characteristics (Excel) associated with the submittal of analytical results by electronic data transfer (EDT).
• Also, see chemical-specific information on arsenic, hexavalent chromium, manganese (which has a secondary MCL), MTBE, nitrate and nitrite, and perchlorate; and information about fluoridation by public water systems.

Public Notification and Information about Contaminants

• Water…