Hexavalent Chromium [Cr(VI)] Maximum Contaminant Level (MCL)

The California State Water Board adopts the proposed regulations for a hexavalent chromium MCL of 10 ppb, and makes modifications to California Code of Regulations, Title 22, sections 64415, 64431, 64432, 64447.2, 64463.4, 64465, and 64481.

Click here for the State Water Resources Control Board Resolution No. 2024-0015

The State Water Board announced a proposed maximum contaminant level for Cr(VI) on March 21, 2022.

• The US EPA Federal safe MCL is 50 ppb for Total Cr
• California is the first state to establish an MCL for Cr(VI) of 10 ppb
• The State Water Board’s recent analysis shows that an MCL for hexavalent chromium of 10 ppb should be achievable for systems serving 95% of Californians.

The MCL was set to 10 ppb and adopted by the State Water Board on April 17, 2024.

(Click here for Media Release)

For more information on California’s MCL for Cr(VI), please visit:

https://www.waterboards.ca.gov/drinking_water/certlic/drinkingwater/SWRCBDDW-21-003_hexavalent_chromium.html