SCH Number 2021110099

Project Info

Title

Adoption of a Regulation for the Hexavalent Chromium Maximum Contaminant Level

Description

The State Water Board is proposing to adopt a primary drinking water standard for hexavalent chromium (Proposed Regulations) under the California Safe Drinking Water Act. The Proposed Regulations include a maximum contaminant level (MCL) for hexavalent chromium of 10 micrograms per liter (µg/L) and a detection limit for purposes of reporting of 0.1 micrograms per liter (µg/L). Public water systems, depending on type, would be required to monitor their drinking water for hexavalent chromium on an initial and ongoing basis. Public water systems would need to comply with the MCL according to a compliance schedule, and prepare Hexavalent Chromium MCL Compliance Plans, as required. The Proposed Regulations include three best available technologies for removing hexavalent chromium from drinking water sources, including reduction/coagulation/filtration, ion exchange, and reverse osmosis. Public water systems using new or modified treatment for hexavalent chromium would need to prepare Hexavalent Chromium Operations Plans. Public water systems are not limited to using best available technologies and may consider other means of compliance, such as blending, drilling a new well, increasing reliance on surface water, purchasing water from, or consolidating with another water system, or using another form of treatment such as stannous chloride. The Proposed Regulations also specify laboratory methods for analyzing hexavalent chromium in drinking water.

4 documents in project