Understanding California’s Chromium MCL: What Water Operators Need to Know
Hexavalent chromium (Cr(VI)) in drinking water is a significant concern for water system operators, engineers, and utility managers in California. With the state’s stringent maximum contaminant level (MCL) for Cr(VI) reinstated at 10 parts per billion (ppb) in April 2024, utilities face ongoing challenges in ensuring compliance while maintaining operational efficiency.
Hexavalent Chromium Treatment Success at Las Lomas, California
California Water Service partnered with ATEC to proactively treat hexavalent chromium in the rural Las Lomas system. Using a Reduction-Coagulation-Filtration (RCF) process, ATEC retrofitted existing iron and manganese vessels to meet the state’s strict 10 ppb MCL. The system has delivered fully compliant water since 2016—safeguarding public health with no disruption to service.