Publications and Information Resources

Groundwater Treatment - Hexavalent Chromium

Pilot Testing Strong Base Anion Exchange for CrVI Removal

California will be the first state in the nation to regulate hexavalent chromium (CrVI) in drinking water. To comply with the MCL, a California utility conducted extensive pilot studies to determine the best‐performing ion exchange resin, empty bed contact time (EBCT), and hydraulic loading rate (HLR).

Hexavalent Chromium Treatment with Strong Base Anion Exchange

Water Research Foundation Project 4488 – This project demonstrated hexavalent chromium [Cr(VI)] treatment performance of strong base anion exchange (SBA-IX) and chemical reductive media (CRM) technologies.

Optimization of strong-base anion exchange O&M costs for hexavalent chromium treatment

Hexavalent chromium [Cr(VI)] in drinking water is pending regulation in California and is being considered for regulation in other locations. While strong-base anion exchange (SBA-IX) can efficiently remove Cr(VI) to low-levels that may be required to comply with future MCLs, operational and maintenance (O&M) costs can be considerable if the spent brine is disposed of as hazardous waste.

Total Chromium and Hexavalent Chromium Occurrence Analysis

Total and hexavalent chromium occurrence in the United States was investigated using three available datasets. The National Chromium and Boron Occurrence Survey, the US Environmental Protection Agency database of chromium from the Second Six‐Year Review, and California Department of Public Health water quality analysis data were obtained and analyzed.

Full‐scale demonstration testing of hexavalent chromium reduction via stannous chloride application

The best available technologies for hexavalent chromium [Cr(VI)] treatment can be cost prohibitive and operationally complex. Direct stannous [Sn(II)] chloride application to reduce Cr(VI) to trivalent chromium is an alternative treatment approach that could substantially decrease treatment costs.

Strong Base Anion Exchange Treatment and Brine Minimization for Hexavalent Chromium Removal

The overarching goal of this Proposition 50 research is to understand the cost implications of advances in SBAIX brine minimization with state-of-the-art brine treatment technologies, reuse schemes, and newly developed SBA-IX resins.