Steve Bigely, Coachella Valley Water District Director of Environmental Services, explains why chromium-6 is found in the ground water of the Coachella Valley. The California Department of Public Health recently released the nation's first draft Maximum Contaminant Level (MCL) for chromium-6 in drinking water. Chromium-6 occurs naturally in Coachella Valley groundwater. If the state's proposed limit is adopted, approximately half the drinking water CVWD delivers is expected to be above this new standard. The cost to design, construct and maintain new treatment facilities to meet the standard could raise water rates by as much as $50 per month, according to preliminary estimates.