On Friday July 19 2019, the Federal Circuit Court of Appeals sent the Rio Linda Elverta Community Water District and Sacramento Suburban Water District’s case regarding hexavalent chromium contamination from McClellan Air Force Base back to Federal Claims Court, determining that the lower court had misunderstood the case.

It was determined that RLECWD and SSWD’s claims were not based on a violation of the since overturned California EPA water contamination standard, but instead on the actual Cr6 contamination in the aquifer which both districts draw their water supply from.

In tests taken from wells near McClellan AFB from 2001 to 2008, the districts found above normal levels of hexavalent chromium (Cr6).


An odorless and tasteless metallic element, chromium occurs naturally in the environment and can be found in things like rocks, plants and soil. According to the Environmental Protection Agency (EPA), the two most common forms of chromium found in water are trivalent chromium (chromium-3) and hexavalent chromium (chromium-6).

A national report released Sept. 20, 2016 found unsafe levels of hexavalent chromium in tap water across the country. The Environmental Working Group (EWG), an independent advocacy group, analyzed data collected by the EPA for a nationwide test of chromium-6 contamination in drinking water.

Chromium-3 is an essential human dietary nutrient and can be found in many vegetables, fruits, meats, grains and yeast. It is known to enhance insulin, as well as help metabolize carbohydrates, fats and proteins, according to the National Institutes of Health.

Chromium-6, however, is a toxic form of the mineral. While this form does occur naturally in the environment, from the erosion of chromium deposits, chromium-6 can also be produced by industrial processes. The EPA has reported instances of chromium-6 being released into the environment from industrial pollution — leakage, poor storage or inadequate industrial waste disposal practices.

The chemical has also been connected to liver damage, reproductive problems and developmental harm, according to the EWG, and presents greater risks to infants and children, people who take antacids, and people with poorly functioning livers.

In 2013, a hydrologist hired by RLECWD and SSWD determined that the source of their Chromium-6 contamination was McClellan AFB. It’s alleged that previous to it’s closure in 2001, McClellan had used and disposed of many products containing Cr6 on the base property which borders both the RLECWD and SSWD districts.

In 2017 both districts sued the Federal Government asserting that contamination from McClellan AFB was the cause of the elevated Cr6 levels found in the wells, which now has to be treated in an expensive process before it can be delivered to consumers.

For more information, refer to the case “Rio Linda Elverta Community Water District et al. v. U.S”, case numbers 18-1761 and 18-1762, in the U.S. Court of Appeals for the Federal Circuit.