The city of Richmond’s Department of Public Utilities has a robust water treatment plant, which produces award-winning water. The water it delivers meets and exceeds federal and state water quality standards including those regulated by the Environmental Protection Agency (EPA). Through the Safe Drinking Water Act (SDWA), the EPA mandates the monitoring of various contaminants to ensure levels found in drinking water have no adverse health effects. With ongoing research and cautionary actions prompted by various factors, the spotlight on particular contaminants occasionally rise to the level of public concern. Chromium is a recent one.
Chromium is a naturally occurring contaminant that is in water supplies. It is an odorless and tasteless metallic element. According to the EPA, “chromium is found naturally in rocks, plants, soil, volcanic dust, and animals. Chromium-6 occurs naturally in the environment from the erosion of natural chromium deposits. It can also be produced by industrial processes. There are demonstrated instances of chromium being released to the environment by leakage, poor storage, or inadequate industrial waste disposal practices.
“The national primary drinking water regulation that established the [maximum contaminant level] for total chromium of 0.1 mg/l was promulgated in 1991. The SDWA requires EPA to periodically review the national primary drinking water regulation for each contaminant and revise the regulation, if appropriate. EPA reviewed total chromium as part of the second six-year review that was announced in March 2010. The Agency noted in March 2010 that it had initiated a reassessment of the health risks associated with chromium exposure and that the Agency did not believe it was appropriate to revise the national primary drinking water regulation while that effort was in process.”
To assess the levels of chromium-6 in drinking water, EPA is requiring a selected number of systems to perform chromium-6 monitoring under the third Unregulated Contaminant Monitoring Regulation (UCMR 3). The city of Richmond has undergone four rounds of this testing. Test results have shown chromium-6 concentrations of between 0.00013 and 0.00052 mg/L. Currently, chromium-6 is unregulated by EPA.
However, there are EPA limits for total chromium, which would include the chromium-6 form. The regulatory limit for total chromium in drinking water is 0.1 mg/L. The City's results for total chromium on the same UCMR 3 testing events resulted in concentrations between 100 and 238 times lower than the EPA standard. The chromium-6 concentrations are even less. In comparison, California has some of the strictest limits for chromium-6 in the country. They set a limit of 0.01 mg/L for chromium-6 in drinking water. The City's water is well below this standard by a factor of 20 or more.
After incidents like the contaminated drinking water supply in Flint, Michigan, more people are paying closer attention to the quality of water they are consuming from their tap. Citizens should expect the providing authority to ensure the delivery of clean and safe drinking water and communicate issues openly and respond to customer questions. The city of Richmond goes above and beyond and consistently meets federal and state drinking water standards for public health.