California proposed a standard for hexavalent chromium in drinking water.
According to CalMatters, traces of hexavalent chromium, also known as chromium-6, are found in the drinking water of millions of Californians. The contamination can occur naturally as well as from industries that work with the heavy metal.
The standard would be a first in the U.S. to specifically target hexavalent chromium. According to CalMatters, several hundred drinking water wells throughout the state exceed the State Water Resources Control Board’s proposed standard of 10 parts per billion (ppb).
The proposed standard will lead to higher monthly rates for many residents, according to water suppliers, reported Cal Matters.
Under the water board’s proposal 10 ppb would be the maximum allowable amount in drinking water.
The proposal is only a draft and is now released to solicit public comment before starting the regulatory process. According to CalMatters, an official drinking water standard will likely be finalized in early 2024. The limit is expected to be tested in court, which also occurred in 2014, when the state set a standard of 10 ppb, which was overturned in 2017 due to economic feasibility.
According to state data, 129 community drinking water systems have reported hexavalent chromium levels above the proposed standard. These drinking water systems serve more than 4.1 million people, reported CalMatters. The highest level reported by the state is in Ventura County, according to CalMatters. One drinking water well was reported with 173 ppb.
Latino communities and those with populations of other people of color are more likely to have drinking water with average levels of hexavalent chromium above 5 ppb, according to a study conducted by Lara Cushing, a UCLA assistant professor of environmental health.
Current federal and California drinking water standards combine hexavalent chromium and trivalent chromium, reported CalMatters. Federal drinking water standards cap total chromium at 100 ppb and California at 50 ppb.
Once a standard is finalized water suppliers will be tasked with removing the chemical from drinking water to below 10 ppb, otherwise they may face penalties that could include fines of up to $1,000 a day.