On August 1, 2017, the California State Water Resources Control Board adopted a resolution to remove the current maximum contaminant level (MCL) for the pollutant hexavalent chromium found in drinking water. The State Water Board will now begin work on establishing a new MCL for the contaminant. Hexavalent chromium, also known as chrome 6, is a naturally occurring heavy metal that is also used in a variety of industrial processes. Long-term exposure to the metal may cause cancer.
The resolution comes on the heels of a recent state court ruling in which the Superior Court of Sacramento County invalidated the MCL for hexavalent chromium, saying the state “failed to properly consider the economic feasibility of complying with the MCL.” The court did “not decide whether the MCL is economically feasible,” nor did it conclude whether the MCL was too high or too low. Rather, the court said the regulation did not adequately document why the MCL was economically feasible.
The State Board points out that it disagrees with the court’s ruling:
“While the Board disagrees with the court’s decision, it has decided not to appeal and instead will begin the process for adopting a new MCL as soon as possible. The Board will use the wealth of data collected over the last three years since the standard was adopted to help craft a new MCL. Generally, regulation development takes between 18 and 24 months to complete.”
With adoption of the resolution, Board staff will now begin the process of having the text of the current MCL deleted from the California Code of Regulations. The State Water Board must let the court know this has been done by Aug. 15. After the Office of Administrative Law approves the proposal to remove the text, it will be effective in late September.
Since the current MCL will be removed, the State Water Board will no longer enforce compliance plans that public water systems entered into for hexavalent chromium.
See: https://www.waterboards.ca.gov/press_room/press_releases/2017/pr080117_mcl_removal.pdf
