Earlier this month, Judge Christopher E. Krueger of the Sacramento Superior Court issued an order invalidating the Maximum Contaminant Level (MCL) for hexavalent chromium. The California Department of Public Health (“DPH”) established an MCL of 10 μg/L, or parts per billion (ppb), pursuant to a rulemaking effort that concluded in 2014. (This rulemaking function has since been legislatively transferred to the State Water Resources Control Board (“State Board”), Division of Drinking Water as of July 1, 2014.) Hexavalent chromium is the chemical made famous by the movie Erin Brockovich.
MCLs are promulgated for specific chemicals under the federal and California Safe Drinking Water Acts. Although established for drinking water programs, the MCLs are also often used as screening levels and cleanup standards at properties where potential environmental impacts are being investigated and remediated. California MCLs are required under the state Safe Drinking Water Act to be at least as stringent as the federal MCL for a given chemical and as close to the California Public Health Goal (“PHG”) for the chemical as technically and economically feasible. The PHG, which is set by the California Office of Environmental Health and Hazard Assessment, is the level of a chemical at which it ostensibly poses no health risk. PHGs are not enforceable standards. They are, as the name implies, simply goals. The PHG for hexavalent chromium is 0.02 μg/L, or 20 parts per trillion, which is an extremely low number.
In 2014, the California Manufacturers and Technology Association and Solano County Taxpayers Association filed a petition for writ of mandate in the Sacramento Superior Court challenging the 10 ppb hexavalent chromium MCL on several grounds. Petitioners’ primary arguments were that DPH failed to consider the economic feasibility of this standard and whether the standard is, in fact, economically infeasible. They contended these defects violated both the California Administrative Procedure Act and the California Safe Drinking Water Act, with the costs of compliance prohibitively expensive for water utilities and their ratepayers, especially for small utilities.