Central Valley Water Districts Get OK to Sue Dow, Shell Over Groundwater Pollution

A state appeals court has upheld California’s cleanup standards for a cancer-causing chemical that was added to pesticides and has polluted groundwater in the Central Valley, rejecting challenges by manufacturers that may have to pay the costs.

The State Water Resources Control Board’s 2017 mandate for removing nearly all TCP (1,2,3-trichloropropane) from drinking water was contested by the California Manufacturers and Technology Association, representing Dow Chemical Co. and Shell Oil, which included the chemical in worm-killing fumigants widely used by farmers through the 1980s. They argued that the board’s criteria were not “economically feasible,” as required by state law.