Evaluation of Copper- and Tributyltin-Containing Compounds

In February 1994, AB 3394 was introduced by Assembly Member Byron Sher (D, Palo Alto) to address excessive discharges of copper and tributyltin into bays, estuaries, and inland surface waters. The bill would have allowed the California Regional Water Quality Control Boards (Regional Boards) to prohibit the sale, use, and discharge of copper-containing root control compounds, and copper- or tributyltin-containing cooling water additives, once the Regional Boards determined that these compounds 1) interfered with obtaining water quality objectives or 2) prevented compliance with national pollutant discharge elimination system (NPDES) permits.

The sponsors of the bill assumed that the Regional Boards have the authority to regulate the sale or use of pesticides on a local basis. However, under current law, the Department of Pesticide Regulation (DPR) h as exclusive authority to regulate the sale and use of pesticides throughout California and customarily does so through administrative rather than legislative processes. After several discussions with Assembly Member Sher, his staff, and representatives from
Publicly Owned Treatment Works (POTWs), the California Environmental Protection Agency and DPR determined that an administrative solution would quickly achieve the goals of AB 3394, under DPR’s current regulatory authority (Department of Pesticide Regulation, 1994). In August 1994, DPR, along with the cooperation and assistance of the State Water Resources Control Board (State Board) and Regional Boards, established a high-priority program to address the sale and use of copper- and tributyltin-containing pesticides.