Cal. Code Regs. tit. 23 § 3917
On November 16, 2005, the San Francisco Bay Regional Water Quality Control Board (San Francisco Bay Water Board) adopted Resolution No. R2-2005-0063, amending the Water Quality Control Plan for the San Francisco Bay Region (Basin Plan). The amendment removes unnecessary text from Chapter 3 of the Basin Plan regarding chronic toxicity. It also removes text that appeared to limit how the San Francisco Bay Water Board could evaluate toxicity and replaces it with text that clarifies that the Water Board can consider all relevant information. These changes do not alter the narrative water quality objective.
The amendment establishes a water quality attainment strategy, including a Total Maximum Daily Load (TMDL), for diazinon and pesticide-related toxicity that, when implemented, is expected to meet water quality objectives and protect beneficial uses of urban creeks in the San Francisco Bay Region. The TMDL sets numeric targets for pesticide-related acute and chronic toxicity in urban creek waters and sediment. These targets require that toxicity not exceed 1.0 acute or chronic toxic units, as determined through standard toxicity tests. In addition, the proposed amendment specifies that diazinon concentrations in the water column must not exceed 100 nanograms per liter as a one-hour average. The TMDL is allocated to all urban runoff, including urban runoff associated with municipal separate storm sewer systems, California Department of Transportation facilities, and industrial, construction, and institutional sites. Allocations are set equal to the targets.
The cornerstone of the attainment strategy is pollution prevention, which can be accomplished by using less toxic pest control methods and by applying integrated pest management techniques. Implementation of the strategy will focus on (1) proactive regulatory programs, (2) education and outreach, and (3) research and monitoring. Pesticide and water quality regulators are requested to better coordinate their various programs to protect water quality. Urban runoff management agencies, regulated under National Pollutant Discharge Elimination System permits, are required to minimize pesticide use, conduct outreach, and design and implement monitoring programs to track progress in implementing the plan and meeting the targets. The monitoring program may be developed jointly by two or more agencies acting in concert. The strategy includes a method to determine appropriate monitoring benchmarks for specific pesticides in water. The need for comprehensive pesticide-related water quality monitoring may be moderated by efforts to monitor other factors, which serve as surrogates or indicators of water quality conditions.
The San Francisco Bay Water Board plans to review the attainment strategy and TMDL every five years to determine if any modifications are necessary.
Cal. Code Regs. Tit. 23, § 3917