Total Maximum Daily Loads for Chlorpyrifos and Diazinon in Lower Salinas River Watershed in Monterey County, California

This page is a a summary of the Regional Water Quality Control Board Central Coast Region report on Total Maximum Daily Load for chlorpyrifos and diazinon for the Lower Salinas River Watershed, Monterey County, California (Rose et al. 2011). The summary was prepared by the Spring '11 ENVS 560/L Watershed Systems class at CSUMB.

Project Definition

Location of TMDL Project Area. Available from:[http://www.swrcb.ca.gov/centralcoast/water_issues/programs/tmdl/docs/salinas/pesticide/sal_op_tmdl_projrpt_pubrev_jan2011

The California Regional Water Quality Control Board for the Central Coast Region (CCRWQCB), in collaboration with the Environmental Protection Agency (EPA), created the Total Maximum Daily Load (TMDL) plan for the pesticides, chlorpyrifos and diazinon, for the Lower Salinas River Watershed in Monterey County, California. The final TMDL reportwas created in January 2011, and discussed in the final report hearing on May 5th, 2011.

The TMDL report addresses the impairment of approximately 195,000 acres within the Lower Salinas River in northern Monterey County by two registered organophosphate pesticides, Chlorpyrifos and Diazinon. In 2001 the EPA mandated the cancellation and restriction of chlorpyrifos and diazinon, until reassessments could ensured that safety requirements were being met (Rose et al. 2011)