San Lorenzo River Watershed (including San Lorenzo River, Branciforte Creek and Zayante Creeks) and Arana Gulch Watershed Chlorpyrifos TMDL
Problem Statement - The San Lorenzo River, Branciforte Creek, Zayante Creek, and Arana Gulch are considered impaired due to exceedances of the water quality objective for pesticides and toxicity; they are impaired due to chlorpyrifos. The designated aquatic habitat beneficial uses were not being supported in these waterbodies because of these impairments (2006). Recent water quality sampling (2010/2011) suggests that these waterbodies are currently meeting numeric targets for chlorpyrifos. This project identifies the probable past causes of impairment and describes existing solutions to achieve water quality objectives and protection of beneficial uses.
- November 25, 2015 - USEPA approves TMDLs for Chlorpyrifos in the San Lorenzo River Watershed and Arana Gulch Watershed.
- May 29, 2014 - Central Coast Water Board Executive Officer certifies the TMDLs for Chlorpyrifos in the San Lorenzo River Watershed and Arana Gulch Watershed.
- Certification (A formal affirmation by the Water Board approving an alternative TMDL implementation approach)
- Project Report (A technical report that provides the scientific and policy-basis for the TMDL)
- Appendix A - Raw Data in MS Excel format
- Response to Public Comments
- Shanta Keeling
Status and Public Notices
- Status: Fully approved and effective.
- Public Notice: None at this time.
- Central Coast Water Board
- Executive Officer certified May 29, 2014, which is the effective date.
- US Environmental Protection Agency
- approved November 25, 2015.