The Los Angeles Regional Water Quality Control Board (Regional Board) and the Sanitation Districts of Los Angeles County (Sanitation Districts) are jointly developing and performing a number of technical studies required by the Upper Santa Clara River Chloride Total Maximum Daily Load (TMDL). On May 6, 2004, the Regional Board adopted an amendment to the Water Quality Control Plan (Basin Plan) for the Los Angeles Region to revise the interim wasteload allocations and Implementation Plan of the Upper Santa Clara River TMDL. The Implementation Plan includes four major studies:

1. Agricultural Chloride Threshold Study: An evaluation of the scientific evidence regarding decisions on the appropriate chloride threshold for the protection of sensitive agriculture.
2. Groundwater Surface Water Interaction Model: Development of a model to determine the interaction between surface water and groundwater.
3. Endangered Species Study: An evaluation of the scientific evidence regarding the appropriate chloride threshold for the protection of endangered species.
4. Site Specific Objectives and Anti Degradation Analysis: An anti-degradation analysis and an analysis of site specific chloride objectives that may be proposed to protect beneficial uses of the river.

For more information, including project schedule and reports, visit the Upper Santa Clara River Chloride TMDL Collaborative Process.  Additional information on Santa Clara River water quality, including TMDL determination and implementation, and the regional Basin Plan, can be found at the Los Angeles Regional Water Quality Control Board.