Middle Fork Project AQ 11 – Water Quality Technical Study Plan Report Overview March 10, 2008

Study Objectives Characterize physical, chemical, and bacterial water quality conditions in the bypass reaches and the peaking reach, comparison reaches, and Project reservoirs and diversion pools. Compare water quality conditions to the Central Valley Regional Water Quality Control Board (CVRWQCB 1998) Basin Plan objectives and water quality objectives.

Water Quality Study Objectives and Related Study Elements and Reports Study Objective Characterize physical, chemical, and bacterial water quality conditions in the bypass reaches and the peaking reach, comparison reaches, and Project reservoirs and diversion pools and compare to the CVRWQCB Basin Plan objectives and water quality standards. Complete 2007 Water Quality Field Program Conduct in-situ Field Measurement Sampling Conduct General Water Quality Sampling Conduct Coliform Sampling Conduct Fish Tissue Analysis Conduct Voluntary Enhanced Water Quality Sampling Document 2007 Water Quality Sampling Results in this report Consult with Aquatic TWG Determine if Additional Water Quality Sampling is Needed Determine if Additional Fish Tissue Analyses are Needed Determine if Additional Water Quality Sampling is Needed to Address any Macroinvertebrate Issues Develop Recommendations and Prepare Contingency Studies, if necessary Complete 2008 Contingency Water Quality Field Program, if necessary Document 2008 Water Quality Sampling Results in Water Quality Report (2009), if necessary

TSP Variances General Water Quality Sampling Fish Tissue Sampling Middle Fork American River peaking reach sampling Manganese sampling Fecal Coliform Sampling Fish Tissue Sampling Fish tissue analysis – French Meadows Reservoir Voluntary Enhancements Leakage channels and weirs Update of Basin Plan Fish tissue sampling

Existing Water Quality Objectives Water quality analytical results were compared to: The Sacramento River Basin and San Joaquin River Basin Plan Water Quality Control Plan (Basin Plan) California Toxics Rule (CTR) National Toxics Rule (NTR) Fish tissue analysis results were compared to: California’s Office of Environmental Health and Hazard Assessment (OEHHA) guidelines

Water Quality Results Rivers and Streams In-situ field measurements General water quality parameters Voluntary enhanced water quality sampling Coliform sampling

Water Quality Monitoring Locations

River and Stream In-situ Field Measurement Results All measurements met listed objectives or were within expected ranges, except: Dissolved oxygen Duncan Creek above Middle Fork American River confluence in spring Middle Fork American River above Duncan Creek confluence in spring Middle Fork American River below Duncan Creek confluence in spring *** These locations were not surveyed in the fall due to unsafe field conditions accessing the sampling locations.

River and Stream General Water Quality Parameter Results All general parameters and dissolved metals analyzed and total mercury samples met listed objectives or were within expected ranges, except: Dissolved manganese Middle Fork American River below French Meadows gaging station in fall

Voluntary Enhanced Water Quality Sampling Below Hell Hole Reservoir Below French Meadows Reservoir

Voluntary Enhanced Water Quality Sampling Hell Hole Dam All in-situ field measurements and general water quality parameters met listed objectives French Meadows Dam In-situ field measurements pH and dissolved oxygen did not meet water quality objectives General water quality parameters Iron and manganese concentrations exceeded water quality objectives

Fecal Coliform Sampling Locations

River and Stream Coliform Sampling All fecal coliform results in spring and fall met listed objectives, except: North Fork Long Canyon Creek (RM3.0) in fall Ralston Afterbay near the Ralston picnic area Exceeded objectives on one day during 30-day, 5 sample sampling

Reservoir Water Quality Results Reservoirs In-situ field measurements General water quality parameters

Reservoir In-situ Field Measurement Results All measurements met listed objectives or were within expected ranges, except: Dissolved oxygen Hell Hole Reservoir in fall French Meadows Reservoir in spring and fall Two locations in spring One location in fall

Reservoir General Water Quality Parameter and Fecal Coliform Results All general parameters and dissolved metals analyzed and total mercury samples met listed objectives or were within expected ranges. All fecal coliform results in spring and fall met listed objectives.

Fish Tissue Collection and Analysis for Methyl Mercury Sample Locations: Hell Hole Reservoir French Meadows Reservoir Middle Fork Interbay Ralston Afterbay Middle Fork American River near Otter Creek confluence

Fish Tissue Analysis Results Methyl mercury concentrations in at least 1 fish from each location exceeded the OEHHA screening value (0.08 mg/kg fish). 23 of 45 individual fish analyzed exceeded the screening value. Highest concentrations were measured in fish from Hell Hole Reservoir, where largest fish were caught.

Fish Tissue Analysis Results