In-Delta Storage Program Water Quality Field Investigations Stakeholders Committee Meeting January 22, 2003 Robert DuVall

Overview of field studiesOverview of field studies Organic carbon loading algorithmOrganic carbon loading algorithm Next stepsNext steps OutlineOutline

Water Quality Studies Conducted: Multi-year, long term studies Water Quality Studies Conducted: Multi-year, long term studies

1999 and 2000 studies focused on peat soil 2002 and 2003 studies included biological productivity mesocosms or physical models of the reservoir islands one soil depth (0.5 m or 1.5 feet) two water depths (4 and 8 feet) four reps and a river water control tank

Bioproductivity in one of the tanks

collected soil from Bacon Island March 5, 2002

added 1.5’ soil then Sacramento River water on March 12, 2002 maintained 4’ and 8’ depth with river water drained reservoirs August 7, 2002 to a maintained 1’ depth

added Egeria fragments to each tank

added fish to each tank

Water Sampling THMFP, TOC and DOC Temperature, DO, pH and secchi depth Total and dissolved nutrients Total mercury Turbidity and UV 254nm Chlorophyll a and pheophytin a Zooplankton and phytoplankton Macrophytes and fish

this photo seven weeks post-filling

tanks drained July 30 through August 7 simulating reservoir releases

inside of “drained reservoir” short tank

tall tank

river water control tank

Carbon Loading Algorithm Old logic based on fitting a logistic equation to tank data New studies are focused on ecological processes and mechanisms Looking at different loading sources and different loading rates over time

For example, abiotic leaching may at times be the dominant source of loading and driven by temperature. Other factors, such as algal blooms or vascular plant decomposition may play important roles at different times. These and other questions are being addressed through integration of field experiments and modeling.

Next Steps Simulate flow through operations Use knowledge gained from field studies and modeling to manage or avoid water quality problems

Use field studies to develop logic in DSM2 and CALSIM Simulate flow through operations Better evaluate water quality effects and project yield