In-Delta Storage ProgramWater Quality

Field Investigations

Stakeholders Committee MeetingJanuary 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:Water Quality Studies Conducted:

1999199920002000

200220022003200320042004

Multi-year, long term studiesMulti-year, long term studies

1999 and 2000 studies focused on peat soil

2002 and 2003 studies included biological productivity

mesocosms or physical models of thereservoir 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 onMarch 12, 2002

maintained 4’ and 8’ depth with river water

drained reservoirs August 7, 2002 to a maintained1’ 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 absorbance @ 254nm• Chlorophyll a and pheophytin a• Zooplankton and phytoplankton• Macrophytes and fish

this photo seven weeks post-filling

tanks drained July 30 through August 7simulating reservoir releases

inside of “drained reservoir” short tank

tall tank

river watercontrol 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

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5-Nov 13-Feb 24-May 1-Sep 10-Dec 20-Mar

DO

C m

g/L

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