HomeMy WebLinkAbout09.a. (Handout) Authorize agreement with the University of California, Davis, in the amount of $105,000 for Dr. Swee Teh to repeat the Full Life-Cycle Bioassay Approach Assess Chronic Exposure of Pseudodiaptomus forbesi to Ammonia studyNutrient Studies Update &
UC Davis Contract
Mary Lou Esparza
Board Meeting
June 6, 2013
Central Contra Costa Sanitary District
NPDES Permit Bay Nutrient
Studies Schedule
• Draft Work Plan
• Final Work Plan
• Studies Complete
• Final report submittal
June 1, 2012 ✓
August 1, 2012 ✓
September 1, 2014
November 1, 2014
9.a.
(94 rodari)
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Bay Nutrient Study Requirements
1. Surface Water Ambient Monitoring
Program (SWAMP) Suisun Bay Study
2. Effluent Characterization Study
3. Collaborative Nutrient Studies by Bay Area
Clean Water Agencies (BACWA)
4. Discharge Modeling
5. Copepod Study
1. SWAMP Suisun Bay Study
• CCCSD has met all participation and funding
requirements.
• Regional Board, Romberg Tiburon Center and
Water Contractors are working toward a final
report.
• Last component needed for the report is algal
speciation.
• Speciation contractor - Alemdar Consulting
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2. Effluent Characterization Study
• Required of all Bay Area POTWs via 13267 letter
• Two years of sampling, began July 1, 2012
• Monitor and report nutrient forms,
concentrations, monthly loadings and treatment
plant removals
• Data will be used for modeling nutrient loads in
San Francisco Bay
• Currently collecting data for the 4t" quarterly
report.
3. Collaborative Nutrient Studies
by BACWA
• Objective is to help advance understanding
of potential nutrient - related impacts on SF
Bay to inform future regulatory decisions
• Progress to date:
• Draft Suisun Bay Synthesis report completed
by San Francisco Estuary Institute
• Draft governance structure developed
4. Discharge Modeling
Determine whether existing sampling
stations in Suisun Bay adequately
characterize the potential impact of
CCCSD's discharge.
• RMA completed an initial round of modeling
and drafted a technical memo.
• Additional sampling is required to further
refine the model and target the spring and fall
periods which are described as the two most
sensitive time periods for Suisun Bay.
5. Copepod Study
• Target of study is to test the lifecycle effects of
food limitation (indirect toxicity) and ammonia
concentrations (direct toxicity) on the copepod
Pseudomonas Forbesi
• Offshoot of work completed in 2010 by UC Davis
researcher Dr. Swee Teh, which was the primary
scientific evidence used to require Sac Regional
to remove ammonia down to very low levels.
Study would use 2010 NH4 LOEC of 0.36 ug/L
which was questioned by CCCSD, Pacific Eco
Risk and Sac Regional.
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5. Copepod Study
• 2010 study
• Significant variability between replicates of the
control sample
• Significant variability between replicates of the
same NH4 concentration
• Variability prevented accurate calculation of the
NOEL and LOEL
• Nauplii and juveniles were not separated from
adult females and were double counted
5. Copepod Study
• Improvements
• Knowledge from past experiment
• 2 additional years in working with the copepod
• Separate the adult females from nauplii to
control predation
• Count nauplii when they are separated from the
adult female to eliminate double counting
• Focus the 31 -day life cycle test
5. Copepod Study
• CCCSD study findings will inform SFCWA on
concentrations to use for the two component
study that is required by the permit.
• The two component study is ultimately under
the control of SFCWA with results due to the
Regional Board by November 1, 2014.
• Fund an expert panel to review study plan by SFCWA
• Contribute financially to the study ($66,000)
In Closing...
• Recommend that the Board Authorize the
General Manager to execute a Professional
Services Agreement with University of
California, Davis, in the amount of $105,000