Mercury Control Program for the SacramentoSan Joaquin River

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Mercury Control Program for the Sacramento-San Joaquin River Delta Estuary San Francisco Bay RMP

Mercury Control Program for the Sacramento-San Joaquin River Delta Estuary San Francisco Bay RMP Annual Meeting October 7, 2008 Michelle Wood 1

Outline l Description of the Delta Mercury Impairment l Overview of Proposed Delta Program

Outline l Description of the Delta Mercury Impairment l Overview of Proposed Delta Program l Comparison to RMP Mercury Strategy’s High Priority Questions l Questions & Discussion 2

>1100 mi waterways Drains ~1/3 of CA on 5 Regi on 2 Regi The

>1100 mi waterways Drains ~1/3 of CA on 5 Regi on 2 Regi The Delta Sacramento San Francisco Bay Hg Control Program: Reduce Central Valley Mercury Outflows by 110 Kg/year Antioch Brentwood Stockton Tracy 3

Who eats Delta fish? Wildlife: Least tern, kingfisher, western grebes, bald eagle, osprey, &

Who eats Delta fish? Wildlife: Least tern, kingfisher, western grebes, bald eagle, osprey, & river otter 4

Who eats Delta fish? ~300, 000 licensed sport & subsistence anglers per year Unknown

Who eats Delta fish? ~300, 000 licensed sport & subsistence anglers per year Unknown # of unlicensed anglers Multiple ethnicities, communities, & income levels 5% of fish consumers in northern Delta: mercury intake rate 10 x the safe dose 5

Goal of the Proposed Delta Mercury Program: Protect fish-eating wildlife & enable humans to

Goal of the Proposed Delta Mercury Program: Protect fish-eating wildlife & enable humans to safely consume more Delta fish. 6

Proposed Fish Tissue Hg Objective for Delta Fish z) o 8 ( al 1

Proposed Fish Tissue Hg Objective for Delta Fish z) o 8 ( al 1 me week per 0. 24 mg/kg mercury in large bass & catfish 7

Average Hg Levels in Large Bass & Catfish (mg/kg) Proposed Objective: 0. 24 mg/kg

Average Hg Levels in Large Bass & Catfish (mg/kg) Proposed Objective: 0. 24 mg/kg na 0. 56 0. 92 0. 32 0. 26 na 0. 50 8

Mercury Strategy for the Bay-Delta Ecosystem (Cal. Fed, 2003): “The problem with mercury in

Mercury Strategy for the Bay-Delta Ecosystem (Cal. Fed, 2003): “The problem with mercury in the Delta’s aquatic ecosystems can be defined as biotic exposure to methylmercury. ” Me. Hg = most toxic, bioavailable form of Hg >90% of Hg in fish = Me. Hg 9

Tributary Me. Hg Agricultural Lands / Delta Islands Wetlands Me. Hg ce rfa Su

Tributary Me. Hg Agricultural Lands / Delta Islands Wetlands Me. Hg ce rfa Su Se di Urban & WWTPs Open m en Channel ts Hg Pore Water Exchange & Diffusion Me. Hg bacterial methylation 10

How do we reduce fish Me. Hg levels? l Local & nationwide studies: Most

How do we reduce fish Me. Hg levels? l Local & nationwide studies: Most important, single factor in determining how much Me. Hg is in fish is water Me. Hg concentration l Most direct way to reduce fish Me. Hg is to reduce the concentration of Me. Hg in water 11

Me. Hg Linkage: Largemouth Bass & Average Water Me. Hg Bass Hg (mg/kg) 1.

Me. Hg Linkage: Largemouth Bass & Average Water Me. Hg Bass Hg (mg/kg) 1. 0 y = 20. 365 x 1. 6374 R 2 = 0. 91 0. 5 0. 0 0. 1 0. 2 Water Me. Hg (ng/l) 12

Me. Hg Linkage: Largemouth Bass & Average Water Me. Hg Bass Hg (mg/kg) 1.

Me. Hg Linkage: Largemouth Bass & Average Water Me. Hg Bass Hg (mg/kg) 1. 0 1. 6374 y = 20. 365 x R 2 = 0. 91 0. 5 0. 24 mg/kg 0. 066 ng/l 0. 0 0. 1 0. 2 Water Me. Hg (ng/l) 13

Proposed Me. Hg Goal l 0. 06 ng/l in unfiltered ambient water, annual average

Proposed Me. Hg Goal l 0. 06 ng/l in unfiltered ambient water, annual average Establishes the assimilative capacity Used to determine how much reduction from Me. Hg sources is needed to achieve fish tissue objective 14

Average Annual Ambient Me. Hg Levels in Water (ng/l) 0. 27 0. 11 0.

Average Annual Ambient Me. Hg Levels in Water (ng/l) 0. 27 0. 11 0. 27 0. 17 0. 08 0. 06 0. 22 0. 16 15

Me. Hg Source Reductions Needed to Achieve Proposed 0. 06 ng/l goal 78% 45%

Me. Hg Source Reductions Needed to Achieve Proposed 0. 06 ng/l goal 78% 45% 65% 25% 0% 0% 73% 63% 16

Proposed Control Strategy l Reduce Hg in sediment (reduces Me. Hg produced by Delta

Proposed Control Strategy l Reduce Hg in sediment (reduces Me. Hg produced by Delta wetlands & open-water areas) l Control activities that enhance production of (and degrade) Me. Hg in wetlands & open-water areas l Reduce Me. Hg discharges from external sources (e. g. , WWTPs, urban runoff & irrigated agriculture) 17

Delta TMDL Adaptive Approach Phase 1 § Studies § Implement Hg pollution prevention measures

Delta TMDL Adaptive Approach Phase 1 § Studies § Implement Hg pollution prevention measures § Improve CC Settling Basin § Identify other high-priority legacy Hg projects § Develop upstream TMDLs § Conduct pilot offset projects ~2017 Re-assess Me. Hg allocations & schedules. ~2009 TMDL Review Phase 2 § Implement Me. Hg controls in the Delta & upstream watersheds § Continue to implement legacy Hg projects § Long-term offset projects 18

Outline l Description of the Delta Mercury Impairment l Overview of the Proposed Delta

Outline l Description of the Delta Mercury Impairment l Overview of the Proposed Delta Program l Comparison to RMP Mercury Strategy’s High Priority Questions l Questions & Discussion 19

RMP Priority Questions 1. Where and when does mercury enter the food web? u

RMP Priority Questions 1. Where and when does mercury enter the food web? u We have a general idea of the “where” in the main channels 20

Cal. Fed Mercury Program Fish Sampling Lower fish Hg in Central Delta during relatively

Cal. Fed Mercury Program Fish Sampling Lower fish Hg in Central Delta during relatively low-flow years Elevated Inland silverside Hg & Me. Hg fish Hg Concentrations, Fall 1999 in Delta (Slotton et al. , 2002) Lower fish Hg periphery in Central Delta during relatively low-flow years Average Hg Concentrations in largemouth bass, 2000 (Davis et al. , 2003) 21

RMP Priority Questions 1. Where and when does mercury enter the food web? u

RMP Priority Questions 1. Where and when does mercury enter the food web? u u We have a general idea of the “where” in the main channels Does Me. Hg uptake into biota occur preferentially during some seasons? — Recent Cal. Fed study results from Darrell Slotton and others indicate increases in biosentinel fish and water Me. Hg have been associated with floodplain inundation that occurred in different times of the year 22

RMP Priority Questions 2. Which processes, sources & pathways contribute disproportionately to food-web accumulation?

RMP Priority Questions 2. Which processes, sources & pathways contribute disproportionately to food-web accumulation? u RMP isotopic composition study of mercury to determine which mercury inputs are contributing most to bioaccumulation — Useful for both Bay & Delta programs! — Compliments the proposed Delta program’s focus on identifying the Me. Hg sources to the Delta & the inorganic Hg sources that supply the Me. Hg sources 23

RMP Priority Questions 2. Which processes, sources, & pathways contribute disproportionately to food-web accumulation?

RMP Priority Questions 2. Which processes, sources, & pathways contribute disproportionately to food-web accumulation? u u u We have a general idea of which sources contribute Me. Hg & Tot. Hg to the different areas of the Delta Sources that cause the impairment in different Delta areas come from different places We need seven different area-specific control strategies 24

…because different areas of the Delta are dominated by different Me. Hg & Tot.

…because different areas of the Delta are dominated by different Me. Hg & Tot. Hg sources Yo By l o p as s Seven Control Programs in One… Southern Delta 25

RMP Priority Questions 2. Which processes, sources, & pathways contribute disproportionately to food-web accumulation?

RMP Priority Questions 2. Which processes, sources, & pathways contribute disproportionately to food-web accumulation? u Need to refine load estimates for wetlands in the Delta & upstream watersheds 26

RMP Priority Questions 3. What are the best opportunities for management intervention for the

RMP Priority Questions 3. What are the best opportunities for management intervention for the most important pollutant sources, pathways & processes? 4. What are the effects of management actions? Proposed Delta TMDL implementation plan includes studies to address these questions. Yolo Bypass wetland management practice study is already underway 27

RMP Priority Questions 3 & 4 Key observations for the Delta: u u Tributary

RMP Priority Questions 3 & 4 Key observations for the Delta: u u Tributary watersheds account for most of the Me. Hg inputs to the Delta No one point or nonpoint source individual or by category - in the Delta or its upstream watersheds causes the impairment 28

RMP Priority Questions 3 & 4 Key observations for the Delta: u u All

RMP Priority Questions 3 & 4 Key observations for the Delta: u u All wetlands are not alike: some act as big sources, some as small sources, and some as sinks All WWTPs are not alike: some have low effluent Me. Hg, others high 29

RMP Priority Questions 3 & 4 Key observations for the Delta: u Two recent

RMP Priority Questions 3 & 4 Key observations for the Delta: u Two recent studies support the hypothesis that Me. Hg in ambient water is a primary factor in determining how much Me. Hg is in fish 30

(1) Floodplain Inundation on the San Joaquin River: Before & After 31

(1) Floodplain Inundation on the San Joaquin River: Before & After 31

RMP Priority Questions 3 & 4 Key observations for the Delta: u Two recent

RMP Priority Questions 3 & 4 Key observations for the Delta: u Two recent studies support the hypothesis that Me. Hg in ambient water is a primary factor in determining how much Me. Hg is in fish 2) Local bioaccumulation study: WWTP effluent contributes about the same amount of mercury to Sacramento River bioaccumulation as expected from its effluent methylmercury loads 32

RMP Priority Questions 3 & 4 Proposed Delta control program does not attempt to

RMP Priority Questions 3 & 4 Proposed Delta control program does not attempt to indicate which Me. Hg sources are more important because: u u u No one source type or individual source causes the impairment We need additional characterization studies, especially for wetlands We don’t know yet which inorganic Hg & Me. Hg sources will be the most feasible to reduce [in terms of efficacy, economics & environmental impacts associated with particular controls and management practices] 33

RMP Priority Questions 5. Will total mercury reductions result in reduced food web accumulation?

RMP Priority Questions 5. Will total mercury reductions result in reduced food web accumulation? Another good question! Further, if “yes”, can we reduce total Hg sources enough to accomplish desired fish Me. Hg reductions? 34

Questions & Comments Updates, reports & comments: http: //www. waterboards. ca. gov/centralvalley/ water_issues/tmdl/central_valley_projects/delta_hg/ 35

Questions & Comments Updates, reports & comments: http: //www. waterboards. ca. gov/centralvalley/ water_issues/tmdl/central_valley_projects/delta_hg/ 35

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