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Regulatory UpdatePart 2

San Francisco Bay Mercury Coordination Meeting

February 22, 2007

Michelle Wood (Central Valley Water Board)

Carrie Austin (San Francisco Water Board)

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DeltaMethylmercury

TMDL

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Outline1. Delta MeHg TMDL & BPA

Background Key Questions

2. State Board’s Scoping Effortsa. Hg Offset Policy for the

Bay-Delta Systemb. Statewide Water Quality Objectives for Mercury

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The Delta

R

S

F

>1100 mi waterwaysDrains ~1/3 of CA

Reg

ion

2

San Francisco Bay

ReduceCentral Valley

Mercury Outflows by 110 Kg110 Kg

Reg

ion

5

Sacramento

Tracy

StocktonAntioch

Brentwood

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Delta MeHg TMDL & BPA

TMDL draft staff report (August 2005, revised June 2006) Scientific background

Basin Plan Amendment draft staff report (scientific peer review June-August 2006) Control program

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Next StepsBoard Workshop in March 2006

Release draft BPA staff report w/ formal comment period

Board Hearing later in 2006

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“The problem with mercury in the Delta’s aquatic ecosystems can be defined as

biotic exposure to methylmercury.”

As stated by Jim Wiener and other researchers in their 2003 Mercury Strategy for the Bay-Delta Ecosystem:

Reduce MeHg exposure to thefish-eating public & wildlife

Delta MeHg Control Program:

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Delta MeHg Control Program1. Revise fish advisories & expand

education & outreach programs to reduce MeHg exposure to the fish-eating public

2. Reduce mercury levelsin Delta fish

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PROPOSED Water Quality Objectives for Delta Fish

0.24 ppm mercury in large predator fish

0.03 ppm mercuryin prey fish California least tern

1 meal/wk

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Average MeHg Levels

in Large TL4 Fish

(mg/kg)[Compare to

Proposed WQO of 0.24 mg/kg]

0.26na

0.50

0.56

0.92

na

0.32

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Control Program

1. Reduce MeHg exposure to the fish eating public & wildlife

2. Reduce mercury levels in Delta fisha.a. Control MeHg sourcesControl MeHg sourcesb. Control total Hg sources

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MeHg Linkage: 350 mm Largemouth Bass & Avg. Annual Water MeHg

y = 20.365x1.6374R2 = 0.91

0.0

0.5

1.0

0.0 0.1 0.2

Aqueous MMHg (ng/l)

350

LMB

Hg

(mg/

kg)

0.24 mg/kg

0.066 ng/l

Mokelumne R.

Central Delta

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Proposed MeHg Implementation Goal

0.06 ng/l in unfiltered ambient water, annual average (~10% margin of safety)

Use goal to establish how much reduction from each source is needed to achieve WQOs

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Average Annual

Ambient MeHg Levels

in Water(ng/l)

0.06

0.27

0.16

0.110.17

0.08

0.22

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Delta TMDL: MeHg Sources Within-Delta Sources (~40%) Wetlands (16%) MeHg flux from open water sediments (15%) Waste water treatment plants (4%) Agricultural return flows (3%) Urban runoff (½%)

Tributary Watersheds (~60%)

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Methylmercury Allocations: Implement MeHg Source

Reductions in the Delta & Yolo Bypass by 2030

CapCap MeHg loads from: Atmospheric, dredging, open channel*

ReduceReduce MeHg loads from: Agricultural, WWTPs, stormwater, wetlands & tributaries with discharge > 0.06 ng/l MeHg

MinimizeMinimize MeHg from new sources:(e.g., wetland restoration, water management changes, new WWTP discharges...)

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Phase 1 (2008-2015)Study Period:

Conduct characterization & control studies to evaluate existing sources’ MeHg & TotHg concentrations and loads

GOALS: Address uncertainty in load estimates Develop technically & economically

feasible MeHg management practicesto reduce on-site MeHg production

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Control Program

1. Reduce MeHg exposure to the fish eating public & wildlife

2. Reduce mercury levels in Delta fisha. Control MeHg sourcesb. Control total Hg sources

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Delta TMDL: TotHg Sources

Within-Delta Sources (~3%)Waste water treatment plants (1%)Urban runoff (1%)Atmospheric deposition (1%)

Tributary Watersheds (~97%)

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Inorganic Mercury Limits: Hg Sources in Delta & Tributaries

Downstream of Major Dams CapCap Hg loads from:

Local atmospheric emissions, dredging, flood conveyance, WWTPs, and urban stormwater

ReduceReduce Hg loads by 110 kg from: Cache Creek Settling Basin, American & Feather Rivers & Putah Creek

MinimizeMinimize Hg from new sources Continue upstream MeHg & TotHg evaluations & implement

control actions as part of future TMDLs

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Pilot Mercury Offset Program Phase 1: allow pilot offset projectspilot offset projects to promote early

implementation of MeHg/TotHg reduction projects & to provide information for Phase 2 offset program.

Phase 2: Regional Board considers adoption of an offset program to allow dischargers to offset MeHg and/or TotHg in their discharges by implementing more feasible or cost effective projects elsewhere in the watershed.

The approved offset program must be consistent with any State Board offset policy.

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Outline1. Delta MeHg TMDL & BPA

Background Key Questions

2. Regional / Statewide Effortsa. Hg Offset Program for the San Francisco Bay, Delta &

Tributary Watershedsb. Statewide Water Quality Objectives for Mercury

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Key Question***Highest Priority for Delta & upstream

MeHg control programs***

Can we develop MeHg control actions & management practices

for wetlands, WWTPs& other sources?

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0

1

2

3

4

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65

Facilities

Me

Hg

Co

nc

. (n

g/l)

Preliminary Municipal WWTP MeHg Monitoring Results

26 < 0.05 ng/l

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Other Key Questions: What types of wetlands are

contributing MeHg to the Delta andits tributaries, and how much?

How much TotHg and MeHg does atmospheric deposition contribute to Delta loading?

How does sulfate affect open water MeHg levels in the Delta?

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• Is it possible to design or manage wetlands to reduce wildlife exposure to MeHg?

• Which aquatic species do humans consume and how much?

Other Key Questions:

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• What are the specific mercury effects on key wildlife species in the Delta & its trib watersheds?

• What are the consumption habits of key wildlife species?

• Where do they consume fish? [main channel versus isolated wetlands and Ag drains]

• Which seasons are critical?• Which aquatic species are consumed?

Other Key Questions:The proposed Delta MeHg control program applies

to hydrologically connected waterways.We need a better understanding of the following for

future phases of the control program:

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Outline1. Delta MeHg TMDL & BPA

Background Key Questions

2.2. Regional / Statewide Efforts by State BoardRegional / Statewide Efforts by State Boarda. Hg Offset Program for the San Francisco Bay, Delta &

Tributary Watershedsb. Statewide Water Quality Objectives for Mercury

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Hg OffsetPolicy forthe SF Bay,Delta &Tributary Watersheds

[“Bay-Delta System”]

The red hatching represents the SFBay watershed and Delta source area downstream of major dams.

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Proposed State BoardBay-Delta System Hg Offset Policy

Policy would provide “General Principles” for Regional Water Boards & dischargers to implement offset projects

Policy would not give specific project offset ratios or address pollutant trading

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Statewide Water Quality

Objectivesfor Mercury

Apply to California’s:• Inland waters• Enclosed bays• Estuaries

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State Water Board Considerations Six Objective Alternatives:

MeHg in fish tissue MeHg in water, TotHg in water Fish / water combinations

Uses national average BAFs & MeHg/TotHg translator to convert from concentrations in fish to water

Alternatives vary by: Consumption rates for humans (USEPA default

vs. San Francisco Bay) Species to which WQO would apply (average of

trophic levels vs. top trophic level only)

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State Board CEQA Scoping for Bay-Delta Offset Policy

& Statewide WQOs: Public Scoping Meeting on Feb 20th

CEQA Scoping comments due Feb 28th

Contact: Tom Kimball or Joanne Cox http://www.waterboards.ca.gov/plnspols/index.html#policies

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35

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Central Valley

Mercury TMDLs

Delta

Clear Lake

Cache Creek Bear Creek

Harley Gulch

American R.

Feather R.

SacramentoRiver

San Joaquin R.

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Adaptive ImplementationAdaptive Implementation

ActionEvaluate

Monitor

Lower Fish Hg

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Water Quality Management Process

Monitoring

Special Discharger Studies

CWA 303(d)

Planning

Assessment

Implementation

Evaluation

Basin Plan- Uses- Objectives- Impl. Program- TMDLs

WDRsWaiversProhibitions

Review- Monitoring Results- Mgmt. Plans

Water QualityImprovement

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Delta Mercury Impairment

High mercury levels in fish

Fish consumption advisories

Federal CWA 303d list

TMDL Program to address impairment

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The Methylmercury Problem Hg is a potent neurotoxicant - impairs nervous,

reproductive, & immune systems in humans & wildlife

Sulfate-reducing bacteria convert mercury to MeHg, the most toxic form of Hg

>90% mercury in top trophic level fish is MeHg

Exposure to MeHg is through consumption of fish & shellfish because of the way MeHg

bioaccumulates

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San Joaquin Subarea Methylmercury Sources

Total Loading: ~478 g/yr

Tributaries77%

OtherInputs23%

Wastewater9%

Agri-culturalLands

5%

Wetlands4%

OpenWater

4% Urban1%

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Yolo Bypass Subarea Methylmercury Sources

Total Loading: ~1,000 g/yr

AgriculturalLands

2%

OpenWater

8%

Other Inputs49%

Wetlands39%Tributaries

51%

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Methylation factors Amount and type of inorganic Hg in sediment Sulfate and pH concentration:

Sulfate in Delta affected by EC and ratio of SJR to Sac R water

% organic matter in sediment Creation of new impoundments increases

MeHg in sediment, water and biota Habitat type, particularly the amount of

seasonally or permanently flooded wetland in a watershed

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Tributary TotHg Sources & Concerns about Reduction

Millions of kilograms released to waterways by historic mining

Much remains in channels & may be untreatable

Natural erosion will remove some mercury, but it may take centuries to wash the mercury from the waterways

TotHg:MeHg relationship varies by habitat, so how do we develop a safe level for TotHg that would protect the Delta without being overly stringent?

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Interrupt the Methylation Cycle

Control TotHg in watersheds that discharge the most Hg-contaminated sediment

Identify Delta & upstream MeHg sources: Reduce on-site methylation, and/or Reduce TotHg sources that supply the

methylation sources

Shorten time to see fish tissue mercury improvements from centuries to decades

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Potential Timeline Years 1 to 7: Conduct characterization & control studies; begin TotHg control actions

Year 8: Update MeHg source analyses & allocations, evaluate discharge control programs & offset program, amend Basin Plan as needed

Year 9 to 2030: Implement MeHg control actions

2030 onward: Continued MeHg controls & natural erosion reduces contaminated in-channel sediments

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What is a Mercury Offset Program?

Voluntary program that enables projects to proceed even if on-site mercury controls are not

feasible. Dischargers could obtain offsets:

1. To help meet their allocations;

2. To allow an increase above their allocations as a result of expansion that would otherwise result in additional mercury loading to the Bay–Delta system; or

3. To initiate a new discharge that would otherwise result in new mercury loading to the Bay–Delta system.

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Mercury Water Quality Objective Alternatives

Option Consumption

rate, g/day

Fish tissue objective, mg/kg

Dissolved MeHg

WQO, ng/L

Total Hg WQO –

rivers, ng/L

1. No action 50

2. USEPA defaults

17.5 0.3, for species mix

0.24 17.1

3. USEPA default

17.5 0.3, for trophic level 4

0.11 7.7

4. SF Bay 32 0.16, for species mix

0.13 9.4

5. SF Bay 32 0.16, for trophic level 4

0.06 4.2

6. SF Bay 32 0.16, water body-specific mix of species

NA NA