Mercury and PCBs TMDL Implementation

Tom MumleySan Francisco Bay Regional Water Quality Control Board

Status of TMDLs

Mercury– Regional Board adoption September 2004– State Board action still pending

PCBs– Draft Basin Plan package Fall 2005– Regional Board action Winter 2006

Clx

Clx

ImpairmentProblem

Sources

ImplementationActions

NumericTarget

Linkage

Allocations

TMDL

Regulatory Actions

TMDL Process Elements

Key Challenge

Make decision despite numerous uncertainties!

Hmmm…Mercury…

Adaptive Implementation

Early actions – Scope based on available information– Improve understanding of problem,

sources, system, and solutions

Make progress towards attaining water quality standards– Take action prevent, manage, control

observe system’s response

 

ImpairmentProblem

Sources

ImplementationActions

NumericTarget

Linkage

Allocations

TMDL

Regulatory Actions

TMDL Process Elements

ImpairmentProblem

Sources

ImplementationActions

NumericTarget

Linkage

Allocations

TMDL

Regulatory Actions

TMDL Process Elements

Mercury Sources and Allocations

SOURCEEXISTING

LOAD (kg/yr)

ALLOCATION (kg/yr)

Central Valley Watershed

440 330

Urban Runoff 160 82

Guadalupe River Watershed

92 2

Wastewater 20 20

Dredging and Disposal net loss ambient

concentration

In-Bay Hotspots ?

PCBs Sources and Allocations

SOURCEEXISTING

LOAD (kg/yr)

ALLOCATION (kg/yr)

Central Valley Watershed

42 42

Urban Runoff 40 10

Guadalupe River Watershed

~ 1

Wastewater 3 3

Dredging and Disposal net loss ambient

concentration

In-Bay Hotspots ? ?

Risk Reduction

Pollutant related health risks to consumers of bay fishClean Estuary Partnership Work Team– Water Board, BACWA, BASMAA– Office of Environmental Health Hazard

Assessment, Dept of Health Services– CEP Environmental Tech Rep

Central Valley Watershed Actions

Mercury– Cache Creek TMDL

• Summer 2005

– Delta TMDL • Summer 2006

Guadalupe River Watershed Actions

Mercury– TMDL Winter 2006/07– New Almaden Mine District – Reservoirs

Dredging and Disposal Actions

Implement LTMS– Long Term Management Strategy

for the Placement of Dredged Material in the San Francisco Bay Region

In-bay disposal ambient

Wastewater Actions

Maintain performance– Pollution prevention– Treatment systems

Confirm no local effects Assist with studies Assist with control of other sources– Strategic treatment of runoff

Watershed Permit

In-Bay Hot Spots Actions

Hunters Point Seaplane Lagoon – (Alameda NAS)

Stege Marsh – (Richmond)

Others?– Relative significance– Opportunity

PCBs in Watersheds

PCBs in Watersheds

PCBs in Watersheds

Distribution of Sediment PCB Concentrations in Storm Water Conveyance Systems

0

10

20

30

40

50

60

<1010-22

22-3535-100

100-200

200-1000

>1000

Concentration Range (µg/kg)

Nu

mb

er

Mercury and/or PCBs - Urban Runoff Control Hypotheses

Hg and PCBs are distributed throughout urban watersheds There are hot zones of Hg and/or PCBs (elevated levels)Sediment bound Hg and PCBs accumulate in the transmission systemThere is buildup of polluted sediment near some storm drain discharge points

Urban Runoff Action

Pollution prevention (light bulbs)

Clean-up on-land, storm drain, and discharge point “hot spots”Strategic retrofitOperation and maintenance

Urban Runoff Action

Pollution prevention (light bulbs)

Clean-up on-land, storm drain, and discharge point “hot spots”Strategic retrofit– Site design – Intercept/treatment– Route to sanitary sewer system

Operation and maintenance– Street sweeping– Inlet and storm drain cleaning

Adaptive Implementation Studies

Sediment and sediment-bound pollutant fate and transport– Erosion of in-bay sediments– Recovery of the bay

Urban runoff loading and effectiveness of controlsMethylation– How, where, and when?– Can we manage it?

Hmmm…Save Bay…

Multibox model Manage methylation– if we can

Mine cleanupStrategic hot spot cleanup - in bay, in storm drains, and on landStrategic urban runoff management

Mercury and PCBs TMDL Implementation