6/22/05 BPP Stakeholder MeetingProcess Profiles1 Copper Source Loading Estimates (Process Profiles) Physical & Chemical Characterization of Wear Debris

6/22/05 BPP Stakeholder Meeting Process Profiles 1

Copper Source Loading Estimates (Process Profiles)

Physical & ChemicalCharacterization of

Wear Debris (Clemson University)

WaterQuality

Monitoring (ACCWP)

Steering Committee, Scientific Advisory Team, andStakeholder Involvement Process (Sustainable Conservation)

AirDepositionModeling

(AER)

WatershedModeling

(U.S. EPA)

BayModeling (URS)

Final ReportData Assessment

Conclusions

Air Deposition

Monitoring (SFEI)

Representative Sample of Brake PadWear Debris

(BMC/Link Test Labs)

BPP Technical Studies BPP Technical Studies


Source Loading Estimates Source Loading Estimates to Watershedto Watershed

• Copper released from brake lining wear

• Copper released from non-brake sources


Copper Released from Brake Copper Released from Brake Lining WearLining Wear

brake lining wear

to air (EFair)

to road(EFroad-dir)

to vehicle

to road(EFroad-ind)

to publicly-owned

treatment works (EFPOTW)


Air Emission FactorAir Emission Factor

Calculated three ways:

1. Composition/Wear Approach

2. Composition/Existing Emission Factor Approach

3. Tunnel Studies


Advantages of Using Tunnel Advantages of Using Tunnel Study DataStudy Data

• Releases measured from fleets in service

• Representative of thousands of vehicles during actual (not simulated) use


PartitioningPartitioning

brake lining wear

to air (EFair)

to road(EFroad-dir)

to vehicle

to road(EFroad-ind)

to publicly-owned

treatment works (EFPOTW)


Emission FactorsEmission Factors

Release Category

Emission Factor

Estimation Approach

Calculated Result (mg copper/km)

Standard Uncertainty in

Calculated Result (mg copper/km)

Airborne emission factor

Tunnel study 0.58 0.07

Roadway emission factor

Partitioning/airborne emission factor

0.5 0.2


Veh

icle

Mile

s T

rave

led

Veh

icle

Mile

s T

rave

led


Results for the Brake Pad Results for the Brake Pad Releases of Copper in the San Releases of Copper in the San Francisco Bay Area WatershedFrancisco Bay Area Watershed

Copper released, kg/y

Standard uncertainty in

copper released, kg/y

Airborne copper released

50,000 10,000

Copper released to roadways

40,000 20,000


Veh

icle

Mile

s T

rave

led

Veh

icle

Mile

s T

rave

led


Results for Brake Pad Releases of Results for Brake Pad Releases of Copper in the Castro ValleyCopper in the Castro Valley

Watershed Watershed (amounts in kg copper/y)

Interstate 580 Surface Streets

Release to air 170 100

Standard uncertainty in release to air

100 10

Release to roadway 160 90

Standard uncertainty in release to roadway

60 30


Questions?Questions?


Air Emission Factor ComparisonAir Emission Factor Comparison

Emission Factor Estimation Approach

Calculated result (mg Cu/km)

Standard uncertainty in

calculated result (mg Cu/km)

Passenger car - composition/wear 0.5 0.2

Passenger car - composition/emission factor 0.4 0.2

MDV - composition/wear 0.7 0.4

MDV - composition/emission factor 0.48 0.09

HDV - composition/wear 0.3 0.2

HDV - composition/emission factor 0.2 0.1

All vehicles – tunnel study/particle size distribution

0.58 0.07


Standard UncertaintyStandard Uncertainty

• Estimated for each value used in calculations• Standard deviation used if possible• More likely to be able to predict a potential

range of possible values and estimate a standard uncertainty based on that


Benefits of Developing Benefits of Developing Standard UncertaintyStandard Uncertainty

• Allows for a standard uncertainty in results to be calculated

22 2

1 21 2

R nn

f f fu u u u

x x x


Benefits of Developing Benefits of Developing Standard Uncertainty (cont’)Standard Uncertainty (cont’)

• Calculating confidence intervals:

e.g. a 95% confidence interval the range of values that includes the result plus or minus two times the standard uncertainty


Copper Source Loading Estimates (Process Profiles)

Physical & ChemicalCharacterization of

Wear Debris (Clemson University)

WaterQuality

Monitoring (ACCWP)

Steering Committee, Scientific Advisory Team, andStakeholder Involvement Process (Sustainable Conservation)

AirDepositionModeling

(AER)

WatershedModeling

(U.S. EPA)

BayModeling (URS)

Final ReportData Assessment

Conclusions

Air Deposition

Monitoring (SFEI)

Representative Sample of Brake PadWear Debris

(BMC/Link Test Labs)

BPP Technical Studies BPP Technical Studies


Copper Released from Copper Released from Non-Brake SourcesNon-Brake Sources

• Architectural copper• Copper in pesticides• Copper in fertilizer• Copper released from industrial facilities• Copper in domestic water discharged to

storm drains


Concepts CommonConcepts Commonto All Release Categoriesto All Release Categories

• Develop separate estimates for each environmental compartment (soil/air/surface water/storm water/bay waters)

• Population and land use values were used to determine how releases within political boundaries are assigned to each watershed


1992 NLCD Land Use in the San Francisco Bay Area Watershed


Architectural CopperArchitectural Copper

• Estimate surface area of copper roofs, copper gutters, and roofs with composite shingles containing copper biocide

• Apply emission factors that are based on surface areas


Architectural CopperArchitectural CopperReleases in the Bay AreaReleases in the Bay Area

• Estimated total release from architectural copper is 1,500 kg/y

• These releases are directly to storm drains; even in residential applications, these features are almost always hard-piped to storm drains


• Pesticides applied to soil in urban areas

• Agricultural applications to soil

• Algaecide treatment of surface waters

• Pool, spa, and fountain algaecides

• Wood preservatives

• Antifouling coatings

PesticidePesticide


Pesticides Applied to Soil in Pesticides Applied to Soil in Urban AreasUrban Areas

• Used adjusted statewide values for sales and use

• Total adjusted sales less adjusted agricultural use, antifouling coating use, algaecide use, use as root killer, and use in pressure-treated lumber is estimated statewide urban application to soil

• Apportioned to the watersheds based on population


Pesticide Releases to Urban Pesticide Releases to Urban Soil in the Bay AreaSoil in the Bay Area

• Total estimated Bay area release of copper from copper-based pesticides to soil in urban areas is 100,000 kg in 2003


Agricultural Applications to SoilAgricultural Applications to Soil

• Based on adjusted reported use in the eight counties

• Apportioned to the watersheds based on agricultural land use area


Agricultural Releases to Soil in Agricultural Releases to Soil in the Bay Areathe Bay Area

• Total estimated Bay area releases of copper from copper-based pesticides to soil in agricultural areas is 12,000 kg in 2003


Algaecide Treatment of Algaecide Treatment of Surface WatersSurface Waters

• Reported adjusted uses to nonagricultural water areas in the eight counties assumed to occur at the shoreline of the bays

• Reported adjusted uses in agricultural areas (apportioned by land use) and estimated uses in non-agricultural rights of way, recreation areas, and public health (apportioned by population) are assumed to be applied to surface waters


Algaecide Surface Water Algaecide Surface Water Releases in the Bay AreaReleases in the Bay Area

• Estimated copper in algaecide applications to shoreline waters are 1,900 kg/y

• Adjusted copper in reported agricultural water area algaecide applications are 100 kg/y

• Estimated copper in algaecide applications in non-agricultural rights-of-way, recreation areas, and public health are 1,200 kg/y


Pool, Spa, and Fountain Pool, Spa, and Fountain AlgaecidesAlgaecides

• Estimate the state-wide algaecide use of copper in copper-based algaecides by adding up reported uses to water along with a portion of sales for algaecide products whose uses are not reported

• Pool, spa, and fountain use estimated as total algaecide use less adjusted reported use as algaecide

• Assumed that 5% of copper used in pool, spa, and fountain algaecides is released to storm drains

• Apportioned to the watersheds based on population


Pool, Spa, and Fountain Pool, Spa, and Fountain Algaecide Releases in the Bay Algaecide Releases in the Bay

AreaArea

• Estimated releases of copper in pool, spa, and fountain algaecides to storm drains are 2,200 kg/y


Copper Released from Pressure-Copper Released from Pressure-Treated LumberTreated Lumber

• Based on nationwide use of copper in pressure-treated lumber (13 million kg/y)

• An estimated 5.5 million kg/y of copper in pressure-treated lumber leaches out

• Assume that 25% of copper leached from pressure-treated lumber is not susceptible to runoff

• Releases are to soil• Apportioned to the watersheds based on

population


Copper Released from Copper Released from Pressure-Treated Lumber in Pressure-Treated Lumber in

the Bay Areathe Bay Area

• Estimated releases of copper from pressure-treated lumber are 72,000 kg/y


Copper inCopper inAnti-Fouling CoatingsAnti-Fouling Coatings

• Estimate surface area of boats berthed in the bay

• Apply emission factors that are based on surface area

• Releases are directly to bay waters


Copper Released from Anti-Copper Released from Anti-Fouling Coatings to Bay WatersFouling Coatings to Bay Waters

• Estimated releases of copper from anti-fouling coatings are 9,000 kg/y


• Based on reported statewide farm and non-farm fertilizer use by fertilizer category coupled with copper concentrations in various fertilizer categories

• Assumed that 25% of farm use was tilled into soil and not available for runoff

• Releases are to soil• Farm use apportioned to the watersheds based

on land use area; non-farm use based on population

FertilizersFertilizers


Copper Released from Copper Released from Fertilizers in the Bay AreaFertilizers in the Bay Area

• Estimated releases of copper from fertilizer use are 9,000 kg/y


• Industrial air emissions

• Industrial runoff

Industrial FacilitiesIndustrial Facilities


Copper Released in Industrial Copper Released in Industrial Air Emissions in the Bay AreaAir Emissions in the Bay Area

• Based on TRI data

• Releases are to air

• Eleven facilities reported air releases of 359 kg copper in 2003


Copper Released in Industrial Copper Released in Industrial Runoff in the Bay AreaRunoff in the Bay Area

• Estimate industrial land use area in each watershed

• Apply an emission factor that is based on industrial land use area

• Releases are direct to storm drains

• Estimated releases of copper in industrial runoff are 1,300 kg/y


• Based on a per-person emission factor that is in turn based on copper concentrations in domestic tap water and the volume of domestic water that is released to storm drains

Domestic Water Discharged to Domestic Water Discharged to Storm DrainsStorm Drains


• Estimated releases of copper in domestic water discharged to storm drains are 510 kg/y

Copper Released in Domestic Copper Released in Domestic Water Discharged to Storm Water Discharged to Storm

Drains in the Bay AreaDrains in the Bay Area


• Estimated releases of copper to soil are 200,000 kg/y

• Estimated releases of copper to air are 359 kg/y

• Estimated releases of copper to Bay waters are 11,000 kg/y

• Estimated releases of copper to surface waters and storm drains are 6,900 kg/y

Overview of Results: Copper Overview of Results: Copper Released from Non-Brake Released from Non-Brake Sources in the Bay AreaSources in the Bay Area


• Fossil fuel combustion• Wood burning• Vehicle fluid leaks• Exposed conducting wire used to power public

transit systems• Runoff from landfills

Sources Not Included in this Sources Not Included in this InventoryInventory


Questions?Questions?


Architectural CopperArchitectural CopperEmission FactorsEmission Factors

Feature

Emission Factor,

kg copper/m2/y

Standard Uncertainty in Emission Factor,

kg copper/m2/y

Copper roofs 0.0018 0.0005

Roofs with copper-impregnated composite shingles

0.0002 0.0001

Copper gutters 0.004 0.001


Estimating Pesticide Estimating Pesticide Releases to Urban SoilReleases to Urban Soil

Type of Use

In California, kg copper in

2003

Adjusted Sales 3,700,000

Adjusted Use in Agriculture, Excluding Application to Water Areas

2,000,000

Estimated Use as Marine Antifouling Coating 660,000

Estimated Use as Algaecide 350,000

Adjusted Use for Pressure-Treating Lumber 35,000

Estimated Use as Root Killer 20,000

Estimated Release to Urban Soil 700,000


Adjusted Reported Agricultural Adjusted Reported Agricultural Uses in the Bay Area CountiesUses in the Bay Area Counties

County kg copper in 2003

San Mateo 120

Santa Clara 1,800

Alameda 110

Contra Costa 6,900

Solano 130

Napa 1,200

Sonoma 9,000

Marin 16,000

Total 36,000


Surface Water Algaecide Use in Surface Water Algaecide Use in the Bay Area Countiesthe Bay Area Counties

(values in kg copper)

County

Estimated Use as AlgaecideUse in Nonagricultural Rights of Way, Recreation Areas, and Public

Health

Adjusted Reported Use in

Nonagricultural Water Area

Adjusted Reported Use in

Agricultural Water Area

Alameda 10 0 0

Santa Clara 0 5 0

San Mateo 0 580 0

Contra Costa 1000 0 0.91

Solano 0 850 0

Sonoma 63 430 0

Napa 360 0 0

Marin 0.45 0 120

TOTAL 1,500 1,900 120

Documents

6/22/05 BPP Stakeholder MeetingProcess Profiles1 Copper Source Loading Estimates (Process Profiles) Physical & Chemical Characterization of Wear Debris