Are Local, Near-Ground Emissions of Mercury and Copper Significant Sources of Water Pollution?

1. Are Local, Near-Ground Emissions of Mercury and Copper Significant Sources of Water Pollution? Geoff Brosseau, BASMAA Doug Steding/Christopher Conaway, UCSC – Mercury Mark Schlautman, Clemson University – Copper WRPPN Annual P2 Conference - 2003

2. Funding • USEPA Great Waters Program (National Estuary Program) – Air Deposition Initiative Grant • BASMAA (Bay Area Stormwater Management Agencies Association) • SFEP (San Francisco Estuary Project)

3. In the Beginning… The Development and Legacy of 70s Environmental Protection Regulations

4. Clean Water Act POCs / PBTs Heavy metals Pesticides Toxics (OCs, PCBs, PAHs, Dioxins/Furans) Sediment Clean Air Act HAPs / TACs Ozone, VOCs NOx, SOx Nutrients PM (Particulate matter) Lost in the Translation?

5. Dimensions ppm, ppb, ppt (ng/l) Aquatic life-driven Discharges Point / Non-Point Watershed Dimensions ppm (ng/m3) Human health-driven Emissions/Deposition Stationary / Mobile / Fugitive Airshed Lost in the Translation? (Cont’)

6. Air Quality / Water Quality – Previous National Work • National studies concentrated on Chesapeake Bay and Great Lakes • Continental / Regional impacts • First federally-funded air quality / water quality studies west of the Mississippi began in 1999

7. San Francisco Bay – Previous AQ/WQ Work • Loading of Toxic Contaminants, AHI, 1987 • Status and Trends, SFEP, 1991 • Site-specific water quality objectives, San Jose, 1991 • State of the Estuary, SFEP, 1992 • Metals Control Measures Plan, SCVURPPP, 1997 • Scoping Study of Air Deposition Monitoring Information Relevant to Water Quality, BASMAA, 1998

8. BASMAA Scoping Study of Air Deposition Monitoring Information Relevant to Water Quality • Prompted by increasing concern about air pollution being a “source” of POCs • Conducted preliminary review of both air pollution monitoring and air quality / water quality work • Showed that air monitoring network was unsuited for water quality POCs and source control work

9. Air Quality / Water Quality West Coast Studies • Deposition • San Francisco Estuary Institute (SFEI) • Southern California Coastal Water Research Project (SCCWRP) • Emissions – BASMAA and SFEP – Develop and implement a monitoring program for specific emission sources to storm water in San Francisco Bay Area watersheds

10. BASMAA / SFEP Study – Scoping • Candidate Pollutants of Concern • Selection criteria • Defined problem (303(d), WQO exceedances) • Storm water identified as significant pathway • Air emissions / deposition identified as significant pathway • Source identification/ characterization information needed • Emissions – Near-ground • Mercury in tailpipe exhaust • Copper in brake pads • Copper • Diazinon • Dioxin • Mercury • PAHs • PCBs

11. BASMAA / SFEP Study – Scoping (Cont’) • Mercury • Diesel exhaust was estimated source of 33% of mercury to South San Francisco Bay and 80% of mercury in urban runoff (SCVURPPP, 1997) • Sample and analyze fuels and lubricating oils • Copper • Brake pads were estimated source of 42% of copper to South San Francisco Bay and 80% of copper in urban runoff (SCVURPPP, 1997) • Characterize physical and chemical properties of brake pad wear debris

12. California Air Resources Board Mobile Laboratory

13. Sampling Plan • 39 total fuel samples • 20 Diesel • 19 Gasoline • 13 Regular gasoline • 6 Premium gasoline • Semi-random locations • Refineries • Transfer stations • Service stations

14. Sampling Plan (cont’) • 25 samples – other automotive fluids • Motor oils • Lube oils • Gear oils • Semi-random distribution of types and weights

15. Analysis • Fuels • Mercury – Cold Vapor Atomic Fluorescence Spectrometry • Full suite of other metals – ICP/OES (direct injection) • Oils – Thermal decomposition method?

16. Results – Mercury in fuels

17. Results – Other metals, Oils • Other metals in fuels – Most of the metals were below the detection limits with the exception of Ni and Pb in a few samples and Cu in one sample • Oils – Mercury appears to be less than 10 ppb BUT analyses were problematic, probably because of product formulation

18. Changing Load Estimates – Mercury • Diesel exhaust – 33% of load to South San Francisco Bay (SCVURPPP, 1997) • Atmospheric deposition – 7% of load to San Francisco Bay (RWQCB, 2003) • Gas / diesel fuel consumption (BASMAA / SFEP, 2003 draft) • 6% of atmospheric deposition • 0.4% of load to San Francisco Bay

19. So, where’s the rest of the Hg in air coming from? • Regional – Bay Area plus surrounding Cos. • Medical waste incineration • Portland cement manufacturing • Municipal waste combustion • Carbon black production • Crude oil refining? • International – Trans-Pacific fluxes from Asia plus local smog

20. City of Palo Alto / BASMAA Brake Pad Wear Debris Testing • Sample – One copper containing brake pad • Development of microwave digestion techniques for brake wear debris • Analyses • Determination of sample heterogeneity and minimum sample size for representative results • Total copper concentration determinations for brake wear debris • Specific surface area analysis • Copper solubility/leaching tests for model test conditions and for environmentally-relevant aqueous environments

21. Preliminary Results – Copper in Brake Pads • Wear debris particles are fine particulatematter (~72% is 10 μm or smaller – PM10) • Highly irregular shapes • Upon initial release, about 47% of the material was released into the air; about 49% fell to the ground

22. SEMs of Brake Wear Debris Source: Brake Manufacturers Council Product Environmental Committee, 2001

23. Preliminary Results – Copper in Brake Pads (cont’) • Copper content depends on individual pad • About 40% increase in copper use in pads between 1998 and 2000, with some probable increase between 1996 and 1998 • If results from one pad are typical, copper from vehicle brake pads probably behaves in the environment like copper from other environmental copper sources • Copper solubility in brake wear debris is probably due to the high surface area of brake pad wear debris and the chemical form of the copper in the wear debris

24. Copper in Brake Pads – Next Steps Proposition 13 Grant – Brake Pad Partnership • Chemical and physical characterization work • Environmental transport and fate modeling • Source loading • Air deposition modeling • Watershed modeling • Receiving water modeling • Environmental monitoring

25. Original Question Are Local, Near-Ground Emissions of Mercury and Copper Significant Sources of Water Pollution? • Mercury – No • Copper – Yes, probably

26. Contact Info. Geoff Brosseau BASMAA (Bay Area Stormwater Management Agencies Association) (510) 622-2326 gabrosseau@attbi.com