soil contamination- overview and case study christopher lyles ess 315 christopher lyles ess 315
TRANSCRIPT
Soil Contamination-
Overview and Case Study
Christopher LylesESS 315
Christopher LylesESS 315
How soil becomes Contaminated
How soil becomes Contaminated
Urban runoff Agricultural runoff Mining Industrial Operations Atmospheric
Deposition Contaminated
Groundwater
Urban runoff Agricultural runoff Mining Industrial Operations Atmospheric
Deposition Contaminated
Groundwater
Sources of ContaminationSources of Contamination
Gas Works ParkGas Works Park
Gas Works ParkGas Works ParkPrevious site of coal and oil gasification (1900 to 1956)
Waste accmulations include: coal, tar, and oil
Polynuclear aromatic hydrocarbons (PAH’s )and volatile organic compounds (VOC’s) are present in groundwater
PCB’s, heavy metals, and cyanides also present
“Gas Works deposit” is as thick as 9 feet across the park and overlies the Vashon Till- consists of waste products from prior operations (
Developed by Seattle Parks and Recreation and subsequently studies by USGS and UW
Borehole and Well Sites- Contour Map
Borehole and Well Sites- Contour Map
Water Table Contour Map and Flow Paths
Water Table Contour Map and Flow Paths
Geologic Cross SectionsGeologic Cross Sections
Important to understand the “Gas Works Deposit” as It’s interaction with the Ground Water is the main concern
Important to understand the “Gas Works Deposit” as It’s interaction with the Ground Water is the main concern
Contamination processesContamination processes
Weathering of Hydrocarbons in soil and NAPL’s
Weathering- dissoultion, volatilization, biodegradation
These processes release water-soluble, low molecular weight orgainc compunds into water, leaving behind stained soils containing insoluble, high molecular weight compounds
Weathering of Hydrocarbons in soil and NAPL’s
Weathering- dissoultion, volatilization, biodegradation
These processes release water-soluble, low molecular weight orgainc compunds into water, leaving behind stained soils containing insoluble, high molecular weight compounds
Not Quite Polluted Enough…
Not Quite Polluted Enough…
…to become a superfund site (in 1980)
But polluted enough to cost tens of millions of dollars to clean up…
Puget Sound Energy and City of Seattle still continuing to monitor and clean the site
Main Concerns/ Remediation Techniques
Main Concerns/ Remediation Techniques
Benzene (toxic/ Carcinogenic)
Naphthalene (Toxic/ non-carcinogenic)
PAHs (vary depending on type but can be both Toxic and Carcinogenic)
Benzene (toxic/ Carcinogenic)
Naphthalene (Toxic/ non-carcinogenic)
PAHs (vary depending on type but can be both Toxic and Carcinogenic)
Air sparging/ Soil Vapor Extraction (AS/SVE)
Monitored Natural Attenuation (possible phyto-remediation to be used in future)
Direct Soil contact Remedy
Air sparging/ Soil Vapor Extraction (AS/SVE)
Monitored Natural Attenuation (possible phyto-remediation to be used in future)
Direct Soil contact Remedy
Air SpargingAir Sparging
Air Sparging/ Soil Vapor Extraction (AS/SVE)
Air Sparging/ Soil Vapor Extraction (AS/SVE)
PhytoremediationPhytoremediation
ReferencesReferenceshttp://www.ecy.wa.gov/programs/tcp/sites/gaswkspk/Gas%20Works%20Agreed%20Order%20DE%202008.pdf
http://www.seattlepi.com/local/331605_gasworks14.html
https://info.ngwa.org/GWOL/pdf/901878014.PDF
http://www.ecy.wa.gov/pubs/0709080.pdf
http://www.epa.gov/superfund/about.htm
http://www.ecy.wa.gov/programs/TCP/sites/gaswkspk/gaswks.htm
http://www.ecy.wa.gov/programs/tcp/sites/gaswkspk/Five%20Year%20Review.pdf