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By: Jennifer Schaffer jenniferscha@gmail.com. LNAPL (Light Non-Aqueous Phase Liquids). Courtesy of U.S. Geological Survey. 3-D Image of LNAPL Plume. Leaks & Spills: 1992-2002 Sampling of Incidents at Shell Group Companies & Joint Ventures*.
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By: Jennifer Schaffer jenniferscha@gmail.com
LNAPL(Light Non-Aqueous Phase Liquids) Courtesy of U.S. Geological Survey
Leaks & Spills: 1992-2002 Sampling of Incidents at Shell Group Companies & Joint Ventures* Derived from: http://www.shellfacts.com/downloads/Leaks&Spills2.pdf
Prevalence of Gasoline Spills • 8 sites on the NPL • According to National Response Center, have been 7,957 gasoline spills on land since 1990. • Gas spills were primarily unreported until recent history. • There were no formal reporting requirements prior to 1970. • From 1970-1980, only spills that reached navigable waters had to be reported
Sugar Creek, Missouri http://www.krohm.com/sugarcrk/index.htm
Methods Used for Cleanup • Biofiltration • Scrubbers • Carbon Absorbtion • Bioremediation - microbials • Free product recovery – Skimming systems • Free product recovery – water table depression • Vapor Extraction • Dual Phase Recovery • Pumps
Circulation pump
Solar powered pump
Enhanced Methods • Steam • Surfactants • Phased soil heating • Chemical oxidation • Hot and cold water floods
Steam This process requires large facilities and operations as well as significant time and money.
Surfactants Wetting agents that lower the surface tension of a liquid, allowing easier spreading, and lower the interfacial tension between the two liquids. These are already used in green cleaning products.
Ways this Gasoline Could be Used • Marine Uses • Aviation Fuel • South America, Asia, Eastern Europe and the Middle East – automotive • Racing cars • Farm equipment • Industrial uses • Energy Production
Patent, 1935 issued to F.E. Neff, Jr.
Patent for using ammonium phosphate to clean lead from gasoline/oil products
Carbon Scrubbers
So, why are more companies not recycling/reusing the gas? • Cost – is it worth the costs? • How do the costs compare? • Are there “hidden costs” to recovery? • Diminishing Returns from recovery • Potentially liability • Ramifications of claiming the gasoline • Property dispute issues
Hydraulic Recovery of the Oil Poses Difficulty • Residual saturation trapped by capillary forces • Heterogeneity of the soil • Conductivity of the LNAPL phase
What could be done to encourage recycling? • Legislation which encourages and or compels recovery • Legislation which removes liability issues • Legislation which resolves property ownership issues • Should it be done? • Would we be trading one pollution for another? • Should there be limits or regulations on how recovered gasoline can be used/sold?