Pilot-Scale Treatability Study for Enhanced In-Situ Microbiological Degradation of Petroleum and Polynuclear Aromatic Hydrocarbons, 1995 Environmental Conference Proceedings

Lance A. Downs

EMCON

Susan T. Zeni, P.E.

Weyerhaeuser

Miles Stumbaugh

EMCON

The cost-effectiveness of removing floating product from a groundwater and treating long-chain-hydrocarbon- impacted soil using enhanced biodegradation, with minimal site disturbance was assessed in January 1993 at the 2.02-km 2 Weyerhaeuser Company Springfield, Oregon Sawmill. A pilot-scale test was designed with a recovery trench to hydraulically control groundwater flow, capture dissolved petroleum hydrocarbons constituents, and recover floating product. An upgradient injection trench was installed for re-injection of treated and nutrient-amended groundwater. Additionally, three sparging wells, one of which was capable of injecting pure oxygen for stripping and increasing dissolved oxygen (DO) were installed. Primary soil impacts were petroleum hydrocarbons in the weathered gasoline, diesel, and oil range (C8 to C30+), although low levels of certain polynuclear aromatic hydrocarbons (PAHs) had also been detected. Groundwater was primarily impacted with phase-separated petroleum hydrocarbons, or floating product, in the diesel and oil range. It also contained dissolved phase concentrations of benzene, toluene, ethylbenzene, and total xylenes (BTEX) in addition to some slightly soluble PAHs. Soil and extracted groundwater monitoring parameters consisted of total petroleum hydrocarbons (TPH), BTEX, PAHs, inorganic nutrients, total heterotrophic and TPH-specific microorganisms, total organic carbon, dissolved oxygen, temperature, and pH during the pilot-scale test.