In situ bioremediation of petroleum in tight soils using hydraulic fracturing

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:488813

Stavnes, S ^[1]; Yorke, C A ^[2]; Thompson, L ^[3]

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1. Environmental Protection Agency, Denver, CO (United States)
2. Foremost Solutions, Inc., Golden, CO (United States)
3. Pintail Systems, Inc., Aurora, CO (United States)

This case study evaluated the effectiveness of in situ bioremediation of petroleum hydrocarbons in tight soils. The study area was contaminated with cutting oil from historic releases from underground piping, probably dating back to the 1940`s. Previous site assessment work indicated that the only chemicals of concern were total petroleum hydrocarbons (TPH). Two fracture sets (stacks) were installed at different locations to evaluate this in situ bioremediation technique under passive and active conditions. Several injection wells were drilled at both locations to provide entry for hydraulic fracturing equipment. A series of circular, horizontal fractures 40 to 50 feet in diameter were created at different depths, based on the vertical extent of contamination at the site. The injection wells were screened across the contaminated interval which effectively created underground bioreactors. Soils were sampled and analyzed for total petroleum hydrocarbons on five separate occasions over the nine-month study. Initial average soil concentrations of total petroleum hydrocarbons of 5,700 mg/kg were reduced to 475 mg/kg within nine months of hydraulic fracturing. The analytical results indicate an average reduction in TPH at the sample locations of 92 percent over the nine-month study period. This project demonstrates that in situ bioremediation using hydraulic fracturing has significant potential as a treatment technology for petroleum contaminated soils.

• OSTI ID: 488813
• Report Number(s): CONF-9610152--
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
BIODEGRADATION
GEOLOGIC FRACTURES
HYDROCARBONS
IN-SITU PROCESSING
INJECTION WELLS
MONITORING
OIL SPILLS
REMEDIAL ACTION
SOILS