BIOREMEDIATION OF PETROLEUM-CONTAMINATED SOIL


BIOREMEDIATION OF PETROLEUM-CONTAMINATED SOIL
Client: Western States Equipment
Boise, there Idaho

Summit Environmental staff provided environmental engineering service to remediate the former drain field and cistern areas of a truck repair shop, where vehicles were steam-cleaned and wash water was treated and discharged.  Phase I and II Site Assessments identified the cistern area for remediation, since soil samples taken from the area contained high concentrations of petroleum fuel, motor oil and grease.

Summit Environmental staff evaluated several remedial options, including in-situ treatment, on-site biological treatment and off-site disposal.  On-site bio-pile treatment was determined to be the most appropriate and cost-effective remedial option, since heavier, long chain hydrocarbons were present.

Summit Environmental staff excavated approximately 2,200 cubic yards of petroleum-contaminated soil from the drain field and cistern areas and processed the soil by sieving to remove large aggregate.   The large gravel material was returned to the excavation as backfill, in order to reduce backfill costs.  The remaining 1,600 cubicyards of petroleum-contaminated soil were then conditioned and placed in a bio-pile for bioremediation.

Summit Environmental personnel provided technical oversight to construct a monitoring well to a depth of 68 feet on-site.  Once the well was developed, groundwater samples were collected and laboratory analysis was conducted to assess BTEX concentrations and to monitor contaminant migration.  Because groundwater monitoring revealed no contaminant impacts above the regulatory levels, “No Further Action” was recommended to the Idaho Division of Environmental Quality.