BIOSTIMULATION REMEDIATION OF JET FUEL IN MARSH WITH HC-2000

A tanker carrying 8,000 gallons of JP-8 on a major interstate rolled down an embankment releasing 2,600 gallons of jet fuel into a wetland next to a stream feeding a recreational lake in North Atlanta. Remtech was engaged by the insurance company to remediate the site.

A series of interceptor trenches were installed to collect free product and function as serve as insitu reactors. HC-2000 (a native microorganism bioremediation accelerator) was applied to enhance the biodegradation of jet fuel in the vadose and saturated zones.

During the first month of operation, 700 gallons of fuel were recovered from groundwater using recovery well pumps and from an oxbow with a polypropylene rope mop. Leachates were pumped to a Remtech treatment system consisting of an oil/water separator, twin LPAS (Low-Profile Air Strippers), and aqueous phase activated carbon filters. This system doubled as a enzyme bio-concentrator by recirculating groundwater.

Following removal of the free product phase from surface and groundwater, HC-2000 injection was initiated. The reactor trenches were utilized to generate foam to increase mass transport in the saturated zone and to elevate groundwater dissolved oxygen levels from 0.5 mg/l to over 3.5 mg/l. Total groundwater heterotrophic plate counts increased from 10,000 CFUs/ml to over 1,000,000 CFUs/ml during the first month.

During the four month treatment period, soil TPH concentrations were reduced over 91% and groundwater TPH concentrations by over 94%. Benzene groundwater concentrations were reduced from 125 ppb to below detection limits. Downgradient monitoring wells demonstrated that offsite migration did not occur. Six years later, groundwater samples were collected from the heart of the spill and no BTEX rebound was observed.

Cost/Benefit Analysis

Insitu enhanced bioremediation was selected over other remedial strategies due to limited site access in a geotechnically unstable and environmentally sensitive area.

This project cost $460,000. A major damage claim was avoided by recognizing and documenting extensive stream bank erosion to a stream running through a golf course. The damage was due to increased runoff from urban development and the removal of buffer trees along the stream during construction of the golf course. Cost estimates to divert the stream, dewater the site, excavate and replace soil was $1,2000,000.

JP-8 Tanker Rollover into Wetland Next to Stream

HC-2000 BioFoam Injection Reactors

HC-2000 Bioconcentrator