Gasoline Remediation in Fractured Rock Restores Building Permit | Athens, GA

GASOLINE IN FRACTURED ROCK PROBLEM

Construction on a $16 M publications building was stopped for four months by the State Fire Marshal when building permits were revoked due to gasoline found in elevator shaft excavations using explosives. A geotechnical firm was initially engaged that indicated that there were thousands of gallons of gasoline under the building footprint when they discovered several feet of gasoline in several of 22 monitoring wells they installed.

GASOLINE REMOVAL FROM FRACTURED ROCK SOLUTION

Remtech was engaged by the building owner to attempt to resolve the gasoline contamination problem and have building permits reinstated by the State Fire Marshal. Remtech demonstrated that fuel in the fractured rock formation was hydraulically connected with minimal fuel production during pump tests. A Sandborne map was discovered in the attic of the city planners office that depicted an old filling station located under the contractors construction trailer.  

The trailer was moved and a forensic excavation was conducted. Remnants of an old pump island and gasoline USTs were located. Chemical linkage was established (by sampling) from the old tank pit to the fuel footprint in fractured rock demonstrating that the source had been found and removed. Remtech prepared and implemented a remedial action plan that was approved by the State Fire Marshal and County permitting officials that allowed building construction to resume.

FRACTURE ROCK GASOLINE REMEDIATION PROGRAM & COST/BENEFITS

• Diaphragm pumps were used to convey groundwater and free product from existing monitoring wells to Remtech's mobile stripping towers.

• Recovered less than 150 gallons of free product during pump tests confirming that a manageable quantity of gasoline was present.

• As a precautionary measure, Four-inch gasoline recovery wells were installed in the building footprint using rotary percussion drilling equipment.

• A vapor intrusion collection system was installed in a membrane covered gravel cavity with a 2" slotted PVC well screen gas collection network.

• Remtech's mobile treatment system was installed in the completed building's annex along with explosion proof vapor intrusion exhaust blowers.

• Building permits were reinstated and $16M building completed.

• Gasoline vapor levels under the building were reduced below 10% of LEL within 6 weeks.

• Gasoline vapors were reduced below detection limits in 2 years.