Accelerated Petrox® Bioremediation of Naphthalene and Methylnaphthalene

Case Study:

UST Remediation in Miami, Florida

Site Summary:

Petrox® bioaugmentation was implemented at a former gas station UST removal site in Miami, Florida to destroy residual petroleum compounds in ground water. The UST and contaminated soil were removed. However, residual ground water contamination persisted and Petrox® bioremediation was implemented to remove the residual low concentrations of BTEX, naphthalene and methylnaphthalene isomers.

Geology and Hydrogeology

The impacted ground water was in a shallow unconfined sandy aquifer. The hydraulic conductivity of the aquifer formation was measured at 560 ft/day. The depth to ground water was approximately 10 feet below grade.

Contamination

Low concentrations of BTEX compounds and naphthalene and methylnaphthalene isomers were present in ground water at and down gradient of the former UST cavity. The following table summarizes the contaminant concentrations in two impacted monitoring wells. The ground water plume area extent was 12,000 square feet.

Implementation

Petrox was applied in one application of 14 units on May 26, 2011. One unit of Petrox® is a 55-gallon slurry with a microbial concentration of 109 cfu/ml. Forty pounds of EHC-O was added to provide an oxygen source for the petroleum metabolism.

Post -treatment samples were taken on August 17, 2011. The following table shows the contaminant concentration treads in the treatment area.

Results

The treatment was successful in reducing the contaminant concentrations. Overall the treatment verified the effectiveness of Petrox® bioaugmentation for a mixed suit of petroleum constituents including aromatics and PAHs.