St. Louis, Missouri
Client:
Penske Truck Leasing Co.
Terra Technologies, Inc. was retained by Penske Truck Leasing Co., L.P. (Penske) to perform remedial actions for a site located in the City of St. Louis, Missouri. Penske historically operated this truck-maintenance and leasing facility and as part of the facility operations, two 10,000-gallon underground storage tanks (one gasoline and one diesel) were maintained for refueling purposes. During March 1988, the two tanks, a pump island, and associated underground pipes were removed from the site. Petroleum impacted soil was encountered during the removal, and approximately 400 tons of visually impacted soil was excavated and transported off site for disposal. Groundwater was also encountered in the bottom of the excavation and free phase petroleum was observed on the groundwater surface. Several investigations and remedial actions were performed with limited success.
The Corrective Action proposed for the Site was the introduction of a dilute concentration of hydrogen peroxide (H2O2) into the subsurface through existing monitoring wells impacted by refined petroleum products. The Corrective Action also included monthly monitoring to ensure that the hydrogen peroxide introduction was having a beneficial effect on the impacted groundwater. The purpose of conducting the proposed activities was to expedite the cleanup of the site in order to obtain closure in accordance with the requirements set forth by the Missouri Department of Natural Resources (MDNR) Underground Storage Tank (UST) Program.
A Pilot Study determined that the addition of a dilute concentration of hydrogen peroxide could provide the dual benefit of oxidizing the petroleum hydrocarbon constituents and providing oxygen to naturally occurring microorganisms to reduce the petroleum hydrocarbon concentrations to acceptable levels. The Correction Action Plan was approved by the MDNR UST Program and a General Permit was issued by the Water Pollution Control Program (WPCP). This is the only site in the state of Missouri to successfully obtain a permit for the introduction of hydrogen peroxide to remediate petroleum hydrocarbons.
Hydrogen peroxide introduction was routinely performed two times per month into the monitoring wells that historically exceeded the MDNR UST Program cleanup guidelines. Monthly monitoring laboratory analytical results indicated a dramatic decrease in petroleum hydrocarbon concentrations (>99%). The introduction of hydrogen peroxide was successful in reducing the concentrations of petroleum hydrocarbons present at the site. A No Further Action (NFA) Letter was provided by the UST Program on April 29, 2003, which indicated that further investigation or remedial actions were not required.
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