Oxygen-Release Compound Remediation Tests
- Testing of Remediation Technologies
- Performance Monitoring
||Laurel Bay, SC
||U.S. Navy, Naval
Facilities Engineering Command (NAVFAC)
||In-Situ Chemical Oxidation (Oxygen Addition to Ground
- Methyl tert-butyl ether (MTBE)
USGS scientists have tested the effectiveness of injecting an oxygen-release compound into the subsurface to remediate a plume of methyl tert-butyl ether (MTBE) created by a leaking underground storage tank at a gasoline station at Laurel Bay, SC. The scientists had previously discovered that MTBE naturally biodegrades when the MTBE plume encounters an interface between anoxic (without oxygen) ground water and the oxic (with oxygen) water in stream-bottom sediments. Because ground water is often contaminated with MTBE in locations where such interfaces are not present, the scientists hypothesized that it would be possible to artificially create such an anoxic/oxic interface in anoxic, MTBE-contaminated aquifers. A test was designed using an oxygen-release compound to create an anoxic/oxic interface similar to those found in streambed sediments and to intercept and remediate the leading edge of the MTBE plume. The scientists used wells to inject the oxygen-release compound into the anoxic plume and instrumented the site with observation wells equipped with real-time oxygen probes. Within 60 days following the introduction of oxygen, MTBE concentrations decreased up to 87% from the originally high (> 20 milligrams per liter) concentrations. This test showed that enhanced bioremediation of MTBE-contaminated ground water could be a successful remediation strategy.
Due to the success of the oxygen-release compound test on MTBE, the U.S. Navy, the owner of the site, is interested in testing the technology on some of the less soluble contaminants (toluene, ethylbenzene, and xylene) still present in the source-area of the plume. Remediation of benzene and MTBE contaminants to regulatory compliance levels has been achieved at the Laurel Bay site by dissolution of the free product in the subsurface site followed by natural attenuation processes. However, remediation of less soluble toluene, ethylbenzene, and xylene contaminants may require treatment (or removal) of the source area. USGS scientists plan to treat the source area with an oxygen-release compound to reduce the concentrations of contaminants there. Treatment of the source area will most likely decrease the remediation time associated with the less soluble compounds from the tens of years required for the contaminants to leach out and attenuate to a few years. The source area will be monitored to document the results.
Note: Trade names are used for information purposes only and
do not denote endorsement by the U.S. Geological Survey.
||James Landmeyer, USGS, South Carolina Water Science Center, Columbia,
- Bradley, P.M., Chapelle, F.H. and Landmeyer, J.E., 2001,
mineralization in surface-water sediment microcosms under denitrifying
conditions: Applied and Environmental Microbiology, v. 67,
no. 4., p. 1975-1978.
- Bradley, P.M., Landmeyer, J.E., and Chapelle, F.H., 2001,
potential for microbial MTBE degradation in surface-water sediments:
Environmental Science and Technology, v. 35, no. 4, p. 658-662.
- Landmeyer, J.E., Chapelle, F.H., Herlong, H.H., and Bradley,
tert-butyl ether biodegradation by indigenous aquifer microorganisms
under natural and artificial oxic conditions: Environmental
Science and Technology, v. 35, n. 6, p. 1118-1126.
Other Toxics Program In-Situ Chemical Oxidation Projects
Other USGS In-Situ Chemical Oxidation Projects
Toxics Program Information on Remediation of Fuel Oxygenates
USGS Information on Fuel Oxygenates
Back to Toxics Program Remediation Activities Index