Using Phytoremediation to Control Fuel Oxygenate Plumes in Northern Climates
- Testing of Remediation Technologies
- Natural Attenuation Evaluation
||Flathead Indian Reservation, Ronan, Montana
- Fuel Oxygenates
- Methyl tert-butyl ether (MTBE)
- Non-MTBE ethers (tert-amyl methyl ether TAME, diisopropyl ether
DIPE, ethyl tert-butyl ether ETBE )
- Tert-amyl alcohol (TAA), and tert-butyl alcohol (TBA)
USGS scientists and their partners are testing the use of phytoremediation in northern climates (nontemperate) to contain and remediate a subsurface plume of gasoline located near Ronan, Montana, on the Flathead Indian Reservation. At the site, an underground storage tank leaked an estimated 10,000 gallons of gasoline that contained BTEX and various fuel oxygenates, such as MTBE. Although the tank has been removed, free product is still present in the subsurface at the site, creating a plume that has migrated from the gasoline station, under Highway 93, and terminates at Spring Creek, about 450 meters away.
The root ball of each poplar
tree was dipped in a solution of mycorrhizae
to inoculate the new trees with beneficial microbial
populations to assist in water uptake. More
The objective of the test is to see if phytoremediation in this northern climate, where it is not uncommon for the top foot of soil to freeze during winter months, could stop the contamination plume from discharging into Spring Creek. To achieve this, water-loving trees (poplars) were planted to capture ground water and dissolved contaminants. The trees planted in 2001 by the USGS at the toe of the plume did not survive the winter. The high rate of mortality was most likely due to planting small, 6-inch cuttings, without a large root mass. In 2002, much larger, 6-foot trees with a substantial root ball were planted. Future monitoring results will be useful in determining the viability of using phytoremediation in this part of the U.S. to control plume migration.
A secondary objective of the project is to test the ability of new analytical methods to measure the concentrations of alternative fuel oxygenates (non-MTBE ethers and polar fuel compounds) in contaminated ground water. Project scientists in conjunction with scientists from the U.S. Geological Survey's National Water Quality Laboratory, the Oregon Graduate Institute, and the University of Oklahoma successfully measured alternative fuel oxygenates (tert-amyl methyl ether TAME, diisopropyl ether DIPE, ethyl tert-butyl ether ETBE, tert-amyl alcohol TAA, and tert-butyl alcohol TBA) in water. The data from this project will enable the scientists to evaluate and compare the natural attenuation of alternative oxygenates to MTBE. The comparison will be aided by the analysis of the composition of stable-isotopes of carbon and hydrogen in the oxygenates. Changes in carbon and hydrogen isotopes will help identify biodegradation reactions of the oxygenates in ground water. This information can be used by resource managers to evaluate using proposed alternatives to MTBE as oxygenates in gasoline.
In addition to the above work, the scientists conducted an investigation to determine the ability of the subsurface microorganisms at the site to degrade MTBE during the winter when ground water temperatures range from 5° Celsius (C) 41° Fahrenheit (F) to 14°C (57.2°F). Because microbial activity often decreases with decreasing temperatures, the scientific and engineering communities have assumed that biodegradation rates are low or insignificant at such cold temperatures. The scientists conducted laboratory microcosm studies on the sediment samples from the Ronan site and the Almena Agricenter Site in northern Kansas, and demonstrated that the microbial communities present at the sites can biodegrade MTBE at temperatures as cold as 4°C (39.2°F). These results indicate that microbial degradation can continue to contribute to the natural attenuation of MTBE in ground water even during winter cold-temperature conditions.
||James Landmeyer, USGS, South Carolina Water Science Center, Columbia,
- Kuder, T., Kolhatkar, R., Philp, P., Wilson, J., Landmeyer,
J., Allen, J., 2002, Compound-specific
carbon and hydrogen isotope analysis - field evidence of MTBE
bioremediation: American Geophysical Union Fall Meeting, San
Francisco, CA, December 6-10, 2002 (abstract).
- Bradley, P.M., and Landmeyer, J.E., 2006, Low-temperature MTBE biodegradation in aquifer sediments with a history of low, seasonal ground water temperatures: Ground Water Monitoring and Remediation, v. 26, no. 1, p. 101-105, doi: 10.1111/j.1745-6592.2006.00075.x.
|| USGS Phytoremediation Information
- USGS Corecast: Phytoremediation of Contaminated Groundwater (Podcast), An interview with USGS research hydrologist Jim Landmeyer
- Can Trees Clean Up Ground
Water? Phytoremediation of Trichloroethene Contaminated Ground
Water at Air Force Plant 4, Fort Worth, Texas
in the Desert?, Amargosa Desert Research Site, NV
Attenuation of Chlorinated Volatile Organic Compounds in Ground
Water at Operable Unit 1, Naval Undersea Warfare Center, Division
of the Ground-Water Flow System and Potential Remediation of the
Logistics Center, Fort Lewis, Washington (see Report,
Fact Sheet 082-98)
Toxics Program Information on Remediation of Fuel Oxygenates
USGS Information on Fuel Oxygenates
Back to Toxics Program Remediation Activities Index