Phytotechnology Project Profiles
Phytoremediation at Edgewood Area J-Field, Aberdeen Proving Grounds in Maryland
Last Updated: Fall 2004 |
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| Site Information | ||
| Site Name, Location: | Aberdeen Proving Grounds, Edgewater, MD, United States | |
| Site Type: | Federal Facility | |
| Is this a Federal Superfund Site? |
Yes | |
| ROD Date, if applicable: | 9/27/2001 | |
| Is this a Federal or Military Site? |
Yes | |
| Entity Responsible for Cleanup: | Army | |
Project Information |
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| Project Name: | Phytoremediation at Edgewood Area J-Field, Aberdeen Proving Grounds in Maryland | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Site History and Background: | Aberdeen Proving Grounds (APG) is located at the tip of the Gunpowder Neck Peninsula in Edgewood Maryland, which extends into the Chesapeake Bay. At APG, the Army practiced open trench (toxic pits) open burning/detonation of munitions containing chemical agents and dunnage from the 1940s to the 1970s. Large quantities of decontaminating agents containing solvents were used during the operation, and the surficial groundwater table was contaminated with solvents (1,1,2,2-TCA, TCE, DCE) at levels up to 260 ppm. The plume is slow-moving due to tight soils and silty clay. The impacted area is a floating mat-type fresh water marsh approximately 500 feet southeast. A low environmental threat is presented by the contaminant plume. A demonstration of phytoremediation to clean up shallow groundwater was performed at the site by the U.S. Air Force (USAF) as part of the Department of Defense's (DOD's) Environmental Security Technology Certification Program (ESTCP) and the SITE Program. At the APG site, a process called deep rooting was used to achieve hydraulic influence. Hybrid poplar trees were planted in the spring of 1996 at five to six feet bgs to maximize groundwater uptake. The field demonstration and evaluation will be for a five year period. The U.S. Geological Survey has estimated that hydraulic influence will occur when 7,000 gallons of water per day are removed from the site. The latest field data indicates that hydraulic influence is occurring. Current tree uptake is 1,091 gpd and is expected to increase to 1,999 gpd at the end of 30 years. Contaminant uptake is minimal at this time but is expected to improve as the trees mature. Groundwater sampling indicates that the contaminated plume has not migrated off-site during the growing season and sampling data showed non-detectable emissions from transpiration gas. There are several on-going studies to determine if deleterious compounds retained in the leaves and soil could pose risks to environmental receptors. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Scale: | Pilot/Field Demonstration | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Project Status: | Complete | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Project Start Date: | April 1996 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Project Completion Date: | Spring 2001 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Media Treated: |
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| Contaminants Treated: |
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| Phytotechnology Mechanism(s): | Phytoremediation Hydraulic Control Phytodegradation |
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| Plants and other Vegetation Used: | Hybrid Poplar Sweet Gum Silver Maple Magnolia |
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| Planting Description: | After agronomic assessment, two year old hybrid poplars (510 trees) were planted at 5 to 6 feet below ground surface in Spring of 1996. Surficial drainage was installed to remove precipitation quickly and allowed trees to reach groundwater. New trees were planted in October 1998 to increase the phytoremediation area and access the usefulness of native species for phytoremediation. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Planting Area: | 0.5 acre | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Evapotranspiration Rates: | Tree uptake is 1,091 gpd; expected to be 1,999 gpd after 30 years growth | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Climate: | Temperature range: -7 to 105 F; Elevation:148 feet; Mean annual precipitation: 105 cm; Growing season: 04/11 to 10/29 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| O & M Requirements: | Insect control; animal control; mowing | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Performance Data: | No reduction in contaminant concentrations. Continuous source. Goal was containment, not reduction. Hydraulic control is working at the site. The contaminated plume has not migrated off-site during the growing season. Contaminant uptake is minimal at this time but is expected to improve as the trees mature. Groundwater sampling indicates that the contaminated plume has not migrated off-site during the growing season and sampling data showed non-detectable emissions from transpiration gas. Examination of groundwater level data revealed an area of depression within the poplar plantation indicating that hydraulic influence is occurring. Currently, the trees are removing approximately 1,091 gallons per day and at the end of 30 years are expected to remove 1,999 gallons per day. There are no ecological impacts that attribute to the plantation area. Sampling data have shown non-detectable off-site migration of emissions from transpiration gas. Peak transpiration is estimated to occur in approximately 10 to 15 years. Limitations include depth of contamination, but there are no limitations for concentrations of up to 260 ppm for solvents. Weather and growing season are the most influential factors. Contaminant uptake is minimal at this time but is expected to improve as the trees mature. A groundwater model is under development to quantify the degree of containment generated by the trees. The model requires an accurate estimate of water withdrawal rates by the trees to determine if phytoremediation will work as a remedial alternative for the site. This demonstration project is on-going and will be further evaluated for efficacy and costs. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Cost of the Phytotechnology Project: | Tree: $80 each; Preparation: $5,000; UXO clearance: $80,000; O&M: $30,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lessons Learned: | Several trees were excavated in the fall of 1998 to determine root growth. The tree roots were found to be confined to the hole in which they were placed. In an attempt to increase root depth and width, new trees were planted in holes of varying sizes and depths. Results indicated that an area of drawdown exists with the tree zone during the spring and summer when tree transpiration is the greatest. Sap flow monitoring was performed to determine the amount of water being removed by individual trees. In order to increase monitoring accuracy, new sap flow probes were purchased which are placed directly into the tree tissue as opposed to resting on the trunk of the tree. Comparison of new equipment with previous methods indicates that the new methodology provides an even more accurate estimation of net transpiration rate with less data interference or "noise." Future sampling objectives for the site include continued seasonal sap flow monitoring for the purposes of estimating transpiration rates. Seasonal tree transpiration gas and condensate sampling continued in the 1998 sampling season to assess the release of VOCs from the trees. Previous methods consisted of placing a 100-liter Tedlar bag over a section of branch and then sampling the gas and any condensate trapped within the bag. This method was modified in 1998 with the addition of a cold trap which would potentially remove excess moisture from the bag and keep the leaves in a more ambient temperature. Comparison of the two methods, with and without could trap, indicates that the cold trap apparatus may not be powerful enough to sufficiently cool the temperature within the bag. Future transpiration gas monitoring was planned for the 1999 sampling season with the addition of a modified cold trap attachment. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Comments: | TCE was detected in leaf tissue during the first year of the project. A transect of monitoring wells has been used to evaluate the program's effect on groundwater and has shown significant hydraulic effects. The U.S. Geological Survey has estimated that hydraulic influence will occur when 7,000 gallons of water per day are removed from the site. A groundwater model is currently being developed to predict potential VOCs removed by the trees when complete hydraulic influence may be attained. Leaves and soil were collected from the phytoremediation area and a reference area for a leaf degradation study. The study is designed to determine whether or not there are deleterious compounds retained within the study leaves or within the associated soil which could pose risk to an environmental receptor. Data collected in 1997 indicated that the nematode community was enhanced in the phytoremediation area as compared with data collected prior to the tree planting. | Point(s) of Contact |
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Steven Hirsch U.S. EPA Region 3 (3HS50) 1650 Arch Street Philadelphia, PA United States Telephone: (215) 814-3352 E-mail: hirsch.steven@epa.gov John Wrobel U.S. Army United States Telephone: (410) 436-4840 Compton Harry U.S. EPA, ERT (MS101) 2890 Woodbridge Avenue Edison, NJ United States Telephone: (732) 321-6751 Fax: (732) 321-6724 E-mail: compton.harry@epa.gov |
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| Information Source(s): | Phytotransformation Groundwater Capture on 1 acre plot, Phytoremediation: Technology Report. GWRTAC TE-98-01 J-Field Phytoremediation Program Document Index http://web.ead.anl.gov/jfield/phyto/index.cfm Project update provided to Ellen Rubin by John Wrobel. Fall 2004. EPA. Federal Remediation Technologies Roundtable. 2002. Technology Cost and Performance Report Summary: Phytoremediation at Aberdeen Proving Grounds, Edgewood Area J-Field Site, Edgewood, MD. http://costperformance.org/profile.cfm?ID=3 EPA. Federal Remediation Technologies Roundtable. 2002. Technology Cost and Performance Report: Phytoremediation at Aberdeen Proving Grounds, Edgewood Area J-Field Site, Edgewood, MD. http://costperformance.org/pdf/NATO-Aberdeen-Phyto.pdf EPA. 2005. Use of Field-Scale Phytotechnology for Chlorinated Solvents, Metals, Explosives and Propellants, and Pesticides. EPA 542-R-05-002. http://www.epa.gov/tio/download/remed/542-r-05-002.pdf |
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| Associated Vendor(s) or Consultant(s): | Other or Not Known |
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