Technology:
Soil and groundwater flushing - Well Injection Depth Extraction (WIDE)
- WIDE system is a hybrid soil flushing/soil gas extraction system that uses prefabricated vertical wells (PVWs) for in situ remediation of low permeability soils
- Demonstration area - 70 feet by 70 feet
- WIDE system used a grid of over 480 PVWs installed to a depth of 15 feet; the above-ground treatment system to treat TCE-contaminated groundwater was granular activated carbon followed by discharge to an on-site wastewater treatment plant. Extracted soil gas was also treated using granular activated carbon followed by release to the atmosphere .
- Demonstration was conducted in extraction only mode, and extraction/injection mode. During extraction only test, the groundwater extraction rate ranged from 25 to 150 gallons per hour and the soil gas extraction rate ranged from 120 to 350 standard cubic feet per minute. The system was operated in extraction only mode for 6 hours per day over a period of 23 days. During extraction/injection test, 120 gallons per hour of water were injected and an equal amount extracted over a 50 hour period. Information is not available for the air extraction rate in the extraction/injection test.
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Cleanup Authority:
Not identified
Contacts:
Technical Contact
John D. Quarenta, Ph.D., P.E.
Principal Investigator
Department of Civil Engineering
North Carolina State University
Phone: (919) 513-2040
E-mail: quaranta@eos.ncsu.edu
Department of Energy Contact
Karl-Heinze Frohne
Project Manager
National Energy Technology Laboratory (NETL)
Phone: (304) 286-4412
E-mail: kfrohn@NETL.doe.gov |
Contaminants:
Trichloroethylene (TCE)
- TCE concentrations up to 632 mg/L in the groundwater
Uranium (U)
- U concentrations up to 13 mg/L in the groundwater |
Waste Source:
Uranium metals processing |
Type/Quantity of Media Treated:
Soil:
- The treatment remediated a 70 foot by 70 foot area from the surface to a depth of 15 feet. The groundwater table ranged from 2 to 3 feet bgs before the demonstration.
Groundwater:
- During extraction only test, the groundwater extraction rate ranged from 25 to 150 gallons per hour. During extraction/injection test, 120 gallons per hour of water were injected and an equal amount extracted.
Purpose/Significance of Application:
Field demonstration of hybrid soil and groundwater flushing/soil vapor extraction treatment of trichloroethylene (DNAPL) in clay soil |
Purpose/Significance of Application:
Field demonstration of hybrid soil and groundwater flushing/soil vapor extraction treatment of trichloroethylene (DNAPL) in clay soil |
Regulatory Requirements/Cleanup Goals:
- TCE: <0.005 mg/L in groundwater
- Design, construct, operate, and monitor the performance of the WIDE system |
Results:
- Groundwater monitoring data over eight months following demonstration indicated TCE concentration reductions ranged from 46% to 57%.
- The TCE and U extraction rates (including contaminants extracted from both groundwater and soil vapor) for the extraction only test were 2,800 mg/hour and 420 mg/hour respectively.
- The TCE and U extraction rates (including contaminants extracted from both groundwater and soil vapor) for the extraction/injection test were 1,300 mg/hour and 640 mg/hour respectively. |
Cost Factors:
- The demonstration program had a capital cost of $386,000 and estimated annual O&M cost (the demonstration was performed in 8 months) of $200,000.
- The estimated costs of treating the entire 1.25 acre TCE groundwater plume were $1.3 million capital cost and $0.2 million annual cost over a treatment time of 5 years to meet the <0.005 mg/L cleanup goal for TCE. |
Description:
The RMI Titanium Plant is a former uranium processing facility which supplied extruded an milled uranium products for use within DOE's weapons complex. A former evaporation pond is responsible for the TCE and U contamination of groundwater at the site. DOE's Office of Science and Technology, in coordination with AEMP, conducted a demonstration of soil flushing at this site.
The soil and groundwater flushing system was tested in several modes of operation over a period of eight months on a 70 foot by 70 foot area covering the former evaporation pond. The technology was tested in extraction only and extraction/injection mode. Eight months after the test, TCE concentrations in the groundwater were reduced from 46% to 57%. |
