Technology:
In Situ Flushing
- Referred to as Mobilization, Extraction, and Removal of Radionuclides (MERR) technology
- The demonstration used 15 extraction wells and 5 injection wells
- Groundwater was extracted, treated above-ground to remove uranium (treatment not identified), and re-injected at a rate of 1,000 gpm (5 wells at 200 gals/well)
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Cleanup Authority:
Not identified
Technical Contacts:
Rob Janke
DOE-FEMP
(513) 648-3124
Dave Brettschneider
Fluor Fernald
(513) 648-5814
Terrall Putnam
Fluor Fernald
(513) 648-6363
Terrall.Putnam@fernald.gov | Management Contact:
Lynton Yarbrough
SCFA Manager
DOE Albuquerque
(505) 845-5520 |
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Contaminants:
Heavy Metals
- Uranium concentrations as high as 490 ug/L |
Waste Source:
Nuclear weapons production operations |
Type/Quantity of Media Treated:
Groundwater
- The Greater Miami Aquifer is an unconfined, anisotopic, heterogeneous buried valley sand-and-gravel aquifer, ranging up to 200 ft in thickness near the FEMP
- A thin veneer of younger glacial-till deposits (mostly clay) overlay the sand and gravel unit, which in turn overlays bedrock |
Purpose/Significance of Application:
Field demonstration of in situ flushing as an enhancement to pump and treat technology |
Regulatory Requirements/Cleanup Goals:
Ohio's re-injection guidelines were used as a design criterion for the re-injection system, with re-injected groundwater required to meet a final remediation level (FRL) of 20 ug/L of total uranium
- The overall goal of the demonstration was to assess the performance and cost of a re-injection system as an enhancement to the existing pump and treat system
- In addition, the demonstration was used to determine if the re-injection system would maintain capture of the 20 ug/L uranium plume |
Results:
Approximately 455 million gallons of treated groundwater were re-injected
- The uranium plume (at 20 ug/L) was contained (horizontal and vertical migration)
- The system flushed contamination south of the injection wells, but not between the injection wells |
Cost Factors:
Information was not provided about the cost of the demonstration
- Use of re-injection was predicted by DOE to save $14.3 million and reduce the remediation by seven years, compared with continued use of pump and treat |
Description:
The MERR system was operated for one year along the southern property boundary, using 15 extraction and 5 injection wells. After removing uranium above-ground, the system re-injected 1,000 gpm of treated groundwater. Results from the demonstration showed that the system flushed contaminants from south of the injection wells, but not between the wells, that capture of the uranium plume was maintained, and that the plume was not pushed into deeper regions of the aquifer. DOE predicted that by re-injection $14.3 million would be saved and the time for remediation would be reduced by seven years, compared with continued use of pump and treat. |
