Mobilization, Extraction, and Removal of Radionuclides at the Fernald Environmental Management Project, Cincinnati, Ohio

Site Name:

Fernald Site


Cincinnati, Ohio

Period of

September 1998 to September 1999


Field demonstration

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)

Cleanup Authority:
Not identified

Technical Contacts:
Rob Janke
(513) 648-3124

Dave Brettschneider
Fluor Fernald
(513) 648-5814

Terrall Putnam
Fluor Fernald
(513) 648-6363
Management Contact:
Lynton Yarbrough
SCFA Manager
DOE Albuquerque
(505) 845-5520

Heavy Metals
- Uranium concentrations as high as 490 ug/L

Waste Source:
Nuclear weapons production operations

Type/Quantity of Media Treated:
- 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

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

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.