Technology Status Report: In Situ Flushing - CLU-IN

In Situ Flushing Project Summaries
GWRTAC Case Study Database
GWRTAC ID: FLSH0044
Project Name: United Chrome Products, Corvallis, OR
City: Corvallis State/Province: OR
Primary GWRTAC Personal
Communication Source
(Name/Organization):
Project Summary:
None
None
Report(s)/Publication(s) (GWRTAC Source):
Internet URL http://www.epa.gov/superfund/index.htm
Mann et al., 1993: Innovative Site Remediation Technology Soil Washing/Soil Flushing, Vol. 3 of
8, WASTECH, William C. Anderson, P.E., DEE, Ed., American Academy of Environmental
Engineers, 1993
U.S. EPA, Nov. 1996: Inn. Trtmt. Techs.: Ann. Status Rpt. (8th Ed.), EPA 542-R-96-010, No. 8,
U.S. EPA OSWER (5102G) TIO, Wash., DC
U.S. Environmental Protection Agency, 1991: Engineering Bulletin In Situ Soil Flushing,
EPA/540/2-91/021, U.S. EPA Office of Emergency and Remedial Response (OERR), Washington,
DC 20460, Office of Research and Development (ORD), Cincinnati, Ohio 45268, 8 pp., October
1991.
The following is excerpted from Mann et al., 1993: Innovative Site Remediation Technology Soil
Washing/Soil Flushing, Vol. 3 of 8, WASTECH, William C. Anderson, P.E., DEE, Ed., American
Academy of Environmental Engineers, 1993:
The site is an eight acre, former industrial hard-chrome plating facility located just north of the
Corvallis Airport Facility. Hexavalent chromium contaminates surface water, soils and
groundwater. The site is underlain by two water-bearing zones separated by a silty clay aquitard.
The upper water-bearing zone is the primary zone of contamination, and consists mostly of silt.
The shallow contaminated zone extends from the source area, to approximately 300 feet
downgradient of the source area, with concentrations of Cr+6 up to 19,000 mg/L. The deep aquifer
consists of sand and gravel, and is capable of supplying potable water for commercial and
residential use. The deep contaminated zone extends from the source area, to approximately 400
feet downgradient of the source area, with concentrations of Cr+6 up to 223 mg/L. Delivery of
flushing solution was accomplished through two open bottom infiltration basins (pits resulting from
excavation of 1,100 tons of soil containing highest chromium concentrations) and one infiltration
trench (used intermittently); these flushed Cr+6 from the vadose zone to the water table. Recovery
of flushing solution was accomplished through a series of 23 shallow extraction wells to extract
groundwater from the upper water-bearing zone. An on-site treatment facility removed chromium
prior to effluent discharge to the POTW. Deep groundwater extraction had not begun at the time of
this project summary.
Ground-Water Remediation Technologies Analysis Center
Operated by Concurrent Technologies Corporation
Appendix - Page 90 of 164
Copyright GWRTAC 1998
Revision 1
Tuesday, November 17, 1998