Pump and Treat
- Groundwater is extracted using 5 wells, located on site, at an average total pumping rate of 232 gpm
- Extracted groundwater is treated with air stripping and discharged to a surface water under a NPDES permit
- ROD Date: 9/7/88
|EPA Point of Contact:|
Ken Glatz, RPM
U.S. EPA Region 5
77 West Jackson Blvd.
Chicago, IL 60604-3507
|State Point of Contact:|
P.O. Box 30426
Lansing, MI 48909-7926
Chlorinated solvents and volatiles - nonhalogenated
Maximum concentrations detected in 1985 sampling event were 1,1,1-TCA (200,000 µg/L), 1,2-DCA (1,600 µg/L), and diethyl ether (DEE, at 5,700 µg/L)
Ruptured drums, leaking underground pipe
Type/Quantity of Media Treated:
- 329 million gallons treated as of December 1996
- DNAPL suspected in groundwater at this site
- Groundwater is found at 20 ft bgs
- Extraction wells are located in 1 aquifer
- Hydraulic conductivity ranges from 9.1 to 45.4 ft/day
Purpose/Significance of Application:
Performed modeling for system optimization (MODFLOW and Randomwalk).
Regulatory Requirements/Cleanup Goals:
- Remediate the groundwater to levels established by MDEQ and the maximum contaminant levels (MCLs) established by the SDWA.
- Cleanup goals include DEE (43 µg/L), 1,1,1-TCA (200 µg/L), 1,2-DCA (5 µg/L), 1,1-DCE (7 µg/L), TCE (5 µg/L), PCE (0.88 µg/L), benzene (5 µg/L), toluene (2,000 µg/L), ethylbenzene (680 µgL), and xylene (440 µg/L).
- A secondary goal of the system is to create an inward hydraulic gradient to contain the contaminant plume.
- The average concentration of total contaminants has decreased from 158 to 67 µg/L over 3 1/2 years of operation; however, contaminant concentrations have declined but remain above cleanup goals.
- Approximately 664 pounds of contaminants have been removed from the groundwater from September 1993 to December 1996.
- Plume containment has been maintained in this application; however, additional contamination has been identified outside of the original plume. This has been attributed to historically elevated levels not discovered during the RI/FS.
Actual costs for the P&T system from 1993-1996 were approximately $1,942,000 ($1,332,000 in capital and $610,000 in O&M), which correspond to $5 per 1,000 gallons of groundwater extracted and $2,925 per pound of contaminant removed.
The site was operated as a non-lubricating automotive fluids manufacturer from the early 1960s until 1978. Fluid manufacturing included repackaging of bulk products and formulation of new products from bulk ingredients. In July 1972, an underground pipe carrying diethyl ether (DEE) broke during excavation activities, releasing an unknown quantity to the soil and groundwater. In November 1978, a fire ruptured chemical-storing drums. The water used to extinguish the fire washed unknown amounts of chlorinated hydrocarbons onto unpaved areas. After the 1978 release, U.S. Aviex performed a groundwater investigation. The site was placed on the NPL in 1983 and a ROD was signed in 1988.
The pump and treat system currently in use at U.S. Aviex consists of five extraction wells installed to 100 ft bgs, and an air stripper 56 ft tall, 4 ft in diameter, and packed with plastic media. Groundwater monitoring data indicate that while maximum contaminant concentrations have dropped (up to 99% for 1,1,1-TCA), they remain above cleanup goals. In addition, contamination has been detected in wells down-gradient of the plume identified in the RI/FS, and EPA is in the process of further characterizing the plume.