Pump and Treat of Contaminated Groundwater at the Old Mill Superfund Site, Rock Creek, Ohio

Site Name:

Old Mill Superfund Site


Rock Creek, Ohio

Period of

Status: Ongoing
Report covers: 9/89 - 7/97


Full-scale cleanup
(interim results)


Aptus Environmental Services, Inc.
Coffeyville, KS 67337

Operation & Maintenance:
Omprakash Patel
Roy F. Weston, Inc.
3 Hawthorn Pkwy, Suite 400
Vernon Hills, IL 60061-1450
(847) 918-4051

Pump and Treat

- Groundwater is extracted using 3 wells and 5 trenches at an average total pumping rate of 3.1 gpm
- Extracted groundwater is treated with air stripping and carbon adsorption
- Treated groundwater is discharged to a surface water under a NPDES permit

Cleanup Authority:
- CERCLA Remedial
ROD Date: 8/7/85

EPA Point of Contact:
Ron Muraawski, RPM
U.S. EPA Region 5
77 W. Jackson Blvd.
Chicago, IL 60604-3590
(312) 886-2940
State Point of Contact:
Mike Eberle
Ohio EPA
(216) 963-1126

Chlorinated solvents and volatiles - nonhalogenated

- Maximum concentrations detected in one plume (Henfield) were TCE (6,100 µg/L), PCE (300 µg/L), trans-1,2-DCE (460 µg/L), and VC (14 µg/L)
- Maximum concentrations detected in other plume (Kraus) were ethylbenzene (19,000 µg/L) and xylenes (43,000 µg/L)

Waste Source:
Illegal waste disposal

Type/Quantity of Media Treated:
- 13 million gallons treated as of 1997
- Groundwater is found at 5 ft bgs
- Extraction wells are located in 2 aquifers
- Hydraulic conductivity ranges from 0.22 to 1.25 ft/day

Purpose/Significance of Application:
Relatively high unit cost, due to small quantity of groundwater extracted and low groundwater flow.

Regulatory Requirements/Cleanup Goals:
- Remedial goals were established for contaminants of concern that must be met throughout the site. These goals were based on achieving a carcinogenic risk level of 1 x 10-5, and consist of 1,2-DCE (1.9 µg/L), TCE (15 µg/L), PCE (8.2 µg/L), and ethylbenzene (8,000 µg/L).
- Treatment system performance standards were established to meet NPDES permit requirements.
- The system was required to contain the plume and prevent off-site migration of contaminants.

- The 1997 annual sampling data indicate that the P&T system has contained the plume, but that contaminant concentrations in much of the plume remain above remedial goals. In addition, two hot spots remain problematic at this site, with TCE concentrations of 1,700 and 1,400 µg/L as of March 1997.
- The P&T system removed approximately 124 pounds of contaminants from 1990 to 1997.
- Treatment performance standards have been met consistently during this application.

Cost Factors:
- Actual costs for the P&T system were approximately $3,236,000 ($1,596,000 in capital and $1,640,000 in O&M), which correspond to $250 per 1,000 gallons of groundwater extracted and $26,100 per pound of contaminant removed.
- The actual capital cost was approximately 22% higher than the original bid cost, due to a need to add collection trenches.

The Old Mill Superfund site includes two parcels of land, the Henfield and Kraus properties. The site was used for illegal disposal of drummed wastes for an undetermined number of years. In 1979, U.S. EPA and Ohio EPA found approximately 1,200 drums of waste including oils, resins, and PCBs on the Old Mill site. Drum and soil removal were completed in 1982 as a Superfund emergency removal action. Limited information is provided about site investigation activities, however, data are presented showing VOCs in the groundwater based on 1984 sampling data. The site was listed on the NPL in September 1983 and a ROD was signed in August 1985.

The P&T system has been designed to remediate plumes from both the Henfield and Kraus properties. The system consists of three deep recovery wells and five collection trenches. Extracted groundwater from both plumes is treated in one treatment plant, which consists of an 18-inch diameter air stripping tower and a granular activated carbon unit. In 1989 and 1994, the collection system was modified by adding collection trenches at the Kraus property needed to maintain containment. After eight years of P&T operation, the cleanup goals for this site have not been met. According to the RPM, the P&T system at this site does not appear to have the typical effect on groundwater contamination. New contaminants have been identified after the initial investigation and contaminant concentrations have increased at times during operations. The reasons for these events is not known at this time.