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Sangamo Weston, Inc./Twelve-Mile Creek/Lake Hartwell PCB Contamination
National Information
Photos/Multimedia
Site photo goes here
- Additional Site Photos
- Site Video
Additional Resources
- Site Cleanup Terms - can be found in EPA's glossary
- EPA Guides to Cleanup Technologies
- Superfund Community Involvement (PDF) (17 pp, 130K, About PDF)
Site Summary Profile
EPA ID: SCD003354412Location: Pickens, Pickens County, SC
Lat/Long: 34.895, -82.7232
Congressional District: 03
NPL Status: Proposed: 01/22/87; Final: 02/21/90
Affected Media: Debris, Ground Water, Sediment, Sludge, Soil
Cleanup Status: Construction complete, new remedial activities underway
Site Reuse/Redevelopment: Portion of Site in reuse as a municipal recreation complex
Site Manager: Craig Zeller (zeller.craig@epa.gov)
Site Background
Sangamo Weston, Inc. owned and operated a capacitor manufacturing plant in Pickens, South Carolina, from 1955 to 1987. During operations, Sangamo used several varieties of fluids which contained polychlorinated biphenyls (PCBs). Waste was disposed of on the plant site as well as at six satellite disposal areas within a 3-mile radius of the plant. PCBs were also discharged with effluent directly into Town Creek, a tributary of Twelve Mile Creek. Twelve Mile Creek is a major tributary of the 56,000 acre Lake Hartwell. As a result of a merger with Sangamo Weston, the potentially responsible party (PRP) for the site is Schlumberger based in Houston, Texas.
Threats and contaminants
The contaminated media of concern for the site are surface/subsurface soils, ground water, sediment and solid waste/sludge. Contaminants of concern include PCBs, and volatile organic compounds (VOCs) to a lesser extent. Potential threats at the site include direct contact/incidental ingestion of PCBs in the surface soils and human health risks associated with the consumption of PCB-contaminated fish.
Site Cleanup Plan
EPA has identified two major portions of the Site requiring remedial action: 1) the land-based source areas including the plant site and six satellite disposal areas; and 2) a large area downstream of the land-based source areas, which is primarily lake and river environment.
EPA's preferred alternative for the land-based area included:
- Excavation, consolidation, and treatment of contaminated soil using low temperature thermal desportion of contaminated soil.
- Recovery and treatment of ground water underlying these parcels.
EPA's preferred alternative for the downstream lake and river area involves Monitored Natural Recovery (MNR) and relies on natural capping of PCB-contaminated sediments by the continued deposition of clean sediment entering Lake Hartwell. Specific parts of the cleanup strategy include:
- Annual fish tissue and sediment monitoring.
- Adoption of risk-based consumption guidelines for Lake Hartwell.
- A public education program designed to increase the awareness of the fish advisory.
- Downstream passage of clean sediments from small impoundments located on Twelve Mile Creek.
Clean-up Progress
Construction of all physical components necessary to achieve cleanup goals at the site is complete. However, various remedial operations will continue until certain cleanup goals are met. EPA has deleted portions of the site from the NPL where all response actions are complete and all cleanup goals have been achieved. Specific cleanup activities include the following:
- Approximately 60,000 tons of PCB impacted material has been excavated and treated. Treated soil was backfilled on the plant site, capped with top soil, graded and properly restored.
- Groundwater recovery and treatment systems installed at the Breazeale and plant sites have recovered 215 million gallons of groundwater, and removed 966 pounds of chlorinated solvents and 7.2 pounds of PCBs.
- A fish consumption advisory, warning the public against eating fish from the Seneca River Arm of Lake Hartwell and Twelve Mile Creek, has been in place since 1976, and since modified.
- The Public Education Program was initiated in 1998 to make users of Lake Hartwell aware of current fish consumption advisories that pertain to consumption of fish harvested from the Lake.
- Annual monitoring of sediments and aquatic biota has been conducted each year since 1994. EPA has also conducted three phases of research on Lake Hartwell. In general, PCB sediment concentrations have decreased steadily. However, annual monitoring results for certain fish species indicate PCB tissue concentrations have not responded measurably to the decreased surface sediment trends.
- Multiple efforts have also been undertaken to ensure regular, downstream passage of sediments trapped behind the impoundments on Twelve Mile Creek.
Site cleanup activities are being led primarily by the PRP with oversight by EPA.
Enforcement Activities
- In 1987, an Administrative Order on Consent with Schlumberger was signed for Performance of Remedial Investigation/Feasibility Study.
- In 1992, a Consent Decree with Schlumberger was lodged in court.
- In 1993 the State entered into a Consent Order with the owners of two small hydroelectric impoundments to develop a more effective sediment management plan.
- In 2004, negotiations between Natural Resource Trustees and Schlumberger took place over a Natural Resource Damage Assessment and settlement.
Community Involvement
EPA has conducted a range of community involvement activities at the site to solicit community input and to ensure that the public remains informed about site activities throughout the site cleanup process. Outreach activities have included public notice and information meetings on cleanup progress and activities.
The community has been involved in site activities starting with site assessment work in the 1980s. Extensive community interest and involvement led to the excavation of approximately 500 tons of PCB impacted soils above the selected cleanup level at two areas on the plant site, and one limited nearby area.
Future Work
Residual source investigations have been conducted at the Plant Site and Breazeale satellite disposal area to identify possible contaminant mass that may be contributing to the long-term groundwater extraction and treatment strategies. Pilot scale in situ chemical oxidation studies were conducted at the Breazeale site from June 2007 to June 2008 using ozone and potassium permanganate. Based on the results of this pilot study, EPA is proposing an amendment to the OU1 Record of Decision to allow injection of potassium permanganate into the subsurface of the Breazeale site to reduce the time required to meet groundwater performance standards. Nine Soil Vapor Extraction (SVE) wells were installed at the plant site in August 2008. These pilot scale SVE wells operated approximately 6 weeks from September to mid October 2008 and extracted approximately 235 pounds of VOCs from the vadose zone underlying the Plant site. A 3 dimensional geophysical survey of the plant site was also conducted for the purpose of identifying residual source areas and/or preferential contaminant transport pathways. The 2nd Five-Year Review for OU1 and OU2 is anticipated by September 2009.
Site Administrative Documents
Site Repository
For more information or to view any site related documents, please visit the site information repository at the following location. As new documents are generated, they will be placed in the information repository for public information.
RM Cooper Library
Clemson University
Clemson, SC 29634
Pickens County Library (Easley, SC)
Hart County Library (Hartwell, GA)
Administrative Record Documents
- Administrative Record Index (OU1) (PDF) (30 pp, 1.6MB)
- Administrative Record Index (OU2) (PDF) (6 pp, 427K)
- Administrative Record Index for Explanation of Significant Differences (OU1 and OU2) (PDF) (1 pg, 45K)
- Deletion Docket Index (OU1) (PDF) (1 pg, 44K)
- Deletion Docket Index (Trotter, Nix, Welborn Properties Partial Deletion) (PDF) (1 pg, 44K)
- Deletion Docket Index (Dodgens Property Partial Deletion) (PDF) (1 pg, 18K)
- Explanation of Significant Differences, OU2(PDF) (7 pg, 497KB)
- Record of Decision Amendment, OU1 (PDF) (102 pg, 12.22MB)
Fish and Sediment Studies
- Letter from James Orr to Joe Ferguson transmitting final 2007 fish and sediment study(PDF 418pgs, 35.97MB) (15 pp, 530K)
- 2008 Final Report, Lake Hartwell Fish and Sediment Study (PDF 451pgs, 37.76MB) (15 pp, 530K)
- OU-2 1995[1] Tissue Study (PDF) (15 pp, 530K)
- OU-2 1995[2] Tissue Study (PDF) (288 pp, 9.6MB)
- OU-2 1996 Fish and Sediment Study (PDF) (367 pp, 13.4MB)
- OU-2 1997 Fish and Sediment Study (PDF) ((278 pp, 9MB)
- OU-2 1998 Fish and Sediment Study (PDF) (273 pp 8.8MB)
- OU-2 1999 Fish and Sediment Study (PDF) (274 pp, 8.5MB)
- OU-2 2000 Fish and Sediment Study (PDF) (318 pp, 13.4MB)
- OU-2 2001 Fish and Sediment Study (PDF) (338 pp, 14.1MB)
- OU-2 2002 Fish and Sediment Study (PDF) (529 pp 9.2MB)
- OU-2 2003 Fish and Sediment Study (PDF) (315 pp, 5.1MB)
- OU-2 2004 Fish and Sediment Study (PDF) (377 pp, 62MB)
- OU-2 2005 Fish and Sediment Study (PDF) (435 pp, 63MB)
- OU-2 2006 Fish and Sediment Study (PDF) (454 pp, 47MB)
- OU-2 2006 Fish and Sediment Study (PDF) (418 pp, 49MB)
- Microinvertabrate biological assessment(PDF) (16 pp, 672K)
- Sediment transport studies (PDF) (167 pp, 6.4MB)
- Biological monitoring of dredging (PDF) (31 pp, 1.3MB)
- Recovery of persistent organics, Phase I (308 pp, 10.3MB)
- Recovery of persistent organics, Phase II (810 pp, 23.6MB)
Site Modeling and Analysis
- Record of Decision (OU1) and supplemental reports (1998-2005) (PDF) (721 pp, 64MB)
- Record of Decision (OU2) with graphics (PDF) (358 pp, 15.5MB)
Annual Ground Water Monitoring Reports
- OU 1 2007 Annual Ground Water Remediation Report (PDF) (523 pp, 25.98MB)
- OU 1 2008 Annual Ground Water Remediation Report (PDF) (2,056 pp, 102MB)
- Report Compilation (reports on OU1 ground water monitoring, OU1 ground water remediation, and Preliminary Close Out Report): (PDF) (2,056 pp, 102MB)
- 2005 Annual Report on Groundwater Remediation for OU1 (PDF) (519 pp, 50.6MB)
- 2006 Annual Report on Groundwater Remediation for OU1 (PDF) (619 pp, 29.6MB)
Decision Documents
- Unilateral Administrative Order (PDF) (53 pp, 2MB)
Other Documents
- OU 2 Soil Vapor Extraction Pilot Study (PDF) (141 pp, 10.54MB)
- Pilot Oxidation Test OU 1 (415 pp, 33.11MB)
- Pre-final Design for Full Scale In Situ Chemical Oxidation OU 1(PDF) (152 pp, 23.01MB)
- Lake Hartwell Sign Installation (PDF) (10 pp, 2.03MB)
- OU 1 Proposed Plan Fact Sheet (PDF) (10 pp, 386KB)
- Telephone interviews with residents (PDF) (115 pp, 2.8MB)
- ATSDR Health Consultation (PDF) (10 pp, 915K)
For documents not available on the website, please contact the Region 4 Freedom of Information Office.