SANGAMO WESTON, INC./TWELVE-MILE CREEK/LAKE HARTWELL PCB CONTAMINATION
On this page:
- What Has Been Done to Clean Up the Site?
- What Is the Current Site Status?
- Sampling and Monitoring
- Enforcement Information
On related pages:
The Sangamo Weston, Inc./Twelve-Mile Creek/Lake Hartwell PCB Contamination site includes the area where Sangamo Weston, Inc. owned and operated a capacitor manufacturing plant from 1955 to 1987. The site also includes six areas where operations disposed of waste as well as areas downstream from the site, including a portion of Twelve-Mile Creek and Lake Hartwell. The U.S. Environmental Protection Agency placed the site on the National Priorities List (NPL) in 1990 because of contaminated debris, groundwater, sediment, sludge, soil and fish tissue resulting from facility operations.
EPA, the South Carolina Department of Health and Environmental Control (SCDHEC) and Schlumberger Technology Corporation, the site’s potentially responsible party (PRP), have investigated site conditions and taken steps to clean up the site in order to protect people and the environment from contamination. Site contamination does not currently threaten people living and working near the site. A water line connects residences and businesses to the public water supply. By treating and monitoring groundwater and undertaking Five-Year Reviews, EPA, SCDHEC and the site’s PRP continue to protect people and the environment from site contamination.
What Has Been Done to Clean Up the Site?
The site is located in Pickens, South Carolina, and includes a former capacitor manufacturing plant, six areas used for waste disposal and areas downstream from the plant, including a portion of Twelve Mile Creek and Lake Hartwell. The former manufacturing plant area and the six waste disposal areas are vacant. Residential land uses and undeveloped land surround the site. From 1955 until 1987, Sangamo Weston, Inc. operated a capacitor manufacturing plant at the site. Operations disposed of wastes at the six areas near the plant and discharged wastewater into Town Creek, a tributary of Twelve Mile Creek which is a major tributary of Lake Hartwell.
In 1990, the EPA listed the site on the NPL. Following cleanup activities, the EPA deleted portions of the site from the NPL. As a result of a merger, Sangamo Weston, Inc. became Schlumberger Technology Corporation. In 1999, Schlumberger Technology Corporation donated part of the site property to the City of Pickens. The locality redeveloped the area into a public recreation complex. The Plant site has been cleaned up to future industrial land-uses; while the satellite sites have been cleaned up to future residential land-uses.
- Schlumberger Technology Corporation, the site’s PRP, led site investigation and cleanup activities, with oversight provided by EPA and SCDHEC.
- EPA placed the site on the National Priorities List (NPL) in 1990 because of contaminated debris, ground water, sediment, sludge, soil and fish tissue resulting from facility operations.
- Between 1993 and 1997, the site’s PRP dug up and treated about 60,000 tons of contaminated sediment, soil and sludge. The PRP placed treated soil back on the plant area, capped the area with top soil and regraded the area.
- In 1994, the PRP began annual monitoring of sediments and fish tissue.
- In 1997, the PRP began groundwater treatment at one of the six disposal areas and operated
- the treatment system for about 10 years. The treatment system recovered 118 million gallons of groundwater and removed 86 pounds of contamination. In 1998, treatment of groundwater at the plant began. The system has recovered 225 million gallons of groundwater and removed 1,630 pounds of volatile organic compounds (VOCs) and 18 pounds of polychlorinated biphenyls (PCBs).
- In 1998, a public education program began to educate users of Lake Hartwell about current fish consumption advisories at the lake. As of 2009, 79 new fish advisory signs have been posted.
- The PRP has made several efforts to make sure sediments are not trapped behind the impoundments on Twelve-Mile Creek.
- In 2011, EPA began a supplemental site investigation to identify the location and amount of residual sediment deposits, determine the concentration of PCBs in those deposits, and conduct a risk assessment.
- The site’s third Five-Year Review, completed in 2015, found that the cleanup remains protective of human health and the environment. EPA also recommended the installation of seep collectors at two freshwater springs near the plant. The collectors will collect VOC-contaminated water discharging from the springs for processing by the site’s groundwater treatment plant.
What Is the Current Site Status?
Site investigations and cleanup activities have focused on two areas, which EPA refers to as operable units, or OUs. These areas include OU-1: the land-based contamination at the plant and six disposal areas; and OU-2: the lake and river areas downstream, including a section of Twelve-Mile Creek and a portion of Lake Hartwell.
- In 1990, EPA issued the cleanup plan (a Record of Decision, or ROD) for OU-1. It included digging up and treating contaminated soil by using low-level heat to pull contamination from soil, as well as treating contaminated groundwater beneath the plant and one of the six disposal areas.
- In 1994, EPA issued the cleanup plan (ROD) for OU-2. It included using monitored natural attenuation to address groundwater contamination; naturally capping contaminated sediments by the continued deposition of clean sediment entering Lake Hartwell; monitoring fish tissue and sediment; adopting fish consumption guidelines; and implementing a fish advisory public education/awareness program.
- In 2009, EPA updated the remedy to address groundwater contamination through the use of chemicals called oxidants to break down contaminants. A second remedy update in 2009 incorporated activities required to remove the Woodside 1 and Woodside 2 dams as part of the OU-2 cleanup plan.
- The PRP continues to conduct annual monitoring of sediments and fish tissue. EPA completed the last Five-Year Review in 2015 and plans to complete the next Five-Year Review in 2020.
Sampling and Monitoring
In 1998, a public education program began to educate users of Lake Hartwell about current fish consumption advisories at the lake. As of 2009, 79 new fish advisory signs have been posted. The PRP continues to conduct annual monitoring of sediments and fish tissue.
EPA negotiated legal agreements with the site PRP to investigate and clean up the site. The PRP continues to fund monitoring and oversight activities.