![[logo] US EPA](http://www.epa.gov/epafiles/images/logo_epaseal.gif){kind=logo}
Townsend Saw Chain Company
| Townsend Saw Chain Company EPA ID: SCD980558050 Location: Pontiac, Richland County, SC Congressional District: 02 NPL Status: Proposed: 06/24/88; Final 02/21/90 Project Manager Site Repository: Northeast Regional Library 7490 Park Lane Rd. Columbia, SC 29223 Documents: 
|
Site Background:
The Townsend Saw Chain Co. site is a small manufacturing facility located along Interstate 20 approximately 15 miles east of Columbia, South Carolina. Textron Inc. utilized the facility since 1971 for manufacturing the chain saw component of chain saws. Between 1964 and 1981, under both Textron and a previous owner, Dictaphone Inc., waste rinse waters from onsite plating and parts-assembly processes were discharged to the ground surface in a low-lying area adjacent to the facility. Under an order issued by the South Carolina Department of Health and Environmental Control (SCDHEC), a five-well pump-and-treat system was installed in 1982. Between 1982 and 1990 SCDHEC continued to oversee Textron's groundwater treatment program. Textron then signed an order in 1991 with EPA to investigate site contamination, including but not limited to groundwater, and propose an overall cleanup plan (remedy) for the site. In 1994, based on an Interim Record of Decision, EPA issued a CERCLA Section 106 order (to which the company voluntarily agreed) requiring design and construction of an improved pump-and-treat system. Textron completed the overall site study in September 1996. The study verified that a plume of chromium-contaminated groundwater extended offsite to the northeast some 700 feet beyond the property boundary, and is discharging to an unnamed tributary of a nearby creek, via an offsite seep. EPA issued its final Record of Decision in December 1996.
Cleanup Progress:Cleanup Underway
Cleanup began at this Site in the early 1980s with the installation of a groundwater pump and treat system. This system operated until 2002 and recovered more than 550 pounds of chromium from the groundwater. During 1995-1996, approximately 75 tons of soil contaminated with chromium, lead and several other heavy metals were excavated from two hotspot locations and properly disposed.
In 2000, in-situ (treat-in-place) technology was initiated at the Site which converts hexavalent chromium into an inert and harmless type of chromium mineral that can safely remain in the subsurface. For groundwater treatment, injection well lines were used to place ferrous sulfate in contact with chromium-contaminated groundwater. Between 2000 and 2003, the treatment was implemented along successive injection well lines, proceeding northeastward across SC Road 53 (property line) and into the adjoining offsite area. Overall results to date indicate the treatment has worked, in general, and the size of the plume has been steadily reduced. The majority of the monitoring wells in the on-site area now have concentrations of chromium below the remediation level of 0.1 mg/L. However, there are a few recalcitrant spots with concentrations as high as 1.6 mg/L (IMW-02B), as of the June 2008 sampling event. In the off-site area (across SC Road 53), concentrations of chromium ranged up to 1.8 mg/L (MW-106) in the June 2008 sampling event.
More complicated geology and other factors in the offsite area have impeded completing the project. In April 2006, Textron submitted and EPA approved a Focused Feasibility Study, which evaluated remediation alternatives to prevent continued discharges of chromium and volatile organic compounds (VOCs) into surface water, as well as address remediation of the remainder of the contaminated groundwater plume. EPA modified the remedy through an Explanation of Signficant Differences (ESD) in April 2007 to allow for a Permeable Reactive Barrier (PRB) to be installed stopping the discharge of contaminants into the tributary. Textron has begun the design process. Design investigations have indicated that the groundwater plume may be wider than originally estimated. Design activities continue. Textron concurrently designed a revised injection system for in-situ chemical treatment on the main Site property. The piping structures were put in place in August 2008. Injection wells were installed in November 2008. Also, in October 2008, Textron's consultants submitted a draft work plan for a biostimulation pilot study in the portion of the groundwater plume that contains VOCs. EPA and SCDHEC approved the work plan on November 4, 2008. Baseline sampling was conducted November 12-14, and the initial injection to adjust the pH took place during the week of November 17. Further ferras sulfate and lactate injections are occurring through the summer and fall of 2009 to identify an effective remedial action for the site.
For information about the contents of this page please contact Brenda Lane