Henry's Knob General Chemical
Site Summary ProfileEPA ID: SCD000407376
Location: Clover, York County, SC
Lat/Long: 35.111182, -081.226583
Congressional District: 05
NPL Status: Superfund Alternative Approach
Affected Media: Ground water, Sediment, Soil, Surface Water
Cleanup Status: A remedial investigation and feasibility study for the site is underway.
Site Reuse/Redevelopment: Privately-owned property.
Site Manager: Beverly Stepter (email@example.com )
The Henry’s Knob Site is located at the corner of Henry’s Knob Road and State Highway 55 in the township of Clover which is adjacent to the city of York, South Carolina. The 185- acre site was an open pit kyanite mine that operated from 1947 to 1970. The site was deeded to York County in 1974 and used as a park. York County sold the property in 1982 and the site has been privately owned since that time. There are approximately 450 residences in this area that rely on drinking water. Current census data for York County indicates there are 2.72 people per household which means approximately 1,224 people within the groundwater area are using private wells impacted by Henry’s Knob.
Katawba Environmental conducted the Phase I and Phase ll studies in March 2000. Samples collected during the Katawba study revealed levels of barium, chromium, cobalt, magnesium, nickel, and zinc in the site’s groundwater. Of these heavy metals, cadmium and lead were above the EPA’s Risk Based Concentrations (RBCs) for groundwater. Cadmium and lead were above EPA Maximum contaminant Levels (MCL). Surface soil samples indicated elevated levels of arsenic, barium, chromium, copper, cobalt, magnesium, nickel, lead, zinc and mercury, with arsenic above RBCs. Surface water collected from the mine pit indicated elevated levels of chromium, copper, cobalt, magnesium, nickel, and zinc. Sediment samples collected from the pit had levels of arsenic, barium, chromium, copper, and lead that exceeded laboratory detection limits. In August 2004, the Environmental Protection Agency (EPA) and Combustion Engineering, the site PRP, negotiated an AOC for the Site.
Samples collected in March 2000 detected barium, chromium, cobalt, magnesium, nickel, and zinc in the site’s ground water. Of these heavy metals, cadmium and lead were above the EPA’s Risk Based Concentrations (RBCs) for ground water. Cadmium and lead were above EPA maximum contaminant levels (MCLs). Surface soil samples indicated elevated levels of arsenic, barium, chromium, copper, cobalt, magnesium, nickel, lead, zinc, and mercury, with arsenic above RBCs. Surface water collected from the mine pit indicated elevated levels of chromium, copper, cobalt, magnesium, nickel, and zinc. Sediment samples collected from the pit had levels of arsenic, barium, chromium, copper, and lead that exceeded laboratory detection limits.
Site Cleanup Plan
The potentially responsible parties (PRPs) are currently conducting a remedial investigation and feasibility study of the site. Once completed, the results from this work will be used to prepare a cleanup plan for the site.
No Construction Underway As Yet
The PRPs prepared a Remedial Investigation/Feasibility Study Work Plan that was approved by EPA and the South Carolina Department of Health and Environmental Control. This approved document dated September 23, 2005, determined the path of investigations for the site in accordance with state and federal requirements.
The overall remedial investigation (RI) was phased and the Work Plan presented the first step of the investigation. This RI was a very thorough and comprehensive sampling of soils, tailings, sediments and surface water. In April 2006, the PRPs submitted a report to EPA entitled “Step l Remedial Investigation Technical Memorandum. The report contained the results of the Phase l investigation and outlined plans for the next phase of sampling and analysis, which will include the installation of monitoring wells and sampling of the groundwater. EPA reviewed the report and recommended comments which will be incorporated into the PRP’s final document.
In November 2007, the PRPs submitted a Step 2 Remedial Investigation Technical Memorandum. The report focused on residential and groundwater monitoring at the site. EPA reviewed the technical memorandum and provided comments to the PRPs. EPA also reviewed the residential well sampling data of the report and recommended that an alternate drinking water system be provided to property owners which wells were contaminated. The PRPs, ABB Inc. provided bottled water to six property owners which wells showed contamination above the secondary MCLs for manganese. EPA conducted site interviews the week of March 3, 2008. All public concerns were addressed in a meeting held on April 17, 2008. EPA presented the results of the Step 2 Remedial Investigation Technical Memorandum and outlined activities at the site in the Step 3 remedial Investigation report. Remedial activities at the site were completed in December 2010.
ABB Inc, submitted the Draft Remedial Investigation, Baseline Human Health Risk Assessment, and Ecological Risk Assessment Reports dated February 15, 2011, for the Henry’s Knob Site. EPA provided comments and forwarded them to the PRPs.
In August 2004, EPA issued an Administrative Order on Consent to the PRPs for performance of a remedial investigation and feasibility study at the site.
EPA has conducted a range of community involvement activities at the Henry’s Knob General Chemical 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 notices, interviews, and public meetings on cleanup activities and updates.
Due to dry conditions, insufficient surface water has been present at the site for sampling. The PRPs will perform the surface water sampling, as described in the EPA-approved remedial investigation and feasibility study workplan, when adequate amounts of surface water are present at the site.
Site Administrative Documents
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.
Clover Branch Library
107 Knox Street
Clover, SC 29710
For documents not available on the website, please contact the Region 4 Freedom of Information Office.