Former Hoechst Celanese Site
Site History The former Hoechst Celanese site has been used for various industrial operations by multiple owners since 1966. A dimethyl terephthalate (DMT) production facility and a polyester fiber production facility have both previously operated at the site. (DMT is a primary ingredient used in manufacturing polyesters and industrial plastics.) Currently, Auriga Polymers, Inc. operates the main part of the site for polyester manufacturing. Auriga is permitted by DHEC and inspected on a regular basis.
Many of our current environmental laws and regulations did not exist when some of the older operations at the site began. A number of contaminants were found when soil and groundwater investigations started in 1990. Extraction wells were installed in 1996 to remove some of the contaminated groundwater. Other cleanup efforts that started in the early to mid-1990s included the installation of a treatment unit to capture 1,4 dioxane prior to discharge to surface water (streams and river), removal of soil and sludge from the wastewater treatment plant impoundments and basins, upgrade of the wastewater treatment plant and removal of liquid DowTherm A from the groundwater.
Groundwater from the site seeps into creeks and the Pacolet River. Although some studies on stream sediments and aquatic life are ongoing, DHEC has concluded these water bodies are safe based on the data collected to date.
Assessment and Remediation
DHEC has directed past and ongoing work at the site to determine the extent of the contamination (assessment) and to cleanup the groundwater and source areas (remediation). Hoechst is responsible for cleaning up the contamination and has been cooperative in these efforts
Sampling and Monitoring
Sampling has been conducted on the soil, groundwater, surface water and sediments. The primary contaminants of concern at the site are 1,4 dioxane, DowTherm A (1,1 biphenyl and biphenyl ether) and various chlorinated solvents, including chloroform. Over 200 monitoring wells located both on and off-site have been installed and sampled to understand and define the groundwater contamination. Ongoing surface water and groundwater sampling monitor the movement and natural break down of the contaminants and the effectiveness of cleanup efforts.
Historic Groundwater Plumes
Although the sources of groundwater contamination have been removed, several areas of contamination still remain onsite. These areas are called plumes. In general, most of the plumes discharge to streams that surround the site. Some contamination has occasionally been detected in the surface water below state and federal standards.
Most of the plumes have multiple contaminants in them. Past groundwater pumping (cleanup) operations have reduced the concentration of these contaminants in many areas. Additionally, some of the contaminants are being broken down naturally. However, these processes do not break down a few of the contaminants. These few contaminants are being monitored for movement both onsite and off site.
Chloroform has been detected in off-site groundwater. Although some areas of chloroform contamination have been cleaned up, additional work is needed to address the plume that remains.
- DHEC has asked Hoechst to conduct a complete assessment of the off-site chloroform plume and develop plans to further clean it up.
- Hoechst will continue to monitor, and conduct additional monitoring, to evaluate where contaminants appear to be increasing.
- DHEC has asked Hoechst to do a follow-up study on the sediment and macroinvertebrate results to determine the source of the chemicals in the sediment. The study will also evaluate effects of the chemicals in sediment, on aquatic life in the stream and if the chemicals may be a threat to human health.
- DHEC will continue to evaluate cleanup methods being used.
- DHEC and Hoechst will continue to monitor the possibility of impacts of groundwater contamination on off-site drinking water wells.
- DHEC region staff will continue to investigate any complaints from residents.