PUBLIC HEALTH ASSESSMENT
LAIDLAW ENVIRONMENTAL SERVICES (TOC), INCORPORATED
ROEBUCK, SOUTH CAROLINA
The Agency for Toxic Substances and Disease Registry (ATSDR) was petitioned in November, 1995, to evaluate the public health impact of a hazardous waste incineration facility in Roebuck, South Carolina. This facility is currently owned by Laidlaw Environmental Services (TOC), Incorporated. Laidlaw operated a hazardous waste management facility at the site which included an incinerator, storage tanks, and a container storage facility.
ATSDR staff met with the petitioner and several concerned residents on July 10, 1996, during a site scoping visit for the purpose of explaining the petition process and collecting health concerns. The primary concern expressed to ATSDR staff during the meeting was the incidence of cancer including brain, colon, rectum, prostate, lung, ovary, breast, liver, stomach, kidney, and throat. Residents also reported noxious odors, especially in the past, that caused difficulty in breathing, burning eyes, asthma, and sinus problems. Several residents were particularly concerned about past exposures to potentially hazardous releases from the incinerator's thermal release vents. These vents had a history of opening regularly in the past. Other concerns reported to ATSDR staff included an alleged drum burial in Roebuck, the contamination of the former ABCO spray field, and the potential release of dioxins.
To determine whether nearby residents are exposed to contamination migrating from the site, ATSDR evaluated the environmental and human components that lead to human exposure. From this evaluation, ATSDR determined that air represented the only completed exposure pathway at this site. Specifically, a past completed exposure pathway existed for workers and nearby residents from contamination of the ambient air. Groundwater, surface water, soil, and sediment represent potential exposure pathways.
Based on a review of available environmental data, ATSDR has concluded that the Laidlaw Environmental Services (TOC), Inc., site poses no apparent public health hazard for current and future exposures. Off-site air monitoring data from 1986 to 1989 indicate that contaminants are not at levels of health concern. Although off-site air monitoring data are available through the present, this assessment focuses on the older data because levels were higher in the past and because cancer was a primary community concern. Due to the absence of air monitoring data prior to 1986, ATSDR is unable to evaluate the public health implications of air contamination at this site prior to 1986 when the facility was owned and operated by ABCO Industries, Ltd.
ATSDR considers that the contaminants detected in on-site soils would not pose any hazard to public health. The occasional, brief exposure to on-site pond water in the past would not be expected to have represented a toxic hazard to humans. The few metals recently detected in off-site private well and sediment samples from a nearby residence would not be expected to result in adverse health effects now or in the future.
Based on the information reviewed for this public health assessment, ATSDR has made the
following recommendations: (1) sample for dioxin in surface soil at the perimeter of the site; (2)
continue groundwater monitoring of the contaminant plumes and in the event that monitoring
wells located outside of Laidlaw's facility line indicate either the volatile organic compound (VOC) or Salt plume are migrating toward private wells, sample nearby private wells; (3) place
institutional controls on the installation of wells in areas of known groundwater contamination to
prevent human exposure to contaminated groundwater; and (4) continue remediation of the VOC
groundwater plume as described in the Corrective Measures Study.
The Agency for Toxic Substances and Disease Registry (ATSDR) was petitioned in November, 1995, to evaluate the public health impact of a hazardous waste incineration facility. The local community is concerned that cancer present today is attributable to air releases from the facility in the past. Located at 301 Railroad Street in Roebuck, South Carolina, the site is about six miles south-southwest of Spartanburg and the incineration facility encompasses approximately 14 acres. Please refer to Figure 1, Appendix A, for a facility location map.
The facility was originally built by ABCO Industries, Ltd., in 1977-78 and the first incinerator began production in March of 1978. The facility was granted interim status authority under RCRA (Resource Conservation and Recovery Act) in November of 1980. Additionally, five surface water impoundments were used during ABCO's ownership including a "frog pond", three scrubber ponds, and a concrete lined gas tar pond. The "frog pond", an unlined impoundment, was used for storage of rainwater runoff collected from the concrete pad under the first incinerator. Scrubber ponds #2, #3, and #4 were unlined impoundments used to store scrubber water for recirculation through the scrubber system of the first incinerator. The gas tar pond was used for the storage of gas tar product.
A second incinerator was constructed by ABCO in 1981 and began operation in 1982. Unlike the first incinerator, the scrubber water from this incinerator is treated by the facility's wastewater neutralization system and discharged to the North Tyger River.
In January 1986, ABCO sold the incineration portion of it's facility to GSX Chemical Services, Inc., who established the Thermal Oxidation Corporation (TOC). Subsequently, GSX Chemical Services, Inc. sold the incineration facility to Laidlaw Environmental Services in October of 1986. However, after the purchase, the facility continued to operate under the name Thermal Oxidation Corporation until July of 1990 when the facility was renamed Laidlaw Environmental Services (TOC), Incorporated. ABCO still continues to own property that borders three sides of the incineration facility.
Laidlaw operated a commercial hazardous waste management facility at the site under a USEPA (Environmental Protection Agency) permit which became effective on August 31, 1990. The primary process at Laidlaw was liquid waste incineration with other activities including a tank farm and a container storage facility. The tank farm comprised the primary storage for liquid wastes and contains 37 tanks with capacities ranging from 10,000 gallons to 20,000 gallons (4). Bulk liquid shipments were received in this area, sampled, and off-loaded into one of the storage tanks. The container storage area handled the drummed wastes and was designed to hold a maximum of six hundred 55-gallon drums. The site also contains four (4) agitated process blend tanks each with a 20,000 gallon capacity which directly fed the incinerator at a rate of 4.5 tons/hour of waste. Please refer to Figure 2, Appendix A, for a facility site plan diagram.
All portions of the first incinerator were removed in March 1987. The "frog pond" and scrubber ponds #2, #3, and #4 were cleaned and certified closed by the South Carolina Department of Health and Environmental Control (SCDHEC) on February 15, 1988. During 1987, coal gasification tar which had been stored in the gas tar pond was removed. In late 1988, the concrete lining of the gas tar pond was removed and approximately one foot of soil excavated from the bottom of the pond.
Laidlaw entered into a consent agreement with SCDHEC to close the operating incinerator by August 31, 1998. It is Laidlaw's position that competitive incineration markets (i.e., cement kilns and other boilers and industrial furnaces) have had a significant effect on the commercial success of the incineration activities at Laidlaw thereby driving prices below that level which can profitably support the high costs associated with the operation of a regulated incinerator (33). Laidlaw has developed a Closure Plan which describes the dismantling process. Recently, Laidlaw decided to close the facility entirely by not only halting the incineration process, but also terminating waste blending and storing operations.
A site scoping visit was made on July 10-11, 1996. During the two day site visit, meetings were held with various individuals. ATSDR staff met with South Carolina Department of Health and Environmental Control (SCDHEC) staff to gather information concerning the cancer cluster investigation underway in Roebuck and to gather information on the site and local community. During the scoping visit, ATSDR staff also met with the petitioner and several community members to clarify health concerns and explain the petition process.
ATSDR staff met with Laidlaw representatives to gather information on the incineration facility. ATSDR staff participated in a site tour. General observations specifically made during the site tour and immediate vicinity tour included: bulging drums in container storage area, slight odor around both the tank farm and drum cleaning area, a day care and playground are near the site (incinerator stack is viewable from play area), middle income single family homes in vicinity of site, and homes with gardens and children's toys (swing sets, bikes, etc.)
According to the 1990 Census of Population and Housing (56), the demographic statistics for within one mile of the site indicated 1,249 persons reside in 470 households. Of the 1,249 persons, 75.74% are white; 24.01% are black; and 0.24% are American Indian, Eskimo, Aleut. There are 107 children aged 6 or younger and 146 adults aged 65 and older. Please refer to Figure 7, Appendix A, for additional demographic statistics.
The Laidlaw incineration facility is located about six miles south-southwest of Spartanburg in a relatively rural area. Please refer to Figure 1, Appendix A, for a facility location map. The land surrounding the facility is used for industrial, light commercial, and residential purposes. The town of Roebuck lies within one-half mile east of the incineration facility. ABCO owns and operates a wastewater treatment plant adjacent to the eastern border of the incineration facility, and owns undeveloped/vacant land to the north and west. While no residences are directly adjacent to the Laidlaw incineration facility, there are residences that border ABCO property. Property located to the north is predominantly residential, including numerous single family dwellings (29). No significant changes from the current land use scenario are expected in the future.
Natural Resource Use
Groundwater flow in the area is generally west/southwest. Groundwater is typically encountered at depths ranging from approximately 25 to 35 feet below ground surface. Since 1958, most of the area has been provided drinking water from the Woodruff-Roebuck Water District. A groundwater well inventory was conducted by the South Carolina Water Resources Commission (SCWRC) for the Roebuck area (4). This inventory identified 15 private wells in the Roebuck area. According to the well inventory, there are no groundwater supply wells located immediately down gradient of the facility (4). The 15 private wells are deep and located in the bedrock aquifer. However, only wells installed after 1986 would be included in this well inventory. Before 1986, well drillers were not required to report the new wells they installed. Therefore, additional private wells that were installed before 1986 may exist in the area.
The surface water bodies closest to the Laidlaw incineration facility are an unnamed tributary, the Stillman Branch, and the North Tyger River (Figure 4, Appendix A). The unnamed tributary west of the site may be an area of shallow groundwater discharge (4). The unnamed tributary is located approximately 800 feet west of the facility boundary and flows approximately 800 feet before merging with the Stillman Branch. The Stillman Branch then flows approximately 3,200 feet before it merges with the North Tyger River. The facility is located approximately 4,600 feet northeast of the North Tyger River. The North Tyger River is classified as a class B waterway and is therefore suitable for recreation and drinking water supply after conventional treatment (4).
Health data for some geographic areas are contained in databases. Information can be collected and entered into the databases on the number of deaths and births in a geographic location including such variables as age, sex, cause of death, birth weight and birth defects. Using the health outcome databases, it may be possible to determine whether the occurrence of certain health outcomes are greater than expected. While the state of South Carolina does not currently have such databases available, SCDHEC recently completed a study that focused on two questions (36):
1) Is there an excess of all cancers in the town of Roebuck?
2) Is there an excess of any specific cancer type in the town of Roebuck?
During this study, the SCDHEC, Division of Cancer Prevention and Control, analyzed cancer incidence and mortality data collected for a 10 year period. Following this study, the American Cancer Society funded an independent epidemiologist to conduct a case review to determine the following (36):
1) Can known causes of cancer explain Roebuck's cancer experience?
2) Does Roebuck's cancer experience differ from that of other communities?
The results of these investigations are discussed in the Health Outcome Data Evaluation section of this public health assessment.
ATSDR staff met with the petitioner and several concerned residents on July 10, 1996, during the site scoping visit. The purpose of the meeting was to explain the petition process and collect health concerns. This group of concerned residents serve on the Roebuck Community Advisory Group which was formed during the SCDHEC cancer investigation. General concerns expressed to ATSDR staff during the meeting included:
- increased incidence of cancer including brain, colon, rectum, prostate, lung, ovary, breast, liver, stomach, kidney, and throat
- noxious odors, especially in the past, that cause difficulty in breathing, burning eyes, asthma, and sinus problems
- potentially hazardous releases from the incinerator's thermal release vents
- alleged drum burial in Roebuck
- contamination of former ABCO spray field
- the potential release of dioxins