PUBLIC HEALTH ASSESSMENT
KOPPERS WOOD TREATING COMPANY
(a/k/a KOPPERS COMPANY INCORPORATED FOREST PRODUCTION GROUP)
CARBONDALE, JACKSON COUNTY, ILLINOIS
The Koppers Wood Treating Company (Koppers) is an abandoned wood treating facility north of Carbondale, Illinois, that ceased operations in July 1991. A maintenance worker periodically visits the site to service the on-site wastewater treatment plant but does not remain at the site full time. A fence surrounds the site, and all access roads into the site are secured by locked gates.
Soils at the site are visibly contaminated with creosote. Groundwater contamination at the site includes phenols, metals, volatile organic chemicals, pentachlorophenol (PCP), and polycyclic aromatic hydrocarbons (PAHs). Limited removal activities took place at the site in 1991, but much of the contamination remains. Past accidental releases of creosote products have resulted in off-site contamination of Crab Orchard Creek sediment.
A public water supply system services most of the homes near the site. Four private residential wells about 0.5 miles north of the site were sampled for site-related contaminants including phenols, PCP, and PAHs. Samples collected in 1989 contained low levels of PAHs in two of the residential wells. In 1992, the Lakeside Water District distribution system was extended to provide water to homes north of Carbondale, including the four homes where private wells were sampled.
Completed exposure pathways include:
Areas of extensive soil and groundwater contamination remain at the site, but access to the site is restricted by a fence and locked gates. From the information reviewed, IDPH concludes that current conditions at the former Koppers wood-treating facility do not threaten the health of nearby residents.
The Illinois Environmental Protection Agency (IEPA) requested that the Illinois Department of Public Health (IDPH) conduct a public health assessment for the Koppers Wood Treating Company (Koppers) site. The purpose of this public health assessment is to evaluate, based on the information currently available, any known or potential adverse human health hazards related to the site.
BACKGROUND AND STATEMENT OF ISSUES
The Koppers site occupies about 136 acres along North Marion Street on the northeastern edge of Carbondale in Jackson County (Figure 1). Land surrounding the Koppers site is used for residential, agricultural, commercial and industrial purposes. An abandoned railroad track borders the southern edge of the site. The nearest homes are immediately south of the track at the western end of the facility. A combination of cultivated, undeveloped, and wooded land is north and east of the site. Only a few rural residential dwellings are scattered throughout the immediate area. An Illinois Central Railroad yard is on land west of the Koppers facility.
The Koppers site was a wood treating facility that began operation in 1905 (Figure 2). It was formerly one of the world's largest creosote treatment plants. The site remained active until July 1991. A similar Koppers facility near Galesburg, Illinois, is listed on the federal National Priorities List (NPL).
Three off-site environmental incidents have been reported in the history of the facility.
The variety of wood treating products used during facility operation included:
Information recording periods of use of these chemicals is not complete. The most recent wood treatment process used only 60-40 creosote. The wood was treated in pressure-vacuum cylinders powered by steam produced by a wood-fired boiler. After treatment, the preserved wood was moved onto drip tracks to air dry [4]. A drain system was in place to collect runoff from the drip track area. Besides the runoff waste, production wastes were also generated. Koppers treated the runoff and production wastes at the facility in an oil-water separator for reclamation of the oil.
In June 1986, Koppers entered into an Administrative Order of Consent (AOC) with the U.S. Environmental Protection Agency (USEPA) and IEPA to perform corrective actions and other response measures at the site.
Before 1988, the Koppers facility treated wastewater by collecting the effluent from the oil-water separators in a wastewater lagoon/spray irrigation field system. In November 1988, the city of Carbondale began accepting wastewater from Koppers. When Koppers abandoned the lagoon system, they generated more wastewater than they could transport and store, so they evaporated wastewater into the atmosphere by heating it in open-topped tanks. When Koppers was evaporating the water, the surrounding community complained about a strong, creosote-like odor originating from the facility.
In July 1991, Koppers ceased operations at their Carbondale facility; the company dismantled and removed most of the equipment and buildings. Storage tanks, the office building, and the wastewater treatment plant are all that remain at the site. Limited soil excavation around the work tanks and treatment cylinders was conducted at the time of dismantling; however, most of the visibly-contaminated soil remains on the site.
To control the shallow contaminated groundwater discharging into Glade Creek, Koppers installed a grout blanket in the bed of the creek. The grout blanket is about 700 feet long and 30 feet wide, extending from bank to bank. The grout blanket collects and conveys the groundwater that is visibly contaminated with creosote to a collection manhole where the material is periodically collected. The collected material is then treated on the site in the activated sludge-wastewater treatment plant.
Carbondale is in the southeastern portion of Jackson County, Illinois. The 1990 U.S. Census reported the population of Carbondale at approximately 32,000 people. This number includes Southern Illinois University (SIU) students who reside within the city limits. The SIU campus is in the southern portion of Carbondale, 2 miles southwest of the Koppers site. The enrollment at SIU is approximately 24,000. The population within a 4-mile radius of the site is approximately 38,000 people.
The nearest populated area is a residential neighborhood immediately south of the western end of the facility. This lower-income neighborhood has a population of about 1,600 persons and is comprised predominately of African Americans. According to the 1990 U.S. Census, the average age of this population is 28 years. A few scattered homes are in the rural area immediately north of the site. Most of those dwellings are along Reed Station Road.
Cedar Lake, which is about 8 miles south of the Koppers site, supplies the drinking water for Carbondale and the surrounding area. Surface water leaving the site has no connection to Cedar Lake [5]. Most of the dwellings in the rural area north and northeast of Koppers are connected to the Lakeside Water District, which also receives water from the Cedar Lake supply system. Prior to 1992, about 40 homes in that area had private wells [6]. Four private wells were within one mile north of the site. Three of the wells were at homes, and the fourth well, at a barn, is used for watering livestock.In September 1992, public water was provided to the area.
Glade Creek flows through the western portion of the site, around the northern edge, and then past the eastern end of the site [2]. Glade Creek merges with Piles Fork Creek and then flows into Crab Orchard Creek about 1 mile downstream of the site. Surface water draining from the site flows into Glade Creek and Piles Fork Creek. Site-impacted shallow groundwater also discharges into Glade Creek. Both Glade Creek and Piles Fork Creek typically have low flow rates and become intermittent during dry periods, which makes them generally unattractive for recreational use such as swimming or fishing. Neither of the creeks is used as drinking water sources; however, in some areas, the water is available to livestock. Piles Fork Creek is used as the receiving stream for treated waste from the Carbondale sewage treatment plant. Crab Orchard Creek is also not a drinking water source for humans, but it may be used for recreational purposes such as wading, swimming and sport fishing. Crab Orchard Creek ultimately flows into the Big Muddy River.
Before 1993, the community of Royalton used the Big Muddy River as its drinking water supply, but the Royalton water treatment plant was about 9 miles upstream of the Crab Orchard Creek confluence. In 1993, Royalton connected to the Rend Lake Water District. The Big Muddy River is not used as a public water supply downstream of this confluence. Recreational use of the Big Muddy River includes boating, swimming, and sport and commercial fishing [7].
IDPH staff visited the site in January 2000. No site personnel were available at that time. The site was vacant and secured by a locked gate. As seen from the fence line, the only structures remaining on the site were four tanks, the former office building, a bathhouse, and the activated sludge-wastewater treatment plant.
IDPH compared the maximum level of each contaminant detected during environmental sampling with appropriate screening comparison values, when available, to select contaminants for further evaluation for both carcinogenic and non-carcinogenic health effects. A detailed discussion of each of the comparison values used is found in Attachment 1.
The comparison values are used only to screen for contaminants that should be evaluated further and do not represent thresholds of toxicity. Though some of these chemicals may exist at levels greater than comparison values, they can only affect someone who comes in contact with the contaminants and receives a high enough dose for adverse effects to occur. The amount of the contaminant, the duration and route of exposure, and the health status of exposed individuals are important factors in determining the potential for adverse health effects.
The chemicals of interest at this site are phenols, pentachlorophenol (PCP), metals, volatile organic compounds (VOCs), and semi-volatile organic compounds (SVOCs), including polycyclic aromatic hydrocarbons (PAHs). The following discussion explains the contamination found in each environmental medium sampled.
An extensive network of 90 monitoring wells is on the site. Results of sampling of those wells shows that on-site groundwater is contaminated with phenols, PCP, metals, PAHs, and VOCs. Groundwater quality is affected beneath the site to the bedrock layer. The extent of the contamination reveals both a vertical and horizontal contaminant migration. The most elevated levels of contamination are PAHs in the shallow monitoring wells [8]. Table 1 shows the contaminants of interest and their concentration range detected in on-site groundwater.
No site related contaminants have been detected off the site. Four residential wells north of Koppers were sampled in 1989. These residences now have a public water supply. Sampling of the perimeter monitoring wells shows that groundwater contamination remains confined to the site.
The soil investigation at the site consisted of subsurface samples collected from areas of both obvious contamination and from areas not affected by previous site activities. The most recent soil sampling activities were completed in 1996.
The areas of known contamination from site activities consisted of eight locations: (1) the treatment cylinder area; (2) the former spray irrigation field; (3) the drip track area; (4) the north ditch area; (5) the storage tank area; (6) the service yard; (7) the off-site spill area; and (8) the former lagoon area. Soil borings from those areas were collected from extended depths until two samples showed no visible creosote; however, borings were not extended any deeper than 30 feet below the water table.
Soil contamination at the site included PCP, oil and grease, phenols, metals, and PAHs. Samples containing elevated levels of PCP were collected from borings exhibiting a diesel fuel odor (Table 2) [8]. A sample collected from the service yard area showed pure creosote at a depth of 16.5 feet. In the storage tank and the north ditch areas, visual contamination was recorded at a depth of 40.5 feet.
Five surface soil samples (0-6 inches) were collected in February 1990 from a livestock pasture area near the "off-site spill" area in the Glade Creek flood plain. Three background surface samples were also collected. Only one background sample was off the site south of the southeastern site boundary along the railroad right-of-way. The other two background samples were within site boundaries, one along the northeastern boundary in the Glade Creek flood plain and the other along the northern boundary east of Smith Ditch.
The surface soil samples were analyzed only for PAHs, PCP, and metals. Laboratory results of the surface soil samples reported the presence of low levels of PAHs. PCP was not detected in any of the "background" samples but was detected in one of the five surface soil samples collected in the Glade Creek flood plain.
Air sampling was conducted at the site in October 1987; however, the plant was not operating during the air sampling activities. Air samples were collected and measured for both VOCs and SVOCs.
Three locations were chosen for ambient air monitoring, one at the center of the plant area, another at an area downwind of the site, and the other at a site determined to be upwind of the site at the time the samples were collected. Five above ground sampling stations for SVOCs were selected based on soil and groundwater sampling results. Soil gas sampling for VOCs was conducted below the surface at three locations near the SVOC sampling stations.
No VOCs were detected in the soil gas samples. Naphthalene was detected at a maximum level of 18.34 milligrams per cubic meter (mg/m3) below ground near the waste pile. Above ground samples in the plant area contained only PAHs; however, upwind samples also contained PAHs. Since groundwater contamination is confined to the site, exposure to soil gas is not expected in nearby homes.
Surface water sampling of the streams was conducted during periods of both low and high flow. Table 3 shows the maximum level of site-related contaminants detected in the surface water samples.
Low levels of PAHs were detected in surface water. Most detections were in samples near the 1939 off-site spill area when Glade Creek was at a low flow level. Sampling during higher flow showed low levels of PAHs farther downstream than were found during the low flow sampling. Only one sample had a detectable level of PCP. Phenol was not detected in any surface water samples. Low levels of VOCs, including benzene, were detected, while no metals were identified at elevated levels.
Visual signs of creosote contamination such as oil globules and an oily sheen were observed in sediments from Glade Creek and Crab Orchard Creek. The length of the ditch along the southern end of the Koppers facility also contained visual creosote in the sediment [5]. Elevated levels of PAHs were detected in the sediment, which confirmed the visual observations (Table 3). The highest level of PAHs was detected in the ditch along the southern end of the facility. The sampling point upstream of the site had sediments with the highest levels of metals. No detectable levels of phenol or PCP were identified in any of the sediment samples.
Attempts were made to sample aquatic biota, but sample takers were unable to collect samples at several locations. A portion of Glade Creek next to the 1939 off-site spill area did not appear to support an aquatic population due to the gross contamination. Crayfishes were selected for tissue analysis from three locations. Samples from five other locations consisted of a single composite sample characterized by whole body or eviscerated and decapitated fish of several species.
Results of the aquatic biota sampling (Table 3) showed the presence of phenol and PAHs. Phenol was found with more frequency in the downstream samples while PAHs were detected with equal frequency in biota upstream and downstream.
IDPH evaluates human exposure pathways to determine the potential for adverse health effects to develop as a result of exposure to contaminants. Exposure pathways are separated into completed and potential exposure pathways. An exposure pathway consists of five elements: (1) a source of contamination; (2) transport through an environmental medium; (3) a point of exposure; (4) a route of human exposure; and (5) a receptor population.
In completed exposure pathways, all five exposure elements exist, and exposure has occurred in the past, is occurring, or will occur in the future without some type of intervention. In potential exposure pathways, at least one element missing, but the missing element could exist. Potential exposure pathways suggest that exposure could have occurred in the past, could be occurring, or could occur in the future. An exposure pathway is eliminated if one or more of the elements are missing and will never be present.
Completed exposure pathways associated with the site are summarized in Table 4. Currently, site workers and trespassers can have direct skin contact with contaminated soils. Exposure may also occur through inhaling contaminant vapors and contaminated dust. Because the site is fenced and access onto the site is controlled by security personnel, trespassing would probably be rare. Only one worker who conducts general maintenance and site security activities currently visits the site regularly.
In the past, area residents are believed to have been exposed to airborne emissions from wood-treating operations at the site. When Koppers was active, area residents reported creosote-like odors originating from site activities. No off-site environmental data are available to identify what contaminants and concentrations were coming from the site at that time. The only environmental data available were air samples collected in 1987 on the site while the plant was not operating. Naphthalene was the only contaminant detected. The highest levels detected were in below ground locations near a waste pile. Low levels of naphthalene were detected in above ground samples in the plant area; however, the levels detected were not of public health concern. Naphthalene does not cling strongly to silt or sediments, but evaporates into the air. Because Koppers is no longer in operation, off-site air is no longer a significant exposure pathway.
Another past completed exposure pathway was through contaminated groundwater at the two homes north of the site. PAHs were identified in the drinking water wells at both of the homes. Residents of the households could have been exposed to contaminants by drinking the water and breathing vapors or dermal absorption during showering, bathing, or cooking with the well water. In 1992, a municipal water district began supplying water to those homes.
A potential exposure pathway exists through shallow, contaminated groundwater migrating to the surface (Table 5). Shallow monitoring wells along the southern site boundary contained elevated levels of PAHs, VOCs, and PCP. The water table in that area is about two feet below the surface. Nearby residents, particularly in the neighborhood near the southern site boundary, could come into direct contact with contaminated groundwater through sump pumps in basements or shallow excavations on their property when landscaping or gardening.
Potential human exposure pathways to site contaminants in the impacted streams could include ingestion and dermal absorption of contaminated sediment and aquatic biota (fish and crayfish) in the impacted streams. Glade Creek and Piles Fork Creek typically have low flow rates and become intermittent during particularly dry periods, which makes them unattractive for swimming or fishing. Glade Creek and Piles Fork Creek converge and then flow into Crab Orchard Creek about 1 mile downstream of the site. Crab Orchard Creek may be used for recreational purposes such as wading, swimming, and sport fishing.
Contact with fugitive dusts blown off the site to the surrounding population is a potential exposure pathway. A residential area is next to the southwest portion of the site. A line of trees separates the neighborhood from the site and may provide a barrier to dusts. The site is currently well vegetated and the only activities on the site that would most likely generate dust are routine maintenance.
PAHs are the chemicals persons have been and may be exposed to in the future. PAHs are a complex group of chemicals that occur in the environment as mixtures of many components with widely varying toxic properties. Benzo(a)pyrene (BaP) is one of the most potent PAHs and probably the most studied. Little is known about many of the other PAHs. USEPA has developed toxicity equivalency factors (TEFs) for many of the PAHs based on their toxicity relative to BaP to estimate the potential for human health effects from exposure to mixtures of PAHs [9].
IDPH estimated the exposure for a maintenance worker and an occasional trespasser to contaminated on-site soil and found no health hazards due to this limited exposure.
IDPH compared the total TEFs for all the PAHs detected in the residential well samples to health guidelines for BaP. Results from the 1989 private well samples showed BaP TEF levels of 0.002 parts per billion (ppb) and 0.006 ppb. These levels are less than the USEPA maximum contaminant level for BaP in drinking water of 0.2 ppb [10].
IDPH estimated the dose to children and adults exposed to PAHs through well water and compared these values to health guidelines. The estimated exposure to children and adults did not exceed these guidelines. The cancer risk due to exposure to PAHs was estimated for a 5-year exposure and was found to pose no increased cancer risk.
When Koppers was active, intermittent complaints from individual residents in the surrounding community would describe a creosote odor originating from the facility. The general complaint described the odor as noxious and bothersome, causing nausea and eye and throat irritation. Most of the complaints appeared to originate from the neighborhood southwest of the facility. When the facility stopped operations, the complaints stopped. No specific community interest group has been identified or has vested interest and concerns regarding the Koppers site. This document was available for public comment from August 6 through September 8, 2000 and no public comments were received.
IDPH recognizes that children are especially sensitive to some contaminants. For this reason, IDPH included children when evaluating exposures to contaminants at the Koppers site. Children are the most sensitive population considered in this health assessment; however, children are not currently being exposed to contaminants from the site.
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