PUBLIC HEALTH ASSESSMENT
DOVER CHEMICAL CORPORATION
DOVER, TUSCARAWAS COUNTY, OHIO
The Dover Chemical Company site poses a public health hazard because of the possibility of past exposure to dioxin and BHC contaminated soil and dust and because of the potential for exposure to several chemicals in drinking water supplies. The available data do not indicate that people are currently being exposed to contaminated soil, dust, or water at levels that would adversely effect their health. Monitoring wells, 500 feet from the city of Dover public water supply wells, contain site-related chemicals above levels of concern. People could be exposed to chemicals above levels of concern if ongoing remediation (pump and treating groundwater) and monitoring of the well field fails to detect chemicals entering the water supply.
The site also poses an indeterminate public health hazard. There is a potential for people eating fish caught in the lagoon and in Sugar Creek to be exposed to site-related chemicals, but the data are insufficient to determine the risk of exposure. There is also a potential for people to be exposed to dioxin by eating contaminated vegetables grown in gardens near the site. However, there are no environmental monitoring data to determine the risk of exposure.
The Dover Chemical site is an operating chemical manufacturing plant on the west side of Dover, in Tuscarawas County, Ohio. Dover Chemical currently produces phenyl phosphites and chlorinated hydrocarbon products which are used to manufacture pressure lubricants, plasticizers, and flame retardants for vinyl products. Prior to the 1970's, dichlorobenzene was also produced at the plant. Chlorobenzene wastes from production processes were disposed of in two unlined on-site pits. The pesticide BHC was also stored on-site in the 1960's.
The Remedial Investigation (RI) discovered dioxin contamination of on-site and off-site surface soil in residential areas along Davis Street and 15th Street, on-site air, dust, fish in Sugar Creek and the lagoon. Volatile organic compounds (VOCs), were detected in groundwater moving off site towards the Dover city well field to the northwest and towards the south along Davis Street.
Due to the threat of the spread of site contaminants into adjacent residential areas and into the community water supply, a number of clean-up activities were completed as part of the interim remedial measures at the site. These remedial activities included fencing the site; excavation and removal of contaminated soils on and off- site.
Community concern appears to be minimal. Ohio Department of Health (ODH) staff have contacted the local union at the plant to determine if workers had any health concerns. Reportedly, workers have not expressed any concerns about their health. Area residents sent ODH some of their concerns when the public health assessment document was released for public comment. These concerns dealt with chlorine vapor rising from the plant, headaches, chest pain, stomach discomfort, dry nose and dry mouth, and concerns that the Department of Health should be able to locate larger fish and requested that her garden be tested.
Additional sampling is needed to evaluate the risk associated with consuming fish caught in Sugar Creek and the lagoon, and soils from any gardens (within 500 feet). The private wells sampled during the RI need to be resampled to confirm the earlier results. Those off-site private wells containing VOCs that are no longer in use should be closed in accordance with Ohio regulations.
The Dover Chemical site is an operating chemical manufacturing plant on the west side of Dover, in Tuscarawas County Ohio (Figure 1, Appendix A). The 60-acre facility is located in the Sugar Creek valley, bounded on the west by I-77, on the east by Davis Street and railroad tracks, on the south by several other industrial facilities, and on the north by an open field (Figure 1, Appendix A). The site also includes property west of I-77, including an 18-acre water-filled lagoon. Historically, wastewater discharged from the Dover Chemical plant flowed through an open canal to the lagoon and then into Sugar Creek. Sugar Creek is a small stream that flows to the southeast. It is a tributary of the Tuscarawas River. A small stream, Goettge Run, flows into Sugar Creek, just south of the Dover Chemical site (Figure 2, Appendix A).
The site is located on the floodplain of Sugar Creek which is underlain by 230 feet of sand and gravel. This deposit forms an unconfined groundwater aquifer that is a source of water for the Dover Chemical plant, the city of Dover municipal water system, and for a number of private wells that are south and east of the site. Natural groundwater flow in the area is from the northwest to the southeast. Pumping by industrial production wells and city of Dover water supply wells has disrupted natural groundwater flow in the vicinity of the site. The city well field is 1,000 feet northeast and upgradient from the site. There are also residential and commercial wells south (downgradient) and east of the site. The closest private water supply well is 500 feet east and southeast of the site (Figure 3, Appendix A). Wind direction in the area is from the west most of the year. It tends to be out of the northwest in the winter months and from the southwest in the spring and summer.
Dover Chemical currently produces phenyl phosphites and chlorinated hydrocarbon products which are used to manufacture pressure lubricants, plasticizers, and flame retardants for vinyl products. The plant has been in operation site since 1950, although previous facilities occupied the site prior to World War II (Weston, 1993). Prior to the 1970's, dichlorobenzene was produced at the plant. Chlorobenzene wastes from production processes were disposed of in two unlined on-site pits (Area H, Figure 2, Appendix A). These wastes included 4,000 gallons of drummed and bulk chemicals (United States Environmental Protection Agency (U.S.EPA, February, 1993). The pesticide BHC was also stored on-site (Area G, Figure 2, Appendix A) in the 1960's.
One water sample collected from the Dover city well field in 1973, contained a small amount of chlorobenzene (U.S.EPA, February, 1993). Subsequent sampling in the well field failed to detect further chemical contamination. In 1978, Dover Chemical ceased production of dichlorobenzene. In 1981, the company reported to the U.S.EPA the discovery of buried drums at the site. Soil samples collected from the two on-site disposal pits revealed high levels of dichlorobenzene and chlorobenzene. On-site groundwater and soil sampling in May, 1981 showed elevated levels of chlorinated organic compounds. The pits were identified as the probable source area. Nine hundred and seventy-five tons of contaminated soil and drummed chemicals were removed from the pits and disposed of off site. Investigations from 1983 to 1986 identified contaminated soils in the canal area and at other areas on site. Investigators determined that no further contamination of the city of Dover well field had occurred.
The Remedial Investigation began at the Dover site in 1989 and was completed in 1993. The RI revealed contamination of on-site and off-site surface soil in residential areas with dioxins and dibenzofurans. Air samples taken on site, dust samples, and personal air samples taken in on-site buildings also contained dioxin. Fish in Sugar Creek and the lagoon contained site-related chemicals. VOCs were detected in groundwater moving towards the Dover city well field and towards the south along Davis Street. One of the off-site industrial production wells and three private wells, all south of the site, were contaminated with VOCs. The production well is not used for drinking water purposes and two of the private supply wells are not used at all. The third well is at a local business and is only used in the restrooms and is not a drinking water supply.
The Dover Chemical site was proposed to the National Priorities List of Superfund hazardous waste sites in May, 1993. The first draft of the Feasibility Study (FS) to determine how to clean up the contaminants at the site was completed in November 1995.
Due to the threat of the spread of site contaminants into adjacent residential areas and into the community water supply, a number of clean-up activities were completed as part of the interim remedial measures at the site. These remedial activities included fencing the site; excavation and removal of contaminated soils on site; on-site storage of some of the contaminated soil on an asphalt pad that was covered by a tarp; paving high-traffic areas with asphalt or concrete; planting grass in non-traffic areas on-site; removal of contaminated off-site soils along Davis Street, 15th Street, between the railroad tracks and the plant, and along the I-77 right-of-way; installation of 21 on-site and 20 off-site monitoring wells (Figure 3, Appendix A); and installation of Production Well #6 at the northeast corner of the site to intercept the contaminant plume moving towards the city well field. Since 1987, a wastewater treatment system with an air stripper to remove VOCs from cooling and process water has been in use at the plant. Treated water is discharged to Sugar Creek.
Soils along on-site roadways and parking lots with dioxin concentrations exceeding 0.001 mg/kg were covered with asphalt, concrete, chip-and-seal, buildings, or placed on the soil consolidation pad. Grassy areas with concentrations greater than 0.001 mg/kg were fenced and hydro-seeded. Other areas were excavated to 18 inches, lined with a geotextile liner, backfilled with clean soil, and seeded. The area with the highest dioxin concentration was either covered with the asphalt pad (used for storage of excavated soil) or with chip and seal. The area surrounding Building 21 (highest BHC concentrations) was covered with a geotextile liner followed by asphalt or chip-and-seal.
ODH staff visited the site April 14, 1993, and again on June 16, 1993. Excavation of contaminated soils was in progress on site along Davis Street at the time of the site visit. Workers were in Level C protection. We noted a number of industrial facilities south of the site on the west side of Davis Street, including a machine shop, a facility that manufactures metal tanks, and a cryogenics plant with liquid hydrogen tanks. Fast food restaurants and other small businesses are located along Davis Street. Small businesses are located on the north side of 15th Street, adjacent to the site. The proximity of the Dover Chemical site to residential neighborhoods east of Davis Street and along 15th Street was noted. Residences were primarily single-family homes. One residence immediately across the street from the plant had a large vegetable garden. Shoulders on Davis and 15th Streets were covered with asphalt or grass. No strong fumes or odors were detected. Winds were out of the west. The plant property was fenced.
Overall, the demographic profile for the area surrounding the Dover Chemical Site indicates a community that is slightly better off compared to Tuscawaras County as a whole and similar compared to the State of Ohio as a whole. The Dover Chemical site is located on the west edge of the city of Dover (population 11,329; 1990 Census). There are approximately 5,791 people living in the area surrounding the Dover Chemical site. The area of concern is defined by 21st St. to the North, Crater and Franklin Ave. to the East, Front St. to the South, and I-77 to the West. The entire area is considered largely urban and the people comprise 1600 families, 2255 households, and occupy 2378 housing units. The population is predominantly white (Table 1).
|Demographic Information -Dover Chemical Site|
1990 Census Data
|State of Ohio||Tuscawaras County||Area of Concern|
|% H.S. Grad||75.7||71.9||78.6|
|% in Labor Force
|Median Family Income||$34,351.00||$29,303.00||$31,874.00|
|% Families Below||9.7||9.1||6.9|
|Median Housing Value||$62,900.00||$49,700.00||$52,719.00|
|Median Gross Rent||$379.00||$311.00||$338.00|
|Information taken from Census of Population and Housing STF3A, 1990|
The area surrounding the Dover Chemical site is a mixture of industrial, residential and commercial properties. There are several industrial facilities and other commercial businesses, including Dover Chemical, on Davis Street, east of I-77 on 15th Street, adjacent to the site. There are residential neighborhoods east of the site, east of Davis Street and along 15th Street. The Dover Elementary School is 2,000 feet east of the site. The area north of the site is an open field. The area west of the site, along Sugar Creek, includes, a sand and gravel mining operation, an automobile junkyard, and a campground.
Natural Resources Use
The Dover Chemical site is on the floodplain of Sugar Creek. The creek flows through a flat area 750 feet west of the site. In the vicinity of the site, Sugar Creek is 50-70 feet wide and flows to the south towards the Tuscarawas River. Sugar Creek is classified by Ohio Revised Code 3745-1-13 (Ohio EPA, 1987) as a warmwater, agricultural, and industrial water suitable for primary contact recreational uses. Warmwater streams are capable of supporting moderately diverse, stable populations of aquatic life, including fish, invertebrates, and aquatic plants. Agricultural waters are suitable for watering livestock and crop irrigation. Industrial waters can be used for commercial and industrial purposes, with or without treatment. The Primary Contact classification indicates that this creek may be suitable for full-body contact recreational purposes, including swimming and boating, with minimal risk to public health.
The creek flows on a sand and gravel bottom and supports at least 17 species of fish, primarily a variety of creek chubs and minnows, gizzard shad, and carp. Gamefish reported from the creek include rock bass, largemouth, and smallmouth bass (Weston, 1993). The Ohio Department of Natural Resources has reported fish kills in lower Sugar Creek in 1988, 1989, and 1990 (Ohio EPA, 1992).
Goettge Run is a small stream that flows west into Sugar Creek at the south end of the site. The stream flows from the northeast, draining largely agricultural and residential areas. It is impacted by coal mining operations upstream near its headwaters (Weston, 1993). General water quality in Goettge Run is degraded (Ohio EPA, 1992). The former discharge lagoon for Dover Chemical is west of the plant facility. It is about 5 acres in size with water depths of up to 40 feet over sand and gravel bottoms. Fish in the lagoon include gizzard shad, carp, suckers, channel catfish, northern pike, largemouth bass, and walleye (Weston, 1993).
The Dover site is underlain by a buried river valley filled with up to 230 feet of sand and gravel. This deposit forms a groundwater aquifer that provides water for local industrial production wells, city of Dover municipal wells, and a number of residential and commercial wells. The water table in the vicinity of the site is shallow, 3-5 feet below the ground surface. Groundwater flow is southeast towards the Tuscarawas River (Weston, 1993). The aquifer is recharged through surface infiltration and lateral flow from upstream areas. The aquifer discharges into Sugar Creek and the Tuscarawas River. Local groundwater flow is disrupted by the high volume pumping by Dover Chemical production wells and the city of Dover water supply wells. It is estimated that the city of Dover well field (four wells) pumps 2.4 million gallons per day (mgd) and the four Dover Chemical production wells pump 3.5 mgd. This causes a downward depression of the water table in the vicinity of these wells, creating two cones of depression beneath these two clusters of wells (Weston, Draft FS, 1993).
There are 12 private water supply wells in the vicinity of the Dover Chemical site. These include seven active residential wells, three active industrial supply wells, and two inactive wells, one at a private school and the other at an industrial facility, both south of the site (Weston 1993). The city of Dover water supply wells are 500 feet north of the site (Figure 2, Appendix A). They are screened at 100-110 feet. Production wells at Dover Chemical are screened at 55-75 feet and residential wells are screened at 40-50 feet deep.
The only health outcome data readily available for review are cancer mortality statistics for Tuscarawas County. These data are not relevant when evaluating the potential effects from one site located in one city in the county.
ODH staff, Tracy Shelley, Robert Frey, and Irena Scott, attended a U.S.EPA public availability session to discuss any health-related concerns of local citizens. One citizen, who lives within a half mile of the site, expressed a concern about planting flowers and shrubs in her yard. Two other citizens expressed concerns about the safety of eating fish caught in the Tuscarawas River. ODH staff have also contacted the local union at the plant to determine if workers had any health concerns. Reportedly, workers at the Dover plant have not expressed any concerns about their health.
Some comments and concerns were expressed in letters sent to the Ohio Department of Health during the public comment period. One citizen commented that on the evening when Dover Chemical had the supposed cloud of chlorine vapor rise from the plant, she had to close all of her windows quickly because of the smell. She also stated that she experienced headaches, chest pain, stomach discomfort, dry nose and dry mouth. Another citizen wanted to know if anything had been done to the former owner at the time of the discovery of the two buried containers. She also indicated that the Department of Health should be able to locate larger fish and requested that her garden be tested.