EAGLE ZINC COMPANY
DIVISION OF T.L. DIAMOND
HILLSBORO, MONTGOMERY COUNTY, ILLINOIS
The U.S. Environmental Protection Agency (USEPA) requested a health consultation for the Eagle Zinc Company site in Hillsboro, Illinois, to determine if a public health hazard exists due to actual or potential exposure to hazardous materials or conditions at the site. USEPA is considering the Eagle Zinc site for inclusion on the National Priorities List (NPL). A USEPA remedial investigation and feasibility study (RI/FS) began in summer 2002. This health consultation is based on the data currently available.
The city of Hillsboro is the county seat of Montgomery County with a population of 5,515, according to 2000 census data (Figure 1). The site is about 132 acres in size and is on the east side of Hillsboro, north of State Route 16. About 13 acres of the site are covered with buildings. Two ponds are located on the site - one in the southeast portion and one in the southwest portion.
The nearest home is part of a residential area about 200 feet southwest of the site. The nearest school is Burbank Grade School, which is about 0.25 miles southwest of the site. Homes to the east of the site are in an area known as Schram City. Northeast of the site are a glass company and trucking firm. North of the site is a small subdivision and a few small businesses. Also, Lake Hillsboro and an accompanying park have been developed north of the site, about 1 mile from the northern border of Eagle Zinc. A country club owns lakeside property with available activities including fishing, boating, camping, and swimming. Low-income multifamily public housing units, a few mobile homes, and privately-owned, single-family homes adjoin the western site property line.
Construction of the zinc facility began around 1910 and early operations reportedly began in 1914. Eagle Picher operated the plant until around 1980. In addition to zinc metal and zinc oxide, the former operators of the site produced lead pigment from lead ores; however, manufacture of lead products stopped following the federal ban on leaded residential paint in the late 1970s. Current specifications for the zinc oxide product do not allow more than 0.06% lead content. This is the same concentration determined by the U.S. Consumer Product Safety Commission for the maximum allowable lead concentration in new residential paints.
An Illinois Environmental Protection Agency (Illinois EPA) inspection in 1973 found that scrap metal, furnace residue, and metal-bearing material sorted by percentage of zinc were stored on the ground. At one time, much of the southwest corner of the property was covered with piles of a black residue. Reportedly, this material was used to surface roads at the facility. At times, efforts were made to ship this residue to other facilities to recover zinc, copper, and carbon, but these efforts were costly and limited in times of low market values.
Sherwin-Williams operated the facility from around 1980 to 1984. Since 1984, the Eagle Zinc Company, a division of T.L. Diamond & Company, Inc., has operated the facility. Since the early 1980s, the method of making zinc oxide uses zinc feedstock and anthracite coal. The fuel and feed stocks are delivered to the site by rail or by truck. Feed stocks vary in quality and might be crude or lower-quality zinc byproducts from other manufacturing facilities.
In 1981 and 1982, Illinois EPA sampled surface water and determined that elevated levels of zinc, cadmium, iron, lead, and copper were migrating off the site. This finding resulted in Sherwin-Williams Company having approximately 36 million pounds of furnace waste removed for reclamation. This material had covered about 10 acres of the site. Raw materials, products, and wastes have regularly been placed on the ground for on-site storage and disposal. No liners or dikes were constructed under or around these piles. Much of the material was at the southwest corner of the site. The spent materials have included rotary furnace residue, rotary furnace clean out, carbon plant hutch, muffle dross, building demolition debris, spent fire brick, silica-slags (zinc silicates, zinc ferrites, and iron silicates), and carbonaceous iron slag.
In 1993, Illinois EPA sampled soil, process wastes, and sediments. Some soil samples were collected from residential properties and school yards. Sediments were analyzed for organic and inorganic compounds, pesticides, and metals. Soil and solid wastes were analyzed for metals and inorganic compounds only. A background soil sample was collected from a residential property in Butler, Illinois. A background sediment sample was taken from a drainage way south of Hillsboro. Another smelting facility is about a mile south of Hillsboro and this facility might have contributed to metals detected in the background sediment sample.
Illinois EPA shared the analytical results for soil samples collected from homes near the site with IDPH. IDPH reviewed the data, evaluated any public health hazards, and mailed letters interpreting the results to the residents in February 1994. Manganese was identified as exceeding the public health guideline for children's soil exposure.
Also in 1993, sediment samples in surface drainage areas were collected on and off the site. Following an interim court order, plans were developed to collect samples during precipitation events to measure some contaminant migration.
On September 13, 1994, the USEPA Chief of Emergency Response concluded that the site did not require a time-critical or non-time-critical removal action; however, lead levels in materials on the site remained a concern.
If any private wells are being used in the area, it is likely that they are outside the city limits. The facility and households within the city limits are supplied with municipal water. As a result of a court order, the company installed groundwater monitoring wells in the late 1990s and sample collection began in late 1998.
The Illinois EPA Division of Water Pollution Control collected storm water samples in January 1998. Samples were collected from a discharge channel of the southwest pond and from the intermittent stream that drains the northeast portion of the site. An upstream sample was also collected. Surface water and storm water samples have been collected regularly during precipitation events since 1998 at two sampling locations at the edge of the plant property to determine the extent of the migration of metals in storm water.
On-site residues were sampled in May 1998 and analyzed for lead and cadmium to help characterize the different waste piles. One pile had a maximum lead concentration of 50,290 parts per million (ppm). The highest cadmium concentration was 66.7 ppm. Three of seven sediment samples contained low levels of PCBs, but the maximum level detected was 0.36 ppm.
Current production generates approximately 5 tons of rotary furnace residue per day, with 400 tons of furnace residue removed from the equipment each year. Besides application as a fungicide, the zinc oxide produced is used in pigments, ceramic glazes, adhesives, and rubber-making (vulcanization process). In the past, many buildings were on the site, with as much as 26 acres covered with buildings and associated structures. Currently, the main buildings include an office building-laboratory, a storage building, and a furnace-bag house where zinc oxide is produced. The plant also adds zinc coatings to shingles to retard fungal growth. The scale of current operations is small relative to past production.
Wastes generated at the facility laboratory are discharged into the public sanitary sewer system, and a small amount of equipment waste oil is collected by a recycling business. These wastes are small compared with the large piles of metal-based residues that have been regularly generated as byproducts of the main processes. Eagle Zinc maintains an air pollution control permit for two rotary furnaces with baghouses, one waezling furnace, one rotary dryer, one muffle furnace door hood and two propane storage tanks.
Ponds, wetlands, and surface water exist on the site property. Two ponds collect surface runoff on the southern end of the property. The slight sloping area topography drains to the west. From there, surface water moves toward the south until captured by the pond in the southwest corner. This pond was formed by damming the drainage with solid residue from the facility. Before the construction of a public swimming pool in Hillsboro, residents reportedly were allowed to swim in the southwestern pond. Inspectors have reported breaches in the dam and that runoff is deposited into unnamed tributaries of Middle Fork Shoal Creek. Runoff also occurs at the northeast portion of the site to an unnamed tributary of Lake Hillsboro, about 0.5 miles from the site. Illinois EPA staff has determined that the site does not appear to affect the area municipal water supply, which originates from lakes north of the site.
In 1998, an interim court order was signed, and environmental sampling data are now being generated on a regular basis. In December 2001, USEPA signed a consent order with T.L. Diamond, Sherwin-Williams, and Eagle-Picher to investigate and assess the extent of contamination at the site. A remedial investigation and feasibility study (RI/FS) began in the summer of 2002 and should be completed in 2004. USEPA has invited IDPH staff to participate in future site visits and assessment activities.
IDPH staff visited the site most recently on May 9, 2002. A public road cuts through the facility. Vegetation on the site appeared to be distressed. Children's outdoor play equipment was observed on the properties along 17th Street in Schram City. The site is easily accessed since fencing does not completely enclose the area.
Chemicals of Interest
IDPH compared the results of the available environmental samples with appropriate comparison values to select chemicals for further evaluation for exposure and possible carcinogenic and noncarcinogenic health effects. Chemicals found at levels greater than comparison values, or those for which no comparison values exist, were selected for further evaluation. A discussion of each comparison value used is found in Attachment 2. IDPH assumed that the samples were collected and handled properly and that appropriate analytical techniques were used.
The chemicals of interest in surface water, sediment, and on-site soil are arsenic, barium, cadmium, cobalt, copper, lead, manganese, and zinc. The only chemical of interest detected in residential soil was manganese.
An exposure pathway consists of a source of contamination, environmental media and transport mechanisms, a point of exposure, and a receptor population. Exposure to a chemical may have occurred in the past, may be occurring now, or may occur in the future. When all these elements linking the chemical source to an exposed population are known, a completed exposure pathway exists. When one of these elements is missing, a potential exposure pathway exists.
The persons who may have been exposed to site-related chemicals in the past, present, or future are site workers and nearby residents. Exposures to inorganic chemicals can occur by ingestion and inhalation of contaminated soil and inhalation of dust from the site.
Chemicals in residential soil are a completed exposure pathway. IDPH assumed that children could be exposed to the highest levels of chemicals found in residential soil while playing and would ingest 200 milligrams of soil daily, 10 months per year.
On the basis of this exposure scenario, no adverse health effects would be expected from exposure to chemicals in residential soil.
On-site Soil, Sediment, and Waste
Exposure to chemicals in on-site soil, sediment, and wastes are a completed exposure pathway for workers and trespassers. IDPH assumed adult workers who did not use personal protective equipment while contacting the soil and waste would ingest dirt and dust when working 5 days per week, 50 weeks per year. For trespassers, IDPH estimated an older child coming onto the site would contact soil and waste 2 days per week for 20 weeks per year.
On the basis of these exposure scenarios, no adverse health effects would be expected for adult workers or trespassers contacting on-site soil, sediment, and waste.
Workers may inhale metals while the facility is operating. Breathing too many metal particles or dust contaminated with metals can cause irritation of the lungs. This can be especially problematic for those with respiratory disorders or allergies. In addition, it can increase the chances of lung infection or make breathing difficult. This phenomenon can occur for many metals as well as mixtures of particles. Some refer to this condition as "metal fume fever." Metal fume fever has occurred as a result of high-dose exposures in other occupational settings, but we do not know if it has occurred at Eagle Zinc. Little is known about the long-term effects of breathing metallic dusts. No airborne particulate data exists for this site.
Past exposures to contaminated water and sediment were likely to have occurred when residents would swim in surface water on the site. This practice no longer occurs. Sampling of sediments and storm water has shown that they contain elevated levels of metals, but IDPH cannot reconstruct the past exposures.
The closest well identified from records reviewed in 1993 was about 0.5 miles east of the site, outside the city limits. The facility and households within the city limits are supplied with public water. Illinois EPA staff reviewed private well records maintained by the Illinois State Geological Survey and found that the existing private wells were approximately 50 feet deep, below a layer of clay that exists at a depth of 12 to 18 feet. Therefore, site-related chemicals are unlikely to affect off-site groundwater because metals are not mobile in soil or very soluble in water, there is a confining clay layer, and the closest private well is some distance from the site.
On May 9, 2002, about 60 people attended a public meeting hosted by USEPA. Updated information on the site was provided. The overall work plan was discussed and the clean-up process was explained. The main community concerns were about procedural and communication issues, and about current operations.
IDPH recognizes that children are especially sensitive to some contaminants. For this reason, IDPH included children when evaluating exposures to site-related chemicals. While manganese was found at elevated levels in residential soil, no adverse health effects would be expected for children while playing and ingesting 200 milligrams of soil daily, 10 months per year.
On the basis of the available data and information reviewed, the Illinois Department of Public Health concludes that under current conditions this site poses no apparent public health hazard to the residents of Hillsboro. Processing and smelting primary ores for zinc and lead, and fueling furnaces with coal, have resulted in accumulation of metals in on-site soil, waste, and sediments. These are not, however, at levels that would cause adverse health effects on the basis of the available data and our trespasser exposure scenario.
Although current data do not show that a public health hazard exists, limiting current exposures would be prudent and prevent future exposures to materials stored at the site. Careful handling of site wastes should prevent undue exposures for workers and nearby residents. IDPH recommends that USEPA prevent public access to the site during any remediation activity. Additional environmental sampling results will be generated as USEPA begins an RI/FS this year. IDPH will review and assess the health significance of these data.
Environmental Health Specialist
Illinois Department of Public Health
- Illinois Environmental Protection Agency, Division of Land Pollution Control. Freedom of Information file inspections on September 19, 1994, and December 10, 2001. Springfield, Illinois: Illinois Environmental Protection Agency.
- Illinois Environmental Protection Agency, Office of Chemical Safety. A summary of selected background conditions for inorganics in soil. Springfield, Illinois: Illinois Environmental Protection Agency; 1994 Aug.
- Agency for Toxic Substances and Disease Registry. Toxicological profiles for arsenic, cadmium, cobalt, copper, lead, manganese, nickel, silver, thallium, and zinc. Atlanta: US Department of Health and Human Services.
This Eagle Zinc Company health consultation was prepared by the Illinois Department of Public Health under a cooperative agreement with the Agency for Toxic Substances and Disease Registry (ATSDR). It is in accordance with approved methodology and procedures existing at the time the health consultation was begun.
W. Allen Robison
Technical Project Officer
Superfund Site Assessment Branch (SAAB)
Division of Health Assessment and Consultation (DAC)
The Division of Health Assessment and Consultation, ATSDR, has reviewed this health consultation and concurs with its findings.
Lisa C. Hayes
for Roberta Erlwein
Chief, State Programs Section
SSAB, DHAC, ATSDR
Environmental media evaluation guides (EMEGs) are developed for chemicals on the basis of their toxicity, frequency of occurrence at National Priorities List (NPL) sites, and potential for human exposure. They are not action levels but are comparison values. They are developed without consideration for carcinogenic effects, chemical interactions, multiple route exposure, or exposure through other environmental media. They are very conservative concentration values designed to protect sensitive members of the population.
Reference dose media evaluation guides (RMEGs) are another type of comparison value. They are developed without consideration for carcinogenic effects, chemical interactions, multiple route exposure, or exposure through other environmental media. RMEGs are very conservative concentration values designed to protect sensitive members of the population.
Cancer risk evaluation guides (CREGs) are estimated contaminant concentrations that are based on a probability of 1 excess cancer in 1 million persons exposed to a chemical over a lifetime.
Maximum contaminant levels (MCLs) have been established by USEPA for public water supplies to reduce the chances of occurrence of adverse health effects from use of contaminated drinking water. These standards are well below levels for which health effects have been observed and take into account the financial feasibility of achieving specific contaminant levels. These are enforceable limits that public water supplies must meet.
Lifetime health advisories for drinking water (LTHAs) have been established by USEPA for drinking water. The advisories represent the concentrations of chemicals in drinking water that are not expected to cause any adverse, noncarcinogenic effects over a lifetime of exposure. LTHAs are conservative values that incorporate a margin of safety.