PRELIMINARY PUBLIC HEALTH ASSESSMENT
NATIONAL SOUTHWIRE ALUMINUM COMPANY
HAWESVILLE, HANCOCK COUNTY, KENTUCKY
The National Southwire Aluminum Company site is an active primary aluminum reduction facility in Hancock County, Kentucky. The 1,200-acre site lies between State Route 334 and the Ohio River, about 3 miles northwest of Hawesville, Kentucky. The facility includes several large production buildings, warehouses, machine shops, and other support units including a dump pad building, a drum storage area, four waste ponds, and a small incinerator.
On-site maintenance workers and any construction or remedial workers who are, or have been in the past, in close contact with surface soil and workers at the waste areas were probably exposed in the past and may be currently exposed to fluoride through incidental soil ingestion at levels that could cause adverse health effects. Crippling skeletal fluorosis could occur if workers experience continuous soil exposure over more than 10 - 20 years. Workers in the potroom area were and are currently exposed to fluoride through inhalation of indoor air. However, the low levels of fluoride in potroom air are not likely to cause adverse health effects. On-site maintenance and construction workers also are likely to have been exposed to PCBs in surface soils. However, they are not likely to develop any adverse health effects because of the low levels of exposure. The exposure of the construction crew to PCBs in subsurface soils from the cooling tower foundation excavation is not likely to cause long term adverse health effects due to the short duration of exposure. In addition, workers on site, and residents who live in the vicinity of the site were probably exposed and may be currently exposed to aluminum, arsenic, cobalt, cyanide, manganese, and nickel through skin contact or soil and water ingestion. Adverse health effects are not likely to occur because of exposure to low levels of contaminants. Residents of the nearby towns of Hawesville, Tell City, Cannelton, Troy, Lewisport, and East Daviess, and possibly Evansville were exposed and may be currently exposed to low levels of fluoride, manganese, and arsenic through their municipal drinking water. Adverse health effects are not likely to occur through use of those water supplies. Moreover, scientific data are very limited on the health effects of multiple contaminant exposure. In addition, the specific natural or man-related sources of contaminants in drinking water cannot be defined.
Potential pathways of human exposure to contaminants off site include ambient air, surface soil and vegetable produce. However, in the absence of pertinent data and information, ATSDR is unable to determine whether adverse health effects may occur.
As part of the site investigation, ATSDR held two informal, one-on-one public availability meetings. Health concerns raised at the meetings, and those received during the public comment period have been addressed in the public health implications section.
Based on the information reviewed, ATSDR has concluded that the
National Southwire Aluminum Company site poses a public health
hazard. This conclusion is
based on evidence that maintenance
and other on-site workers were probably exposed and may be
currently exposed to hazardous substances at concentrations that
may cause adverse health effects. The Agency for Toxic
Substances and Disease Registry (ATSDR) referred the National
Southwire Aluminum Site to the Kentucky State Health department
and to the National Institute of Occupational Safety and Health
(NIOSH). NIOSH completed a Health Hazard Evaluation at the NSA
site on May 11, 1993, and made recommendations to NSA relating to
the urinary fluoride monitoring program at the site. NSA reports
they will implement NIOSH's recommendations to adequately
characterize the fluoride body burden of workers throughout the
work year. Because off-site contamination is not well
characterized, and because there are no documented exposures off
site at levels that could cause illness or injury, no further
public health actions are planned at this time for that
population. However, upon completion of the Remedial
Investigation (RI), the EPA will conduct a Baseline risk
Assessment to quantify (estimate) the human health risks posed by
the contaminants found at the site. In addition, ATSDR has also
made recommendations to reduce and prevent exposure to
contaminants, better characterize the site, and implement
institutional controls and other activities. If pertinent
additional data and information become available, ATSDR will
reevaluate the site for indicated followup.
The Agency for Toxic Substances and Disease Registry (ATSDR), in Atlanta, Georgia, is a federal agency within the U.S. Department of Health and Human Services and is authorized by the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) to conduct public health assessments at hazardous waste sites. ATSDR has, under this mandate, evaluated the public health significance of the site--more specifically, ATSDR has considered whether health effects are possible and has recommended actions to reduce or prevent possible health effects. ATSDR has not conducted prior activities associated with this site.
The public health assessment was available for public review and comment from March 3, through April 20, 1993. A summary of the comments received and responses to those comments can be found in Appendix C.
The National Southwire Aluminum (NSA) Company, Hancock County, Kentucky has been proposed by the U.S. Environmental Protection Agency (EPA) for addition (Update 11) to its National Priorities List (NPL). The property, approximately 1,200 acres, is between State Route 334 and the Ohio River, about 3 miles northwest of Hawesville, Kentucky. Principal area and site features are shown on the Site Location Map, Figure 1, and Site Layout Map, Figure 2, which are provided in Appendix A.
NSA is an active primary aluminum reduction facility that converts alumina into aluminum metal. Alumina ore is decomposed into aluminum in each of 448 electrolytic reduction cells, or pots. The aluminum then is processed further and marketed. NSA began operations in 1969 (1). The process area was observed by ATSDR to include several large production buildings, warehouses, machine shops, other support units, a building that encloses a concrete pad (dump pad) used for demolishing potliners, a drum storage area, and a small incinerator. The process area is enclosed by a fence and has a guard house to control access. Four disposal ponds, a site drainage ditch, and an airport runway and support buildings lie outside the controlled-access area. These facilities are partially enclosed by an outer fence system, but public access is not fully controlled. NSA reported they own the runway and airport buildings and lease the facility to a local operator. ATSDR observed that parts of the property outside of the process area are used for growing forage crops.
NSA's representative reports that spent (used) potliners contain substantive concentrations of cyanide. Potliners, when they become unusable, are taken to the dump pad building and broken into pieces (1). The dump pad was diked, enclosed, and provided with a dust-collection system a few years ago to eliminate spent potliner from being released to the environment (2). During early plant operations, potliner pieces were disposed of in an on-site pond; however, since July 1986, the spent liner pieces have been sent off site to a permitted waste disposal facility. Runoff at the pad has been collected in a sump and disposed of in one of the ponds.
Airborne pollutants generated by the pots during alumina reduction are vented to an air control system that contains multiclones, precipitators, and scrubbers. NSA reports that the precipitators were added about 1980 to reduce particulate emissions from their stack and from roof vents on potline buildings. Wastes from the air quality control system have been disposed of in four ponds at locations shown in Figure 2 (1).
Two ponds (North and South Ponds) were constructed initially (1). The North Pond contains spent potliners, a small quantity of waste paint filters, and calcium fluoride and other residues from the air control system. The South Pond contains only air system wastes. The ponds cover 5 to 7 acres each. A tamped clay base was reportedly installed in each pond. In 1986, the North Pond was closed with a plastic liner and fill dirt after which the area was seeded. The South Pond is essentially inactive, and NSA reports it will be capped. The East Pond, which was not lined, was filled with air system wastes and closed in 1987, using cover soils from elsewhere on the property. In 1989, the New Pond was constructed to receive current air system wastes. The pond has a synthetic liner. NSA reports they also operate an unlined landfill on site for nontoxic solid waste materials.
In early 1992, NSA reported to the Kentucky Department for Environmental Protection (KDEP) and EPA that high levels of polychlorinated biphenyls (PCBs) were discovered near the bottom of a 17-foot deep foundation excavation (3). EPA reported to ATSDR that NSA's subsequent remediation of PCB levels in soils at the excavation bottom to 2.3 parts per million (ppm), or less, met their agency's criterion. The lateral extent of subsurface PCB contamination beyond the excavation was not defined. NSA grouted the sheetpile wall surrounding the excavation to prevent contamination from entering the finished foundation pit. Soil removed from the excavation was stored temporarily in piles in a field on site and covered with plastic; the soil then was transported to an approved chemical waste landfill in Alabama. When loading the stored soil, action also was taken to remove surface soils that may have been in contact with the stockpiled materials. NSA reported to ATSDR that testing performed on surface soils after the piles were removed showed PCBs, where present, were mostly below 10 ppm; the maximum detected was 48 ppm. NSA cordoned off the former storage area and is planning remediation.
Some storm runoff water, noncontact cooling water, sanitary waste water, and some process waste waters discharge directly into the Ohio River under permits issued by the state (1). The remainder of the runoff and process waste water, plus some occasional pond overflow, discharges to the drainage ditch that flows from south to north across the western area of the property and drains into the river beyond the north end of the process area. In late 1990 and early 1991, NSA reports they removed some gray-colored materials from the ditch (2).
The site lies in a broad valley bisected by the Ohio River. Ground surface rises to approximately Elevation 450 to 500 feet (National Geodetic Vertical Datum of 1929) along the valley rim. The valley floor on site, and elsewhere between Kentucky Route 334 and the river bank, ranges from about Elevation 400 to 410. West of Route 334, and for several thousand feet more, ground surface is lower--on the order of Elevation 390. A U.S. Corps of Engineers representative reports that the 50- and 100-year river flood levels adjacent to the site are Elevations 398.2 and 399.9, respectively. The plant process and waste disposal areas should not be flooded at their indicated ground elevations, except under extreme events; but a local farmer reports that areas at lower elevation, especially west of Route 334 (about 1,500 feet west of the process area), flood fairly frequently.
Average wind speed at the site is estimated to be about 8 miles per hour, based on information for meteorological stations at Evansville, Indiana, and Louisville, Kentucky. The prevailing wind direction at the site, based on these same stations, would appear to be from the south or southwest. However, wind direction could also be affected by the valley configuration.
NSA reports that, whether or not the site is placed on the NPL, they intend to further investigate environmental contamination and consider remediation measures.
ATSDR representatives--Dr. Moses Kapu and Messrs. Don Gibeaut, Carl Blair, and Robert Safay--visited the site area between December 10-13, 1991. Pertinent information obtained during that visit is described in appropriate sections of this document.
Tell City, about ½ mile east of the site on the Indiana side of the river, is the nearest community and has a population of about 8,000, according to the 1990 census. Other nearby towns in Indiana are Cannelton, the Perry County seat with a population of about 1,800, and Troy, which has about 500 residents. Hawesville, which is the Hancock County seat and the nearest town in Kentucky--about 3 miles southeast of the property--has a population of about 1,000. The population for Hancock County Kentucky is approximately 8,000; for Perry County, Indiana, population is about 19,000. The racial makeup for both Hancock and Perry Counties is about 98% white. About 30% of the population in both counties is under 18 years of age and about 10% is over 64 years of age.
The nearest residence was observed by ATSDR to be about 200 feet southwest of the site perimeter. Three additional homes were observed within ½ mile west and south of the site, and up to a dozen more homes were observed within 1 mile--mostly to the west and northwest.
The Hancock County High School and Middle School complex, on U.S. Route 60 about 1½ miles to the southwest of the site, was observed by ATSDR to be the nearest school in Kentucky. Three schools in Tell City, to the east, are closer; their distance from the property ranges from about ¾ to 1¼ miles. The towns of Cannelton and Hawesville, about 3 miles to the southeast, each have two schools within their urbanized areas.
The Perry County Hospital was observed by ATSDR to be about 1¼ miles southeast of the property. A nursing home, in Tell City, is about 1½ miles east of the site.
NSA and adjacent industries employ more than 1,000 persons. NSA reports that combined current employment for its plant and for the adjacent Southwire-Kentucky Division plant totals about 900. The airport lessor has only a few employees. The Hancock County Industrial Foundation reports that the Hancock County Ready-Mix Company near the south edge of the site has about 10 employees. Alumax Aluminum Company, also at the south edge of the site, closed in 1991 and had about 125 employees. Big Rivers Electric Corporation, immediately north of the site has about 150 employees.
The property is part of a wide alluvial plain, which supports a mixture of agricultural and industrial uses. ATSDR observed that edible and forage crops, mostly soybeans and corn, are grown on much of the surrounding land. The nearest field is immediately west of the site, across Route 334. Few cattle are reportedly raised in the area. Principal nearby industries include the Big Rivers electric generating station immediately north of NSA and Southwire-Kentucky Division and Alumax, which is closed, immediately to the south. Hancock County Ready-Mix Company is also south of NSA. World Source, an aluminum coating mill, is immediately south of Alumax.
Natural Resource Use
Groundwater is the source of public and private water supplies in the site vicinity for both Kentucky and Indiana. The closest municipal systems are at Troy (3 miles north), Tell City (½ mile east), and Cannelton (3 miles southeast), Indiana, and Hawesville (3 miles southeast), Kentucky. State personnel report the approximate populations served by these water systems are: Troy, 600; Tell City, 9,000; Cannelton, 2,800; and Hawesville, 2,700. NSA, the only privately owned public system in the vicinity, reports their drinking water well provides potable water to approximately 900 persons at their plant and at the adjacent Southwire-Kentucky Division and airport. NSA also withdraws substantial groundwater from other wells on the property for industrial purposes--they report their withdrawal during 1991 averaged from about 700,000 to almost 1,000,000 gallons per day. Wells supplying the water systems draw from the thick alluvial soil zone that overlie bedrock along the river (2). Two other municipal well systems in the area, the East Daviess and Lewisport wells, are more than 3 miles northwest and west of the site.
Evansville Indiana, approximately 60 miles down river, is the closest down-stream user of river water for potable purposes (2).
An Indiana state health department representative reports that Tell City and Cannelton adjust the fluoride level in their public water supply to 1 part per million (ppm). Troy, Indiana, does not fluoridate its water. A Kentucky Department for Environmental Protection (KDEP) representative reports that Hawesville, Kentucky, also fluoridates its public water supply. Water department personnel indicate they target fluoride levels at 1 ppm. The natural fluoride level in the groundwater withdrawn by these systems is reported to be about 0.3 ppm.
At the Big Rivers electric plant north of the site, drinking water reportedly was obtained from wells until about 1987 when they connected to the Hawesville municipal system. Alumax, just south of NSA, reportedly had initially used bottled water for drinking (2) and connected to the public water system in 1991. The Hancock County Ready-Mix Company to the south of NSA obtains its potable water supply directly from a well near the river bank on its property.
Most of the Kentucky residents in the immediate site area obtain their water from the Hawesville public water system. A Hawesville Water Department representative reports that only four residences within a mile of the site use a well for water supply. Nearby in Indiana, predominantly municipal water is used by residents and industry and, during dry periods, by some farmers for watering cattle (2).
NSA has three industrial wells available to supply process and potable water needs (2). Well #1 has been used to supply drinking water, but this use was discontinued in mid 1985 because of cyanide levels. Well #3 has supplied the drinking water since then. Well #2 can be used as a back-up drinking water source. NSA reports they soften and chlorinate groundwater used for potable purposes, but do not fluoridate it.
The river is used extensively for recreation purposes, principally fishing, boating, and water skiing (2). A park with picnic tables is located on the river immediately west of Troy Indiana. One official reported that no beaches are present on the river in the immediate area, but many boaters make use of a beach on an island a few miles downstream. Boat ramps exist at Troy, Tell City, and Hawesville. A marine service representative reported that considerable recreational fishing and skiing occurs on the river (2). A Kentucky Department for Environmental Protection (KDEP) representative reported that Kentucky and several other states have issued fish advisories for the Ohio River for paddlefish and roe, channel catfish, white bass, and carp because of excessive levels of polychlorinated biphenyls (PCBs) and chlordane. Kentucky reissued its advisory in February 1992.
A Tell City official identified nine public parks, a public pool, and a golf course in the area; some are within a mile of the site. About 2 miles south of the property, Hawesville maintains a large public recreation area that includes a lake for swimming. Another recreation area, the Fish and Game Park, is along the Hancock/Daviess County line (2). A Cannelton official reported a large public recreation area is next to their high school.
Health outcome data relevant to the completed exposure pathways
do not exist in the states of Kentucky and Indiana.
As part of the site investigation, ATSDR staff held two informal, one-on-one public availability meetings on Wednesday, December 11, 1991, to learn about residents' site-related concerns. One person came to the sessions. He said he did not feel he was being affected by the site; but he was concerned about the health problems of his family members. He and one person who contacted ATSDR staff during the public comment period raised the following health-related questions:
- Are the few cases of autoimmune disease (especially multiple sclerosis and lupus) reported by one resident who also suffers from a mild form of multiple sclerosis, caused by site-related chemicals?
- Is it safe to drink water from private wells in the area?
- Is it safe to eat beef and produce from farms in the area?
- Is it safe to live in the NSA area?