The U. S. Environmental Protection Agency (U.S. EPA) has listed the Bofors-Nobel Inc. (Bofors) site on the National Priorities List (NPL). Various owners have operated chemical plants on the Bofors site since 1960. Chemicals produced at the site have included pesticides, herbicides, benzidine, and other aromatic amines, specifically 3,3'-dichlorobenzidine (DCB). Organic chemicals, including DCB, benzidine, and various solvents, have been found in soils on and near the site, sludges in now-abandoned wastewater lagoons, sediments, surface water and groundwater. Studies in 1980 and 1981 documented that some Bofors workers had inadvertently transported DCB on their clothing and shoes to their residences, a process called track-out.

A system of purge wells is in place to draw contaminated groundwater out of the ground for treatment and discharge to a nearby creek. The purge well system also confines the contaminated water and prevents it from reaching nearby surface water. The most contaminated areas are fenced.

The site poses a past public health hazard due to exposure to site-related contaminants which may have occurred through track-out and contamination in the groundwater, surface soils, and sediments. Currently, the site poses no apparent public health hazard because, although contaminated soil and sludge remain on the site, it would be difficult for a trespasser to gain access due to the site restrictions in place. The current remediation prevents human exposure to the contaminated groundwater, but future access may occur before the remediation is complete. The site has been included in a pilot health study by the Michigan Department of Community Health (MDCH) with support from the Epidemiology and Medicine Branch, Division of Health Studies, Agency for Toxic Substances and Disease Registry. There has been and continues to be a considerable amount of community health concern regarding this site. MDCH and ATSDR have responded to health concerns at public meetings, during site visits, and in this Public Health Assessment.

On March 31, 1989, the U. S. Environmental Protection Agency (U.S. EPA) listed the Bofors-Nobel, Inc. (Bofors) site on the National Priorities List (NPL) due to extensive contamination of the groundwater, soil, surface water, and sediment at and near the site by 3,3'-dichlorobenzidine (DCB), benzidine, and other chemicals.

A. Site Description and History

Bofors-Nobel, Inc., is an 120-acre site 6 miles east of downtown Muskegon at 5445 Evanston Avenue. The site lies south of Evanston Avenue and extends to the south bank of Big Black Creek, which flows to the west-southwest across the site. It is approximately in the center of Section 32 of Egelston Township (T. 10 N., R. 15 W.). Figure 1 shows the site location; Figure 2 (Taken from Reference 1, Figure 2-1) is a detailed map of the site. Various owners and operators have operated chemical manufacturing facilities on the Bofors site since 1960. Chemicals produced at the site include pesticides, herbicides, and dichlorobenzidine (DCB), benzidine, and other aromatic amines. Many other volatile and semi-volatile organic compounds have been used as solvents and intermediates in the manufacturing processes used on the site.

In 1960, chemical production on the site began under the ownership of Lakeway Chemicals, Inc. (Lakeway). Lakeway merged with Bofors Industries, a U.S. subsidiary of Bofors A.B. of Sweden, in 1977 to form Bofors Lakeway, Inc. In 1983, Bofors A.B. acquired KemaNobel and changed its name to Nobel Industries, and Bofors Lakeway was renamed Bofors-Nobel, Inc. Bofors-Nobel, Inc. filed for protection under Chapter 11 of the U.S. bankruptcy laws in 1985. During the bankruptcy proceedings, with the approval of the Bankruptcy Court, Bofors-Nobel sold the assets on the site to Lomac Inc. in March 1987. As part of the purchase agreement, Lomac Inc., the State of Michigan, and the U.S. EPA signed an "Agreement and Covenant Not to Sue", allowing Lomac to operate the plant free from liability for past site activities of previous owners. Lomac Inc. currently occupies only the plant area of the site (approximately 35 acres) which is fenced off from the remainder of the property which includes the contaminated lagoon area. The Michigan Department of Environmental Quality (MDEQ)⁽¹⁾ administers the remainder of the site (approximately 85 acres). The MDEQ is responsible for directing cleanup activities, under a "Modified Consent Agreement" between Bofors and the State of Michigan signed in 1987.

Before 1976, operators of the plant at the Bofors site used several unlined lagoons and settling ponds for wastewater and sludge disposal. In 1965 and 1975, dikes around some of the lagoons failed, causing wastewater to spill into Big Black Creek. Two million gallons of wastewater is estimated to have spilled in the 1975 incident.

Beginning in 1976, Lakeway Chemicals discharged its waste water to the Muskegon County waste water treatment system. In 1977, the U.S. Food and Drug Administration (U.S. FDA) tested corn that had been irrigated with water from that treatment plant for contamination by volatile organic chemicals, aromatic amines, various halogenated compounds, and phthalates. The treatment plant was receiving waste water from other industrial sources as well as from Bofors Lakeway. The U.S FDA tests found no sign of contamination of the corn.

Studies at the Bofors site in 1976 documented groundwater contamination. A system of 12 purge wells was installed in late 1976 to collect and pump groundwater for treatment. One purge well broke down in 1994, and the remaining 11 are in continuous operation. A new on-site groundwater treatment facility was completed in September 1994. Treated water from this facility is discharged to Big Black Creek.

In 1980, the Michigan Department of Natural Resources (MDNR) Air Quality Division discovered that soil on the Bofors-Nobel property contained DCB (2). The Michigan Department of Public Health (MDPH) responded to this with a soil sampling survey and a track-out study in late 1980 and early 1981 to determine if DCB was being inadvertently carried into the community and into homes of workers. The soil survey found DCB in soil east of Bofors (3). The track-out study found DCB in the urine of ten Bofors employees participating in the study and some of their family members. Samples collected from vacuum cleaner bags and dryer lint from the homes of nine of these employees also contained DCB (4). In 1982, a survey of Big Black Creek found DCB and benzidine in the sediments (5). Soil sampling by the MDNR and Bofors in 1984 found DCB in soil both to the east and west of Bofors, as far as one-half mile from the site (6). In 1985, Bofors-Nobel excavated the contaminated sediments from the creek.

In 1985, the National Institute for Occupational Safety and Health (NIOSH) released the results of a study evaluating the occurrence of dermatitis, cancer, and possible reproductive effects among workers at Bofors exposed to oryzalin (3,5-dinitro-N⁴,N⁴-dipropylsulfanilamide), dinitrochlorobenzene (DNCB), DCB, and benzidine. NIOSH concluded "there was a potential hazard from exposure to dichlorobenzidine. Skin problems were common among workers exposed to dinitrochlorobenzene, but not statistically significantly more so than among unexposed workers. The limited number of reproductive events precluded any determination of whether there was a reproductive hazard from exposure to oryzalin." The NIOSH investigators reported ten diagnosed cases of bladder cancer among the cohort, with unconfirmed reports of two other cases, but did not offer any evaluation as to the significance of the cancer incidence (7).

In 1987, a contractor hired by MDNR completed a work plan for the Remedial Investigation/Feasibility Study (RI/FS) for the Bofors site. The site was nominated for the U.S. EPA NPL in July 1988, and listed on the NPL in March 1989. Field work for Phase I of the RI/FS was completed in late 1988, and Phase II in the Summer of 1989. The RI report was released in February 1990 (1).

In April 1990, an accidental release of hydrogen chloride gas occurred at the Lomac plant. In response, the Egelston Township Fire Department temporarily evacuated approximately 1,300 nearby community residents from their residences and places of business.

The MDPH, working under a cooperative agreement with the ATSDR, released a Preliminary Health Assessment (PHA) for the Bofors-Nobel site on August 27, 1990. The PHA concluded that the site was of potential risk to human health because of possible exposure to hazardous substances. The assessors referred the site to the Division of Health Studies, ATSDR, for appropriate follow-up health studies (8). The site has since been included in a pilot health study administered by the Michigan Department of Community Health (MDCH)⁽²⁾ and supported by the ATSDR.

The U.S. EPA signed a Record of Decision (ROD) for one Operable Unit (the Lagoon Area) at the Bofors site in September 1990. This ROD called for excavation and thermal treatment or incineration of the most highly-contaminated sludges, disposal of other contaminated sludge and soil in an on-site landfill, and upgrading of the existing groundwater pumping and treatment system (9). After further evaluation of the site, an amendment to the ROD was signed in July 1992. The revised remediation does not include the thermal treatment or incineration of contaminated soils and sludges. All contaminated soils and sludges will be excavated and transferred to an on-site landfill (10). Construction of an upgraded groundwater treatment facility was completed in September 1994 (11).

The MDPH, working under a cooperative agreement with the ATSDR, released an Interim Public Health Assessment (IPHA) for the Bofors-Nobel site on August 27, 1990. The IPHA concluded that the site posed an indeterminate public health hazard because of possible past exposure to DCB, benzidine, VOCs, and metals through worker track-out, surface water, air, soil, and sediment. Contaminated groundwater also posed a risk of future exposure. The IPHA included recommendations for further investigation of the site and its vicinity, continued operation of the groundwater purge system, and health studies (12).

Site Hydrogeology

The site lies on glacial deposits of varying composition over sandstone bedrock, part of the Marshall Formation. The subsurface soil in the site area is sandy, approximately 90 feet thick above a series of clay or sandy clay layers. The clays are approximately 150 feet thick atop the sandstone bedrock. The static water level is approximately 40 feet below the ground surface, and this upper, unconfined aquifer is approximately 40 to 50 feet thick. The sandy clay layers form an aquitard which is believed to be continuous beneath the site. Beneath the aquitard there is another aquifer in the Marshall Formation sandstone that is also approximately 150 feet thick. Shale, part of the Coldwater Formation, is reached at a depth of about 400 feet from the ground surface and forms the base of the bedrock aquifer.

The groundwater flow in the upper aquifer is southerly, toward Big Black Creek, at a very rapid rate. Estimates of groundwater velocities range from 3.8 to 10.8 feet per day for water in the upper aquifer. Figure 3 shows the potentiometric surface and inferred flow directions of the groundwater at the Bofors site. The potentiometric surface shows the water pressure in the groundwater, and flow direction can be inferred from the pressure, because water flows from areas of higher pressure to lower. Big Black Creek acts as a local groundwater discharge area, with shallow groundwater flow converging at the creek from the north and south. Groundwater flow south of the site is northward toward the creek and the purge well system, as seen in Figure 3.

B. Site Visits

In January 1989, Charles Campbell of MDPH accompanied MDNR personnel on a tour of the MDNR-administered area of the Bofors site. Most of that portion of the site is fenced, and access is controlled by MDEQ personnel. Wearing appropriate protective clothing, agency personnel viewed the lagoons, chemical spill areas, and Big Black Creek. Some surface construction debris was observed on the site. In May 1991, MDPH representatives John Hesse and James Bedford toured the site perimeter vicinity. On July 11, 1995, John Filpus of the MDPH visited the site. The MDNR site manager showed him around the MDNR-administrated area of the site and gave him a tour of the water treatment facility. Afterward, Filpus toured the vicinity of the site. The observations and information collected on these visits are included in this assessment.

C. Demographics, Land Use, and Natural Resource Use

Most of the area around the Bofors site is undeveloped forest, with some industrial and commercial facilities interspersed. Another chemical plant, Sun Chemical, which produces organic pigments, is contiguous with the Bofors site border on the west. To the north, across Evanston Avenue, are several small businesses (a foundry, tool and machine shops). Approximately 0.5 mile to the east is an old fill area used by the Muskegon County Road Commission as a borrow area and for disposal of construction debris. Across Big Black Creek to the south, the land is largely undeveloped between the creek and Ravenna Heights Road, 1.5 miles south of Evanston Avenue, with a few scattered residences along Summit Road, 1 mile south of Evanston Avenue. The nearest residences to the site are 0.5 mile to the east, along Wolf Lake Road. The nearest residential area west of the site along Evanston Avenue is approximately 1 mile from the site. There is a residential area along Carr Lake Road, approximately 0.7 miles northwest of the site, and scattered residences along Summit Road, 1 mile south of the site. Approximately 500 people live within a 1-mile radius of the site.⁽³⁾ The population living within a three-mile radius is approximately 6,500, including part of the City of Muskegon. The 1990 U.S. Census reported the population of the block group⁽⁴⁾ including the site and the two block groups closest to the site to be overwhelmingly non-Hispanic white, with 1.0% African-American, 1.4% Native American, 0.1% Asian/Pacific Islander, and 0.6% other, with 2.5% Hispanic. Thirty-three per cent of the population of these block groups was under 20 years of age, and 8.7% was age 65 and over. The population of Muskegon County as a whole is primarily non-Hispanic white, with 13% Black, 2.3% Hispanic, 0.8% Native American, 0.3% Asian or Pacific Islander, and 1% other races. Twenty-eight per cent of the County population was under 18 years of age, and 13% was 65 or older (13).

A trailer park is located less than 1 mile northwest of the site. The Muskegon Correctional Facility is 3 miles west of the site. An elementary school is located 1.5 miles to the northwest.

Other surface waters near the site include Carr Lake and its wetlands (also known as Five Lakes) located 0.25 to 0.5 mile northwest of Bofors, and Mona Lake, approximately 10 miles to the southwest, into which Big Black Creek eventually flows. Portions of Big Black Creek and Mona Lake are used for recreational activities, including boating, fishing and swimming. The MDPH has issued fish consumption advisories against eating carp from Mona Lake due to excessive levels of polychlorinated biphenyls (PCBs) (not associated with the Bofors site) (14). Mona Lake discharges to Lake Michigan, approximately 10 miles southwest of the site.

The Thermochem, Inc., NPL site, where solvent reprocessing and liquid waste disposal took place from 1969 to 1980, is located approximately 1 mile west of the Bofors-Nobel site. Groundwater and soil at this site are contaminated with volatile organic compounds including trichloroethylene, toluene and xylene. The SCA Independent Landfill NPL site is located approximately 1.3 miles southwest of the Bofors-Nobel site.

The nearest public water supply system, the Muskegon municipal water system, supplies the area west of Sheridan Road, approximately 3 miles west of the Bofors site. The Muskegon municipal water system uses water from Lake Michigan exclusively. Residents of the site vicinity outside the Muskegon municipal water supply service area rely on private wells for their water supply. Private residential wells near the site are located near the residences they serve. As described above, the nearest private residential wells are 0.5 mile to the east, 0.7 mile to the northwest, 1 mile to the south, and 1 mile to the west. All potable water supply wells in the site area tap the upper aquifer because the bedrock aquifer contains water that has high concentrations of salts and other minerals.

The Lomac plant (formerly Lakeway/Bofors-Nobel) has been supplied by as many as 10 wells on their property, providing both process water and water for workers' showers and potable use. Currently, they use 3 wells for process water and water for showers. In response to worker complaints about the quality of the water, the company has supplied its workers with bottled water for potable uses since 1979. The Sun Chemical plant west of Lomac has four process wells and several monitoring wells on their property, and there are three wells serving the machine shops across Evanston Avenue from the Lomac plant. All of these wells have recently tested free of contamination. As a precaution, because of the Bofors site contamination, these operations all provide bottled water to their employees. The companies in the area, with the support of the MDPH/MDEQ⁽⁵⁾, as of April 1996 were negotiating with the City of Muskegon and Egelston Township to have the Muskegon municipal water system extended to the area (15, 16, 17).

D. Health Outcome Data

In 1985, NIOSH released the results of a 1980-82 study which evaluated the occurrence of dermatitis, cancer, and possible reproductive effects among workers at Bofors exposed to oryzalin (3,5-dinitro-N⁴,N⁴-dipropylsulfanilamide), dinitrochlorobenzene (DNCB), DCB, and benzidine. The conclusions of the NIOSH study are included in the Health Outcome Data Evaluation section later in this assessment.

The MDCH health assessors have obtained data on the incidence of bladder cancer and cancer of all sites from the MDCH Office of the State Registrar and Center for Health Statistics. These data are discussed in the Health Outcome Data Evaluation section later in this assessment.

According to a letter received by the MDNR, a resident living approximately 1 mile south of the Bofors site was diagnosed in 1987 as having invasive bladder cancer. This individual had not been employed at Bofors or any of the other chemical plants in the area. The report was confirmed following a review of physician records. See pages 28-29 for a more in-depth evaluation of bladder cancer concerns.

During public meetings held as part of the NPL process, some residents of the area of the Bofors site have expressed concern about conditions at the site. The primary public concern has been about groundwater contamination, although evidence suggests that no one is using or likely to use water from the contaminated plume. A diagnosed case of bladder cancer in one area resident was mentioned by a member of the patient's family, which roused further concerns in the community.

A series of complaints has been made about workers' health and safety in the plant on the Bofors site. The Bureau of Environmental and Occupational Health, MDPH, issued citations to plant operators in 1985 (18), 1989 (19, 20), and 1993 (21) concerning unsafe or unhealthy workplace practices. The NIOSH study mentioned above was initiated in response to union complaints. Three former Lakeway Chemicals Inc. workers filed suit in August 1988 against E.I. DuPont de Nemours (DuPont). The suit contended that some cases of cancer are attributable to the workers' exposure to benzidine that Lakeway manufactured for DuPont. The suit reportedly has been settled out of court.

In April 1990, a spill of phosphorous oxychloride in the Lomac plant released hydrogen chloride gas. About a thousand people from the surrounding area were temporarily evacuated by the Egelston Township Fire Department. This incident has elevated the level of concern in the community about the potential for future chemical releases.

A draft of this public health assessment for this site was released for public comment on February 27, 1991; comments were accepted until March 29, 1991. ATSDR published a draft of this assessment as an Interim Public Health Assessment on March 24, 1992, including the responses to the comments (12). The MDPH released a revised draft of this Public Health Assessment for public comment on March 1, 1995. The comment period lasted until March 31, 1995, and was extended to April 15, 1995, at the request of a representative of a Potentially Responsible Party (PRP) for the site. The Responsiveness Summary at the end of this document includes updates to the responses published in the Interim Public Health Assessment and responses to comments from the later draft. As always, further information on the site and comments on the assessment will be considered during future assessments or consultations relating to the site.