PUBLIC HEALTH ASSESSMENT
NORTH BRONSON INDUSTRIAL AREA
BRONSON, BRANCH COUNTY, MICHIGAN
The North Bronson Industrial Area site was placed on the Environmental Protection Agency's National Priorities List (NPL) on June 6, 1986. The site proper consists of two sets of lagoons formerly used, between 1939 and 1981, for industrial wastewater disposal and a surface drain (County Drain #30) flowing past the lagoon areas on the north side of Bronson, Michigan. The groundwater, soil, surface water, sediment, and sludges at the lagoons and the drain are contaminated with metals and organic chemicals. Investigations of this contamination revealed that the soil and groundwater throughout approximately 230 acres of the north end of Bronson (the site study area) were contaminated with metals and organic chemicals. Water from several residential wells in the site study area have become contaminated. A former industrial facility in the site study area is dilapidated, filled with debris from collapsing and collapsed structures, and currently poses hazards to any trespassers. The facility is located in the center of a residential block, with residential yards adjacent to the facility grounds. Access to this facility from adjacent residences is unrestricted, and neighbors report their children are frequently on the facility property.
The site poses a public health hazard from the physical hazards and contaminated soil near the former industrial facility previously mentioned. Residents of the site study area used the contaminated groundwater in the recent past for household drinking water. The wells that are known to have been contaminated have been replaced with connections to the municipal water system; however, additional private wells that have not been sampled might be in the area of contaminated groundwater. Volatile organic chemicals in soil and groundwater may also evaporate into the air, potentially collecting in closed structures such as basements.
health assessment includes recommendations for a survey of private well
use in the site area, access restriction with eventual clean-up of the abandoned
facility described previously, and air sampling of residential basements in
the site area. The Agency for Toxic Substances and Disease Registry, the Michigan
Department of Community Health, and the local health department will coordinate
to develop an appropriate program of community and physician health education
regarding the site.
The North Bronson Industrial Area site was listed on the Environmental Protection Agency's (EPA) National Priorities List (NPL) on June 6, 1986.
The North Bronson Industrial Area (NBIA) site study area covers approximately 230 acres in the northern part of Bronson, Michigan (see Figure 1). The site study area boundaries are County Drain #30 on the north; Lincoln Street extended to the drain on the east; Fillmore, Matteson, and Union Streets on the south; and Albers Street extended to County Drain #30 on the west (see Figure 2). Two smaller toxic waste sites in the area, the Bronson Plating and the Bronson Wastewater Treatment Plant (WWTP) sites, and the Residential Well Blaskie incident, have been consolidated into the NBIA site study area. The east and west ("new" and "old," respectively) lagoon areas and County Drain #30 (see Figure 2) have been identified as the NPL site by EPA and are being addressed under the Superfund program. The remainder of the site study area will be addressed by the Michigan Department of Environmental Quality (MDEQ)1 under the equivalent State of Michigan program.
In 1939, the City of Bronson constructed the first of five seepage lagoons south of County Drain #30 (the "old" or west lagoons, see Figure 2) to serve an industrial sewer system. In 1949, the city constructed an additional set of five lagoons (the "new" or east lagoons, see Figure 2). In 1969, Bronson Plating bought the property including the east lagoons from the City and continued to use them for disposal of their own process wastewater. Industrial wastes disposed of in the lagoons included untreated plating wastes containing cyanide, nickel, copper, zinc, and cadmium. All disposal to both sets of lagoons ceased in 1981. The eastern lagoons have since been filled in and part of the Bronson Plating Company building was constructed over three of the former lagoons.
In 1974, samples of water from a private well south of the western lagoon area (RW-1 in Figure 2) contained approximately 5,000 parts per billion (ppb) each of acetone and methyl ethyl ketone (MEK).2 Water from dewatering wells for construction at the Bronson municipal WWTP, southeast of the lagoons and northeast of RW-1 (Figure 2), also contained acetone and MEK, at concentrations of about 1,000 ppb. Investigators named an industrial facility south of RW-1 as a potential source for this contamination, but this was not verified by further investigation. In 1974, the well was abandoned and the residence was connected to the Bronson municipal water system (1).
Water samples collected in 1979 from monitoring wells around the western lagoons contained trichloroethylene (TCE) and heavy metals. Sediment samples collected in 1979 from County Drain #30 contained elevated concentrations of polychlorinated biphenyls (PCBs) downstream from the western lagoons. Groundwater samples collected in 1981 from monitoring wells around the eastern lagoons and Bronson Plating contained TCE, chloroform, and heavy metals (1). In 1983 and 1984, Bronson Plating dredged sediment from County Drain #30 east of Matteson Street to the company's easternmost outfall in an attempt to remove contaminated sediment. The dredging spoils were reportedly disposed of elsewhere. Also in 1983 and 1984, Branch County dredged the drain west of Matteson Street to the outfall from the wastewater treatment plant to improve water flow in the drain. These spoils were reportedly left stockpiled on the north bank of the drain (2).
A contractor for the Michigan Department of Natural Resources (MDNR) carried out a Remedial Investigation of the site between September 1988 and December 1991 (1). The feasibility study was completed in May 1995 (2). MDEQ and EPA are preparing an amendment to the feasibility study to reflect subsequent changes in MDEQ clean-up standards and practices.
On April 24, 1989, the Michigan Department of Public Health (MDPH),3 working under a cooperative agreement with the Agency for Toxic Substances and Disease Registry (ATSDR), issued a Preliminary Health Assessment (PrHA) for the North Bronson Industrial Area. Preparers of the PrHA concluded that the site was of potential public health concern because of the possibility of human exposure to surface soil, sludge, and surface water contaminated with metals, volatile organic chemicals (VOCs), and PCBs. Further evaluation of the site and monitoring of residential wells in the site area were recommended; follow-up health studies were not recommended (3).
In July 1995, the EPA, under the Emergency Response Program, removed between 50 and 60 barrels (all empty) from the abandoned Scott Fetzer building in the site study area. The agency also covered several vats in the building and boarded up broken windows.
In May 1996, MDEQ removed a collapsing building from the abandoned Scott Fetzer "Cyanide Destruction" facility and installed a fence around the property.
The site is located in an area of glacial outwash. The general geological strata beneath the site area consist of a surficial layer of silt, clay, and sands (0 to 17 feet thick); 7 to 63 feet of sand and gravel (upper aquifer); 17 to 50 feet of silt and clay (an aquitard or barrier to water flow); 50 feet of sand and gravel (lower aquifer); and bedrock of the Coldwater Shale Formation. The water table is 6 to 9 feet below the ground surface. The regional groundwater flow in the upper aquifer is towards the west, but near County Drain #30 the groundwater is strongly influenced by the drain, to the northwest south of the drain and to the southwest north of the drain. The groundwater appears to discharge to the drain. No information is available on the groundwater flow in the lower aquifer. Information is not sufficient to determine whether the silt and clay layer between the aquifers serves as a confining layer separating the aquifers.
County Drain #30 flows from east to west through the site, along the northern side of the site study area. The drain turns northwest at the western end of the site, and empties into Swan Creek approximately 1.5 miles northwest of the site. Swan Creek, 10 miles northwest of the site, joins the St. Joseph River which flows into Lake Michigan.
On June 15, 1995, Brendan Boyle, Michelle Borgialli, and John Filpus of the MDPH visited the NBIA site. Observing County Drain #30 from Matteson Road, they saw that the water was clear and that aquatic vegetation was growing in it. They briefly visited the east lagoons area, but could see no obvious signs of the lagoons. They could not gain access to the west lagoons.
They drove through the industrial-residential area in the south part of the study area. Some of the industrial facilities were operating, others were vacant, and several vacant lots with the foundations of buildings were still visible. They stopped in front of the former Scott Fetzer "Cyanide Destruction" facility. The facility grounds were fenced along the front, though not along the sides and rear. The sides and rear of the facility grounds abut to neighboring residential yards, and there was nothing to prevent access between these yards and the facility grounds. The grounds were filled with debris from collapsed and collapsing buildings.
In the 1990 U.S. Census, the city of Bronson had a population of 2,332. The entire city is within a 1-mile radius of the NBIA site. Bronson Township, surrounding the city, had a population of 1,199. Branch County as a whole was predominately white, with 1.7% African-American, 0.5% Native American, 0.4% Asian/Pacific Islanders, and 0.3% other race. Another 1.1% of the county population claimed Hispanic descent. Twenty-eight percent of the County population was under 18, 13% over 65 (4).
The area north of the site is primarily agricultural, with scattered residences along the roads. The site study area is mostly industrial, though the southern part includes residential areas, and the area south of the site is residential. A ball field is in the southeast corner of the site study area, and another is just outside the southwest corner of the study area.
The primary source of drinking water in the Bronson area is groundwater. The Bronson municipal water system serves the entire city from two wells located east of the site. The city had a third well (PW-3) within the site study area, but this well was recently closed and abandoned. PW-3, which was screened in the lower aquifer, had never been reported as being contaminated. However, PW-3 needed major maintenance, and NBIA-related and other sources posed several potential threats to the quality of the water at PW-3 (5). The two other municipal wells have sufficient capacity for the city's needs.
Some residences in Bronson and outside the city limits north and west of the site have private wells for their household consumption. Farms north and west of the site also take irrigation water from wells. Some of these private wells are screened in each of the two aquifers.
Residents of the site study area who used contaminated wells have been exposed
at levels that could produce adverse health effects. A resident of Bronson has
expressed concern about a perceived high rate of cancer within the city. The
MDCH Environmental Epidemiology Division has requested cancer incidence data
for the city of Bronson from the MDCH Office of the State Registrar and Division
of Health Statistics. These data and information on reported health effects
among the residents of the site study area will be discussed in the Health
Outcome Data Evaluation section.
At a June 15, 1995, public meeting called by the Michigan Department of Natural Resources to discuss the results of the remedial investigation and feasibility study for the North Bronson Industrial Area site, residents raised many concerns about the site. The major health-related concerns cited included the physical hazards at the former Scott Fetzer "Cyanide Destruction" facility, the quality of the water provided by the municipal water system, and whether the groundwater contamination would affect vegetables grown in gardens in the site study area.
During an interview in a well-use survey in July 1995, one of the residents whose well had been contaminated asked what type of health effects could result from the contamination. Other residents surveyed asked whether their water was safe to drink. A resident who lives next to County Drain #30 expressed concern about water from the drain.
A resident of Bronson, living west of the site study area, has expressed to the Michigan Department of Community Health (MDCH) concerns about a perceived high incidence of cancer in the city.
The MDCH released a draft of this public health assessment for public comment on November 6, 1996. The comment period lasted until December 6, 1996. Comments received and MDCH responses are listed in the Responsiveness Summary at the end of the document.