PUBLIC HEALTH ASSESSMENT
BAY CITY MIDDLEGROUNDS
BAY CITY, BAY COUNTY, MICHIGAN
The Bay City Middlegrounds Landfill (BCM) site was proposed for the United States Environmental Protection Agency (U.S. EPA) National Priorities List (NPL) on February 16, 1995. The site is a closed combined municipal and industrial landfill located on Middleground Island in the Saginaw River in southwest Bay City, Michigan. The site is on the west bank of the island, adjacent to the west channel of the Saginaw River.
The landfill began operations in the 1950s in borrow pits that provided material for building a road on the island. The operators dug additional trenches for waste disposal. In 1974, the original pits and trenches were closed and some were covered with a 5-foot-thick clay soil layer. In the late 1970s, an above-ground, bermed disposal cell was constructed atop the cap over the original landfill. The U.S. Army Corps of Engineers used part of the site to dewater sediments dredged from the river, and the dewatered sediments were used as cover for the landfill. This cell was closed in 1984, and, in 1987, a 2-foot-thick clay cover was constructed over the landfill.
The clay cover over the second, above-ground phase of the landfill was not sealed to the clay cover on the original landfill, and there have been reports of leachate seeping from the landfill into surrounding ditches. Organic chemicals, including polychlorinated biphenyls (PCBs) have been found in the soil and groundwater, especially on the west side of the landfill, where a layer of organic chemicals has been found at the bottom of the groundwater. Surface soil on the landfill contains elevated concentrations of metals, pesticides, polynuclear aromatic hydrocarbons (PAHs), and other semi-volatile organic chemicals. There have also been reports that wastes from the older phase of the landfill have been seen on the surface where the landfill was not capped. Sediments in the Saginaw River near the site contain the same chemicals. Some fish living in the Saginaw River contain high concentrations of PCBs, from the BCM site and many other sources in the river's watershed. The Michigan Department of Community Health (MDCH) maintains an advisory that no one eat any carp or catfish or large quantities of fish of any other kind from the Saginaw River because of this contamination and contamination with dioxin, not attributed to the BCM site.
There is no evidence that groundwater on the island is used for human consumption. All residences on the island are connected to the Bay County public water supply, whose source is in Saginaw Bay approximately 15 miles north of the site. The municipal system is regularly tested for chemical contaminants, and there is no record of any contamination found in this monitoring. One resident reported using well water only to water domestic animals. Groundwater at the site flows primarily into the Saginaw River. There is a fence around three sides of the landfill, though not along the river side. There are plans to install a fence along the river side of the site in the summer of 1996.
The BCM site poses a public health hazard under current conditions. The surface soil on the site contains organic chemicals and metals at concentrations potentially of human health concern, access to the site is not completely restricted, and some trespass has occurred. PCB-contaminated groundwater from the site discharges to the Saginaw River. The concentrations of PCBs in the water and sediments of the river do not pose a significant health threat from direct human exposure. However, the PCB discharge contributes to PCB contamination in the fish of the river through bioaccumulation of the chemicals in the food chain. Exposure to the soil on the site is not likely to be sufficient to cause adverse health effects, however, consumption of fish from the river might expose the consumer to sufficient PCBs to risk adverse health effects. The assessment recommends that access to the site be further restricted to deter future exposure, that environmental transport of contaminated material from the site during remedial activities be minimized, that the groundwater be further investigated to determine whether potential exposure pathways are complete, that leachate from the landfill on the site be controlled, that access to the ditches on the site be restricted, and that remediation to prevent discharge of contaminated groundwater to the river be implemented promptly. The MDCH will renew efforts to increase public awareness of and compliance with the existing fish consumption advisories on the Saginaw River. Health education activities included in the Public Health Assessment process should include advice about the potential health hazards to children playing on the site or in the perimeter ditches at the site.
The Bay City Middlegrounds Landfill site was proposed for the United States Environmental Protection Agency (U.S. EPA) National Priorities List (NPL) on February 16, 1995.
The Bay City Middlegrounds (BCM) site is an abandoned landfill located on Middleground Island in the Saginaw River in southwestern Bay City, Michigan. The site covers approximately 40 acres on the west side of the island, between the west channel of the river and Evergreen Road, north of Hotchkiss Street (Cass Avenue) (see Figure 1). Features of the site are shown in Figure 2.
In the early 1950s, the City excavated soil and gravel from the site to provide fill for the construction of Evergreen Road. Beginning in 1956, the excavations on the site were used for disposal of wastes. When the existing pits were filled, new trenches, 15-20 feet deep and extending below the water table, were dug for further waste disposal. Though there are few records of the specific wastes disposed of at the site during this period, available records and interviews with landfill workers indicate that the wastes disposed of included wood, paper, demolition material, garbage, and industrial wastes.
In the early 1970s, the trench and fill method of disposal was abandoned at the site, and by 1974, a 5-foot-thick cap of clay and soil was placed over the southern part of the trench and fill areas (1). Approximately one-third of the landfill was not capped (2). The City then constructed berms on top of the cap and deposited more wastes between the berms. At the same time, the City agreed to allow the U.S. Army Corps of Engineers (CoE) to deposit sediments from dredging the Saginaw River on the north end of the site. A dewatering basin was constructed at the north end of the site using berms and the dewatered sediments "were then used for other purposes which included being used for daily cover at the landfill."(1) The landfill ceased operation under orders from the State of Michigan in August 1984. In 1987, a 2-foot-thick clay cap was constructed over the bermed landfill and a leachate collection system installed around the bermed landfill (1). In late 1993 or early 1994, the site was fenced (4), on the north, east, and south sides only. The west side of the site, along the river bank, is not fenced and the fence at the north and south ends does not extend into the river. A group of Potentially Responsible Parties (PRPs) for the site is planning to install a fence along the river side of the site in the Summer of 1996 (5).
The entire Middleground Island was originally wetlands, whose surface was barely above the river level before the island was developed. The initial fill materials included wood chips from nearby sawmills. There had been another landfill on the north end of the island for years before the BCM-site landfill was used. Borings drilled in 1929 for the footings of the bridge across the north end of the island found compacted trash. The Bay City Boys and Girls Club and Bay City Rowing Club buildings on the north end of the island were built atop the old landfill (6).
The cap over the bermed landfill was not fully sealed to the lower cap, and leachate has seeped out of the mound and flowed into the ditches along Evergreen Road and Hotchkiss Street (6).
Contractors for Bay City conducted two phases of a Remedial Investigation (RI) of the site in 1989 through 1991. Bay City's contractors found high concentrations of PCBs in soil and groundwater, primarily in a relatively small area on the west side of the landfill. The highest concentration of these chemicals were found in a layer of organic solvents at the bottom of the shallow groundwater in that area.
Bay City's contractors identified five layers of subsurface materials (from the top down): 1-5 feet of soil cover, 25-30 feet of sandy soil mixed with landfilled materials, 10-20 feet of sandy silty clay, approximately 20 feet of sand with some interbedded clay on the west, and at least 5 feet of clay. The second and fourth layers contain aquifers, apparently hydraulically separated from each other by the clay between them though both aquifers are hydraulically connected to the Saginaw River. The sandy silty clay layer has not been proven to be continuous across the site, and may not effectively separate the aquifers (4). Contamination has only been found in the shallower aquifer (1, 7). Bay City's contractors conducted a third phase of the RI in September and October 1992 (8).
The Michigan Department of Natural Resources (MDNR) conducted an Expanded Site Inspection (ESI) of the site in April 1992 (3). Surface soil samples ranged in depth from 3 to 6 inches. A pilot study of a low-temperature thermal desorption technology for treatment of PCB-contaminated soils was carried out from September to December 1992 using wastes from the site (3, 9).
In May 1994, the Michigan Department of Public Health (MDPH)(2) prepared a Health Consultation for the Bay City Middlegrounds site. The consultation concluded that the BCM site posed a health hazard under current conditions, however, people were not likely to be sufficiently exposed to contaminants of concern at the site to incur adverse health effects. Surface materials on the site contain concentrations of contaminants at levels potentially of health concern on frequent or long-term exposure, but trespassers are not likely to be on the site frequently or for long periods of time. The consultation recommended improving the restriction of access to the site and further investigation to determine if contaminants were migrating off the site (10).
On February 10, 1994, John Filpus of MDPH, MDNR personnel, and U.S. EPA personnel visited the site. The site was heavily snow-covered, which prevented observation of the ground surface. They did see the proximity of the homes on the south end of the site and the relative location of the area of high PCB concentration in the groundwater. They also noted snowmobile tracks across the site.
On June 10, 1994, Brendan Boyle of MDPH visited the site area. He observed the site from outside the fence and the neighboring properties. He also talked with a resident of the island.
The nearest residences to the site are two houses and an unoccupied trailer located less than 200 feet from the site fence, across Hotchkiss Street to the south. There are 34 houses on the south end of the island, including the two along Hotchkiss Street. Across Evergreen Road east of the landfill are commercial properties, including a marina, boat storage, and a now-closed restaurant. On September 8, 1995, the MDNR and the U.S. Army Corps of Engineers issued a wetlands permit application for a marina renovation and boardwalk installation project on Middleground Island across Evergreen Road from the landfill (4). The north end of the island includes several ball fields, the Bay City Boys and Girls Club, and a rowing club. On the mainland, the east shore of the Saginaw River near the island is well-developed, with a marina and other commercial enterprises along the shore and residences further inland. The west shore of the river near the island is undeveloped, except for the Prestolite factory (now owned by Allied Signal) across from the north end of the landfill.
As of the 1990 U.S. Census, 7,635 people lived within 1 mile of the BCM site. A partial ethnic and age breakdown of the population within 1 mile of the BCM site is given in Table 1. Approximately half of Bay City (1990 total city population 38,730) is within 3 miles of the BCM site. As of the 1990 U.S. Census, the population of Bay County was primarily non-Hispanic white, with 1.1% African-American, 0.7% Native American, 0.7% Asian or Pacific Islander, 1.4% other race. Three per cent of the county population was Hispanic (11).
During Phase I of the RI in 1989, Bay City's contractors carried out a door-to-door survey on Middleground Island, to locate any private wells on the island. All residents interviewed reported that their homes were served by Bay County public water system. The Bay County public water system uses water from Saginaw Bay on Lake Huron, approximately 15 miles north of the site. The residents reported that there had never been wells for human consumption use on the island. Attempts to drill wells had never succeeded in finding potable water. Until the municipal water system was extended to the island in the 1960s (12), bottled water was brought onto the island for drinking and cooking. River water was used for laundry, washing, lawn watering, and other purposes. The occupants of one residence, north of the landfill, whose private well had been tested by the MDPH the year before, said the well was only used for summer watering of domestic animals. The owner of the restaurant east of the landfill said there was a well on his property, but it was not currently used (1). As of this writing, the restaurant is closed. The residence north of the landfill has since been vacated and demolished (4).
The Saginaw River flows to the north around Middleground Island. The west channel of the river is adjacent to the BCM site, the east channel is approximately 1,000 feet east of the site. The river empties into Saginaw Bay, part of Lake Huron, approximately 7 miles northeast of the site. The river is used for recreation, including fishing and boating.
According to Michigan Department of Environmental Quality (MDEQ)(3) staff, small-game and bird hunters hunt on the island during the appropriate seasons. Hunters have been seen near the piles of dredged sediment from the Saginaw River within the fenced area of the site fence (2).
Trespassers on the site have been exposed to chemical contaminants, but the exposure is not likely to have been extensive enough to result in adverse health effects. A resident of Bay City has expressed concern about the incidence of cancer in his community. The MDCH Division of Health Risk Assessment has obtained cancer incidence data for the area from the MDCH Office of the State Registrar and Division of Health Statistics.
The MDNR/MDEQ has organized a Community Information Committee (CIC) for environmental contamination concerns in the Saginaw River area. At regularly-scheduled meetings of the CIC, people living on the island south of the site have asked whether it was safe to allow their children to play in the ditch around the landfill (13).
On September 8, 1994, John Filpus of the MDPH attended a meeting of the CIC. The meeting included presentations by the U.S. EPA about the status of the BCM site in the Agency's Superfund Accelerated Cleanup Model (SACM) program and by a U.S. EPA contractor about a demonstration project on the site. One citizen expressed concern that the chemicals from the site might get into the city water supply. The city's water intake is in Saginaw Bay approximately 15 miles north of the BCM site, and at least potentially downstream of the site, depending on the currents within the bay.
The MDPH released a draft of this Public Health Assessment for public comment on January 31, 1996. The initial public comment period lasted until March 1, 1996, and a second public comment period was provided from March 14, 1996, to April 15, 1996. MDPH/MDCH received comments on the draft assessment from a representative of the City of Bay City and from a contractor for a group of the PRPs for the site. MDCH responses to these comments are given in the Responsiveness Summary at the end of this document.
During the public comment periods, MDCH also solicited health-related concerns and questions about the site from the public. Their concerns and questions included the following:
- Soil and water contamination on surrounding property.
- Are there any health hazards from living in the area of the landfill? I am concerned about radioactive contaminants, airborne contaminants, and any substance that may be surfacing that are harmful to health. Will traveling to and from my home on the Middlegrounds and passing the dump site daily put me and my family at an increased health risk? If so, what risks? (A consolidation of comments from several residents of the south end of Middleground Island.)
- Does swimming and boating in the waters of the Saginaw River near the Middlegrounds increase my (our) risk of health problems? If so, how?
- Should we be buying bottled water? Could our drinking water be contaminated?
- I wish that you would let people know that there are no proven PCB-related health risks instead of scaring everyone unnecessarily.
- (From a resident of Middleground Island): It is rumored that there is a high incidence of cancer in families that have lived on Evergreen [Road, on Middleground Island] for a long time. (From a Bay City resident, not living on Middleground Island): We here in Bay City have a very high cancer rate. Four of my peers (age 50s) are presently struggling with cancer. Two others are already deceased. Some doctors are now saying it's the environment.
- Is there any documented health problems that have been reported that could be directly linked to the Middlegrounds? Historic health impact and effects on Bay City residents during the 1950s through current.
- How will notification be made to the public regarding not eating the Great Lakes fish? I don't think it is well known.
These concerns are addressed in the "Community Health Concerns Evaluation" section later in this assessment.