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HEALTH CONSULTATION

BENDIX CORPORATION/ALLIED AUTOMOTIVE
ST. JOSEPH, BERRIEN COUNTY, MICHIGAN


DISCUSSION

In preparing this Health Consultation, the MDCH relied on the information provided in the referenced documents and assumed that adequate quality assurance and quality control measures were followed with regards to chain-of-custody, laboratory procedures, and data reporting. The validity of the analysis and conclusions drawn for this Health Consultation is determined by the reliability of the referenced information.

The Tables presented in this consultation include maximum and median concentrations in the samples collected. Health discussions are based on the maximum concentrations reported and long-term, frequent exposure scenarios, which are reasonably conservative assumptions to develop "worst case" results for initial evaluations. This is not meant to indicate that anyone actually experienced the exposure described. We compare the amounts potentially ingested each day per kilogram of body weight (the potential dose) with doses linked to adverse health effects in laboratory and epidemiological studies. We use standard body weights and water consumption rates, assuming that an adult of 70 kg drinks 2 liters of water per day or a child of 10 kg drinks 1 liter of water per day. The laboratory data cited includes studies on animals, who may or may not experience similar health effects to humans.

Anyone using the groundwater in the plume is likely to be exposed to several chemicals simultaneously. When more than one chemical is present in the body, the chemicals may interact so that the effects of the combined dose are equal to the sum of the effects of each chemical independently, the total effect is increased over the sum, or the total effect is decreased. Such interactions are not well understood, and there is little information to permit an evaluation of the probabilities and effects of such interactions in the area of the Bendix site. The toxicological discussions below do not consider the effects of interactions between the chemicals.

RW-1 is the closest active residential well to the northwest contaminant plume that has been sampled, and is the only one which has been confirmed as containing contaminants at concentrations above the U.S. EPA Maximum Contaminant Levels (MCLs)2(trichloroethylene and vinyl chloride). Since April 1984, the well was used only for lawn watering, because the house it serves was connected to the municipal (St. Joseph city) water system in April 1984 (9). In the fall of 1997, the owner stopped using the well entirely at the suggestion of MDCH staff. The owner has reportedly accepted an offer from Bosch Braking Systems to permanently abandon the well, which has been scheduled for April 1998 (11). RW-2 is the only residential well that was sampled that is still used to supply household water for all uses. Its water has not contained any contamination except for a trace of chloroform, not apparently connected to the Bendix site in the latest sampling. The house served by RW-3 was connected to the municipal water system in August 1988, and the well is not being used. Well RW-4 was used for all household purposes until April 1994, when the house it served was vacated. Part of the house had collapsed into Lake Michigan because of beach erosion, and the house has since been demolished. RW-5 is only used for lawn watering, and the house it serves was connected to the municipal water system in March 1991 (9, 10, 12).

According to the well-use survey carried out by Bosch Braking Systems in August 1997, other houses along Lake Bluff Terrace were connected to the municipal water system between 1972 and 1978. The residents of four of these houses reported to Bosch that they had inactive private wells. A residence with a Lakeshore Drive address just north of Lake Bluff Terrace was connected to the municipal water system in July 1984, and they still have an inactive, though potentially sampleable, private well (RW-6) that has not yet been sampled. MDCH and MDEQ have arranged to collect a sample of water from this well in May 1998. Two other residences along Lake Bluff Terrace and Lakeshore Drive within the area of the contaminant plume (10 ppb total VOCs in March 1985) have inactive wells and were connected to the municipal system in 1976 and 1978. These wells have not yet been sampled. A residential development is currently under construction between Lakeshore Drive and the lake and between Lake Bluff Terrace and RW-5 (10, 12).

The people using RW-1, the one residential well that has contained contamination above the MCLs, had their house connected to the municipal water system in April 1984, and a water sample collected from their well in October 1984 contained VOC contamination at high levels (Table 4). It is probable that the people using the well were drinking and washing with VOC-contaminated water before they switched to the municipal water supply.

The household formerly served by the inactive RW-6, located further inside the contaminant plume than RW-1, connected their residence to the municipal water system in July 1984 (10, 12). RW-6 has not been tested. Water collected from a monitoring well on property between RW-1 and theirs (OW-29) in March 1985 contained as much as 9,950 ppb of five VOC contaminants of concern (1,1-dichloroethane, 1,2-dichloroethane, trans-1,2-dichloroethylene, trichloroethylene, and vinyl chloride) (5).

It is not known how long some of the residents of the Lake Bluff Terrace neighborhood may have been exposed to contaminated groundwater. We do know when they started using municipal water, from the residents' own reports and St. Joseph city records, as mentioned above, between 1972 and 1984. However, there is no information available on when the VOCs first migrated into the groundwater in the neighborhood. The Bendix lagoons were in use from 1965 through 1975. The first collections of groundwater samples in the area, in 1984 and 1985, found a well-established plume of contamination already under the neighborhood, extending to Lake Michigan. Various mathematical estimates of the flow of contaminants through the groundwater indicate that the plume took approximately two decades to reach its full extent. The residential wells in question are located inside the plume, about halfway between the probable source area and the lake. Based on the history of the lagoons and the flow of contaminants through the groundwater, the MDCH estimates that, as of 1985, these wells had probably been inside the plume for at least 10 years.

Currently, no private well in the area with any history of contamination above MCLs is supplying water for household use. The one private well which has contained contaminant concentrations above the MCLs (RW-1) was only used for lawn watering at the time the contamination was discovered. RW-1 had been used for all household purposes until six months before the contamination was discovered. There is no information available on whether, at what levels, or for how long the water in the well might have been contaminated before it was taken out of service. We will discuss the potential health hazard from using this water based on the maximum concentrations found in the residential wells, primarily the sample collected from RW-1 in October 1984 (Table 4). From these concentrations, no one is likely to ingest as much of any of the chemicals each day, body weight for body weight, as has been observed to cause adverse health effects in humans or laboratory animals at any exposure duration in published studies. Vinyl chloride is a known human carcinogen (U.S. EPA Class A), and 1,2-dichloroethane and trichloroethylene are probable human carcinogens. (1,2-Dichloroethane is U.S. EPA Class B2. The U.S. EPA has withdrawn its classification of B2 for trichloroethylene to reevaluate the data.) (13, 14, 15) Lifetime use of water containing the maximum concentrations of the three carcinogens found in RW-1 might result in a low increased risk of contracting cancer.

Five private wells in the affected area have been sampled and only RW-1 contained any chemicals at concentrations above the MCLs. A survey of property owners in the area conducted by Bosch identified several other residences in the area which are currently connected to the municipal water system and also have inactive private wells on the property. The owners of these inactive wells took them out of service before the first studies of the groundwater in the neighborhood were conducted, one (RW-6) three months before (10, 12). In this section, we attempt to evaluate the potential health hazards from past use of these wells before they were taken out of service and from any future use of the wells. There is no record that any of these inactive wells, except for RW-3 and RW-4, have been sampled. Available records do not indicate that the inactive wells were fully abandoned, that is, sealed so they could not be used again. In the absence of data from the wells in the period they were used, we will evaluate the potential human health hazard from the use of these wells assuming the maximum concentrations found in monitoring wells in the northwest plume area during the documented studies of the area (Table 1). This does not necessarily mean that there is any evidence that anyone in the area has ever been exposed to that degree of contamination, but is a "worst case" assumption for an initial evaluation.

No one is or was likely to ingest enough 1,1-dichloroethane each day, body weight for body weight, from the groundwater in the northwest plume area to exceed the amounts that were observed to cause adverse health effects in humans or laboratory animals at any exposure duration. Some laboratory animals who ingested liquids containing large amounts of 1,1-dichloroethane developed more cancers of the breast, uterus, or blood vessels than did others who ingested liquid that did not contain the chemical. The U.S. EPA has classified the chemical as a possible human carcinogen (U.S. EPA Class C). There is not sufficient information available about the chemical to evaluate the potential risk of contracting cancer upon exposure to it (16).

No one is or was likely to ingest enough 1,2-dichloroethane each day, body weight for body weight, from the groundwater in the northwest plume area to exceed the amounts that were observed to cause adverse health effects in humans or laboratory animals at any exposure duration. Lifetime consumption of the groundwater might result in an moderately increased risk of contracting cancer (13).

No one is or was likely to ingest enough 1,1-dichloroethylene each day, body weight for body weight, from the groundwater in the northwest plume area to exceed the amounts that were observed to cause adverse health effects in humans or laboratory animals. The U.S. EPA has classified 1,1-dichloroethylene as a possible human carcinogen (U.S. EPA Class C). Lifetime consumption of the groundwater might result in a moderately increased risk of contracting cancer (17).

No one is or was likely to ingest enough 1,2-dichloroethylene each day, body weight for body weight, from the groundwater in the northwest plume area to exceed the amounts that were observed to cause adverse health effects in humans or laboratory animals at any exposure duration. Exposure to 1,2-dichloroethylene has not been linked to cancer in humans or animals (18).

Anyone whose drinking water contains the maximum concentration of trichloroethylene found in monitoring wells in the northwest plume area (Table 1) might ingest more of the chemical each day, body weight for body weight, than did rats whose offspring had heart abnormalities after long-term exposure in a laboratory study. No one would be likely to ingest enough trichloroethylene from the groundwater to exceed the amounts fed to laboratory animals who developed cancer. Some laboratory animals who inhaled or ingested trichloroethylene developed elevated rates of cancers of the livers or kidneys. The U.S. EPA had classified trichloroethylene as a probable human carcinogen (U.S. EPA Class B2), though the Agency is reconsidering the classification. Lifetime consumption of the groundwater might result in a moderately increased risk of contracting cancer (14).

Anyone whose drinking water contains the maximum concentration of vinyl chloride found in monitoring wells in the northwest plume area (Table 1) might ingest more of the chemical each day, body weight for body weight, than did rats who developed liver problems after long-term exposure in a laboratory study. A child using similar water might ingest more of the chemical than did rats who developed an increased incidence of liver cancer after long-term exposure in a laboratory study. No studies could be located that document and quantify health effects in humans after ingestion exposure to vinyl chloride. Lifetime consumption of the groundwater might result in a very high increased cancer risk (15).

The plume discharges into Lake Michigan. The maximum vinyl chloride concentration found in the groundwater, from nearly every monitoring well sampling event listed in Table 1, exceeded the MDEQ Interim Groundwater Contact Criteria3 (19). This has raised the question of whether it is safe to use in the lake or the beach near where the groundwater discharges for swimming or other recreation. Water samples collected from the lake in the area have not contained any contamination at the limits of detection for the analytical techniques (20). Children might dig into the sand on the beach and reach the groundwater at about 2 feet below the surface. However, the contaminant plume is located at the bottom of the aquifer, with a layer of cleaner water, as much as 10 to 25 feet thick, depending on conditions, above it (1). It is not likely that any child would dig a hole 12 to 25 feet deep, most of the distance below the water table, and so reach the heavily contaminated water.

Any VOCs evaporating from the groundwater into the air spaces in the sand above would have to come from the upper layers the of groundwater, where the contaminants have not been detected. There would probably not be any VOCs in the soil above the plume. Even if the VOC concentration at the top of the aquifer was that in the plume the VOC vapors are likely to disperse as soon as they reach the air at the beach, and not reach concentrations of human health concern.

None of the residential well samples has contained vinyl chloride or any other chemical above the Contact Criteria. The vinyl chloride concentration in the air of a shower using water from RW-1 (Table 4), calculated from the model presented by Little (21), would not reach the levels at which adverse health effects were observed, though a lifetime breathing air containing that concentration of the chemical might result in a moderate increased risk of contracting cancer. The concentration of vinyl chloride in the air in a shower using groundwater from the area, based on the maximum concentration found, from OW-29 in March 1985 (Table 1), and using the model presented by Little (21), might exceed the levels that caused changes to the liver and heart and cancer in laboratory animals who breathed air containing the chemical for long periods (over 1 year) (15).

We have considered the possibility of VOCs in the groundwater volatilizing in the soil, migrating upward into a basement in the residential area, and there collecting to levels of potential human health impact. The concentrations of 1,2-dichloroethane, trans-1,2-dichloroethylene, trichloroethylene, and vinyl chloride found in groundwater under the residential area along Lake Bluff Terrace (Table 1) exceed MDEQ screening criteria for exposure in residences from groundwater volatilization to indoor air (19). However, the groundwater in the area is thirty feet or more below the surface (5), therefore there is little likelihood that the groundwater would enter a basement of typical depth, and the volatilized VOCs are likely to disperse and diffuse to much lower concentrations before they near the surface. In addition, the contaminant plume is located on the bottom of the aquifer, with a layer of cleaner water, as much as 15 to 20 feet thick, depending on conditions, above it, which further inhibits transfer to the surface (1). The MDEQ is planning to investigate the migration of contaminants through subsurface air in the area of the northeast plume from the Bendix site, where the concentrations in the groundwater are higher and the contaminated aquifer not so deep.


2  Under the federal Safe Drinking Water Act, the U.S. EPA has issued regulations for the amounts of many chemicals that are allowable in public drinking water supplies. The concentrations that are permissible, the Maximum Contaminant Levels (MCLs), are levels that are generally considered to pose no human health hazard after a lifetime of drinking the water, with modificatins for the technical capability of detecting the chemical or for the economics of removing the chemical from water where it occurs naturally.

3  The MDEQ Groundwater Contact Criteria were developed to protect utility workers from adverse systemic health effects after dermal contact with contaminated water. See Reference 19 for complete details.


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