PUBLIC HEALTH ASSESSMENT
MALVERN TCE SITE
MALVERN, CHESTER COUNTY, PENNSYLVANIA
The Chemclene (Malvern TCE) site is a National Priorities List (NPL) site in Chester County, Pennsylvania, 5.5 miles south of Phoenixville. Chemclene is a solvent recycling company that has been in operation since about 1950. Over the years, careless waste handling and waste burial have contaminated soil and groundwater with trichloroethene (TCE), 1,1,1-trichloroethane (TCA), and tetrachloroethene (PCE). Contaminants have moved in groundwater to residential wells some 2,000 feet southwest of a Former Disposal Area (FDA). Aquifer dewatering by quarries 6,000 feet northeast of the site, and continuous groundwater pumping by a public supply well 3,000 feet southeast of the site have greatly complicated contaminant migration and the groundwater flow regime. Local private wells are also going dry as a result of recent drought combined with increased groundwater withdrawal.
Based upon the information reviewed, the Pennsylvania Department of Health and the Agency for Toxic Substances and Disease Registry have concluded that this site is a public health hazard because past exposures through the use of contaminated well water were at levels of public health concern. Human exposure to volatile organic compounds (VOCs) may still be occurring through the use of private well water, and the potential for exposure from the nearby public well exists should the contaminant plume reach that well.
The information and data developed in the public health assessment for the Malvern TCE site, Malvern Pennsylvania, have been evaluated by ATSDR's Health Activities Recommendation Panel (HARP) for appropriate follow-up with respect to health activities. HARP determined that community health education should be conducted after the results of the private well sampling are available. The Pennsylvania Department of Health (PADOH) will take the lead for the community health education. In addition, HARP determined that those persons exposed to TCE, through consumption of contaminated drinking water, should be considered for ATSDR's TCE subregistry.
PADOH will conduct community health education upon completion of private well sampling
and the results become available. ATSDR will consider including persons exposed to TCE,
through contaminated drinking water, in that agency's TCE subregistry.
The Chemclene (Malvern TCE) facility is on a tract of approximately 5 acres in northeastern Chester County, Pennsylvania, about 5.5 miles south of Phoenixville (see locations in Figures 1 and 2). The site and facility are underlain by limestone and dolomite bedrock in a valley bounded by two northeast trending, erosionally resistant ridges of quartz-rich metamorphic rocks. Two northeast trending faults, each over two mile in length, approximate the northwest and southeast boundaries of the site and adjacent areas of interest (Figure 2).
Chemclene has been operating at this location since about 1950 (5). The company formerly recycled solvents, and still recycles non-hazardous chemicals (e.g., used synthetic hydraulic fluids) and sells trichloroethene (TCE), 1,1,1-trichloroethane (TCA), tetrachloroethene (PCE), and methylene chloride (MEC). No records relating to operational history are known to exist prior to 1980, at which time written manifests became a requirement of applicable laws. The historical information for this public health assessment was obtained from the personal knowledge of the current owner (5).
The recycling process at Chemclene was based upon distillation that resulted in the formation of waste condensates and sludges, both of which contained spent solvents. The distillation building is composed of the one story block building and storage area #2 (Figure 3). A laboratory and office were added at a later date (exact date unknown). Storage area #1 (see location in Figure 3) now contains the materials used in, and resulting from, the distillation process, including waste solvents (TCE, PCE, TCA, MEC), "virgin" solvents (TCE, etc.), acetone, mineral spirits, and alcohol (5). Virgin hydrogen peroxide is stored on the concrete pad area outside the block building.
There are currently five tanks in the above ground storage tank area, two of which have been decommissioned, according to the site owner. The remaining tanks contain concentrated hydrogen peroxide (oral communication with a Pennsylvania Department of Environmental Resources (PADER) official).
At the former underground storage tank area, there were four tanks; one (tank #1) contained gasoline and three contained methylene chloride (see locations in Figure 3). It is believed that the methylene chloride tanks were excavated and removed by Chemclene by 1986, but no written records regarding this removal are known to exist (5). Tank #1 was excavated and removed in May 1988.
A Former Disposal Area (FDA) has been identified about 1,900 feet west of the plant (see location in Figures 1 and 4). Just south of the FDA is a section of the Transcontinental gas pipeline right-of-way. The FDA once contained two pits, each measuring 50 feet by 30 feet by 15 feet deep. From 1952 to 1976, the pits were used to dispose of drums containing distillation residue. Between 1981 and 1984, Chemclene removed all of the drums and some soil (down to about 15 feet) and sent this material to a permitted landfill in Ohio. An unknown number of drums from an area outside the FDA remain on site. The partial remediation was performed under the supervision of PADER. The pits remain open and one is currently partially filled with water. No other records of site excavation were maintained. The FDA is surrounded by an 8-foot high chain-link fence with a locked gate.
Material handling practices in the past involved the disposal of condensate water on the ground near the plant (5). In addition, the underground gasoline storage tank may have leaked part of its contents to the subsurface (see on-site contamination section). Some excavated tanks are now stored above ground on the southern part of the site along the natural gas pipeline right-of-way.
On April 8, 1992, J.E. Godfrey of the Pennsylvania Department of Health (PADOH) visited the site with the owner, his consultant, and officials of the Environmental Protection Agency (EPA). This group made a general survey of the site and adjacent properties, and discussed groundwater contamination on and off the site. The area where almost all surface soil contamination has been identified lies within the 8-foot high fence, which restricts public access to the FDA. Chemclene still operates as a solvent recycler.
On July 2, 1992, J.E. Godfrey and Robert M. Stroman (PADOH) visited the community and spoke with residents on Hillbrook circle, a residential subdivision south of the FDA (Figures 1 and 7). Most discussions centered around public health concerns and the regional aquifer dewatering that is causing private wells to go dry.
The Malvern TCE site is in East Whiteland Township in Chester County. East Whiteland Township had a 1990 Census population of 8,398 persons compared to 8,468 in 1980 (8). Only 10.4 percent of the population in East Whiteland Township was 65 or older in 1990 compared to 10.9 percent in Chester County and 15.4 percent in Pennsylvania. The population of East Whiteland Township was 93.7 percent White in 1990 (9). The Great Valley Senior High School with 837 students in grades 9-12 for the 1990-1991 school year is about 0.5 miles south of the site (10). There are no nursing homes or hospitals within a two-mile radius of the site (11,12).
The Malvern site is in a mostly residential and industrial area. About one mile north of the site (north of the Pennsylvania Turnpike), the land is used primarily for farming. Two residential subdivisions of about 35 homes each are adjacent to the site on the northern and southwestern borders (Figure 1). The closest homes are within 500 feet of the plant and the FDA. An industrial park is 0.5 miles northeast of the site, and two active limestone quarries are 0.5 miles farther northeast. Groundwater pumpage from those quarries (several million gallons per day) and local geologic structure affect groundwater flow beneath the site such that deep groundwater flows eastward rather than southward under otherwise normal, topographically controlled gradients (Figures 5 and 6).
About 1,000 feet south of the high school is the Philadelphia Suburban Water Company (PSWC) Great Valley well (Figures 2 and 5). This well is part of a public water supply system serving an unknown number of local users since 1976. The well is creating a cone of depression which, like the quarries, is influencing groundwater flow direction and may also be contributing to dewatering of the aquifer. According to local residents and the author's personal observation, nine or more private wells were drilled on Hillbrook Circle (Figure 7) since about 1980 to replace original wells that went dry. At least eight of the wells have been drilled since June of 1992. Reduced precipitation during recharge months (November-April) for the past two years has further aggravated the groundwater supply problem (13).
An estimated 120 residences and perhaps a dozen businesses north and east of the Malvern TCE site rely primarily on a public water supply. Residents immediately south and southwest of the site (Hillbrook Circle) use private wells. Most private well users are topographically and hydrogeologically downgradient of the FDA, and at least 14 private water supplies have shown site-related contamination above EPA drinking water standards. Currently, all private wells which are known to be contaminated have been fitted with activated carbon filtration systems. Filters are changed approximately yearly.
Using state health data bases, special studies or other relevant health outcome data bases, it may be possible to compare health outcome in areas around hazardous waste sites in Pennsylvania with the state as a whole. This section introduces these data bases and discusses their limitations. An evaluation of the usefulness of these health data as they relate to the Malvern TCE site is presented in the Public Health Implications section.
PADOH has maintained resident death records since 1906. PADOH maintains two major program operations related to improving the quality of information received on death certificates - the query and field programs.
The query program is a system used to follow-back with hospital personnel, funeral directors and/or physicians concerning incomplete or conflicting information. The follow-back contact is usually done by telephone and is based both on a manual and computer editing procedure.
The field program attempts to improve death certificate information by educating the participants in the vital registration systems, i.e., hospital personnel, funeral directors, physicians, etc., of the uses and importance of vital statistics data. The field program completes this mission by conducting seminars with various associations representing the types of individuals listed above. In addition to regularly scheduled seminars, the field representative makes site visits when problems with registration relating to a particular area or institution are discovered.
These long-standing programs allow mortality data to be collected at the minor civil division (MCD) level with a high degree of accuracy.
However, the Pennsylvania Cancer Registry has collected cancer data for all areas of
Pennsylvania only since 1984. Field representatives interact with local hospitals to audit the
accuracy of all Pennsylvania Cancer Registry Report Form information. However, the mobility
of the patients, the variance in compliance rates among hospitals, and the newness of the
program create difficulty in collecting meaningful data of geographic areas smaller than the
county level. The most recent report, published in September 1991, is entitled Cancer Incidence
and Mortality in Pennsylvania, 1988. The report only presents data applicable at the county
level (smallest geographic area). PADOH is unaware of the existence of any special studies or
other relevant health outcome data bases associated with this site.
During interviews with area residents, health concerns were noted and are listed below.
- What is the current status of residential well #50 (Figure 7) with respect to chemical contamination? What, if any, changes in contaminant concentrations have occurred in the past several years? Are benign tumors that I and my family have experienced attributable to contaminated well water?
- Are the carbon filtration units furnished by Chemclene effectively removing contaminants from my water supply?
- What are the adverse health effects of exposure to TCE through well water?
The above health concerns will be addressed in the Public Health Implications section of this document. Other comments were received during and after the public comment period. Those comments are addressed in the Attachment of this document.