The North Penn Area 1 site, a National Priorities List (NPL) site, is located in the Borough of Souderton, Montgomery County, Pennsylvania. The North Penn Area 1 site is one of six NPL sites that involve the North Penn Water Authority (NPWA) wells that supply drinking water to people living northwest of Philadelphia. Gentle Cleaners, Inc., one of the parties potentially responsible for the site contamination, has been in business since 1953 and used tetrachloroethene (PCE) from 1953 to 1983 in dry cleaning operations. A PCE spill of 75 gallons was documented in the early 1970s. Very close to the Gentle Cleaners is the Granite Knitting Mills, a hosiery mill that has operated for over 50 years. This facility also used PCE as part of its dry cleaning operations. In 1979, NPWA discovered PCE in municipal well S-9 in the area and took the well out of service. The NPWA serves over 65,000 people in ten municipalities. Approximately 8,000 people live within 1 mile of the site. The site is 800 feet northwest of Skippack Creek, which is used for recreational activities.
At present, groundwater is the only medium that is known to be contaminated. Environmental data for surface soil, surface water, sediment, and air do not exist. Past, present, and future completed exposure pathways for volatile organic compounds such as PCE and TCE in groundwater exist for nearby residents. The site is considered an indeterminate public health hazard because limited data are available; however, data that are available do not indicate that humans are being or have been exposed to levels of contaminants that would be expected to cause any adverse health effects.
The evaluation of health outcome data was negative, and there were no specific concerns from the citizens regarding morbidity and mortality. There was limited concern about possible health effects from past exposure to contaminated drinking water.
The data and information developed in the North Penn Area 1 Public Health Assessment have been evaluated for appropriate follow-up actions. The Agency for Toxic Substances and Disease Registry's (ATSDR) Health Activities Recommendation Panel (HARP) determined that no follow-up public health actions are necessary. ATSDR will reevaluate this site and conduct appropriate public health actions if new data become available that indicate a need to do so.
The Pennsylvania Department of Health (PADOH) will review the findings of the North Penn Area 1 Phase II Remedial Investigation Report. This report should better characterize the site by defining the extent of contamination and determining if there is any public health risk from surface water, soil, sediment, and air pathways.
As other information become available on the status of recommendations made in this public health assessment, ATSDR and PADOH will evaluate that information to determine if conditions have changed at the site and if other follow-up actions are necessary.
North Penn Area 1 is within the Borough of Souderton in Montgomery County. The site is one of six proposed or final NPL sites within the North Penn Water Authority (NPWA) service district in Montgomery County, Pennsylvania (Figure 1). Previous investigations by the NPWA, the Pennsylvania Department of Environmental Resources (PADER), and the U.S. Environmental Protection Agency (EPA) Region III detected elevated levels of volatile organic compounds (VOCs) in groundwater samples from wells at each of the sites. The primary contaminants identified to date have been trichloroethene (TCE), tetrachloroethene (PCE), and 1,1-dichloroethene (1).
This public health assessment will pertain only to North Penn - Area 1. Three potentially responsible parties (PRPs) were initially identified: Gentle Cleaners, Inc., Granite Knitting Mills, Inc., and Parkside Apartments. These PRPs are located near the center of the town and are all within a half-mile radius of two municipal wells, S-9 and S-10, which are owned by the NPWA; well S-9 is not currently being operated due to contamination by PCE. Figure 2 indicates the three PRPs and existing well locations. However, based on a PRP search conducted by EPA in 1989, the following additional two facilities were added to the PRP list for Area 1: Lexco Engineering and Standard Terry Mills (2). For the purpose of this public health assessment, on-site will be defined as the area revised in 1991 to include the five PRPs as shown in Figure 3. A brief description and history of the PRPs follow.
Gentle Cleaners' operation began before 1953. Between 1953 and 1983, the company used 70 to 100 gallons of PCE per month as well as less than 1 gallon per month of spotting chemicals containing 1,1,1-trichloroethane and other chlorinated solvents of unknown composition. Since 1983, the volume of PCE used has been reduced to about 50 gallons per month. The PCE was stored onsite in either an above-ground storage tank or drums. An underground storage tank may also have been used to store PCE. A spill of 75 gallons of PCE was documented in the early 1970s. PCE flowed out the rear door onto the grassed area behind the building. Also, discharge of PCE to a sink that drained into the same grassed area may have contributed to soil contamination (1).
Granite Knitting Mills operated a knitting mill before the early 1960s. From 1967 to 1979, a dry cleaning machine using PCE was maintained at the facility. Use of the machine may have stopped before 1979. PCE for the machine was stored in a tank inside the building. Wastes generated from the machine were estimated to contain about 2 percent PCE and were stored in drums on the southwest side of the building (1).
The Parkside Apartments property once included a dry cleaning establishment. Before that, the property was used as a beer distributor, and prior to that as a slaughter house. Three underground storage tanks containing petroleum hydrocarbon fuels were once located on the property, but were removed around 1980. There may be additional underground storage tanks still on the property, as evidenced by the presence of an inlet at the south corner of the building (1). The Parkside Apartments contain eight units and have been available for occupancy since 1975. The Apartment occupants obtain their water from the North Penn Water Authority.
Lexco Engineering has been at its current location for about 30 years and uses organic solvents, including kerosene and 1,1,1-trichloroethane, in the manufacturing of hydraulic lifts. The facility has two underground storage tanks, one containing heating oil and the other, unused for years, appears to still contain gasoline (1). Eleven people were employed by Lexco in 1990 (3).
Standard Terry Mills at one time consisted of a knitting mill operation and may have been a dry cleaners. Several holes in the pavement southwest of the building indicate that underground storage tanks may have been located there and have subsequently been removed (1). A fire in May of 1991 destroyed the building and only a concrete foundation remained at the time of the site visit. Eighty-one persons were employed by Standard Terry Mills in 1990. Products manufactured included kitchen and tabletop textiles, towels, pot holders, oven mitts, kitchen cloths, place mats, napkins, and seat pads (3).
Groundwater sampling was initiated at wells S-9 and S-10 in 1979 when the NPWA discovered PCE contamination in well S-9. Pumping of well S-9 was discontinued at that time. In July 1986, NUS Corporation completed a site discovery for EPA, and in August 1986, a NUS Field Investigation Team (FIT III) sampled residential wells. The site was proposed for the NPL in January 1987 and made final on March 31, 1989. In June 1988, ATSDR issued a preliminary public health assessment for the site. This report concluded that a thorough survey of wells used in the area was necessary along with an alternate water supply for any contaminated private wells.
The Preliminary Boundary of Area 1 (1986) and the revised boundary of Area 1 (1991) are shown on Figure 3. The location of North Penn Area 1 in relation to other North Penn Area sites is shown on Figure 1. Residences are in close proximity to the PRPs and, in the case of the Parkside Apartments, these served as residences. A promised well survey by CH2M Hill and ensuing Remedial Investigation/Feasibility Study (RI/FS) should provide answers to the nature and extent of contamination in the area.
Mr. Thomas Hartman and Mr. Robert M. Stroman of PADOH, Mr. Charles Walters of ATSDR, a representative of EPA, and a representative of the Montgomery County Department of Health visited the site on November 19, 1991. The day was mild (65F) and all visits were exterior observations. There were no visible signs of contamination. Standard Terry Mills, Inc., experienced a fire in May 1991 and the remains had been cleared down to the foundation. The other four areas were operable and no entry was deemed necessary. Well S-9 was observed in close proximity to the Parkside Apartments. West Street Park, a public recreation facility, operated by the Department of Community Affairs was near Parkside Apartments and the location of well S-9. An unnamed stream runs through the West Street Park. The stream was low at this time but would be subject to rapid rise from runoff during heavy rains.
The EPA Remedial Project Manager (RPM) led the group on a driving tour in which we located North Penn Areas 2, 5, 6 and 7. This tour was informative and provided insight into the complex nature of the North Penn Water Authority and the large number of PRPs subject to investigation (Figure 1).
As of December 23, 1993, no physical changes had occurred at the site. Well S-9 remains out of service.
Souderton Borough is on the northeastern border of Montgomery County adjacent to Bucks County. Telford Borough joins Souderton Borough to the north and Franconia Township lies to the south. Souderton Borough had a 1980 census population of 6,657 and a 1990 census population of 5,957. This is a decline in population of 10.5 percent, whereas the population of Montgomery County increased by 5.4 percent from 643,371 to 678,111 in 1980 and 1990, respectively (4). Approximately 8,000 people live within 1 mile of the North Penn Area 1 site (1).
Montgomery County is a wealthy county with the median home value being $143,400 compared to $69,700 for Pennsylvania according to the 1990 census. Median rentals for the county are $521 a month compared to $322 a month for Pennsylvania. Souderton Borough had a median home value of $118,000 and a median rental of $446 (5).
The 1990 census indicates Souderton Borough had 16 percent of its population 65 and over compared to 15 percent for Montgomery County and 15.4 percent for Pennsylvania. Souderton Borough was 96.1 percent White and 2.7 percent Spanish origin in 1990 (5).
The Souderton Area School District had an enrollment of 4,920 students in the public school program K-12 for the 1990-91 school year. The public schools within Souderton Borough and their 1990-91 enrollment are as follows (6, 7, 8):
|E.M. Crouthamel Elementary School||(353)|
|West Broad Street Elementary School||(434)|
|Indian Crest Middle School||(232)|
|Souderton Area High School||(1,291)|
The Souderton Mennonite Home, a 59-bed nursing home, lies just beyond the Borough limits. There are no hospitals within 5 miles of Souderton Borough; however, Grand View Hospital, a 230-bed facility in Sellersville, Bucks County, and North Penn Hospital, a 150-bed facility in Lansdale, Montgomery County, are less than 10 miles from Souderton Borough (9, 10).
Souderton Borough is a residential, commercial, and industrial community. The 1990 Pennsylvania Industrial Directory indicates 36 businesses in Souderton Borough and 31 businesses in Telford Borough, an adjoining community. The 1991 Annual Report of the NPWA indicates the NPWA serves over 65,000 people in the Borough of Lansdale, Souderton and Hatfield, and the Townships of Franconia, Hatfield, Lower Salford, New Britain, Skippack, Towamencin and Worcester. The site is 800 feet northwest of Skippack Creek, which is used for recreational activities (11). There are areas of less dense population between communities; however, the area is generally commercial with only limited farming.
The area around the PRPs was residential and business. Single family homes in close proximity to one another line the street near Granite Knitting Mills. There are some multi-unit dwellings in the Souderton Borough area which are rental properties. However, all residences in the area of concern use the North Penn Water Authority as their source of potable water.
Natural Resource Use
The site is located in the Triassic Lowland Section of the Piedmont Physiographic Province (1). The topography of the area is gently rolling, with low-lying ridges and hills. The land and drainage in the vicinity of the site generally slopes to the southeast, toward the Delaware River. Most of the region around the site is drained by Skippack Creek and its tributaries. Skippack Creek then discharges into the Schuylkill River which ultimately discharges into the Delaware River.
An estimated 15 to 21 inches of precipitation enters the surface-water drainage system as surface runoff. In the vicinity of the site, it appears that the surface runoff probably moves southeastward toward the unnamed, intermittent tributary of Skippack Creek, although some runoff may be directed elsewhere by stormwater collection systems. When the water table is high, water entering this stream may flow southwestward and southward into Skippack Creek and thence to the Schuylkill and the Delaware Rivers. When the water table is low, the surface runoff may seep into dry stream beds and emerge at the surface farther downstream.
The residential wells sampled in Souderton Borough during the site investigation were all shallow, hand-dug wells. None of these wells were used as a source of potable water. A well survey just completed (1992) indicates that there are no residential wells used for drinking water at present in the area of perceived groundwater contamination. Only a few of the wells had active hand pumps and were used for watering plants and outdoor activity only (12). Presently, only five NPWA wells serve Souderton Borough, all of which are 300 feet deep with the exception of S-2 which is 216 feet deep.
The Granite Knitting Mills well and the Old Souderton Borough well served as monitoring points in the site investigation. The Granite Knitting Mills well served as a production well over a decade ago, but was taken out of service. The Souderton Borough well has been inactive as a source of drinking water for over 25 years (12).
D. Health Outcome Data
Using state health data bases, special studies, or other relevant health outcome data bases, it may be possible to determine whether certain health effects are higher than expected in areas surrounding hazardous waste sites. This section introduces these data bases and discusses their limitations. An evaluation of the usefulness of these health data as they relate to the North Penn Area 1 site is presented in the Public Health Implications section.
PADOH has maintained death records since 1903. The Pennsylvania Cancer Registry has collected cancer data for all areas of Pennsylvania since 1984. Field representatives interact with local hospitals to audit the accuracy of all reporting. However, the mobility of the patients, the variance in compliance rates among hospitals and the newness of the program create difficulty in analyses 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 organized citizens action groups or widespread public health concern related to this site. The Remedial Program Manager (RPM) for EPA and the Borough Manager indicate that public concern about this NPL site is minimal at present. NPWA tests the water regularly (monthly testing normally) and the water meets drinking water standards. Contact with the citizens will be maintained by EPA and PADOH during the RI/FS investigation. There was some concern about adverse health effects from past exposure to contaminated water through the NPWA. This concern will be addressed in the Community Health Concerns Evaluation section.