UNfTED STATES ENVIRONMENTAL PROTECTION AGENCY REGION III 841 Chestnut Building Philadelphia, Pennsylvania 19107 SDMSDOCID 20/4531
SUBJECT: UGI Columbia Gas Plant Site DATE: 7-27-95 EPA Health Assessment Comments FROM: Steven J. Donohue, RPM $j3 //;/K,r Central Pennsylvania Section (3HW24) TO: Jack Kelly, Regional Representative ATSDR Region III
EPA has received and reviewed the Public Health Assessment for the UGI Columbia Gas Plant Site which you transmitted to me on June 2, 1995. EPA has the following comments on the Assessment. Page 1 In the fourth paragraph of the Summary section, PAHs can bioaccumulate in aquatic organisms, via the pathways of sediment and diet. Bioconcentration is greater for the higher molecular PAHs than for the lower weight compounds. Bioconcentration also tends to be very species specific, with lower forms of organisms showing higher BCFs than higher forms. While fish can metabolize PAHs, some PAHs are associated with tumors, neoplasms, and other growth anomalies. Some metabolic intermediates of PAHs are likely to be a much greater threat to aguatic biota than to fishermen. Page 2 In the fourth paragraph, the Borough of Columbia waste water treatment plant is directly across Front Street to the south of the Site. Page 6 In the fourth paragraph, the Lancaster Water Authority water intake on the Susquehanna River is approximately 400 feet offshore. Page 8 In the Environmental Contamination and Other Hazards section, EPA believes that some contaminants of concern at the UGI Site have not been included in the Public Health Assessment including but not limited to xylene. Also, considering benzo[a]pyrene but not other PAHs is likely to lead to an underestimate of risk. Page 9 In the first paragraph, please define B(a)P as benzo (a) pyrene the first time it is used in the report. Page 11 The River Sediments paragraph states that in 1991 the contaminated sediments could not be found. More recent investigation of the sediments, in 1994, confirmed and located contaminated tar in the sediments. Page 13 In the first paragraph of the Air, it is not clear what the last sentence is referencing. Page 18 In the last paragraph of the Arsenic section, it is unclear what the basis is for the conclusion reached in the second sentence. Page 22 In the second paragraph in the Conclusion section, there are plans to sample the private water wells in the area during the summer of 1995. In the last paragraph of the Conclusion section, surface soil samples will be taken as part of the ongoing Remedial If you have any guestions on these comments please contact me at (215) 597-3166. OF HEALTH & HUMAN SERVICES Public Health Service
Agency for Toxic Substances and Disease Registry Atlanta GA 30333 June 2,1995
From: Regional Representative ATSDR Region III
Re: Public Health Assessment UGI Columbia Gas Plant
To: Steven J. Donohue, Remedial Project Manger EPA Region III
Enclosed is the final Public Health Assessment on the UGI Columbia Gas Plant, Columbia Borough, Lancaster County, Pennsylvania. This Public Health Assessment, prepared by the Pennsylvania Department of Health under a cooperative agreement with the Agency for Toxic Substances and Disease Registry, represents an evaluation of the relevant health and environmental data and community concerns collected for this site.
If you have any questions or comments, please contact me at (215) 597-8216.
Attachment cc: Monty Howie, ATSDR/DHAC/PERIS Art Dalla Piazza, PADER, Southcentral Office Peter Gearhart, PADOH, Southcentral Office */**»« l» Kandiah Sivarajah, Ph.D., PADOH
\ Public Health Service DEPARTMENT OF HEALTH & HUMAN SERVICES Agency for Toxic Substances and Disease Registry Memorandum
Date May 23, 1995
From Chief, Program Evaluation, Records, and Information Services Branch, DHAC, ATSDR Subject public Health Assessment
To Charles J. Walters Senior Regional Representative, ATSDR, Region III Attached are seven copies of the May 23, 1995, Public Health Assessment on the following site prepared by the Pennsylvania Department of Health under a cooperative agreement with the Agency for Toxic Substances and Disease Registry. UGI COLUMBIA GAS PLANT COLUMBIA, LANCASTER COUNTY, PENNSYLVANIA CERCLIS NO. PAD980539126 The Program Evaluation, Records, and Information Services Branch requires copies of all letters used to transmit this document to the agencies, departments, or individuals on your distribution list. The copy letters will be placed into the administrative record for the site and serve as the official record of distribution for this Public Health Assessment. Please address correspondence to the Chief, Program Evaluation, Records, and Information Services Branch, Division of Health Assessment and Consultation, ATSDR, Mailstop E-56, 1600 Clifton Road, N.E., Atlanta, Georgia 30333. If you have any questions, you may call Ms. Chris Brandt, our Community Involvement Specialist, at 1-800-447-4784, then dial 329-1175.
Max M. Howie, Jr.
Attachments r cc: B. Johnson D. Cronin H. Longest S. Williams-Fleetwood H. Cassell (no attachs) R. Gillig J. Andrews G. Godfrey Public Health Assessment for
UGI COLUMBIA GAS PLANT COLUMBIA, LANCASTER COUNTY, PENNSYLVANIA CERCLIS NO. PAD980539126 MAY 23, 1995
U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES PUBLIC HEALTH SERVICE Agency for Toxic Substances and Disease Registry PUBLIC HEALTH ASSESSMENT
UGI COLUMBIA GAS PLANT
COLUMBIA, LANCASTER COUNTY, PENNSYLVANIA
CERCLIS NO. PAD980539126
Prepared by
Pennsylvania Department of Health Under Cooperative Agreement with the Agency for Toxic Substances and Disease Registry THE ATSDR PUBLIC HEALTH ASSESSMENT: A NOTE OF EXPLANATION
This Public Health Assessment was prepared by ATSDR pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA or Superfund) section 104 (i)(6) (42 U.S.C. 9604 (i)(6), and in accordance with our impkmenting regulations 42 C.F.R. Part 90). In preparing this document ATSDR has collected relevant health data, environmental data, and community health concerns from the Environmental Protection Agency (EPA), state and local health and environmental agencies, the community, and potentially responsible parties, where appropriate.
In addition, this document has previously been provided to EPA and the affected states in an initial release, as required by CERCLA section 104 (i)(6)(H) for their information and review. The revised document was released for a 30 day public comment period. Subsequent to the public comment period, ATSDR addressed all public comments and revised or appended the document as appropriate. The public health assessment has now been reissued. This concludes the public health assessment process tot this site, unless additional information Is obtained by ATSDR which, in the Agency's opinion, indicates a need to revise or append the conclusions previously issued.
Agency for Toxic Substances and Disease Registry David Satcher, M.D., Ph.D., Administrator Barry L. Johnson, Ph.D., Assistant Administrator
Division of Health Assessment and Consultation Robert C. Williams, P.E., DEE, Director Juan J. Reyes, Deputy Director
Exposure Investigations and Consultations Branch Edward J. Slcowronslti, Acting Chief
Federal Facilities Assessment Branch Sandra G. Isaacs, Acting Chief
Petitions Response Branch Cynthia M. Harris, Ph.D., Chief
Superfund Site Assessment Branch Sharon Williams-Fleetwood, Ph.D., Chief
Program Evaluation, Records, and Information Services Branch Max M. Howie, Jr., Chief
Use of tnde names is for identification only and does not constitute endorsement by the Public Health Service or the U.S. Department of Health and Human Services.
Additional copies of this report are available from: National Technical Information Service, Springfield, Virginia (703) 487-4650 The Agency for Toxic Substances and Disease Registry, ATSDR, is an agency of the U.S. Public Health Service. It was established by Congress in 1980 under the Comprehensive Environmental Response, Compensation, and Liability Act, also known as the Superfimd law. This law set up a fund to identify and clean up our country's hazardous waste sites. The Environmental Protection Agency, EPA, and the individual states regulate the investigation and clean up of the sites. Since 1986, ATSDR has been required by law to conduct a public health assessment at each of the sites on the EPA National Priorities List. The aim of these evaluations is to find out if people are being exposed to hazardous substances and, if so, whether that exposure is harmful and should be stopped or reduced. (The legal definition of a health assessment is included on the inside front cover.) If appropriate, ATSDR also conducts public health assessments when petitioned by concerned individuals. Public health assessments are carried out by environmental and health scientists from ATSDR and from the states with which ATSDR has cooperataive agreements. Exposure: As the first step in the evaluation, ATSDR scientists review environmental data to see how much contamination is at a site, where it is, and how people might come into contact with it. Generally, ATSDR does not collect its own environmental sampling data but reviews information provided by EPA, other government agencies, businesses, and the public. When there is not enough environmental information available, the report will indicate what further sampling data is needed. Health Effects: If the review of the environmental data shows that people have or could come into contact with hazardous substances, ATSDR scientists then evaluate whether or not there will be any harmful effects from these exposures. The report focuses on public health, or the health impact on the community as a whole, rather than on individual risks. Again, ATSDR generally makes use of existing scientific information, which can include the results of medical, toxicologic and epidemiologic studies and the data collected in disease registries. The science of environmental health is still developing, and sometimes scientific information on the health effects of certain substances is not available. When this is so, the report will suggest what further research studies are needed. Conclusions: The report presents conclusions about the level of health threat, if any, posed by a site and recommends ways to stop or reduce exposure in its public health action plan. ATSDR is primarily an advisory agency, so usually these reports identify what actions are appropriate to be undertaken by EPA, other responsible parties, or the research or education divisions of ATSDR. However, if there is an urgent health threat, ATSDR can issue a public health advisory warning people of the danger. ATSDR can also authorize health education or pilot studies of health effects, full-scale epidemiology studies, disease registries, surveillance studies or research on specific hazardous substances. Interactive Process: The health assessment is an interactive process. ATSDR solicits and evaluates information from numerous city, state and federal agencies, the companies responsible for cleaning up the site, and the community. It then shares its conclusions with them. Agencies are asked to respond to an early version of the report to make sure that the data they have provided is accurate and current. When infomed of ATSDR's conclusions and recommendations, sometimes the agencies will begin to act on them before the final release of the report. Community: ATSDR also needs to learn what people in the area know about the site and what concerns they may have about its impact on their health. Consequently, throughout the evaluation process, ATSDR actively gathers information and comments from the people who live or work near a site, including residents of the area, civic leaders, health professionals and community groups. To ensure that the report responds to the community's health concerns, an early version is also distributed to the public for their comments. All the comments received from the public are responded to in the final version of the report. Comments: If, after reading this report, you have questions or comments, we encourage you to send them to us. Letters should be addressed as follows: Attention: Chief, Program Evaluation, Records, and Information Services Branch, Agency for Toxic Substances and Disease Registry, 1600 Clifton Road (E-56), Atlanta, GA 30333. Table of Contents
SUMMARY . 1
BACKGROUND 2 A. Site Description and History 2 B. Site Visit 4 C. Demographics, Land Use, and Natural Resource Use 6 D. Health Outcome Data 7
COMMUNITY HEALTH CONCERNS 7
ENVIRONMENTAL CONTAMINATION AND OTHER HAZARDS 8 A. On-Site Contamination 9 B. Off-Site Contamination 10 C. Quality Assurance and Quality Control 12 D. Physical and Other Hazards 12
PATHWAYS ANALYSES 12 A. Completed Exposure Pathways 13 B. Potential Exposure Pathways 14 C. Eliminated Exposure Pathways 16
PUBLIC HEALTH IMPLICATIONS 16 A. Toxicological Evaluation 17 B. Health Outcome Data Evaluation 21 C. Community Health Concerns Evaluation 21
CONCLUSIONS 22
RECOMMENDATIONS 23
PUBLIC HEALTH ACTIONS 24
PREPARERS OF REPORT 25
CERTIFICATION 26
REFERENCES 27
APPENDDC A. Figures 29
APPENDIX B. Tables 37 SUMMARY
The UGI Columbia Gas Plant site in Columbia Borough, Lancaster County, Pennsylvania, was proposed for listing on the Environmental Protection Agency's National Priorities List in June 1993. Coal tar waste and boiler ash from a gas manufacturing plant were disposed both on site and off site. Extensive on-site corrective measures were undertaken in 1987, but an indeterminate amount of coal tar remains on site.
On-site exposures to coal tar wastes occurred in the past but are no longer occurring. Most exposures were occupational through inhalation. Data to substantiate airborne exposures both on site and off site are inadequate to evaluate accurately any adverse health effects that may result from the exposures.
Contamination in on-site groundwater has migrated off site and has been detected in deep groundwater near the Susquehanna River. The selected contaminants of concern for the UGI site are the following: arsenic, benzene, benzo(a)pyrene (B[a]P), ethylbenzene, naphthalene, and toluene. A very low potential for exposure to contaminated off-site groundwater exists. About three residential dwellings in the area use private wells for domestic water. Discharge of contaminated groundwater into the river channel presents a remote possibility that some contaminants could enter one of two nearby public drinking water supply intakes of surface t water. Potable water supplies do not show evidence of being impacted by the site contaminants.
An area of coal tar-contaminated sediments in the Susquehanna River was identified, but the ^ exact mechanism of placement is uncertain. It has been attributed to active migration of coal tar through the floodplain stratigraphy between the site and the Susquehanna River, but three unidentified pipes with outfalls near the contaminated sediments have been mentioned as possible conduits of the coal tar. Potential exists for human exposure to the contaminated ^x/f< river sediments. A low potential exists for exposure to fish that may bioconcentrate coal tar wastes. Bioconcentration has not been demonstrated in this case.
There are currently no known exposure pathways associated with this site that would have a significant impact on public health. There are no organized or ad hoc groups in the area seeking relief or redress from health problems perceived to be caused by the site. Inadequacies in the available data used to evaluate both completed and potential exposure pathways have led to the conclusion that the UGI Columbia Gas Plant Site is an indeterminate public health hazard. Recommendations are made to address the inadequacies.
The data and information developed in the UGI Columbia Gas Plant Site Public Health Assessment have been evaluated for appropriate follow-up health actions by the ATSDR Health Activities Recommendation Panel (HARP). HARP determined that people are not being exposed to contaminants from the UGI Columbia Gas Plant site at levels that would be expected to cause illness. Therefore, no follow-up health actions are needed at this time. ATtSDR will reevaluate this site for additional follow-up public health actions if new data become available that indicate a need to do so. BACKGROUND
A. Site Description and History.
On June 23, 1993, the United States Environmental Protection Agency (USEPA) proposed adding the UGI Columbia Gas Plant Site (UGI site), at South Front and Mill Streets in the Borough of Columbia, Lancaster County, Pennsylvania, to the National Priorities List as a Superfund hazardous waste site. The wastes associated with the UGI site are from the manufacture of "water gas" that occurred there for approximately 100 years between 1851 and into the 1950s (1).
The UGI site occupies a 1.6 acre tract of land in predominantly industrial surroundings about 400 feet northeast of the Susquehanna River's Lake Clarke (Appendix A, Figure 1). It is bordered on the northeast by a railroad retaining wall and Conrail tracks, on the southeast by private residential property, on the southwest by Front Street (Pennsylvania Route 441), and on the northwest by an automobile body repair shop (2).
The chief on-site surface features are man-made. Little significant vegetation is present. The ground is relatively flat with no major drainage swales apparent. Most of the area is covered with clean gravel fill, although there are some areas of concrete and a few buildings that were used until recently for boat display, maintenance, and storage (Appendix A, Figure 2). Although one 1935 drawing of the UGI site shows a 12-inch drainage pipe underlying the property (1), neither an inlet to nor an outlet from this structure could be found during site visits. Access to the site is restricted by chain link fencing, topped with barbed wire. The main gates are locked at all times unless activity related to site clean up is underway.
Directly across Front Street to the south-southwest is the Borough of Columbia Wastewater Treatment Plant and a corridor of Conrail tracks. Shawnee Run, a tributary stream to the Smquehanna River, is about 350 feet northwest of the site. A residential area is 200 feet northeast and across a second set of Conrail tracks. About five residences are approximately 1,200 feet southeast of the UGI site, along Route 441, in an otherwise undeveloped tract of land at the Borough boundary (1).
The UGI site was formerly occupied by the Columbia Gas Company, originally organized in 1851 to supply the Borough of Columbia with manufactured water gas. Ownership passed to the Pennsylvania Power and Light Company (PP&L) in 1935 and then to the Lancaster County Gas Company (later merged into UGI) in 1949 (1). For a time the site was privately owned (6). On January 27, 1994, PP&L repurchased the site (23).
Gts reportedly was generated from wood in the earlier years of operation from 1851 to about 1910, although processes probably varied to a certain extent. In 1910 the plant was completely rebuilt except for two gas holders and one boiler. The city gas holder was 40 feet in diameter and was held in a pit to a depth of 17 feet. A poured concrete bottom was discovered in this holder during test borings of the site. The relief holder was 60 feet in diameter and was held in a pit that was 26 feet deep. No man-made base was observed for this holder during test borings (1).
Other structures at the site were two 5-foot UGI water gas sets, a tar separator, and a double unit purifier (1). The 1935 drawing shows that additional smaller equipment such as oil tanks, a cooler tank, and tar tanks were also present (1). Gas manufacturing ceased about 1960 (4).
The process of manufacturing gas consisted of alternately heating a charge of solid organic fuel such as wood or coal to a high temperature inside a generator vessel and passing steam over the heated fuel. Chemical reactions between the steam and the fuel resulted in the production of combustible water gas that was high in hydrogen and carbon monoxide content. Water gas was useful for industrial purposes. Additional treatment of water gas with any of a variety of gaseous hydrocarbon fuels produced "carburetted water gas" that had a higher heating value and was rendered useful as a domestic fuel (5). From the literature reviewed, it is unclear whether or not the latter process was employed at the UGI site.
Byproducts and wastes were generated during the manufacture of these gases. Coal tar was one byproduct, but it also formed one of the three major waste streams at the site. The other two waste streams were boiler ash and spent purifier chips. For purposes of description, the term "tars" as used in this report refers to dark oily liquids and stained soils which have a distinct odor similar to creosote (1).
All liquid waste streams from the manufacturing process were directed to the tar separator. Tars were pumped to the relief holder pit and stored to allow for separation of the tar/water emulsion. Dewatered tars were then pumped to storage tanks and later sold or used as fuel. Overflows from the tar separator were known to occur and the resultant discharges were directed to an open ditch thence to the Susquehanna River (4). Fishermen reported getting tar on their boats at times when fishing in the river.
Boiler ash was the unburned residue of combustion of carbonaceous fuel such as wood, coal, coke, or oil. Most of the boiler ash was hauled away by a contract hauler, but some was disposed in the area across Front Street from the site (1).
Purifier chips were wood chips coated with iron oxide that were held in gas purifier units through which the manufactured gas was passed before storage in the city gas holder. When the chips became saturated with coal tar and could not be economically regenerated, they were spread around the site as paving and dust control material (1).
The relief holder suffered a structural failure in 1947 and was not used as a gas holder after that point in time, but the pit was still used for separation. Good quality tar was removed for sale and unbreakable tar emulsion was left in or returned to the pit. The pit reportedly was filled with general refuse, construction fill, and dirt after gas manufacturing ceased (1). Tars that were also reportedly left behind in the relief holder pit were displaced from the pit during a site leveling and grading operation. The displaced tars were pushed into a former pedestrian tunnel under the Conrail tracks to the northeast and a small dike, damming up the tars in the tunnel, was built across the entrance (1). The tunnel was accessible to employees at that time and is still accessible from the UGI site but was sealed off at its northeast entry under the tracks during an earlier railroad expansion project.
Extensive remedial action took place at the site in 1987. This consisted of recovery of the pedestrian tunnel and capping of the city gas and relief holders. The recovery of the pedestrian tunnel involved removing the coal tar and visibly contaminated soil, steam clewing the inside of the tunnel walls, and constructing an eight-inch cement floor. Concrete slabs were poured over both the city gas and relief holders, allowing an undetermined amount of coal tar to remain on site (4).
As part of past studies of the UGI site a number of test pits and borings were excavated on site and off site, and a number of monitoring wells were installed. Samples of soil, river sediment, surface water, and groundwater from areas on site and off site were obtained and chemically analyzed. The results of chemical analyses will be discussed in the Environmental and Other Hazards section.
B. Site Visit
On Wednesday, October 13, 1993, J. E. Godfrey, William G. Schmeer, and Mark A. Lavin, Hetlth Assessors for the Pennsylvania Department of Health (PADOH), conducted a site visit at die UGI site. A second site visit was conducted two weeks later on October 27 by Mr. Lavin, Gail Godfrey from the Agency for Toxic Substances and Disease Registry (ATSDR), and by representatives of the Pennsylvania Department of Environmental Resources (PADER) and Maryland's Department of the Environment. This section discusses relevant observations made by these two teams during the site visits.
At the time of the visits, the site was in use as a boat dealership. We entered the site on Front Street through the main gate, which was open during normal business hours and closed and locked at other times. We found the boat dealership buildings to our left as we entered and to our right we found open-air boat storage. Most of the area was covered with either clean fill, concrete, or the buildings; hence, little vegetation was present on site. In the off- season, boats, trailers, and boating equipment were crowded into the 1.6 acres encompassing the site. Access to the site was restricted by chain link fencing topped with barbed wire. Two watch dogs were kept on site, and the area was lit during hours of darkness.
The northeastern property line abuts a railroad retaining wall that supports Conrail tracks 20 feet above the UGI site elevation. A tunnel, formerly used for pedestrian traffic, passes through the wall and under the tracks. The tunnel is sealed at the northeastern end and was used as a parts storage area. We noticed no odors on site, but some old tar stains were visible on the retaining wall outside the mouth of the tunnel. The only remaining visible evidence of the gas holders' existence are two rectangular concrete pads at ground level serving as caps for the holder pits. The smaller pad, measuring 40 feet by 45 feet, is situated to the rear of the main building. A demonstration well with a locked cover is near the center of the pad. This pad was constructed during the remedial action of 1987 (4). The larger pad, about 30 feet southeast of the smaller pad and measuring 60 feet by 65 feet, has a similar demonstration well centered in it. This pad was constructed during the same remedial action in 1987 (4). Both pads had freshly patched drill holes in them suggesting that recent sampling of the contents of the pits below had occurred, and, in fact, sampling was done on the day before the first site visit (7).
Two monitoring wells are within the fenced area on site, monitoring wells 3S (MW3S) and 3D (MW3D). Both wells have locked covers on them, and they are between the relief holder pit and Front Street. One is considered a shallow well, the other deep.
We found no large stormwater drainage swales or storm sewer inlets on site. Rainwater that falls on the property appears either to soak into the ground on site or run off as sheet runoff in a poorly defined drainage pattern.
After we inspected on-site areas, we turned our attention to off-site features as we traced the pathway that contaminated groundwater is taking. We inspected such areas as nearby land surfaces and stream banks for signs of contamination that could result in exposure through soils, surface water, or air. We checked areas where off-site disposal of boiler ash was reported to have occurred and where off-site soil borings revealed evidence of tars.
We could see the following off-site features from the main gate: to the southeast, a private residential property; to the southwest, Front Street, a main corridor of Conrail tracks, the Borough of Columbia Wastewater Treatment Plant, and a vacant lot, reportedly the site of a former lace mill; to the northwest, an auto body repair shop; to the northeast, another set of Conrail tracks and rooftops of houses beyond the tracks.
We found monitoring well 4 (MW4) in a grassy area between Front Street and the Conrail tracks just southeast of the UGI site's southeast property line. This well was intact and locked.
We found monitoring well 2 (MW2) in a vacant lot about 40 feet southeast of the point where Shawnee Run emerges from beneath the main corridor of Conrail tracks. During the first site visit this well was intact and locked. However, we discovered during the second site visit that a bulldozing operation of the vacant lot damaged the wellhead by shearing off the casing and exposing the well to the atmosphere. PADER's representative made note of the damage and indicated that action would be taken to correct this problem. The bulldozing also turned over soils on the lot and released some faint odors thought by one person during the site visits to resemble tar odors. We examined about 1,000 feet of the Susquehanna River bank just west and south of the site. Thousands of small, lively minnows were noted in the water just offshore. A fisherman was angling from the bank and replied, when asked, that he had not seen any tars or oil in the river. No visible tar or odors of tar were detected in the water or along the river banks.
We then found monitoring well 5 (MW5) between the wastewater treatment plant and the river. It was intact and locked.
We then inspected Shawnee Run just upriver from the vacant lot. This stream appeared to be dear and free of tars or oil.
Monitoring wells 6S (MW6S) and 6D (MW6D), which are between the City of Lancaster's Water Supply Pump Station and the river, were northwest of the mouth of Shawnee Run. The former well is a shallow well, and the latter is deep. These are situated on the river bank about 100 feet from the City of Lancaster's water supply intake, which is about 70 feet offshore in the Susquehanna River and about 2,200 feet downstream from the Columbia Water Company's surface water intake.
None of the team members from either site visit detected any visible signs, other than some old tar stains on site. Although one person detected tar-like odors while touring the property across from the UGI site, the odor cannot definitively be associated with the site. Other possible sources, such as creosote-treated railroad ties, were in the area. A demographic survey of the surrounding area conducted during the second site visit is summarized in the next section.
C. Demographics, Land Use, and Natural Resource Use
The UGI site is in a commercial/industrial area of Columbia on the 100 year floodplain of the Susquehanna River (3). According to the 1990 Census, about 10,701 people reside in the Borough of Columbia (10). Of that number, 10,097 are white, 415 are black, and the remainder comprise other categories; 7,649 are 21 years of age or older.
In the northeast quadrant of a one-mile circle centered on the site is a mix of residential, commercial, and industrial properties. Two elementary schools are in this quadrant, each of which is over one-half mile away. Also in this quadrant are many single and multiple family dwellings, a park, and a large foundry.
In the southeast quadrant and within one mile are many residential structures, a small private airfield, an apparently idle factory, an active sawmill, and the confluence of Strickler Run with the Susquehanna River.
In the southwest quadrant within one mile are the Borough of Columbia Wastewater Treatment Plant, the City of Lancaster's water supply intake, the Borough of Columbia's water supply intake, and the confluence of Shawnee Run with the Susquehanna River. The river dominates this quadrant.
In the northwest quadrant within one mile are a large number of residential structures, two active foundries, the central business district of Columbia, a hospital about one mile away, and the Susquehanna River (8).
Most of the residential structures within one mile of the site are frame or brick-and-frame dwellings older than 16 years. Along the Susquehanna River, about 700 feet west of the UGI site, is the first of about 25 cottages, apparently occupied seasonally. Although a public water supply is available to all residences in the borough, not all the cottages are connected to it. A well survey conducted in 1988 identified two cottages that use private well water (19). In 1990, three private wells servicing those cottages were sampled (20). The wells are about 600 feet northwest of MW6D. USEPA initially estimated that 20 residents used these private wells as a source of drinking water (3). However, following the 1990 round of sampling of private wells, USEPA determined that the well water was not used for drinking (20).
The Susquehanna River is the dominant natural feature and resource near the UGI site. It is used by many people for fishing, boating, and swimming. It is a source of water for many uses, including drinking water for the City of Lancaster and the Borough of Columbia, and it receives many wastewater discharges. It flows past Columbia from northwest to southeast to the Chesapeake Bay. It is used for hydroelectric power generation both upstream and downstream from the site.
D. Health Outcome Data
By using state health data bases, special studies, or other relevant health outcome data bases, we may be able to determine whether certain health effects are higher than expected in areas surrounding hazardous waste sites. This section introduces these data bases. An evaluation of the usefulness of these health data as they relate to the UGI site is presented in the Public Health Implications section.
PADOH maintains vital records of live births and resident deaths (including infant and fetal deaths). Resident birth and death information is reasonably accurate to the minor civil division level (township, city, or borough).
COMMUNITY HEALTH CONCERNS
PADOH determined community health concerns by asking questions during the site visit, by telephone interviews, by soliciting comments during a public comment period, and by conducting public availability sessions. USBPA's Remedial Project Manager for the UGI site, PADER's Project Officer for the site, Columbia's Borough Manager, and Columbia Borough's Health Officer all indicated that there are no organized or ad hoc groups in the area seeking relief or redress from health problems perceived to be caused by the site.
On November 2, 1994, PADOH placed a paid legal notice in the Columbia (Pennsylvania) Press that a public comment period ending December 9, 1994, had been opened to receive written comments about the site. No written comments were received during that period.
The only question that was raised by a concerned citizen by telephone was as follows:
Can exposure to coal tar vapors cause a skin rash?
This question will be addressed in the Community Health Concerns Evaluation section.
PADOH convened two public availability sessions on December 14, 1994, at the Columbia borough offices to provide an opportunity for people to meet PADOH representatives and discuss the public health implications of the UGI site. The sessions were advertised in the Columbia (Pennsylvania) Press on November 30, 1994. Only three people attended these sessions. The people were interested in the health assessment process, especially pertaining to public availability sessions. None had concerns about the site.
ENVIRONMENTAL CONTAMINATION AND OTHER HAZARDS
PADOH selects and discusses contaminants of concern based upon several factors, including (a) concentrations of chemicals on site and off site; (b) comparison of on-site and off-site concentrations with health assessment comparison values for carcinogenic and noncarcinogenic end points; (c) community health concerns; and (d) quality of the field and laboratory data.
In the data tables in Appendix B under On-Site Contamination and Off-Site Contamination, the fact that a contaminant is listed does not mean that it will cause adverse health effects from exposure. Instead, the list indicates which contaminant will be evaluated further in the public health assessment. The potential for adverse health effects resulting from exposure to contaminants of concern is discussed in the Public Health Implications section of this document. When selected as a contaminant of concern in one medium, the contaminant will be reported in all media sampled.
Comparison values for public health assessments are contaminant concentrations in specific environmental media that are used to select contaminants for further evaluation. ATSDR and other agencies developed the values to provide guidelines for estimating the media concentrations of a contaminant that are unlikely to cause adverse health effects.
8 The selected contaminants of concern for the UGI site are the following: arsenic, benzene, B[a]P, ethylbenzene, naphthalene, and toluene. B[a]P is a member of a class of chemicals known as polycyclic aromatic hydrocarbons (PAHs). PAHs are a group of chemicals that are formed during the incomplete burning of coal, oil and gas, garbage, or other organic substances. They are found throughout the environment in the air, water, and soil. There are over one hundred different PAH compounds. Although the health effects of the individual PAHs are not exactly alike, several of the PAHs can cause harm to human health. Of the three PAHs found in excess of ATSDR's comparison values, B[a]P is the only one discussed in the Public Health Implications section. The other two, anthracene and pyrene, are discussed in the Eliminated Pathways section of this report.
The Toxic Chemical Release Inventory (TRI) data bases for the years 1987 through 1991 were accessed by PADOH through the National Library of Medicine's Toxicology Data Network and searched for estimated annual releases of toxic chemicals to the environment. Reports from industries within the same zip code as the UGI site (i.e., Columbia) were searched to identify possible facilities that could contribute to groundwater and other media contamination near the site.
In the 1990 and 1991 TRI data bases, one facility reported nonpoint air releases of 80,000 pounds and 81,000 pounds, respectively, of toluene. It is not felt that the reported releases have contributed to the contaminants associated with the UGI site. In the 1987 through 1989 TRI data bases, no reports of releases of contaminants of concern were found.
A. On-Site Contamination
Waste Material in Pits
Visually identified tars were noted in the 1985 site investigation during test borings of the city gas and relief holder pits (1). The city gas holder had tars visibly identifiable between 7 and 27.2 feet below the surface. The relief holder had tars visibly identifiable between 4 and 31.5 feet below the surface. Appendix A, Figure 4, shows the location of test borings made in 1985 (1).
A sample was taken from a depth of 15 to 17 feet in the relief holder in 1985 and analyzed as a soil sample for a variety of coal tar-related compounds (1). The results of analyses of this sample shows that no contaminant of concern exceeds the comparison value for soil. In June 1993, a sample of sludge taken from the relief holder showed high levels of benzene. Appendix B, Table 1, summarizes maximum levels of contaminants found.
In 1991 and 1993, samples were taken from the demonstration wells in both holder pits and analyzed as aqueous samples. Appendix B, Table 2, shows the maximum concentrations of selected contaminants found in samples taken from the demonstration wells. The contaminants found include arsenic, benzene, B[a]P, ethylbenzene, naphthalene, and toluene. The results show that both holder pits are a source of coal tar-related compounds. The relief holder is of greater concern due to its history as both a tar separator and holding tank and the pit bottom's being essentially soil and bedrock, thus providing a direct route to fractures in the rock and, hence, groundwater. Leakage through the side walls of the holder pits is a factor in contamination of soil and groundwater. In 1985 tars were seen to be leaking through the side wall of the city gas holder pit into a test pit that had been excavated next to the exterior surface of the side wall (1).
SoU
Appendix B, Table 3, shows the maximum concentrations of contaminants found in on-site soils. Surface soil sampling was conducted, but the depths of sampling were not clearly defined. Arsenic and B[a]P are the major contaminants identified in this medium. Surface soil data (defined as 0-3 inches) are not available.
Groundwater - Monitoring Wells
Appendix B, Table 4, shows that on-site groundwater is contaminated with coal tar-related compounds, including arsenic, benzene, B[a]P, ethylbenzene, naphthalene, and toluene. All contaminants of concern exceed the comparison values used by PADOH to select contaminants for further evaluation. The concentration of benzene found in 1985, 300,000 Hg/L, exceeds the comparison value of 1 /ig/L by a factor of 300,000. Table 4 does not indicate the fact that the concentrations found in 1991 were about 15 times lower for benzene, toluene, and ethylbenzene than those concentrations found in 1985 (1,4). Estimated concentrations of volatile organic compounds found in 1993 were lower than in 1991 (21). These results show that contaminants are not contained and are available for off-site migration.
Air
Limited air sampling data exist; however, the air sampling data were obtained through the use of equipment that cannot identify specific chemicals. Therefore, no tables are provided for contaminants of concern in air.
B. Off-Site Contamination
Sett
Off-site soils have been found to be contaminated with coal tar-related compounds, in particular B[a]P. However, no data for surface soil (0-3 inches) are available. In 1985, test boring B-4, which was made across Front Street from the site (see Appendix A, Figure 4), contained measurable quantities of PAHs, indicating an area of direct tar waste disposal (1). This may be the location of the former open ditch that received tar separator overflows and might now be a source area of the tars reported to be actively migrating through the alluvial stratigraphy of the flood plain and entering river sediments. In 1991, subsurface soil samples
10 were taken from the area across the street from the site. All three of the samples contained PAHs, with one of the samples containing significantly higher concentrations than the other two (4). Appendix B, Table 5, shows the results of analyses of these samples.
One item regarding arsenic should be noted. In one soil sample, S9, arsenic was found to be in excess of the comparison value. No depth of sampling was given, so it is not known if this sample was taken from surface soil (0-3 inches). Other metals in this sample were also higher than in other surface soil samples. Sample S9 was reportedly taken as a background sample northeast of the UGI site across the Conrail tracks (12). For that reason, this occurrence of arsenic is not considered site related.
Groundwater
Off-site groundwater is contaminated with benzene, ethylbenzene, naphthalene, and toluene. Appendix B, Table 6, shows the maximum groundwater contaminant concentrations found in monitoring well MW6D. These results strongly suggest the existence of a deep groundwater migration path of contaminants. Further discussion on this issue is presented in the Pathways Analyses section.
On August 16, 1988, NUS Corporation conducted a home well survey in the area and found two residences near the corner of Union and Front Street where drilled private wells were in use for domestic drinking water (19). On July 31, 1990, PP&L collected well water samples from three seasonal cottages approximately one quarter of a mile north of the site. No organic contaminants were detected in any of the samples (20).
Arsenic is found in excess of the comparison value in both MW5 and MW6S, but no coal tar-related compounds were found in these wells. Therefore, these occurrences of arsenic are not thought to be site related.
River Sediments
River sediments are contaminated with arsenic and B[a]P. In 1985 an area of coal tar was identified in river sediments (1). In 1987 the volume of these contaminated sediments was estimated to be 800 cubic yards. Furthermore, in 1987, the contamination found in the river was estimated to have been there for no more than 15 years. A source area of the tars was not identified. However, in 1987 tars reportedly were migrating in both the flood plain and the river (2). In 1991 the area of sediments was reported to have been covered with fill and . could not be found (4). Maximum sediment contaminant concentrations are shown in Appendix B, Table 7. Appendix A, Figures 5 and 6, show the locations of sediment sampling (1,4). The area of river affected is shown in Appendix A, Figure 4. This area of contamination may have resulted in part due to surface runoff of coal tar from the UGI site, but the exact nature of its deposition is uncertain.
11 Surface Water
Surface water runoff from the UGI site may have at one time been directed to ditches, swales, or even storm sewer pipes that no longer are apparent and that probably served as a direct surface water pathway to the Susquehanna River. When the UGI site was actively producing water gas, the surface drainage features undoubtedly served to convey tar separator overflows to the Susquehanna River.
Surface water in the Susquehanna River showed some low level contamination with benzene just downstream from the area of sediments identified as being contaminated with tars. Appendix B, Table 8, shows the maximum level of contamination found in surface water samples. Appendix A, Figures 5 and 6, show the locations of surface water sampling (1,4).
C. Quality Assurance and Quality Control
In preparing this public health assessment, ATSDR relies on the information provided in the referenced documents. We assume that adequate quality assurance and quality control measures were followed regarding chain-of-custody, laboratory procedures, and data reporting. The analyses, conclusions, and recommendations in this public health assessment are valid only if the referenced documents are complete and reliable.
An analytical review of chemical analyses results was provided for the samples taken in 1993. All aromatic volatile compounds (benzene, toluene, ethylbenzene, and total xylenes) should be considered approximate because hold times were exceeded (21). Summaries of inofganic and organic laboratory data validation were provided for the samples taken in 1991 (4). These summaries state that no major problems were found in the analyses of contaminants of concern. However, no formal summary of quality assurance or quality control was located for the samples taken in 1985 (1).
D. Physical and Other Hazards
No obvious physical or other hazards are present. Security fencing around the site effectively restricts access to the site.
PATHWAYS ANALYSES
To determine whether nearby residents are exposed to contaminants migrating from the site, PADOH evaluated the environmental and human components that lead to human exposure. An exposure pathway consists of five elements: (a) a source of contamination; (b) an environmental medium in which the contaminants may be present or may migrate, for example, groundwater; (c) points of human exposure, such as well water; (d) routes of exposure, such as inhalation, ingestion, or dermal absorption; and (e) a receptor population, for example, people who drink contaminated water from private wells. Tables 9, 10, 11, and 12 describe exposure pathways at the UGI site are included in Appendix B.
12 PADOH and ATSDR identify exposure pathways as completed, potential, or eliminated. In completed exposure pathways, the five elements exist, and so exposure has occurred, is occurring, or will occur. In potential exposure pathways, however, at least one of the five elements is missing, but could exist. Potential pathways indicate that exposure to a contaminant could have occurred in the past, could be occurring now, or could occur in the future. An exposure pathway can be eliminated if at least one of the five elements is missing and will never be present.
A. Completed Exposure Pathways
Completed exposure pathways are shown in Appendix B, Table 9. An estimate of the number of people potentially affected by completed pathways is shown in Appendix B, Table 10.
Direct Contact
As previously discussed, the tunnel under the railroad tracks at the site was closed to pedestrian traffic, and tars removed from the relief holder ptf were placed in the tunnel. At some unspecified time prior to the 1987 recovery of the pedestrian tunnel, an employee entered the tunnel and attempted to walk atop the coal tar that was contained therein. The surface of the coal tar was encrusted from exposure to the air but was not strong enough to withstand the employee's weight, and he sank into the tars up to his knees (7). Others were not likely exposed to contaminants to this extent, but could have come into direct skin contact with contaminants when entering the tunnel or when taking part in grading activities. The 1987 remediation of the tunnel eliminated the source, thereby eliminating the exposure pathway.
Air
Employee exposure to volatile coal tar compounds in the air on site occurred prior to the 1987 remediation. While no accurate figures are available, fewer than 50 people are estimated to have been exposed through inhaling the compounds. "Strong tar odors" coming from the tunnel were noticed by employees at the UGI site, especially during the hot summer months (6). The practice of spreading spent purifier chips around the site underscores this assumption.
Air sampling data prior to 1985 are not known to exist. Following remediation, coal tar pitch volatiles, and naphthalene were not detected in or around the tunnel (11). Limited air sampling data exist and show that, following the 1987 remediation of tars in the pedestrian tunnel, on-site contamination of air does not pose a current problem (3). However, future remediation of the holder pits, soils, and sediments may expose tars to the atmosphere and could lead to the release of coal tar-related compounds to the air. By following a USEPA approved health and safety plan, human exposure during remediation efforts is expected to be minimal.
13 B. Potential Exposure Pathways
The principal potential exposure pathways are off site. Appendix B, Table 11, shows that the pathways involve the following environmental media: groundwater, river sediments, river surfice water (recreational contact), fish, and river surface water (public water supply). No data are available for surface soil (i.e., 0-3 inches). The estimated number of people that could be affected by potential exposure pathways are shown in Appendix B, Table 12.
Groundwater
Contaminants of concern (i.e., benzene, ethylbenzene, naphthalene, and toluene) have migrated from the UGI site through groundwater westward along the axis of the Columbia Syncline (a complex geologic feature resembling a trough or a fold in the Earth's crust) to the Susquehanna River. See Appendix A, Figure 7. At monitoring well nest 6, which is about 1,000 feet west of the UGI site next to the Susquehanna River, the deeper well (MW6D, 65 feet deep) contains site-related contaminants, but the shallow well (MW6S, 35 feet deep) does not. If the river is 10 feet deep at this point, then MW6D is screened about 47 feet below river bottom. With only a'slight upward flow component (suggested by water levels at 6D and 6S), it is possible that any groundwater discharge of contaminants to the river takes place far off shore near the channel center.
This could explain why no site-related contaminants have been detected at the Lancaster City water intake approximately 100 feet from the eastern riverbank. This position is about 900 feet west-southwest of the UGI site. Mixing of contaminated groundwater with surface water and volatilization of contaminants could also explain the absence of those contaminants from the public water supply intake.
There are no known private or public water supply wells withdrawing water from the zone of grotindwater contamination beneath and downgradient of the site. Hence, no known exposure to contaminated groundwater through wells is occurring. However, as previously mentioned, there are at least two uncontaminated private wells in use near the corner of Union and Front Streets (19), or about 600 feet west of MW6D. This position would place the wells about 400 feet north of the predicted position of the plume of contamination.
Because of the positions of these sources of water supplies with respect to the axis of the Columbia Syncline, the principal migration path of groundwater contaminants presents a remote or a very low potential for exposure.
Sediment
Sediments in the Susquehanna River near the UGI site were found to contain coal tar in 1985 (1). This area of sediments was more fully defined in 1987 (2). The source of the coal tar is most likely the UGI site. Since 1987 the area has become less well defined, but it is still of concern as it represents a potential exposure pathway to arsenic and B[a]P and serves as a
14 source area for contamination of surface water. The river depth at this point varies somewhat with flow, but at times it is shallow enough for people who wade in the area to come into contact with contaminated sediments. Recreational users, such as children or adults who wade in the river without hip boots, are potentially exposed to contaminated sediments.
Surface Water - Recreational
A small amount of benzene was found in surface water downstream from the area of contaminated sediments. It is possible that this is arising from the coal tar in the sediments. A remote possibility exists that recreational users of the river might ingest some of this contaminated water.
In the past, individuals who used the Susquehanna River downstream from the UGI site may have been exposed to coal tar discharges to surface waters that occurred from the tar separator (1). Historical records show that when the plant was in operation complaints were received from local fishermen whose boats were being coated with tar (2). However, no data to quantify these possible exposures have been found.
Surface Water - Public Water Supply
The nearest downstream public water supply intake is over three miles away and is not affected by site-related contamination because of the enormous dilution factor. The upstream public water supply intakes are nearer to the site and to possible discharges of contaminated groundwater into the river channel. A remote possibility exists that contaminants of concern could enter the Lancaster City water intake or the Columbia Water Company intake, which is about 3,000 feet west-northwest of the UGI site. Even if this were to occur, dilution could reduce contaminant levels to below analytical detection limits, and treatment processes for the drinking water could further reduce contaminant levels to extremely low levels.
None of the specific public water suppliers discussed above routinely analyzes the raw water for contaminants of concern. Both analyze the finished water for volatile organic compounds, and none have ever reported having detected contaminants of concern in their respective supplies (22). Because of the dilution factor and monitoring procedures that would warn the water suppliers of contamination, exposure to contaminants through use of the public water supplies at levels greater than those that can be detected are unlikely.
Fish
Fish in the river may be exposed to contaminated sediments and introduce contaminants of concern into the aquatic food chain. Naphthalene and toluene exhibit moderate tendencies to bioconcentrate in the fatty tissues of aquatic animals (17,18). Fish in the river might conceivably be exposed to small amounts of benzene, also, but biomagnification of benzene in aquatic food chains does not appear to be important (14). No studies were found to
15 indicate that fish were sampled and analyzed for contaminants of concern. People who consume fish from the river would be the exposed population. It is not known exactly how much fishing occurs here, but the Susquehanna River is a very popular warm water fishery.
Soil
Information on surface soil (0-3 inches) contamination both on site and off site has not been provided. This information is needed to determine if human contact with contaminated surface soil has public health implications associated with it. On-site soil contamination was found in subsurface soils but does not present a point of exposure to people on site. If future remediation efforts involve excavating contaminated subsurface soils, we anticipate that USEPA and PADER will take necessary precautions to prevent or limit exposures.
Subsurface soil contamination that may have been caused by disposing of spent purifier chips on site, spills, or overflows of the tar separator represents a source area. Contaminants may leach out of the chips and/or soil and travel in solution or otherwise into groundwater, which may then migrate off site. The recent grading of the vacant land across the street from the site ihows the possibility that subsurface contaminants could be exposed to the surface; however, no data are available to evaluate that possibility. Therefore, exposure pathways involving these media are not discussed further in this report.
C. Eliminated Exposure Pathways
Aside from the exposure pathways discussed under Completed Exposure Pathways for areas on site, additional on-site potential exposure pathways have either been eliminated during past remediation or eliminated by assuming that USEPA and PADER will institute control measures to prevent one or more elements of the exposure pathway from existing in future remediation efforts.
Oil-site Groundwater
Exposure to on-site groundwater contamination is not likely to occur because there are no on- site private wells drilled into the plume of contaminants. Although the PAH contaminants anthracene and pyrene, which were found in excess of the comparison values on site but not in off-site groundwater, are present in on-site groundwater, no drinking water or supply water wells are expected to be drilled on the site because the building formerly used as a boat business has a public water supply for use by employees and visitors.
PUBLIC HEALTH IMPLICATIONS
In this section, we will discuss potential health effects that may result from exposure to environmental contaminants, available health outcome data, and community health concerns. The Toxicologic Evaluation section provides information on the noncarcinogenic and
16 carcinogenic effects of exposure to contaminants that are above comparison values. The Health Outcome Data Evaluation section contains an evaluation of available community health information to determine whether adverse health effects have occurred. The Community Health Concerns Evaluation section contains a discussion on public health concerns voiced by the community about possible exposure to contaminants relative to documented exposures and potential health effects.
A. Toxicological Evaluation
Introduction
In this section, PADOH discusses health effects that could result from exposure to site- related contaminants. To determine the possible health effects of specific chemicals, PADOH researches scientific literature. To evaluate health effects, ATSDR's minimal risk level (MRL), USEPA's reference dose (RfD), and USEPA's Cancer Slope Factor (CSF) have been used. When RfDs and MRLs are not available, a no observed adverse effect level (NOAEL) or lowest observed adverse effect level (LOAEL) may be used to estimate levels below which no adverse health effects (noncancerous) are expected. The MRL is an estimate of daily exposure to a contaminant below which noncancerous adverse health effects are unlikely to occur. The chronic RfD is an estimate of a daily exposure (mg/kg/day) to the general public (including sensitive groups), which is likely to be without an appreciable risk of noncancerous harmful effects during a lifetime exposure (70 years). CSFs are usually derived from animal or occupational studies and are used to calculate the exposure dose likely to result in one excess cancer per million people exposed over a lifetime (70 years).
The primary public health issues of the UGI site concern the uncontrolled release of the site-related contaminants arsenic, benzene, B[a]P, ethylbenzene, naphthalene, and toluene into the groundwater and the Susquehanna River through discharge in solution in groundwater, and the presence of them in Susquehanna River sediments. Concerns of potential exposures through ingestion, dermal contact, and possibly inhalation under some circumstances (private wells or riverine recreation activities) as discussed under the Pathways Analyses section, must be considered.
Arsenic
There is a very low potential that exposure to arsenic has occurred, is occurring, or will occur through sediment contact by recreational users of the river in the area where tars were found in sediments. Ingestion of arsenic-contaminated sediments is the most likely route of exposure. Also, an extremely low potential exists that exposure to arsenic has occurred, is occurring, or will occur through people consuming bottom-feeding fish that have ingested contaminated sediments or other organisms that ingested arsenic. An important fact to bear in mind is that much of the arsenic present in fish and shellfish is naturally occurring in an organic form that is essentially nontoxic (13). On direct contact with small amounts of
17 arsenic such as those in sediments, little is expected to go through the skin, so dermal contact in this case is not of health concern (13).
For uoncancerous effects, ATSDR has developed a chronic oral MRL of 0.0003 mg/kg/day for arsenic (13). If a person were to ingest arsenic-contaminated sediments at the highest level detected (i.e., 10 mg/kg), noncancerous health effects are not likely to occur because an estimated exposure dose is lower than the MRL.
Arsenic is classified as a human carcinogen by USEPA and the National Toxicology Program (NTP) of the U.S. Department of Health and Human Services (13). People are not likely to ingest contaminated sediments on a regular basis. If people were to be orally exposed to arsenic at a level of 10 mg/kg, for example, for two days per week, then there would be no apparent increased risk of developing cancer.
One background soil sample, S9, contained arsenic at a level of 12.9 mg/kg. This occurrence is not considered site-related. Also, the depth of the soil sample was not given. Because surface soil (0-3 inches-depth at which people normally come into contact with soil) data are not available, an exposure assessment cannot be made.
One off-site monitoring well sample, MW5, contained an arsenic level of 16.4 /*g/L. This occurrence is not considered site-related. Also, no exposure pathway exists because people do not drink or use the monitoring well water for other purposes.
Benzene
There is a low potential that exposure to benzene could occur through groundwater use by residents in the cottages along Front Street. There is a low potential that exposure to benfcene has occurred, is occurring, or will occur through surface water contact by recreational users of the river. Groundwater use for domestic purposes by residents who have private wells could lead to ingestion, inhalation, or dermal absorption of benzene. Surface water contact by recreational users of the river could lead to ingestion or dermal contact with benzene-contaminated surface water downstream from the area of contaminated sediments.
In humans, noncancerous health effects that may result from eating or drinking foods containing lower levels of benzene are not known (14). However, studies in animals revealed decreases in number of erythrocytes, leukocytes, and lymphocytes following exposure to benzene. For example, mice exposed to low levels of benzene in drinking water for 4 weeks had a decreased number of erythrocytes and lymphocytes (14). For noncancerous effects, ATSDR has not developed an MRL from the known animal and human toxicity studies of oral exposure to benzene because the data were insufficient. Also, USEPA has not developed an RfD; therefore, no guidance on the safe levels of oral exposure to benzene are available to evaluate low-level exposure (14).
18 Benzene is classified as a human carcinogen by USEPA (14), NTP, and the International Agency for Research on Cancer (IARC), and a CSF has been developed to help evaluate exposures. If recreational users of the river ingest or come into dermal contact with surface water contaminated with benzene at a level of 20 /xg/L, they are not subject to a significant cancer risk.
A large data gap exists with respect to past on-site exposure of employees to benzene. The toxicologic effects of on-site airborne exposure to benzene cannot be accurately evaluated because of the lack of air sampling data. Long-term exposure to relatively high levels of benzene in the air can cause cancer of the blood. This condition is called leukemia.
B[a]P
A very low potential exists that exposure to B[a]P has occurred, is occurring, or will occur through sediment contact by recreational users of the river in the area where tars were found in sediments. Ingestion of B[a]P-contaminated sediments is the most likely route of exposure. Although B[a]P does not normally enter the body through the skin, small amounts could enter if contact occurs with sediment that contains high levels of B[a]P or if contact is made with heavy oils containing B[a]P (15). An extremely low potential exists that exposure to B[a]P has occurred, is occurring, or will occur through ingestion of fish that have accumulated B[a]P from sediments or from bottom-feeding organisms.
In humans, noncancerous health effects that may result from eating or drinking foods containing low levels of B[a]P are not known (15). ATSDR has not developed an MRL from the known animal and human toxicity studies of oral exposure to B[a]P because the data were insufficient. Also, USEPA has not developed an RfD (15). Therefore, no MRLs or RfDs are available to provide guidance on the safe level of oral exposure to B[a]P.
B[a]P is classified as a probable human carcinogen by USEPA, NTP, and IARC (15). If recreational users of the river ingest sediments contaminated with B[a]P at a level of 8.3 mg/kg, they are not subject to an apparent increased cancer risk if the exposure frequency is two days per week.
A large data gap exists with respect to past on-site exposure of employees to B[a]P. The toxicologic effects of on-site airborne exposure to B[a]P cannot be accurately evaluated because of the lack of air sampling data.
Ethylbenzene
A very low potential exists that exposure to ethylbenzene could occur through groundwater use by residents in the cottages along Front Street. Groundwater use for drinking water by residents who have private wells could lead to ingestion, inhalation, or dermal absorption of ethylbenzene. An extremely remote possibility exists that exposure to ethylbenzene has occurred, is occurring, or will occur through surface water use by customers of the Lancaster
19 City Water Department; dilution and treatment would probably reduce levels to below detection limits. Surface water used for drinking water by these customers could lead to ingestion, inhalation, or dermal absorption of undetectable amounts of ethylbenzene.
In humans, health effects that may result from eating or drinking foods containing lower levels of ethylbenzene are not known (16). For noncancerous effects, USEPA has developed an HfD of 0.1 mg/kg/day for ethylbenzene, based on animal studies that demonstrate changes in the livers and kidneys of animals orally exposed to ethylbenzene (16). If children were to be exposed to ethylbenzene at the highest level found in off-site groundwater, then some of those children may experience noncancerous adverse health effects because the RfD would be exceeded by a factor of about two.
Naphthalene
A very low potential exists that exposure to naphthalene could occur through groundwater use by residents in the cottages along Front Street. Groundwater use for drinking water by residents who have private wells could lead to ingestion, inhalation, or dermal absorption of naphthalene.
In most humans, health effects that may result from eating or drinking foods containing lower levels of naphthalene are not known (17). For noncancerous effects, ATSDR has not developed an MRL from the known animal and human toxicity studies of oral exposure to naphthalene because the data were insufficient. Also, USEPA has not developed an RfD (17). Therefore, no MRLs or RfDs are available to provide guidance on the safe level of oral exposure to naphthalene.
From animal studies where an intermediate LOAEL of 133 mg/kg/day was found, noncancerous adverse health effects in humans would not be expected to occur following exposure to the highest level of naphthalene found in off-site groundwater (17). This is because the child dose would be less than the LOAEL by three orders of magnitude.
Toluene
A very low potential exists that exposure to toluene could occur through groundwater use by residents in the cottages along Front Street. Groundwater use for drinking water by residents who have private wells could lead to ingestion, inhalation, or dermal absorption of toluene.
Long-term exposure to low and moderate amounts of toluene has caused slight effects on the kidneys in some people, but these people were also exposed to other solvents at the same time, and it is difficult to tell which chemical may have caused the effects (18). For noncancerous effects, USEPA has developed an RfD of 0.2 mg/kg/day for toluene based on animal studies that demonstrate changes in the weights of livers and kidneys of animals orally exposed to toluene (18). If children were to be exposed to toluene at the highest level found
20 in off-site groundwater, then some of those children may experience noncancerous adverse health effects because the RfD would be exceeded slightly.
B. Health Outcome Data Evaluation
No community health concerns were voiced relating to the UGI site. There are several private residences in the area that use private water wells for drinking water (19). Available water quality data for these wells show that no volatile organic chemical contamination is present. The population in the area where the wells are located is most likely seasonal and the population is less than 50 people. The perceived small number of people who use the cottages, and the fact that their permanent places of residence are unknown (possibly from diverse geographic areas), made a search of vital records impractical. On-site occupational exposure to coal tar most likely occurred, but exposure data are inadequate to evaluate. No other completed exposure pathways were identified that could adversely affect public health. Therefore, no health outcome data bases were evaluated.
C. Community Health Concerns Evaluation
No organized or ad hoc groups with concerns about community health have been identified. Contact was made with USEPA, PADER, and local government officials to determine if they knew of any concerns. In all cases there were no known concerns.
The following discussion addresses the one community health concern that has been identified:
Can exposure to coal tar vapors cause a skin rash?
Although skin irritation can occur by exposure to coal tar, this would generally be found by direct contact with the tar rather than from vapors.
21 CONCLUSIONS
PADOH has concluded that the UGI Columbia Gas Plant site is an indeterminate public health hazard. Limited available data do not indicate that humans are being or have been exposed to levels of contamination that would be expected to cause adverse health effects; however, some data are not available to adequately evaluate all possible exposure scenarios.
Thfrgas holder pits and subsurface soil areas of contamination represent source areas for groandwater contamination. Groundwater in the vicinity of the UGI site is being contaminated with coal tar-related compounds that originated from gas manufacturing activities at the site. However, no one is presently using groundwater that is contaminated, although a remote possibility exists that some private wells serving seasonally inhabited cottages could become contaminated. No indication of ongoing sampling to evaluate the quality of private well water that may be in use among the residents of the cottages on Front Street could be found.
Coal tar that originated from gas manufacturing activities at the UGI site is entering the Susquehanna River and its sediments. People wading in the river in that area could be exposed to the contaminants in the river. The extent of sediment contamination in the river has not been thoroughly studied since 1987 at which time tars were reported to be actively migrating into the river and no source area had been identified.
On-site exposures to coal tar wastes occurred, primarily through inhalation. The exposures could not be evaluated for public health implications because of a lack of environmental sampling data. Remediation of on-site coal tar wastes in 1987 eliminated the possibility of exposure. If remaining waste is excavated, workers could be exposed; however, USEPA and PADER require that workers follow a health and safety plan that should provide for protection against exposure.
For other potential exposure pathways, data are inadequate to evaluate public health implications. That data include: (a) no ongoing monitoring of raw surface water at public water supply intakes; (b) no information on possible contaminant levels in fish; and (c) no surface soil data for the top three inches of soil in areas on and off site where subsurface soils are contaminated.
22 RECOMMENDATIONS
Cease/Reduce Exposure Recommendations
1. Remove coal tar wastes still on site in the holder pits to reduce the source of groundwater contamination.
2. Monitor water quality from private wells at the cottages on a routine basis. If found to be contaminated, provide uncontaminated water supplies immediately.
3. Remediate coal tar in river sediments, or restrict access to areas of contamination, to eliminate potential exposures to contaminated sediments through recreational use of the river.
Site Characterization Recommendations
1. Sample private wells in use for benzene, ethylbenzene, naphthalene, and toluene at least annually.
2. Sample the City of Lancaster water supply intake for benzene, ethylbenzene, naphthalene, and toluene at least annually.
3. Identify and remediate the source area of tars that are migrating into and contaminating river sediments.
4. Sample fish in the vicinity of sediment contamination and analyze fish tissues for site-related contaminants of concern to determine if contaminants are entering aquatic food chains.
5. Sample surface soils near the UGI site at 0-3 inch depths for site-related contaminants to determine if contact with surface soil could result in exposure.
Health Activities Recommendation Panel (HARP) Recommendations
The data and information developed in the UGI Columbia Gas Plant Site Public Health Assessment have been evaluated for appropriate follow-up health actions by the ATSDR Health Activities Recommendation Panel (HARP). HARP determined that people are not being exposed to contaminants from the UGI Columbia Gas Plant site at levels that would be expected to cause illness. Therefore, no follow-up health actions are needed at this time. ATSDR will reevaluate this site for additional follow-up public health actions if new data become available that indicate a need to do so.
23 PUBLIC HEALTH ACTIONS
A public health action plan (PHAP) contains a description of specific actions to be taken by ATSDR and/or other governmental agencies at and in the vicinity of NPL sites subsequent to the completion of a public health assessment for any given site. The purpose of the PHAP is to ensure that the public health assessment not only identifies public health hazards, but provides a plan of action designed to mitigate and prevent adverse human health effects resulting from exposure to hazardous substances that may be released uncontrolled from NPL sites into the environment. Included is a commitment on the part of PADOH and ATSDR to follow up on this plan to ensure that it is implemented.
Currently, HARP determined that no follow-up health actions are indicated at the UGI Columbia Gas Plant site at this time. Additional information will be evaluated as it becomes available.
24 PREPARERS OF REPORT
Mark A. Lavin, B.S. Environmental Health Specialist Health Assessment Program Division of Environmental Health Assessment
I.E. Godfrey, M.S., M.Ed. Hydrogeologist II Health Assessment Program Division of Environmental Health Assessment
ATSDR Regional Representative:
Charles Walters Senior Regional Representative ATSDR, Region III Office Office of Regional Operations
ATSDR Technical Project Officer:
Gail Godfrey Technical Project Officer Superfund Site Assessment Branch Division of Health Assessment and Consultation
25 CERTIFICATION
The UGI Columbia Gas Plant Site public health assessment was prepared by the Pennsylvania Department of Health under a cooperative agreement with the Agency for Toxic Substances and Disease Registry (ATSDR). It is in accordance with approved methodology and procedures existing at the time the public health assessment was begun.
Technical Project Officer, SPS, RPBf,pHA(
\J The Division of Health Assessment and Consultation, ATSDR, has reviewed this public health assessment, and concurs with its findings.
Chief, State ProgJ&ms S
26 REFERENCES
1. TRC Environmental Consultants, Inc., Final Report of Investigations Volume I, Columbia Gas Plant Site, Columbia, Pennsylvania, December 17, 1986.
2. Atlantic Environmental Services, Inc., Investigation of the Extent of Contamination in the Susquehanna River Near the Former Columbia Coal Gas Site, Columbia, Pennsylvania, September 30, 1987.
3. NUS Corporation Superfund Division, Site Inspection of UGI (PP&L) Columbia Gas Plant, Columbia, Pennsylvania, July 17, 1989.
4. NUS Corporation Superfund Division, Expanded Site Inspection of UGI Columbia Gas Plant, Columbia, Pennsylvania, October 7, 1991.
5. Farnsworth, JF. Carbonization of Coal and Gas Making. In: Baumeister, T. ed. Marks' Standard Handbook for Mechanical Engineers. 8th Ed. New York: McGraw-Hill, 1979: 7.37-7.47.
6. Conversation with Mr. Bruce Roach, Sr., during site visit, October 13, 1993.
7. Conversation with Mr. Bruce Roach, Jr., during site visit, October 13, 1993.
8. Site visit demographic survey, October 27, 1993.
9. Telephone conversation with Mr. Charles Gohl, General Manager, Columbia Water Company, October 14, 1993.
10. Summary of General Population Characteristics, 1990, Census of Population and Housing, 1990; Summary Tape File 1A, U.S. Department of Commerce, Bureau of the Census, June, 1991.
11. Letter dated November 19, 1987, from Gene Gockley, PP&L, to PADER.
12. Telephone conversation with Mr. Tony Martinelli, PADER, November 19, 1993.
13. ATSDR, Toxicological Profile for Arsenic-Update, U.S. Public Health Service, Atlanta, Georgia, April 1993.
14. ATSDR, Toxicological Profile for Benzene-Update, U.S. Public Health Service, Atlanta, Georgia, April 1993.
27 15. ATSDR, Toxicological Profile for Benzo(a)pyrene, U.S. Public Health Service, Atlanta, Georgia, May 1990.
16. ATSDR, Toxicological Profile for Ethylbenzene, U.S. Public Health Service, Atlanta, Georgia, December 1990.
17. ATSDR, Toxicological Profile for Naphthalene and 2-Methylnaphthalene, U.S. Public Health Service, Atlanta, Georgia, December 1990.
18. ATSDR, Toxicological Profile for Toluene, U.S. Public Health Service, Atlanta, Georgia, December 1989.
19. NUS Corporation Superfund Division, Nonsampling Site Reconnaissance Summary Report, UGI (PP&L) Columbia Gas Plant Site, Columbia, Pennsylvania, November 3, 1988.
20. Halliburton NUS Corporation, Final Hazard Ranking System, UGI Columbia Gas Plant Site, Columbia, Pennsylvania, April 12, 1993.
21. Roy F. Weston, Inc., Lancaster Gas Works (UGI) Site, Columbia, Pennsylvania, August 11, 1993.
22. Telephone conversations with representatives of Columbia Water Company and Lancaster City Water Department, March 28, 1994.
23. Letter dated July 14, 1994, from Steven J. Donohue, EPA, to ATSDR.
28 APPENDIX A. Figures
29 V... ' TT^ 7W •_^^-^5«<~~T'«'=v^ . .-. . ' . ^<^^.C^ »-- 3«.-^i " J .: • C / ^ r^t,V«. - ,-B-><£"--«5 --V _ : :• CITY OF LANCASTER s / T—! -• >x.-*«-->ii • Tfti•«••••- - / '•^>" ^ - •.•••. • . v. AUTHORITY INTAKE X -V. -e-» WEST HTMPFIELD
1300 MO 2000 3000 «000 WOO WOO
SOURCE'. (7,3 MINUTE SERIES) U.S.G S. COLUMBIA EAST & WEST. PA.. QUADS SITE LOCATION MAP UG1 CORP. (PP&D-COLUMB1A GAS PLANT -HINJUS SCALE I: 24000
30 TO SHAWNCE CREEK (330 FT.) -^
Figure 2 / BOAT STORAGE AREAS GRASS AREA GRAVEL. COVER
o
BULOMGS USED FOR SLOPE BOAT OCAIERSH*
45' u 7 i 1 GRAVEL AREA 40 45'
CONCRETE SLAB OVER 1 i GAS HOLDER ENTRANCE/BRICK __ JK ARCHWAY 'T
SLOPE 3ES7 TUNNEL ON \
Ov 65 OCAP •60' 1
MONITORING WELLS 65' CONCRETE SLAB RELIEF HOLDER
BOAT STORAGE AREAS SLOPE
FENCE
SITE SKETCH UGI CORP. (PP&D-COLUMB1A GAS PLANT ( NO SCALE > IMUS CXDRPORATON 31 Figure 3
\. LEGEND
BONING. NO I HID OR IU1NMI HO IAHS PfUSlNI CROSS SICIIUN HHIS
BOW INI, HAVING flflO ANO/OR IAHUNAIUHT IDlNllfllD TARS
AKIA Of »IVCR HAVING HUD IUINIII 110 IAMS LEQENO: SS - SIOIMINT SAMP14. SW - tURFACl WATIH
34 Figure 6 H EkL Kf I ?\
SITS LOCATION
;;f v QF i_ A _ _^ iUfMOHITY INTAivE r 5W-3
HEMPFIELD
M A N 0 R
LEGEND: AQUEOUS & SEDIMENT SAMPLE
-co :MO x» 1000 woo sxo
~: V«iMU*£ :£^ ES; - i : 5. -CLuMBIA EAST i WEST PA QUADS SURFACE WATER MIGRATION PATHWAY SAMPLE LOCATION MAP UGI CORP iPP&D-COLUMBIA GAS PLANT IMUS SCALE I. 24CCO i CORPORATOM 35 SOURCE: ATLAS OF PRELIMINARY GEOLOGIC QUADRANGLE MAPS OF PENNSYLVANIA GEOLOGIC MAP IMUS ATON UGI (PP&L) COLUMBIA GAS PLANT SITE APPENDIX B. Tables
37 Table 1. Relief Holder Pit Contaminant Concentrations (1,21)
Contaminant Location Maximum Comparison Value Concentration mg/kg (solid) mg/kg Source
arsenic relief holder ND 0.4 CREG benzflBe relief holder 320 20 CREG
B[a]P relief holder ND 0.1 CREG ethylbenzene relief holder 1,200 5,000- RMEG naphthalene relief holder 1,320 NA - toluene relief holder 920 10,000- RMEG a-Child. mg/kg - Milligrams Per Kilogram. NA - Not Available ND - Not Detected NT - Not Tested. CREG - Cancer Risk Evaluation Guide. RMEG - Reference Dose Media Evaluation Guide.
Table 2. Maximum Demonstration Well Contaminant Concentrations (4,21)
Contaminant Location Maximum Comparison Value Concentration jig/L (liquid) Mg/L Source
arsenic relief holder 270.0 0.02 CREG benmie relief holder 8,100 1 CREG BMP relief holder 530 0.005 CREG ethyftenzene relief holder 3,800 1,000- RMEG naphthalene relief holder 25,000 20 LTHA toluete relief holder 7,900 2,000- RMEG a-Child. fig/L - Micrograms Per Liter. CREG - Cancer Risk Evaluation Guide. LTHA - Lifetime Health Advisory RMEG - Reference Dose Media Evaluation Guide.
38 Table 3. Maximum On-Site Soil Contaminant Concentrations (4)
Contaminant Location Maximum Comparison Value Concentration mg/kg mg/kg Source
arsenic Subsoil 4 11.8 0.4 CREG benzene Subsoil 4 0.094 20 CREG B[a]P Subsoil 4 19 0.1 CREG ethylbenzene Subsoil 4 0.12 5,000- RMEG naphthalene Subsoil 4 13 NA - toluene Subsoil 4 0.022 10,000- RMEG a - Child. mg/kg - Milligrams Per Kilogram. NA - Not Available CREG - Cancer Risk Evaluation Guide. RMEG - Reference Dose Media Evaluation Guide.
Table 4. Maximum On-site Groundwater Contaminant Concentrations (1,4,21)
Contaminant Location Maximum Comparison Value Concentration Mg/L Mg/L Source
arsenic MW3S.MW3D 2 0.02 CREG benzene MW3S 310,000 1 CREG B[a]P MW3S 150 0.005 CREG ethylbenzene MW3S 60,000 1,000- RMEG naphthalene MW3S 7,600 20 LTHA toluene MW3S 190,000 2,000- RMEG a - Child. ftg/L - Micrograms Per Liter. ND - Not Detected. CREG - Cancer Risk Evaluation Guide. LTHA - Lifetime Health Advisory. RMEG - Reference Dose Media Evaluation Guide.
39 Table 5. Maximum Off-site Soil Contaminant Concentrations (4)
Contaminant Location Maximum Comparison Value Concentration mg/kg mg/kg Source
arsenic S9 12.9 0.4 CREG benzene All ND 20 CREG
B[a]P Subsoil 2 350 0.1 CREG ethylbeazene All ND 5,000- RMEG naphthalene Subsoil 2 73 NA . toluene All ND 10.000* RMEG a-Child. mg/kg - Milligrams Per Kilogram NA - Not Available ND - Not Detected CREG - Cancer Risk Evaluation Guide. RMEG • Reference Dose Media Evaluation Guide.
Table 6. Maximum Off-Site Groundwater Contaminant Concentrations (1,4)
Contaminant Location Maximum Comparison Value Concentration Mg/L MB/L Source
arsenic MW5 16.4 0.02 CREG
benzene MW6D 14,000 1 CREG B[a]P MW6S, MW6D ND 0.005 CREG ethylbenzene MW6D 1,600 1,000* RMEG
„,* naph^alene MW6D 5,650 20 LTHA
tolw|e MW6D 2,100 2,000- RMEG a-Child. pg/L - Micrograms Per Liter ND - Not Detected. CREG - Cancer Risk Evaluation Guide. LTHA* Lifetime Health Advisory. RME<§ - Reference Dose Media Evaluation Guide.
40 Table 7. Maximum Sediment Contaminant Concentrations (1,4)
Contaminant Location Maximum Comparison Value Concentration mg/kg mg/kg Source
arsenic SD4 10 0.4 CREG benzene SD1,2,3,4 ND 20 CREG B[a]P SS2 8.3 0.1 CREG ethylbenzene SD1,2,3,4 ND 5,000- RMEG naphthalene SS2 12 NA -
toluene SD1, 2,3,4 ND 10,000' RMEG a - Child. mg/kg - Milligrams Per Kilogram. NA - Not Available ND - Not Detected CREG - Cancer Risk Evaluation Guide. RMEG - Reference Dose Media Evaluation Guide.
Table 8. Maximum Surface Water Contaminant Concentrations (1,4)
Contaminant Location Maximum Comparison Value Concentration Mg/L H8/L Source
arsenic SW1,2,3,4,5 ND 0.02 CREG benzene SW3 20 1 CREG
B[a]P SW1, 2,3,4,5 ND 0.005 CREG ethylbenzene SW3 6 1,000- RMEG
naphthalene SW1,2,3,4,5 ND 20 LTHA
toluene SW3 4 2,000- RMEG a - Child. fig/L - Micrograms Per Liter ND - Not Detected CREG - Cancer Risk Evaluation Guide. LTHA - Lifetime Health Advisory RMEG - Reference Dose Media Evaluation Guide.
41 Table 9. Completed Exposure Pathways
Pathway Name Exposure Pathway Elements Time Source Environmental Point of Route of Exposed Medium Exposure Exposure Population tunnel tars UGI direct contact on site dermal, employee past inhalation tunnel tars UGI air on site inhalation employees past purifier chips UGI air on site inhalation employees past
Table 10. Estimated Population Potentially Affected By Completed Exposure Pathway
Potentially Exposed Populations Affected by a Completed Pathway Location Estimated Number Pathway Type P.nntamii^ntf in the Pathway on site 1 direct contact coal tar on site runnel Jars and purifier fewer than 50 air coal tar-related volatiles chips
42 Table 11. Potential Exposure Pathways
Pathway Exposure Pathway Elements Time Missing Pathway Name Component Source Environmental Point of Route of Exposed Media Exposure Exposure Population groundwater UGI groundwater cottages dermal, cottage future point of exposure ingestion, residents inhalation sediment UGI sediment river dermal, river users past, exposed ingestion, present, population future surface water- UGI surface water river dermal, river users past, exposed recreational ingestion, present, population inhalation future fish UGI fish river fishing ingestion persons who past, environmental consume fish present, media, point of from the river future exposure, exposed population surface water- UGI surface water Lancaster City dermal, potable water past, environmental public water Water intake ingestion, supply present, media, exposed supply inhalation customers future population
43 Table 12. Estimated Population Potentially Affected By Potential Exposure Pathway
Potentially Exposed Populations That Would Be Affected If Pathways Were Completed Group/Location Estimated Number Pathway Type Contaminants in the Pathway residents of cottages 12 groundwater benzene, ethylbenzene, naphthalene, toluene recreational liters of river unknown sediment arsenic, B[a]P recreational uters of river unknown surface water-recreational benzene people who consume fish from unknown fish arsenic, B[a]P the Susquehaana River people who u*e Lancaster 105,000 surface water-public water benzene, ethylbenzene, City's public Water supply supply naphthalene, toluene
44