PUBLIC HEALTH ASSESSMENT
TRAVELER'S REST, GREENVILLE COUNTY, SOUTH CAROLINA
Data in this section are from the 1993 Remedial Investigation and Feasibility Study (RI/FS)Reports and represent the latest available data for the Rochester site.
The tables in this section list the contaminants identified as being of concern. We evaluate thesecontaminants in the subsequent sections of the public health assessment and determine whetherexposure to them has public health significance. SCDHEC and ATSDR select and discuss thesecontaminants based upon the following factors:
- Contaminants of Concern on and off the site.
- Field data quality, laboratory data quality, and sample design
- Comparison of on-site and off-site concentrations with public health assessment comparison values for (1) non-carcinogenic endpoints and (2) carcinogenic endpoints.
- Community health concerns.
In the data tables that follow under the On-site and the Off-site Contamination subsections, thelisted contaminant does not mean that it will cause adverse health effects from exposures. ThisPublic Health Assessment identified iron and manganese as contaminants of concern. The othercontaminants listed in the tables were not at levels likely to cause adverse health effects.
=Cancer Risk Evaluation Guide
=Environmental Media Evaluation Guide
=Reference Dose Media Evaluation Guide
=parts per million, milligrams per kilogram in soil (mg/kg)
=parts per billion, micrograms per liter in water (µg/kg)
Comparison values for public health assessments are contaminant concentrations in specificmedia that are used to select contaminants for further evaluation. These values include EMEGs,CREGs, and other relevant guidelines. CREGs are estimated contaminant concentrations basedon one excess cancer in a million persons exposed over a lifetime. CREGs are calculated fromEPA's cancer slope factor. EMEGs are derived from ATSDR Minimal Risk Levels (MRL), theestimate of a daily human exposure to a chemical likely to be without an appreciable risk of non-carcinogenic adverse effects, generally for a period of a year or longer. EPA's RfD is an estimateof the daily exposure to a contaminant that is unlikely to cause adverse health effects. RMEGsare media-specific comparison values derived from EPA reference doses and are used to selectcontaminants of concern at hazardous waste sites.
Toxic Chemical Release Inventory (TRI)
TRI was developed by the EPA from chemical release information provided by certain industries. The chemical release information is based on contaminants released to air, surface water,groundwater, and/or soil.
Project staff conducted a search of the TRI database to include the years 1987 through 1991. TRIlocated three facilities within one mile of the Rochester site. This includes the South CarolinaGalvanizing Division, Air Products and Chemicals Company, and the Rocky Mountain IndustriesKerr Finishing Company. However, available data cannot link releases from these industries tocontaminants detected in media on or near the Rochester site.
As part of the RI, RMT collected soil samples from on-site locations to determine what impactthe waste disposal activities may have had on the site. RMT additionally wanted to determinethe success of the soil removal actions previously performed on the site. RMT collected 11surface soil samples and 30 subsurface soil samples from on-site locations (Figures 2 and 3). The RI defines surface soil samples as samples collected from 0" to 12" below the land surface;however, ATSDR defines surface soil samples as those collected from 0" to 3" in depth. ATSDR's definition is representative of depths of soil that people are most likely to be exposedto. Therefore, this public health assessment will address the RI surface soil samples as SoilSamples (0" - 12" deep).
The site is situated in the Piedmont physiographic province of South Carolina. Piedmont sitesgenerally have a thick layer of highly weathered residual soil and weathered rock (saprolite - ofshallow aquifer) overlying the bedrock (deep aquifer). Residual soils are formed by mechanicaland chemical weathering of rocks and other materials. The residual soil and saprolite thicknessin the Piedmont province is variable, and can be greater than 80 feet. The soils on the site wereformed by in-place weathering of the underlying rock. The exception is the fill material found inthe former waste disposal trenches.
- Soil Samples (0" - 12" deep)
RMT collected 11 on-site soil samples (0" - 12" deep) designated as SS-03 to SS-13 (Figure 2). Two samples were collected from off-site locations upgradient of the site to provide informationabout naturally occurring concentrations in the region (SS-01 and SS-02). No contaminants ofconcern were identified in this medium.
- Subsurface Soil
RMT collected 30 subsurface soil samples from 18 on-site soil borings (Figure 3). Additionally,samples were collected from two off-site background locations (SB-01- and SB-02). The depthsat which the samples were collected range from 11.5' to 20' below ground surface. Nocontaminants of concern were identified in this medium.
RMT installed 6 on-site monitoring wells to characterize geologic and hydrogeologic conditionsbeneath the site and to assess groundwater quality (Figure 4). As with the soil investigation,samples were also collected from an off-site location (MW-01) to provide backgroundconcentration information for this region. Each monitoring well was installed in pairs: one wascompleted in the saprolite (shallow) aquifer and the other in the bedrock (deep) water tableaquifer. Monitoring wells (MW) #5 and #8 were installed only in the saprolite aquifer. Samplesfrom the monitoring wells completed in the bedrock aquifer were collected to monitorcontaminant migration patterns.
Water tables were encountered at depths ranging from 5.5' to 23' below the ground surface. TheRI concluded that groundwater flow in the shallow portion of water table aquifer (saproliteaquifer) is to the east-northeast towards the North Stream and groundwater in the deep aquiferflow to the northeast.
Sampling data indicate that groundwater contamination exists on the site. Volatile organiccompounds (VOCs) and inorganic compounds were detected in the samples. Samples collectedfrom the background location identified VOCs, semi-volatile organic compounds and inorganiccompounds at lower concentrations than those detected on-site. Table 2 presents contaminants ofconcern identified in this medium.
RMT conducted on-site air monitoring during the Remedial Investigation field work to evaluateany impacts on ambient air quality associated with potential release of site-related contaminantsat or near the site. However, no data are available for review.
- Soil Samples (0 - 12 inches deep)
As part of the RI, two off-site soil samples (SS-01 and SS-02) were collected to provideinformation about concentrations expected in the region (Figure 2). No contaminants of concernwere identified in this medium.
|Contaminant||Concentration Range-ppb||Location of Maximum Value||Comparison Value|
* = Data Source: RMT, Inc., 1993 RI
ND = The contaminant was not detected in the sample
J = The value for the contaminated is an estimated value
- Subsurface Soil Samples
Two background subsurface soils samples were collected and analyzed as part of the RI (Figure 3). No contaminants of concern were identified in this medium.
RMT collected samples from seven off-site groundwater monitoring well locations (Figure 4). One of these sampling locations (MW-01) was used to represent background concentrations ingroundwater for this region. The remaining monitoring wells (MW-05 to MW-08) are locatedhydraulically downgradient of the waste trenches at the site. The purpose of this investigationwas to monitor migratory patterns of site-related contaminants in groundwater. Table 3 presents the contaminants of concern identified in this medium.
|Contaminant||Concentration Range-ppb||Location of Maximum Value||Comparison Value|
* = Data Source: RMT, Inc., 1993 RI B = Concentration less than Contract Required detection limit but greater or equal to Instrument detection limit.
Surface Water and Sediment
The highest concentrations of inorganic compounds in sediments were detected in SD-01upgradient of the site. In general surface water and sediment samples collected from the northstream contain the highest contaminant concentrations. Contaminants of concern identified insurface water are presented in Table 4. Table 5 presents the contaminants of concern identifiedin sediment samples.
|Contaminant||Concentration Range-ppb||Location of Maximum Value||Comparison Value|
* = Data Source: RMT, Inc., 1993 RI ND = The contaminant is not detected in the sample J = The value for the contaminant is an estimated value
|Contaminant||Concentration Range-ppm||Location of Maximum Value||Comparison Value|
* = Data Source: RMT, Inc., 1993 RI
j = Concentration is an estimate based on data validation
The data in this section are from the 1993 Remedial Investigation report and represent the latestinformation for this site. Quality Assurance and Quality Control (QA/QC) conclusions drawn forthis public health assessment are determined by the validity of the analysis and conclusions madeand the availability and reliability of the referenced information. SCDHEC assumes thatadequate quality assurance and quality control measures were followed with regard to chain-of-custody, laboratory procedures, and data reporting. All data have undergone a quality assurancereview. Overall, the data appears to be reliable; however, some inconsistencies were noted indata validation for groundwater, surface water, and sediment samples.
The holding times for mercury and cyanide analysis were exceeded for sediment samples SD01,SD02, and SD03; therefore, these samples were not analyzed for mercury and cyanide. Bis(2-ethylhexyl)phthalate, butyl benzyl phthalate, and di-n-butylphthalate were detected in laboratoryquality control samples during phase I of the RI; however, they were not validated because theywere also detected in the associated method blanks.
Data for groundwater monitoring wells #3 and 4 appear to have been reversed between the firstand second phases of sampling collection. Specifically, trichloroethene (TCE) was detected inMW-04A but not in MW-03 during the first phase of sampling; however, during the secondphase of sampling TCE was detected at an estimated concentration in MW-03 and was notdetected in MW-04A. Additionally, bis(2-ethylhexyl) phthalate was not validated in fivesamples collected during the first phase of sampling because it was detected in method and fieldblanks; it was also not validated in seven samples collected during the second phase of samplingbecause it was detected in method blanks; and, it was not validated in twelve samples collectedduring the third phase of sampling. During the third round of groundwater sampling, acetone,chloroform, 1,1-dichloroethene, methylene chloride, and toluene were detected but not validatedin some samples because these compounds were detected in the associated blanks.
The EPA has restricted access to the Rochester site and local residents are not believed totrespass onto the site. Therefore, the physical hazards are only expected for people who work onthe site. As part of the 1993 site visit, project staff only noted that heavy vegetation over most ofthe site and approximately fifty which presents a physical hazard to people who enter the site. Additionally, staff noted approximately fifty 55-gallon drums in different clusters throughout thesite. These drums may also pose a physical hazard to people who enter of work on the site.
To determine whether nearby residents are exposed to contaminants migrating from the site,ATSDR evaluates the environmental and human components that lead to human exposure. Thispathways analysis consists of five elements: A source of contamination, transport through anenvironmental medium, a point of exposure, a route of human exposure, and an exposedpopulation.
ATSDR categorizes an exposure pathway as a completed or potential exposure pathway if theexposure pathway cannot be eliminated. Completed pathways have all five elements and indicatethat exposure to a contaminant has occurred in the past, is currently occurring, or will occur inthe future. Potential pathways, however, have at least one of the five elements missing, but couldbecome completed. Potential pathways indicate that exposure to a contaminant could haveoccurred in the past, could be occurring now, or could occur in the future. An exposure pathwaycan be eliminated if at least one of the five elements is missing and will never be present. Table 10 identifies the potential exposure pathways. The discussion that follows incorporates onlythose pathways that are important and relevant to the site.
Currently, there are no known past or present human exposures occurring at the Rochester site. Therefore, no completed exposure pathways were identified in this public health assessment. On-site workers may have been exposed to contaminants in the past; however, no data areavailable from the past to evaluated the length of exposure, the concentrations of contaminationin the past, or the health effects associated with exposures.
Some of the contaminants present in soil may leach into groundwater. Infiltration andprecipitation will aid in the leaching process. Once in groundwater, contaminants are transportedin the direction of groundwater flow, but at a slower rate. Groundwater flow beneath the site isto the east and northeast toward the north stream. The site topographically slopes to thenortheast, east, and southeast; therefore, contamination found on the ground surface couldmigrate off the property in these directions after precipitation.
|Exposure Pathway Elements||Time|
|Source||Environmental Medium||Point of Exposure||Route of Exposure||Exposed Population|
|Rochester||Surface Water and Sediment||Off-Site||Ingestion|
As part of the RI, a private well survey was conducted to assess the number of residences thatutilize private drinking water wells as their source of potable water. Sixty two residences wereidentified within a one-half mile radius of the site; of these 35 residences participated in thesurvey. Of these residences all but two use private wells as their primary potable water source. Springs were listed as the water supply source for two of these homes. A potable water supplypipeline is available in the vicinity of most of the homes identified that still use private wells. The RI reports that water is primarily used for drinking, household uses, irrigation, and forlivestock.
During the June 1993 EPA-sponsored public meeting, one resident living near the site, expressedconcerns that his private drinking water well has not been tested. An EPA representative statedthat the EPA would collect sampling data from the well to determine possible extent ofcontamination. No private well sampling data were available for review during the preparationof this public health assessment. This pathway will be updated when data become available.
In the future, exposures to contaminated groundwater could occur to anyone who installs aprivate well in the area of groundwater contamination. Exposures could occur through ingestionor dermal contact with the contaminated medium.
Surface Water and Sediment Pathway
Surface water drainage from the site is toward the north, northeast, south, and southeast. As partof the RI, groundwater flow was determined to be to the north and northeast toward the northstream. Contamination was detected in the north and in the south surface streams.
Past, current, or future exposure pathways may result from exposures to contaminants detected insurface water and sediments from both water bodies located near the site (the north and southstreams). Currently, exposures are not expected to result in adverse health effects. Pastexposures cannot be evaluated due to lack of data from the past. Future exposure pathways couldoccur through incidental ingestion or through dermal contact with the contaminated media.
In this section, we will discuss the health effects in persons exposed to specific contaminants,evaluate state and local health databases, and address specific community health concerns. Toevaluate health effects, ATSDR has developed Minimal Risk Levels (MRLs) for contaminantscommonly found at hazardous waste sites. The MRL is an estimate of daily human exposure to acontaminant below which non-cancer, adverse health effects are unlikely to occur. MRLs aredeveloped for each route of exposure, such as ingestion and inhalation, and for the length ofexposure, such as acute (less than 14 days), intermediate (15 to 364 days), and chronic (greaterthan 365 days). ATSDR presents these MRLs in Toxicological Profiles. These chemical-specific profiles provide information on health effects, environmental transport, human exposure,and regulatory status. If no MRLs are available, RfDs will be used in the following discussion. The following evaluation will only address potential exposure pathway scenarios as nocompleted exposure pathways were identified for this site.
Iron is essential in the human diet. The Recommended Daily Allowance for iron in the diet is10-18 mg/day. However, excess iron in the diet may result in adverse health effects. Ingestion oflarge amounts of iron may cause vomiting, liver damage, and renal failure. Excessive iron in thediet over time may lead to accumulation of iron in the liver, disturbance of liver function, andcardiovascular effects (Klaassen 1986).
This public health assessment identified potential exposure pathways for iron. Exposure to ironmay occur in the future through the ingestion of or dermal contact with contaminated on-sitegroundwater or off-site surface water or sediment.
ATSDR has not established a MRL for iron and the EPA has not established a RfD for iron. Available data suggest that the levels of iron identified in the samples are not sufficient to causeadverse health effects. However, the levels of iron in groundwater may make the water taste bad.
Manganese is a naturally-occurring element. Small amounts of manganese are an essential partof the human diet. Some manganese compounds are used in the production of batteries, and as acomponent of some ceramics, pesticides, fertilizers, and nutritional supplements.
This public health assessment identified potential exposure pathways for manganese. Humanexposures may occur in the future if contaminated on-site groundwater or if off-site groundwateror surface water is ingested or comes into contact with the skin.
The EPA established a chronic oral reference dose of 0.005 milligrams per kilogram per day(mg/kg/day) for manganese. The following scenarios represent exposures to manganese thatcould occur above the reference dose: 1) adults who ingest contaminated on-site groundwater;and, 2) adults and children who ingest contaminated off-site groundwater. The precedingscenarios state what may occur, not that people are exposed to water containing elevated levels ofmanganese.
The reference dose for manganese is based on a Greek study where people were chronicallyexposed to manganese in their drinking water. This study concluded that people who wereexposed to elevated dietary manganese (0.059 mg/kg/day) for 50 years or more may be morelikely to experience neurological effects. The levels of manganese at the Rochester site are lowerthan those documented in the Greek study and no health effects are anticipated from ingestion ordermal exposure to manganese.
Contaminants Not Considered of Public Health Concern
The following chemicals were detected at the Rochester site; however, analysis of theconcentrations of these compounds do not present levels considered to be of public healthconcern at this time: aluminum, arsenic, benzene, beryllium, bis(2-ethylhexyl)phthalate,chloroform, cobalt, copper, 1,2-dichloroethene, lead, thallium, 1,1,1-trichloroethane, andtrichloroethene. SCDHEC and ATSDR will continue to monitor the levels of these contaminantsat the Rochester site. If conditions at the site change, SCDHEC and ATSDR will reevaluate thepublic health implications of these contaminants.
As no health outcome data are available for the Rochester Property site, there is no furtherdiscussion at this time.
Community members were concerned about the potential for site-related contaminants to havemigrated to Armstrong Creek. Surface water and sediment samples collected as part of the RIidentified contaminants of concern in these media; however, the levels of the contaminants arelow and not expected to cause adverse health effects.
During the June 1993 EPA-sponsored public meeting, one resident living near the site, expressedconcerns that his private drinking water well has not been tested. An EPA representative statedthat the EPA would collect sampling data from the well to determine possible extent ofcontamination. No private well sampling data were available for review during the preparationof this public health assessment; therefore, this community health concern cannot be evaluated inthis public health assessment.