PUBLIC HEALTH ASSESSMENT
PALMETTO WOOD PRESERVING, INC.
CAYCE, LEXINGTON COUNTY, SOUTH CAROLINA
ENVIRONMENTAL CONTAMINATION AND OTHER HAZARDS
Data in this section are from the 1987 Remedial Investigation report and Feasibility Study. This represents the latestinformation for this site.
The tables in this section list the contaminants of concern. We evaluate these contaminants in the subsequent sections ofthe public health assessment and determine whether exposure to them has public health significance. This public healthassessment selects and discusses these contaminants based upon the following factors:
- Concentrations of contaminants on and off the site.
- Field data quality, laboratory data quality, and sample design.
- Comparison of on-site and off-site concentrations with background concentrations, if available.
- 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.
Contaminants that are listed in the data tables for this section should not be interpreted to mean that they will cause harmfulhealth effects. Rather, the list identifies contaminants that need to be evaluated further in later sections of the public healthassessment.
The data tables include the following acronyms:| CREG | = Cancer Risk Evaluation Guide |
|---|
| EMEG | = Environmental Media Evaluation Guide |
|---|
| MCLG | = EPA Maximum Contaminant Level Goal |
|---|
| MCL | = EPA Maximum Contaminant Level |
|---|
| PMCLG | = EPA Proposed MCLG |
|---|
| PMCL | = EPA Proposed MCL |
|---|
| RfD | = EPA Reference Dose |
|---|
| LTHA | = EPA Lifetime Health Advisory |
|---|
Contaminants requiring further evaluation are selected by using medium-specific, comparison values. These valuesinclude EMEGs, CREGs, and other relevant guidelines. CREGs are estimated contaminant concentrations based on theprobability that one additional cancer case may occur in excess of the number that will be expected to occur among onemillion persons (assuming they have been exposed to the contaminant for a lifetime). CREGs are calculated from EPA'scancer slope factors. EPA's MCLG is a drinking water health goal. EPA believes that the MCLG represents a level atwhich "no known or anticipated adverse health effect on human health occurs which allows an adequate margin of safety." PMCLGs are MCLGs that are being proposed. MCLs represent contaminant concentrations that EPA deems protectiveof public health over a lifetime (70 years) at an exposure rate of 2 liters of water per day; however, in deriving these levelsthe EPA takes into consideration the technical feasibility and economics of water treatment. While MCLs are regulatoryconcentrations, PMCLGs and MCLGs are not. EPA's RfD is an estimate of the daily exposure to a contaminant that isunlikely to cause adverse health effects.
Toxic Chemical Release Inventory (TRI)
TRI is developed by the U.S. Environmental Protection Agency (EPA) from the chemical release information providedby certain industries. The chemical release information is based on contaminants found in air, surface water, groundwater, or soil.
Project staff conducted a search of EPA's Toxic Chemical Release Inventory (TRI) for the years 1988, 1989, and 1990. The search included a 1-mile radius from the plant. As the site was not active in these years, TRI does not provide a listingfor this site. TRI did not include any other facilities within a 1-mile radius of the site.
A. On-site Contamination
Sampling data from the 1987 RI indicate that soil and groundwater contain elevated levels of arsenic, chromium, andcopper. In addition to these metals, a number of organic compounds have been identified at the site.
Soil
The soil samples collected on-site range from 0' to 3' and represent four major areas: (1) the drip shed; (2) the narrowgauge railway; (3) the storage yard; and (4) surface water pond areas near the eastern boundary of the site (Figures 7-1to 7-4). The highest concentrations of contaminants were found in the drip shed and narrow gauge railways areas. Samples were collected from fifty locations.
Soil analyses showed that the metal concentrations found decreased with depth, with the contamination principallyconfined to the upper 10 feet of soil. The highest concentrations of contaminants found in subsurface soil samples wereassociated with the drip shed, narrow gauge, and storage tank areas. Subsurface soil sampling depths for the RI variedfrom 0 to 27.5 feet.
Arsenic, chromium, and benzo(a)pyrene were detected in on-site soil and found to exceed the comparison values for soil. Contaminants detected in on-site soil are listed in Tables 2 and 3.
Soil remediation on the PWP site is complete. Additional soil samples are needed to better characterize the extent ofcontamination found on-site after remediation.
Table 2.
Contaminants of Concern -- Concentration in Soil On-site* | Contaminant | Concentration
Range - ppm | Location
Of
Maximum
Value | Comparison
Value |
|---|
| ppm | Source |
|---|
| Arsenic | 2.4 - 6200J | NG16
DS02 | 210 | Rfd(Adult) |
|---|
| Chromium | ND - 6200 | DS02 | 3500 | Rfd(Adult) |
|---|
| Copper | ND - 3600 | DS02 |
| No Value |
|---|
| Sodium | ND - 960J | NG03 |
| No Value |
|---|
| Benz(A)Anthracene | ND - 1.2 | NG01 |
| No Value |
|---|
| Chrysene | 0.045J - 1.2 | NG01 |
| No Value |
|---|
Benzo(B and/or K)
Fluoranthene | 0.2J - 0.9 | DS02 |
| No Value |
|---|
| Benzo(a)pyrene | 0.062J - 0.66 | DS02 | 0.12 | CREG |
|---|
| Indeno(1,2,3-cd)pyrene | 0.25J - 0.38J | DS02 |
| No Value |
|---|
| Dibenz(A,H)Anthracene | 0.13J - 0.15J | DS02 |
| No Value |
|---|
| Benzo(ghi)Perylene | 0.068J - 0.32 | DS02 |
| No Value |
|---|
* = All data were obtained from (
Camp et al 1987a)
** = Only 1 sample taken
J = Estimated value
ND = Not detected
Table 3.
Contaminants of Concern -- Concentration in Subsurface Soil On-site* | Contaminant | Concentration
Range - ppm | Location
of
Maximum
Value | Comparison
Value |
|---|
| ppm | Source |
|---|
| Arsenic | ND - 520 | SB17 | 210 | Rfd(Adult) |
|---|
| Copper | 3.7 - 620 | SB17 |
| No Value |
|---|
* = All data were obtained from (
Camp et al 1987a)
** = Only 1 sample taken
J = Estimated value
ND = Not detected
Groundwater
Samples from six clusters of twelve permanent monitoring wells and twenty-one temporary wells were taken during theRI. Arsenic, chromium, vanadium, and 1,1-dichloroethene were found to exceed the comparison values for groundwater.Iron was also detected in groundwater samples but does not have a comparison value (Figure 10). The RI concluded thatthe extent of contamination in water is principally confined to the shallow unconfined aquifer.
Groundwater remediation on-site has not been completed. Additional on-site samples are needed to better characterizethe extent of groundwater contamination. As the groundwater remediation is completed, additional samples will be neededto determine the degree of contamination on the PWP site.
Table 4.
Contaminants of Concern -- Concentration in Groundwater On-site* | Contaminant | Concentration
Range - ppb
| Location
of
Maximum
Value | Comparison
Value |
|---|
| ppb | Source |
|---|
| Arsenic | ND - 170J | MW08 | 3 | Rfd(Child) |
|---|
| Chromium | 18 - 1,150 | MW12 | 50 | Rfd(Child) |
|---|
| Vanadium | 34 - 36 | MW08 | 20 | LTHA |
|---|
| Iron | ND - 13,000 | MW04 |
| No Value |
|---|
| 1,1-Dichloroethene | 1J ** | MW01 | 0.058 | CREG |
|---|
* = All data in this table were obtained from (Camp et al 1987a)
** = Only 1 sample reported
J = Estimated value
ND = Not detected
Groundwater - Temporary Wells
Twenty-one temporary wells were drilled during the RI (15 were drilled on-site) to evaluate potential contaminantmigration in the shallow unconfined aquifer and to determine if contaminants have migrated off-site.
On-site groundwater concentrations of arsenic, chromium, and copper were found to exceed comparison values (Figure11). Contaminants found in temporary wells are included in Table 5.
Data gaps exist in temporary well samples on-site. Data was not reported for all temporary wells and concentrationsreported indicate that soil contamination of the wells may have resulted. Additional sampling is needed to characterizethe contaminants found in on-site temporary wells.
Table 5.
Contaminants of Concern -- Concentration in Temporary Wells On-site* | Contaminant | Concentration
Range - ppb | Location
of
Maximum
Value | Comparison
Value |
|---|
| ppb | Source |
|---|
| Arsenic | ND - 1,600 | GW03
GW04 | 3 | Rfd(Child) |
|---|
| Chromium | 95 - 110,000 | GW10 | 50 | Rfd(Child) |
|---|
| Copper | 24 - 2,000 | GW10 | 1,300 | MCL |
|---|
| Sodium | 3,500 - 160,000 | GW05 |
| No Value |
|---|
* = All data in this table were obtained from (
Camp et al 1987a)
J = Estimated value
N = Presumptive evidence of presence of material
ND = Not detected
Air
The investigative team for the RI used air monitoring equipment prior to the site visit, and during the initial site visit. During the RI, the air was continuously monitored. Results of air monitoring on-site indicated no readings of organicvapors that exceeded action levels.
The on-site soil remediation has been completed, making the possibility of soil becoming airborne and resulting in aircontamination very unlikely. However, if the area should become further developed, additional monitoring should to beconducted and this conclusion may change.
B. Off-site Contamination
Soil
No surface soil data exist for this site. Surface soil is defined by ATSDR to be from 0" - 3" of soil.
During the RI, soil samples were taken and analyzed to characterize the type and extent of vertical soil contamination. A total of twenty-one boreholes were drilled at/or near the site. The soil boring sampling locations were in the mainprocess/narrow gauge railway and drip shed areas (Figure 8).
Two laboratories collected samples to evaluate migration patterns of contaminants from the PWP site; one an on-sitelaboratory, the other a contracted laboratory. The on-site laboratory analyzed soil samples for chromium, copper, andPCP. The contracted laboratory detected arsenic and benzo(a)pyrene at levels exceeding comparison values. Table 6 listscontaminants of concern for soil off-site.
Subsurface soil samples were taken in the same manner as on-site subsurface soil samples. Arsenic and chromium weredetected at levels that exceeded the comparison values. Copper, which has no comparison value, was also detected. Table7 presents contaminants of concern found in subsurface soil samples.
The on-site soil remediation has been completed; however, we have no current data to evaluate contaminant levels foundon-site or off-site. When this data becomes available, we may better evaluate the current concentrations of contaminantsfound. Surface soil samples (ATSDR definition - 0 - 3") are needed to better characterize the extent of contamination andto better determine the possibility for exposures to surface soil by local residents.
Table 6.
Contaminants of Concern - Concentration in Soil Off-site* | Contaminant | Concentration
Range - ppm | Location
of
Maximum
Value | Comparison
Value |
|---|
| ppm | Source |
|---|
| Arsenic | 3.6 - 32 | NG15 | 15 | Rfd(Child) |
|---|
| Benz(A)Anthracene | 0.087J - 0.18J | SWP11 |
| No Value |
|---|
| Chrysene | 0.19J - 0.3J | SWP11 |
| No Value |
|---|
Benzo(B and/or K)
Fluoranthene | 0.21J - 0.31J | SWP11 |
| No Value |
|---|
| Benzo(a)pyrene | 0.16J | SWP10
SWP1 | 0.12 | CREG |
|---|
| Lead | 1 - 280 | SWP07 |
| No Value |
|---|
| Dibenz(A,H)Anthracene | 0.15J - 0.15J | SWP07 |
| No Value |
|---|
* = All data in this table were obtained from (
Camp et al 1987a)
J = Estimated Value
Table 7.
Contaminants of Concern - Concentration in Subsurface Soil Off-site* | Contaminant | Concentration
Range - ppm | Location
of
Maximum
Value | Comparison
Value |
|---|
| ppm | Source |
|---|
| Arsenic | ND - 970 | SB10 | 15 | Rfd(Child) |
|---|
| Chromium | 4 - 1400 | SB09 | 250 | Rfd(Child) |
|---|
| Copper | 3.7 - 1100 | SB10 |
| No Value |
|---|
* = All data in this table were obtained from (
Camp et al 1987a)
J = Estimated Value
ND = Not detected
Groundwater
Samples from six clusters of twelve monitoring wells and twenty-one temporary wells were taken during the RI. Chromium, copper, and vanadium concentrations exceeded comparison values. Iron, which has no comparison value, wasalso detected in off-site groundwater. Table 8 presents the contaminants of concern found in groundwater off-site.
Site topography shows three water drainage patterns and the groundwater flow through the PWP site (Figure 6). Additional monitoring wells are needed to better ascertain the extent of contaminant migration from the site.
Three of the four contaminants of concern were detected in one sample cluster. This sample cluster is on the sameproperty but at different locations and varying depths (Figure 10). These samples give an accurate reading of contaminantmigration from the site to that area; however, the property has been abandoned and more sampling locations and additionaldata are needed to determine contaminant migration to the southwest and southeast of the site.
Table 8.
Contaminants of Concern - Concentration in Groundwater Off-site* | Contaminant | Concentration
Range - ppb | Location
of
Maximum
Value | Comparison
Value |
|---|
| ppb | Source |
|---|
| Chromium | 13 - 7,800 | MW10 | 50 | Rfd(Child) |
|---|
| Copper | ND - 2,700 | MW16 | 1300 | MCL |
|---|
| Vanadium | ND - 79 | MW04 | 20 | LTHA |
|---|
| Iron | 400 - 24,000 | MW04 |
| No Value |
|---|
* = All data in this table were obtained from (
Camp et al 1987a)
J = Estimated value
ND = Not detected
Groundwater - Temporary Wells
Temporary wells were drilled to evaluate potential contaminant migration in the shallow unconfined aquifer and todetermine if contaminants have migrated off-site.
Arsenic, nickel, lead, vanadium, and manganese concentrations exceeded comparison values. Several other contaminants,see Table 9, were also detected but no comparison values were available.
Data reported for off-site temporary wells included only one temporary well and cannot be considered an adequaterepresentation of migration from the site; therefore, a significant data gap exists in assessing the site's public healthimplications. Additional sampling of off-site temporary wells is needed to better characterize the extent of contaminantmigration.
Table 9.
Contaminants of Concern -- Concentration in Temporary Wells Off-site* | Contaminant | Concentration
Range - ppb | Location
of
Maximum
Value | Comparison
Value |
|---|
| ppb | Source |
|---|
| Arsenic | 2,200 ** | GW08 | 3 | Rfd(Child) |
|---|
| Nickel | 200 ** | GW08 | 100 | LTHA |
|---|
| Lead | 270 ** | GW08 | 50 | MCL |
|---|
| Vanadium | 890 ** | GW08 | 20 | LTHA |
|---|
| Manganese | 2,600 ** | GW08 | 1,000 | Rfd(Child) |
|---|
| Iron | 320,000 ** | GW08 |
| No Value |
|---|
| Sodium | 23,000 ** | GW08 |
| No Value |
|---|
* = All data in this table were obtained from (
Camp et al 1987a)
** = Only 1 sample reported
Groundwater - Private Wells
Nine private wells were sampled in the vicinity of the PWP site to indicate the extent of contaminant migration viagroundwater and to assess potential health hazards to neighboring residents (Figure 5).
Only one well (PW01) showed contamination by chromium in excess of comparison values (Table 10). PW01 is locatedsoutheast of the site and is no longer used. When contamination was detected, the homeowners were supplied with wellwater and later with municipal water.
Groundwater remediation for the PWP site is not complete and current private well sampling is needed to characterize theextent of contaminant migration from the site to local residential wells.
Table 10.
Contaminants of Concern -- Concentration in Private Wells Off-site* | Contaminant | Concentration
Range - ppb | Location
of
Maximum
Value | Comparison
Value |
|---|
| ppb | Source |
|---|
| Chromium | ND - 8,600 | PW01 | 50 | Rfd(Child) |
|---|
* = All data in this table were obtained from (
Camp et al 1987a)
ND = Not detected
Surface Water and Sediment
Surface water and sediment samples were collected to investigate the possibility that surface water runoff represents amigratory pathway for contaminant movement off-site. Areas sampled consisted of a discharge point at the pond locatedapproximately 150 feet southwest of the site, a swampy area located approximately 3,000 feet northeast of the site, adrainage area approximately 1,500 feet southeast of the site, an unnamed creek exiting the swampy area locatedapproximately 7,000 feet east of the site, and a discharge feature from the swampy area approximately 6,000 feet northeastof the site (Figure 9).
Surface water samples were collected in compliance with EPA protocol. Samples were analyzed for extractable(semivolatiles - compounds which do not readily evaporate) and volatile organic compounds (VOCs), pesticides, metals,and cyanide. Surface water samples detected arsenic, vanadium, manganese, and bis(2-ethylhexyl)phthalate at levels thatexceed the comparison values. Table 11 presents contaminants of concern for surface water.
Sediment sampling detected arsenic at a level that exceeded the comparison value. No organic compounds were detectedin these samples. At this time, there are no plans to remediate surface water and sediments. Table 12 presentscontaminants of concern for sediment.
More current sampling data and more sampling locations are needed to determine the extent of contamination in these media.
Table 11.
Contaminants of Concern -- Concentration in Surface Water Off-site* | Contaminant | Concentration
Range - ppb | Location
of
Maximum
Values | Comparison
Value |
|---|
| ppb | Source |
|---|
| Arsenic | ND - 78 | SW01 | 3 | Rfd(Child) |
|---|
| Vanadium | ND - 36 | SW02 | 20 | LTHA |
|---|
| Manganese | 180 - 8,200 | SW04 | 1000 | Rfd(Child) |
|---|
| Iron | 1100 - 77,000 | SW01 |
| No Value |
|---|
| Sodium | 3100 - 16,000 | SW03 |
| No Value |
|---|
Bis(2-Ethylhexyl)
Phthalate | ND - 5,500 | SW02 | 2.5 | CREG |
|---|
* = All data in this table were obtained from (
Camp et al 1987a)
ND = Not detected
Table 12.
Contaminants of Concern -- Concentration in Sediment Off-site* | Contaminant | Concentration
Range - ppm | Location
of
Maximum
Value | Comparison
Value |
|---|
| ppm | Source |
|---|
| Arsenic | ND - 33 | SD01 | 15 | Rfd(Child) |
|---|
* = All data in this table were obtained from (
Camp et al 1987a)
ND = Not detected
Air
The investigative team for the RI used air monitoring equipment during the initial site visit and throughout the remedialinvestigation. Results of the monitoring off-site indicated no readings of organic vapors above EPA action levels. However, should the area be further developed the air should be monitored again to confirm these conclusions.
C. Quality Assurance and Quality Control (QA/QC)
The data in this section are from the 1987 Remedial Investigation/Feasibility Study. Thus, this report contains the latestdata for this site. Quality Control and Quality Assurance conclusions drawn for this public health assessment aredetermined by the validity of the analysis and conclusions made and the availability and reliability of the referencedinformation. SCDHEC assumes that adequate quality assurance and quality control measures were followed with regardto chain-of-custody, laboratory procedures, and data reporting.
Analyses of different media for chromium obtained data on only total chromium. Therefore, no analytical informationexists on the state/form of chromium in the sampled media. In this public health assessment, we have assumed thatchromium in the environment exists in the Chromium VI state.
At the end of each medium discussion in the preceding subsections of On-site and Off-site Contamination, we haveexplained whether the information is sufficient to make an assessment of the levels of contaminants to which persons areor might be exposed. Overall, the data appears to be reliable; however, data reported for temporary wells, both on-siteand off-site, do not present reliable information and will not be evaluated further in this public health assessment.
D. Physical and Other Hazards
The site is secured by an 8-foot high chain-link fence with barb wire on top and evidence does not indicate trespassinghas occurred or will occur in the future. There are high weeds and an abandoned old truck in the southwestern border ofthe site. There are several wood piles on the former manufacturing company located next to the site. These conditionspotentially present a physical hazard to anyone who may wander into the area.
PATHWAYS ANALYSES
To determine whether nearby residents are exposed to contaminants migrating from the site, SCDHEC evaluates theenvironmental and human components that lead to human exposure. Pathway analyses consist of the following fiveelements: a source of contamination, transport through an environmental media, a point of exposure, a route of humanexposure, and ultimately the exposed population.
SCDHEC identifies exposure pathways as completed, potential, or eliminated. Completed pathways are those that meetthe five elements listed above. Potential pathways indicate that exposure to a contaminant may have occurred, may beoccurring, or may occur in the future. A potential pathway exists when one of the above listed five elements is missing,but could exist. An eliminated pathway occurs when at least one of the five elements is missing and will never be present.
A. Completed Exposure Pathways
Groundwater
Past, current, and future exposure pathways may result from contamination of groundwater at several points of exposure:residential wells, undeveloped areas, and the site. While several points of exposure could occur in the future, we believethat only residential wells and undeveloped areas represent likely points of exposure.
The RI sampling data show that contaminants have migrated off the PWP site. Contaminants exceeding the comparisonvalues were detected in off-site monitoring wells and one private drinking well (PW01). PW01 (Figure 5) is locatedsoutheast of the site. A past exposure pathway exists for people who used PW01 by ingestion of groundwater and dermalcontact. The owner of PW01 was advised to discontinue use of the well. No data are available from the past to evaluatelength of exposure or health effects to people who used PW01; however, sampling conducted during the RI detectedchromium levels in excess of the comparison values and municipal water was made available to this resident.
We believe contamination of this well may have occurred due to the site topography and drainage patterns for this site(Figure 6). There are three major drainage pathways for the site. The PWP site slopes from the northwest toward severalresidences located to the southeast of the site. A small swamp is located approximately 300 feet from the southwest cornerof the site, across South Carolina Road 129. This pond discharges into a small drainage area located approximately 250feet south of the property boundary of the adjacent manufacturing site.
B. Potential Exposure Pathways
Table 13.
Potential Exposure Pathways | Exposure Pathway Elements | Time |
|---|
| Source | Environmental
Medium | Point of
Exposure | Route of
Exposure | Exposed
Population |
|---|
| PWP | Soil | Off-Site | Ingestion
Dermal
Contact | Children
Adults
Workers | Past
Present
Future |
|---|
| PWP | Groundwater | On-Site
Off-Site | Ingestion
Dermal
Contact | Children
Adults
Workers | Past
Present
Future |
|---|
| PWP | Surface Water
and
Sediment | Off-Site | Ingestion
Dermal
Contact | Children
Adults
Workers | Past
Present
Future |
|---|
| PWP | Air | On-Site
Off-Site | Inhalation | Children
Adults
Workers | Past
Future |
|---|
Soil
In the past, exposure to contaminants at the PWP site could have occurred prior to the removal of the contaminated soil,and prior to the site being secured by an 8-foot high chain-link fence. This past exposure could have happened to anyonewho wandered onto, worked on, or to children who played on the site. The routes of exposure could have occurredthrough dermal contact, ingestion of soil, or inhalation of soil particles. However, because soils were not sampled priorto the site closing and because the area is sparsely populated, this past exposure pathway cannot be evaluated in this publichealth assessment.
The results of on-site soil sampling conducted in 1986 indicated several metals and extractable semivolatile organiccompounds. In 1989, approximately 12,685 cubic yards of contaminated soil were excavated, treated, solidified, andplaced under a concrete pad to eliminate off-site contaminant migration.
The on-site soil remediation has been completed; however, we have no data to evaluate contaminant levels currently foundon-site or to evaluate off-site contaminant migration. Therefore, this pathway will be considered a potential pathway inthis public health assessment.
Off-site sampling conducted during the RI showed contaminants in the southern corner of the site. Residents may beexposed to contaminants from the PWP site through dermal contact, ingestion of soil, or inhalation of soil particles. Whenadditional data becomes available, we may better evaluate the concentrations of contaminants found and determine thedegree of off-site migration.
Soil surveys produced by the United States Department of Agriculture, Soil Conservation Service (SCS, 1976) indicatestwo types of surface soil in the area of the PWP site. These are the Lakeland soils and Pelion loamy sand. In arepresentative profile, the surface layer is very dark gray sand approximately three inches thick. This material is underlainto a depth of 90 approximate inches and is sandy. Runoff is slow but permeability is rapid with a very low available watercapacity. The pelion loamy sand is typically sandy loam underlying a stratified sand or clay subsoil which extends to adepth of up to 40 inches. Runoff is moderate on this soil and in places bonds briefly after rains. Permeability is moderatein the upper soils and slow in the deeper soils (LETCO, 1983). Based on this information and due to the vegetative coveron the site, the possibility for soil contamination to migrate extensively off-site is not likely.
Groundwater
Past, current, and future exposure pathways may result from contamination of groundwater from private drinking wells. Contamination was detected in PW01 prior to the RI; however, no data are available as to length of exposure prior tosampling of this well. No contamination was found that exceeded the comparison values in other private wells sampledduring the RI; therefore, no health effects were predicted for well users at that time.
One home in the southeastern border of the site showed chromium contamination that exceeded the comparison valuesin 1982. At that time, this home was supplied with well water, and municipal water was made available to this area. Thehome has since been abandoned and there is a possibility that the new owners may utilize private wells in the future.
Other residents in the area are still utilizing private wells as the source for drinking, bathing, and cooking. Groundwaterremediation is not complete on this site and the site topography and water drainage patterns reflect the possibility thatmigration of contaminants could extend to local residential wells affected by groundwater flow.
Since we have no current sampling data for residential wells, we cannot assume that contaminants have migrated to thesewells. Because PW01 showed contamination exceeding the comparison value, groundwater at this location representsa potential future exposure pathway to residents through ingestion of water or from dermal contact.
Access to the site is restricted to the public; therefore, no exposures to contaminants are known to be occurring from on-site sources. The levels of contaminants found on-site during the RI were not considered to be of concern; however,current sampling data need to be evaluated to determine on-site contaminant levels. On-site workers may be exposed togroundwater contamination through ingestion or dermal contact.
As a groundwater treatment plant is being constructed to remediate the groundwater contamination on the site, we do notforesee this to be a pathway of concern.
Surface Water/Sediments
The surface water and sediment sampling performed during the RI indicated contaminants of concern. Samples werecollected to investigate the possibility that surface water runoff represents a migratory pathway for contaminant movementoff-site. Samples taken to determine stream flow in the vicinity of the site are monitored at three locations: the CongareeRiver, Gills Creek, and Big Beaver Creek.
Surface water runoff from the site drains to the Congaree River, which is one of the major tributary rivers in theSantee-Cooper River Basin. Drainage to the Congaree River occurs by two major routes, Dry Creek and Congaree Creek,which flow northeastwardly and southeastwardly from the site to the Congaree River, respectively. The Congaree Riveris formed by the confluence of the Saluda and Broad Rivers near northeast Columbia. Much of the Congaree river andlower portions of its tributary streams blend with swampland.
Stream flow on the Congaree River is affected by regulated discharges from hydroelectric power plants on the Saluda andBroad Rivers and several flood control and recreational impoundments along Gills Creek. Except for occasional waterquality problems, physical, chemical, and biological water quality data indicate that current conditions in the main stemriver are generally good. Upstream and downstream samples from this River are needed to better ascertain contaminantmigration from the PWP site.
If additional sampling shows contamination, there is a potential for exposure via ingestion or dermal contact withcontaminants; however, this route of exposure is considered unlikely. Available data are not adequate to estimate anyfuture concentrations or exposures.
Air
Air monitoring conducted during the RI for the PWP site indicated no readings of contaminants above action levels. Atthis time, the RI concludes that exposure to contaminants transported in air is not likely. Therefore, this pathway will notbe evaluated further.
This pathway may be of concern in the future if contaminants from the PWP site become airborne. At that time, air onthe site may serve as a vehicle for contamination and allow workers on-site to inhale contaminants or transportcontaminants off-site where they may be inhaled by local residents.
PUBLIC HEALTH IMPLICATIONS
A. Toxicological Evaluation
Introduction
In this section we will discuss the health effects in persons exposed to specific contaminants. To evaluate health effects,ATSDR has developed Minimal Risk Levels (MRL) for contaminants commonly found at hazardous waste sites. TheMRL is an estimate of daily human exposure to a contaminant below which non-cancer, adverse health effects are unlikelyto occur. MRLs are developed for each route of exposure and for the length of exposure.
When a MRL is not available, ATSDR refers to EPA's Reference Dose (RfD). The RfD is an estimate of daily humanexposure to a contaminant for a lifetime below which (non-cancer) health effects are unlikely to occur.
The calculated doses are estimations of the amount of chemicals a person can be exposed to. The computations are basedon the assumptions that an adult weighs 70 kilograms (154 pounds) and a child weighs 10 kilograms (27 pounds). Anadult ingests 2 liters of water per day, and a child drinks half that amount. Adults typically ingest 50 to 100 milligramsof soil per day (mg/day) by inhalation of small soil particles carried in the air, and by placing soiled hands and otherobjects in the mouth. We assume that small children ingest a greater amount of soil, typically 200 mg/day, because theygenerally tend to place objects in their mouths.
These assumptions and the respective exposure scenarios are used to determine the estimated doses for each chemical.The estimated doses will be compared to health guidelines and the available scientific literature to determine if healtheffects are likely to occur.
Arsenic
Arsenic is a naturally-occurring element in the earth's crust. Pure arsenic is a gray metal-like material, but this form is notcommon in the environment. Arsenic is usually found combined with other elements. Most arsenic compounds are whiteor colorless powders that do not evaporate. They have no smell, and most have no special taste. Thus, you usually cannottell if arsenic is present in food, water, or air (ATSDR 1989a).
The main use of arsenic in the United States is as a preservative for wood to make it resistant to rotting and decay. It isalso used in different types of pesticides like insect killers and weed killers. The use of arsenic as a pesticide hascontributed to elevated levels of arsenic in several areas within the southeastern United States (ATSDR 1989a).
Arsenic was not detected in off-site private wells and no completed exposure pathway currently exists for arsenic. However, if potential exposure pathways become completed pathways, people could be exposed to arsenic by ingestionof or dermal contact with contaminated soil or surface water. In the future, arsenic migration in groundwater and/or theinstallation of new private wells may lead to exposure and adverse health effects associated with arsenic.
ATSDR has not established an MRL for arsenic; however, EPA has established a reference dose of 0.0003 mg/kg/day. The following discussion on possible health effects is based on a comparison of site related doses to the EPA referencedose.
Ingestion of arsenic over many years (typically 10 years or more) may lead to irritation of the gastrointestinal tract,including nausea, vomiting, diarrhea, and abdominal pain. Other effects may include a decreased production of red andwhite blood cells, abnormal heart function, blood-vessel damage, and impaired nerve function causing a "pins andneedles" sensation in hands and feet. The single most characteristic effect of long-term oral exposure to inorganic arsenicis a pattern of skin changes including the darkening of the skin and the appearance of small "corns" or "warts" on thepalms, soles, and torso (ATSDR 1989a).
Direct skin contact with arsenic compounds may cause the skin to become irritated with some redness and swelling. However, it does not appear that skin contact with arsenic is likely to lead to any serious internal effects.
Exposure to arsenic is not anticipated to result in acute (immediate) health effects at the PWP site.
Bis(2-Ethylhexyl)Phthalate
Bis(2-Ethylhexyl)Phthalate, also known as Di(2-Ethylhexyl)Phthalate or DEHP, is a liquid used to make plastic moreflexible. These plastics are used in a variety of consumer products such as imitation leather, rainwear, footwear,upholstery, flooring, tablecloths, shower curtains, food packaging materials, and children's toys. It is also used as ahydraulic fluid and as a dielectric fluid in electrical capacitors (ATSDR A989d).
DEHP was not detected in private wells and no completed exposure pathway for DEHP currently exists. However, ifpotential exposure pathways become completed pathways, people could be exposed to DEHP by ingestion of or dermalcontact with contaminated surface water from a swamp area northeast of the site.
The EPA reference dose for DEHP is 0.02 mg/kg/day. Most of what is known about the health effects of DEHP comesfrom animal studies, especially studies in rats and mice. Because DEHP appears to affect rats and mice differently thanit affects humans and other animals, it is difficult to predict health effects in humans using information from animalstudies.
DEHP is classified by the EPA as a probable human carcinogen. A probable human carcinogen is a chemical for whichthere is sufficient evidence of carcinogenicity in animals, but inadequate evidence or no data from human epidemiologicstudies. DEHP has also been shown to cause an increased incidence of cancer in rats and mice. Exposure to the levelsof DEHP related to the PWP site represent an "insignificant risk" of cancer.
While human studies are not available, laboratory animals exposed to high doses of DEHP have experienced liver damageand male reproductive system damage. Reproduction in these animals was affected and birth defects were more likely. However, none of these effects have been documented in humans. Human absorption of DEHP in the body is differentfrom that of rodents (ATSDR 1989d). Therefore, many of the effects seen in animals after exposures to DEHP may not occur in humans.
Chromium
Chromium is a naturally occurring element which is found in three different states: chromium 0, chromium III (trivalentchromium), and chromium VI (hexavalent chromium). Chromium is used to make steel and other alloys, bricks formetallurgical furnaces, for chrome plating, in the manufacture of pigments, for leather tanning, wood treatment, and watertreatment for industrial applications (ATSDR 1989b).
Chromium was detected in one off-site private well (PW01) and a past completed exposure pathway exists for chromium. In addition, potential exposure pathways may also become completed pathways with people becoming exposed tochromium by ingestion of or dermal contact with contaminated groundwater or soil. In the future, chromium migrationin groundwater and/or the installation of new private wells may lead to exposure and adverse health effects associated withchromium.
Sampling has not determined if chromium is present in the trivalent (chromium III) or hexavalent state (chromium VI)at the PWP site although hexavalent chromium is used in the wood preserving process.
Chromium VI has an EPA chronic reference dose of 0.005 mg/kg/day and Chromium III has an EPA chronic referencedose of 1 mg/kg/day; however, potential exposure doses estimated for all media at the PWP site did not exceed thereference dose for chromium III. However, since chromium VI may be reduced to chromium III, possible health effectsfrom chromium III exposure will be mentioned as well.
Health effects associated with ingestion of or dermal contact with chromium VI contaminated water from private wellPW01 over many years may lead to the enhancement of dermatitis. Dermal contact with water from this well may causereddening of the skin. Other health effects that may occur from exposure to chromium at these levels have not been wellcharacterized. Recent evidence has suggested that exposure to chromium III may caused decreased spermatogenesis inmice; however, this has not been shown to occur in humans (ATSDR 1989b).
A potential soil pathway for chromium was also identified. Long-term ingestion of contaminated soil may result in theenhancement of dermatitis. However, it is not likely that a person would ingest the amount of soil necessary to result inadverse health effects.
Copper
Copper occurs naturally in rock, soil, water, sediment, and air. The U.S. penny, electrical wiring, and some water pipesare made with copper (ATSDR 1990f).
Potential exposure pathways were identified for copper. Exposure to copper may occur in the future through the ingestionof or dermal contact with contaminated groundwater or soil; however, no current exposures to copper are known to haveoccurred or to be occurring.
Copper is necessary for good health; it is an essential element for all living organisms, including man. However, theestimated dose a person would receive from the levels of copper associated with the PWP site exceed the lowest observedadverse effect level (LOAEL) of 0.056 mg/kg/day. Therefore, ingestion of maximally contaminated soil or groundwatermay cause vomiting, diarrhea, stomach cramps, and nausea.
Studies have shown that some individuals may show signs of allergic contact dermatitis from skin contact with materialscontaining copper. However, neither the dose nor the duration of exposure necessary to produce this effect was available(ATSDR 1990f).
1,1-Dichloroethene
1,1-Dichloroethene (DCE) is a chemical used to make certain plastics such as packaging materials and flame-retardantfabrics. It is a clear, colorless liquid that evaporates quickly at roomtemperature and has a mild, sweet smell like chloroform (ATSDR 1989c).
Potential exposure pathways were identified for DCE. Exposure to DCE may occur in the future through the ingestionof or dermal contact with private well water if it becomes contaminated; however, no current exposures to DCE are knownto have occurred or to be occurring.
Limited information is available regarding the systemic effects of human exposure to DCE. High amounts of DCE inanimal studies have caused liver, kidney, heart, and lung damage and have also caused nervous system disorders and deathafter short exposures. The amount of damage depends on the level of exposure and the length of time exposed. However,the oral dose from exposure to DCE in groundwater on the PWP site is not expected to result in adverse systemic health effects.
No studies were located regarding health effects in humans or animals following dermal exposure to DCE.
DCE is classified as a possible human carcinogen. A possible human carcinogen is a category for which there is limitedevidence from animal studies and no human studies. The oral dose from exposure to DCE on-site is expected to causeno apparent increased cancer risk.
Iron
Iron is an essential metal in the human diet. The Recommended Daily Allowance for iron in the diet is 10-18 mg/day.However, excess iron in the diet may result in adverse health effects. Ingestion of large doses of iron may cause vomiting,liver damage, and renal failure. Excessive iron in the diet over time may lead to the accumulation of iron in the liver,disturbance of liver function, and even cardiovascular effects (Klaassen 1986).
Potential exposure pathways were identified for iron. Exposure to iron may occur in the future through the ingestion ofor dermal contact with contaminated groundwater or surface water; however, no current exposures to DCE are knownto have occurred or to be occurring.
Some individuals may be genetically sensitive to iron (e.g. Wilson's disease). Individuals should consult with theirphysician before ingesting water containing high levels of iron.
The levels of iron in water associated with the PWP site may make the water taste bad should exposure to iron occur inthe future; however, the levels of iron in groundwater do not exceed the Recommended Daily Allowance and no adversehealth effects are expected.
Lead
Lead is a naturally-occurring element which may be found in most environmental media. It has a wide range of usesincluding storage batteries (automobile batteries), solders, pipes, various chemicals, and gasoline additives (ATSDR1990d).
Potential exposure pathways were identified for lead. Exposure to lead may occur in the future through the ingestion ofor dermal contact with soil; however, no current exposures to lead are known to have occurred or to be occurring.
Although lead may cause both acute and chronic effects, major concern has focused on the neurotoxicity of lead inchildren which may manifest itself as learning disorders. Lead toxicity in adults may contribute to hypertension,particularly in middle-aged males (ATSDR 1990d).
ATSDR has not set an MRL for lead. EPA has not set a reference dose (Rfd) for lead. Although exposure to lead saltshas been associated with an increased rate of cancer in laboratory animals, EPA has not set an estimate of carcinogenicpotency of lead.
Manganese
Manganese is a naturally-occurring element. Small amounts of manganese are an essential part of the human diet. Somemanganese compounds are used in the production of batteries, andas a component of some ceramics, pesticides, fertilizers, and nutritional supplements (ATSDR 1990a).
Potential exposure pathways were identified for manganese. Exposure to manganese may occur in the future through theingestion of or dermal contact with surface water; however, no current exposures to manganese are known to haveoccurred or to be occurring.
The EPA reference dose for manganese is 0.1 mg/kg/day for chronic (a year or more) exposure. A child's estimated oraldose for manganese in surface water monitored near the PWP site is higher than the reference dose. However, adversehealth effects in humans who ingest higher than normal amounts of manganese are not well characterized. Some datasuggest that ingestion of higher than normal amounts of manganese may have limited neurological effects (ATSDR1990a). This data is not conclusive and other factors may be necessary for the effects to occur.
No studies were located regarding health effects resulting from skin exposure to manganese.
Polycyclic Aromatic Hydrocarbons (PAHs) - Carcinogenic
Polycyclic aromatic hydrocarbons are a group of chemicals that are formed during the incomplete burning of coal, oil andgas, garbage, or other organic substances. PAHs can be man-made oroccur naturally. PAHs are found throughout the environment and are used in medicines and to make dyes, plastics, andpesticides. Benzo(a)anthracene, benzo(b and/or k) fluoranthene, benzo(ghi)perylene, benzo(a)pyrene, chrysene, andindeno(1,2,3-cd)pyrene are PAHs detected at the Palmetto Wood Preserving site (ATSDR 1990e).
Potential exposure pathways were identified for PAHs. Exposure to PAHs may occur in the future through the ingestionof or dermal contact with soil; however, no current exposures to PAHs are known to have occurred or to be occurring.
In evaluating the potential human carcinogenicity of chemicals, EPA uses the approach given in "Guidelines forCarcinogenic Risk Assessment" (51 FR 33992, September 24, 1986). The EPA has classified PAHs as probable humancarcinogens. Probable human carcinogens are chemicals for which there is sufficient evidence of carcinogenicity inanimals, but inadequate evidence or no data from human epidemiologic studies.
Laboratory animals that ingest PAHs have developed tumors. These animals also developed tumors after PAHs wereapplied to their skin or after they had inhaled them over a long period of time. Reports in humans show that individualsexposed by breathing or skin contact for a long period of time to mixtures of other compounds and PAHs can also developcancer (ATSDR 1990e).
Mice fed high levels of benzo(a)pyrene during pregnancy had difficulty reproducing and so did their offspring. Birthdefects were also more likely to occur. While similar effects may be seen in humans, no evidence is available to supportthis assumption (ATSDR 1990e).
An estimate of the carcinogenic potency of PAHs is under review; this public health assessment will be updated when thisinformation becomes available.
Sodium
Sodium is a component of table salt (sodium chloride). Is also found in salt water. Evidence indicates that an increasedintake of sodium may worsen high blood pressure in some sensitive individuals. Additionally, people taking somemedicines may need to limit their intake of sodium.
Potential soil and surface water pathways were identified for sodium. However, no reliable evidence suggests that peopleworking on or living near the site are currently exposed to excess sodium.
Vanadium
Vanadium is a white to gray metal and is a natural element in the earth. Vanadium is also found naturally in fuel oils andcoal. These compounds are used in the making of steel, rubber, plastics, ceramics, and certain other chemicals.
Potential exposure pathways were identified for vanadium. Exposure to vanadium may occur in the future through theingestion of or dermal contact with contaminated groundwater or surface water; however, no current exposures to DCEare known to have occurred or to be occurring.
The ATSDR MRL for vanadium is 0.003 mg/kg/day. The oral dose for vanadium in groundwater and surface water onor near the PWP site slightly exceeds the MRL. Animals studies have shown various adverse health effects afterconsuming high levels vanadium in water. For example, rats who ingested water with 4000 ppb of vanadium in it for 3months had minor changes in the cells in their kidneys and lungs. However, the dose that these rats received is muchgreater than humans would receive from vanadium at the PWP site; therefore, adverse health effects from oral exposureto vanadium at levels associated with the PWP site are not expected.
B. Health Outcome Data Evaluation
As no health outcome data exists for the Palmetto Wood Preserving site, there is no further discussion at this time.
C. Community Health Concerns Evaluation
The first concern expressed about this site was possible drinking water contamination of PW-01 in 1983 (Figure 5). Thewell was tested and showed high levels of chromium and the owner wasadvised to discontinue use of the well. Water was provided for this household and it utilized municipal water. All privatewells within the vicinity of the site were tested at that timeand contamination was not found. Since these wells showed no contaminants, they were not considered to be a health risk.
As the site has been closed since 1985 and site access is restricted by an 8-foot high chain-link fence, there are no knownexposures to contaminants on-site. Municipal water is nowavailable to local residents; however, residents in the southeastern corner of the site are still utilizing private wells. Conversations with these residents during the 1992 sitevisit indicated the citizens are still concerned about groundwater contamination. We cannot address this issue at this timebecause of lack of recent sampling data.
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