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PUBLIC HEALTH ASSESSMENT

LAIDLAW ENVIRONMENTAL SERVICES (TOC), INCORPORATED
ROEBUCK, SOUTH CAROLINA


APPENDIX A - Figures

Figure 1: Facility Location Map

Figure 2: Facility Site Plan Diagram

Figure 3: Cancer Study 1.5 Mile Radius

Figure 4: Location of Surface Water Bodies with Respect to Laidlaw

Figure 5: Location of Air Monitoring Stations with Respect to Laidlaw

Figure 6: Location of Groundwater Monitoring Wells

Figure 7: Demographic Statistics for Within One Mile of Laidlaw

Figure 8: Aerial Extent of VOC Contamination Based on 1996 Data



Figure 1: Facility Location Map


Figure 2: Facility Site Plan Diagram


Figure 3: Cancer Study 1.5 Mile Radius


Figure 4: Location of Surface Water Bodies with Respect to Laidlaw


Figure 5: Location of Air Monitoring Stations with Respect to Laidlaw


Figure 6: Location of Groundwater Monitoring Wells


Figure 7: Demographic Statistics for Within One Mile of Laidlaw


Figure 8: Aerial Extent of VOC Contamination Based on 1996 Data



APPENDIX B - Data Tables

Table 1: Completed Exposure Pathways

Table 2: Potential Exposure Pathways

Table 3: Groundwater Sampling Results -- Organics

Table 4: Groundwater Sampling Results -- Inorganics

Table 5: Off-site Air Sampling Results for 1986-1989 -- Organics

Table 6: Off-site Air Sampling Results for 1986-1989 -- Inorganics

Table 7: On-site Soil Sampling Results for 1988-1989 -- Organics

Table 8: On-site Soil Sampling Results for 1988-1989 -- Inorganics

Table 9: On-site Pond Sampling Results for 1980-1981

Table 1.

COMPLETED EXPOSURE PATHWAYS
Pathway Name SourceEnvironmentalMediumPoint of ExposureRoute of ExposureExposed Pop.Time
Air Laidlaw/
ABCO
AirOn-site Work AreasInhalationWorkersPast
Air Laidlaw/
ABCO
AirOff-site Residential AreasInhalationArea ResidentsPast


Table 2.

POTENTIAL EXPOSURE PATHWAYS
Pathway Name Source Environmental
Medium
Point of ExposureRoute of ExposureExposed
Pop.
Time
Surface WaterABCO Surface WaterOn-site PondsDermal, IncidentalIngestionWorkersPast
Surface Water ABCO/
Laidlaw
Surface WaterOff-site Unnamed TributaryDermal, IncidentalIngestionArea ResidentsPast, Current,Future
Groundwater ABCO Ponds/
Spills
Private Groundwater
Wells
Off-site Private WellsInhalation,Ingestion, DermalArea ResidentsFuture
Soil ABCO/
Laidlaw
SoilOn-site Shallow and DeepSoilDermalWorkersPast
Sediment ABCO/
Laidlaw
SedimentOff-site Sediment Dermal,
Incidental Ingestion
Area Residents Past
Current
Future


Table 3.

Groundwater Sampling Results -- Organics
Contaminant Concentration
Range (ppb)
Year of Max. Comparison Valuea
Value (ppb) Source
Benzene 0.3 - 15 1987 5 MCL
Bromodichloromethane 0.5 - 5.6 1995 200 Chronic EMEG (child)
Bromoform 1.0 - 99 1988 2,000 Chronic EMEG (child)
Carbon Tetrachloride 0.5 - 851 1987 5 MCL
Chloroethane 1.0 1992 8,600 RBC (n)
Chloroform 0.6 - 180 1991 100 Chronic EMEG (child)
Chloromethane 5.8 1989 3 LTHA
Chloromethlymethyl ether 14 - 86 1994 0.00184 AWQC
(10-6 cancer risk level)
Dibromochloromethane 1.2 - 2.7 1987 300 Chronic EMEG (child)
Dibromomethane 2 - 12 1989 (See Bromoform above) (Methylene Bromide is less toxic than Bromoform.)
1,1-Dichloroethane 0.5 - 20 1991 810 RBC (n)
1,2-Dichloroethane 0.6 - 61,300 1990 5 MCL
1,1-Dichloroethene 0.51 - 103 1991 7 MCL
1,2-Dichloroethene, total 0.7 - 1,400 1995 70 (cis)
100 (trans)
LTHA
1,4-Dioxane 124 1990 3 CREG
Heptachlor 0.08 1991 0.4 MCL
Methylene Chloride 0.1 - 232 1992 5 MCL
1,1,2,2-Tetrachloroethane 1.2 - 1,013 1992 3,000 Chronic EMEG (child)
Tetrachloroethene 1.0 - 3,900 1995 5 MCL
1,1,1-Trichloroethane 0.7 - 817 1987 200 LTHA / MCL
Trichloroethene 0.5 - 610 1995 5 MCL
Vinyl Chloride 0.5 - 3.0 1995 2 MCL

a Please refer to Appendix C for information on comparison values.


Table 4.

Groundwater Sampling Results -- Inorganics
Contaminant Concentration
Range (ppb)
Year of Max. Comparison Valuea
Value (ppb) Source
Arsenic 0.5 - 125 1990 50 MCL
Barium 100 - 50,000 unknown 2,000 MCL
Cadmium 4 - 18 1994 5 MCL
Chloride 1,000 - 1,596,000 1988 250,000 sMCL
Chromium 10 - 420 1990 100 LTHA / MCL
Iron 910 - 163,000 1994 300 sMCL
Lead 2 - 840 1990 15 Action Level
Manganese 28 - 4,410 1994 50 RMEG (child)
Mercury(inorganic) 0.2 - 3.9 1991 11 RBC (n)
Nickel 21 - 360 1993 100 LTHA / MCL
Sodium 1,200 - 699,000 1989 20,000 DWEL
Sulfate 1,000 - 48,000 1993 250 sMCL

a Please refer to Appendix C for information on comparison values.


Table 5:

Off-site Air Sampling Results for 1986-1989 -- Organics
Contaminant Concentration (ug/m3)
Cromer
Concentration (ug/m3)
Pecan
Concentration (ug/m3)
Parklane
(background)
Concentration (ug/m3)
Cromer
Concentration (ug/m3)
Pecan
Comparison
Valuea
(ug/m3)
24 hour Episodic
Acenapthene 0.030 0 --b 0.020 0 220 RBC (N)
Acenapthylene 0 0 -- 0.020 0 220 RBC (N)
Anthracene 0.006 0 -- 0.010 0 1,100 RBC (N)
Benzoic Acid 0.116 0.130 -- 2.990 0 15,000 RBC (N)
Benzothiazole 0.080 0 0.016 68.910 -- NONE
Bis(2-ethylhexyl)phthalate 0 0.011 -- 0.040 0.020 0.45 RBC (C)
Butyl benzene -- -- -- 0.015 -- 37 RBC (N)
Butyl benzyl phthalate 0.030 0 -- 0 0 730 RBC (N)
Caprolactan 0.158 0.203 0.096 6.105 -- 1,800 RBC (N)
Chrysene 0.005 0 -- 0 0 1.0 RBC (C)
Decane 0.353 0.323 -- 0.300 1.798 NONE
Undecane 0.598 0.250 -- 0.290 1.804 NONE
Dodecane 0.238 0.123 -- 0.150 0.575 NONE
Tetradecane 0.110 0.071 -- 0.040 0.312 NONE
Hexadecane 0.052 0.023 -- 0.020 0.304 NONE
Octadecane 0.038 0.009 -- 0.005 0 NONE
Eicosane 0.043 0 -- 0 0 NONE
Docosane 0.018 0 -- 0 0 NONE
Tetracosane 0.005 0 -- 0 0 NONE
Dibenzofuran 0.030 0.006 -- 0.030 0 15 RBC (N)
1,2-Dichlorobenzene 0.005 0.005 0.007 1.842 0 150 RBC (N)
1,3-Dichlorobenzene 0 0 0 0.491 0.429 320 RBC (N)
Diethyl phthalate 0.005 0 -- 0 0 2,900 RBC (N)
1,2-Dimethyl benzene

(o-xylene)

0.457 0.181 0.104 27.780 -- 730 RBC (N)
1,3/1,4-Dimethyl benzene

(m/p xylene)

1.464 0.207 0.250 70.310 0 730/310 RBC (N)
Dimethyl phthalate 0.087 0.005 0 0.029 0 37,000 RBC (N)
Di-n-butyl phthalate 0.006 0 -- 0 0 370 RBC (N)
4-Ethyl benzaldehyde 1.171 0 0.090 0 -- NONE
2-Ethyl hexanoic Acid 0 0 0 2.941 -- NONE
4-Ethyl hexanoic Acid

(Ethyl Caproate or

Ethyl Hexanoic Acid)

-- -- -- 0.345 -- NONE
Fluoranthene 0.007 0 -- 0 0 150 RBC (N)
Fluorene 0.026 0 -- 0.020 0 150 RBC (N)
Indene 0.123 0 0 0.943 -- 48,000 TLV
Isopropyl toluene

(p-Cymene)

-- -- -- 0.050 -- NONE
Methyl benzene

(toluene)

-- -- -- 0.420 -- 420 RBC (N)
2-Methyl naphthalene 0.179 0.070 -- 0.160 0.697 NONE
2-Methyl phenol

(o-Cresol)

0.022 0 -- 0.080 0 180 RBC (N)
4-Methyl phenol

(p-Cresol)

0.005 0.008 -- 0.130 0 18 RBC (N)
Naphthalene c 2.543 0.310 0.722 181.800 1.562 150 RBC (N) CREG=10
Nitrobenzene 0.018 0 -- 0 0 2.1 RBC (N)
2-Nitrophenol 0.007 0.023 -- 0.070 0 NONE
4-Nitrophenol 0 0 -- 0.010 0 230 RBC (N)
most toxic isomer
Nonanal 0.399 0.127 0.129 22.890 -- NONE
Nonane 0.581 0.227 0.116 19.040 1.107 1,050,000 TLV
Octanal 0.133 0.033 0.037 5.652 -- NONE
Pentachlorophenol 0.009 0 -- 0 0 0.052 RBC (C)
Phenanthrene 0.035 0 -- 0.030 0 mouse LD50=700 mg/kg
Phenol 0.036 0.010 -- 0.120 0 2,200 RBC (N)
alpha Pinene 0.143 0.410 0.099 7.412 -- NONE
beta Pinene 0.125 0.415 0.072 7.089 -- NONE
Pyrene 0.005 0 -- 0 0 110 RBC (N)
1,2,4-Trichlorobenzene 0.022 0.026 -- 0.020 0 210 RBC (N)
1,2,4-Trimethylbenzene 1.131 0.380 0.650 97.250 -- 180 RBC (N)
1,3,5-Trimethylbenzene -- -- -- 0.190 -- 180 RBC (N)

a Please refer to Appendix C for information on comparison values.
B The -- indicates no data available for the time frame reviewed.
C The comparison value (chronic EMEG) for naphthalene is 2 ppb or 10 ug/m3.

Table 6.

Off-site Air Sampling Results for 1986-1989 -- Inorganics
Contaminant Concentration (ug/m3)
Cromer
Concentration (ug/m3)
Pecan
Concentration (ug/m3)
Parklane
(background)
Comparison Valuea
(ug/m3)
Arsenic 0.00298 --b 0.00163 0.0002 CREGc
1.1 RBC(N)
Copper 0.280 0.695 0.164 150 RBC(N)
Iron 1.110 0.930 0.520 1,100 RBC(N)
Lead 0.101 0.270 0.123 1.5 NAAQS
Magnesium 0.293 0.303 0.680 essential nutrient
(high doses cause metal fume fever)
Nickel 0.029 0.025 0.064 73 RBC(N)
0.004 CREG
(for Ni subsulfidec)
Selenium 0.00126 -- 0.000400 18 RBC(N)
Zinc 0.127 0.309 0.411 1,100 RBC(N)

a Please refer to Appendix C for information on comparison values.
b The -- indicates no data available for the time frame reviewed.
C Note: From a risk assessment point of view, the population within 1 mile of the site (< 1,300) is not large enough to express the small theoretical cancer risk associated with the maximum detected concentrations of arsenic and nickel (0.007 per thousand and 0.015 per thousand, respectively)in anything less than 7,000 years. The concentration of nickel at Parklane appears to be 10-100 times too high for a true background level. The lower concentrations at Cromer and Pecan are within the range of concentrations found in urban areas without a metallurgy industry.


Table 7.

on-site soil sampling results for 1988-1989 -- organics
Contaminant Concentration (mg/kg)
Shallow Samples
(0-2 feet)
Concentration (mg/kg)
Deep Samples
(2-47 feet)
Concentration (mg/kg)
Gas Tar Pond Soil Samples
(8 feet)
Concentration(mg/kg)
Backgrounda
Comparison Valuee
Value (mg/kg) Source
1,2-Dichloroethane 80 7 - 344 Db --c BDLd 8 CREG
105 intermediate EMEG (adult)
Dimethyl
phthalate
-- -- 0.84 BDL 106 RBC (n)
Methylene Chloride 7 - 13 6 - 128 -- BDL 90 CREG
4x104 RMEG (adult)
1,1,2,2-Tetrachloroethane 22 6 - 14 -- BDL 4 CREG
2x105 Chronic EMEG (adult)

a Background samples were taken from on-site locations not expected to have been impacted from site activities
b D = secondary dilution needed
c The -- indicates no data available
d BDL = below detection limit
e Please refer to Appendix C for information on comparison values.


Table 8.

On-site Soil Sampling Results for 1988-1989 -- Inorganics
Contaminant Concentration (mg/kg)
Shallow Samples
(0-2 feet)
Concentration (mg/kg)
Deep Samples
(2-47 feet)
Concentration (mg/kg)
Gas Tar Pond Soil Samples
(8 feet)
Concentration
(mg/kg)
Backgrounda
Comparison Value e
Value (mg/kg) Source
Aluminum --b -- 58,000 - 67,000 49,000 106 RBC (n)
Arsenic <5x c <10x 0.7 BDL d 0.5 CREG
200 Chronic EMEG (adult)
Barium 60 - 140 60 - 800 257 - 598 70 - 430 50,000 RMEG (adult)
Cadmium < 0.5 0.8 - 1.0 -- <0.5 700 Chronic EMEG (adult)
Chromium 14 - 27 3 - 163 23 - 39 11 - 82 60 Hexavalent CREG
4,000 Hexavalent RMEG (adult)
Copper -- -- 9 - 33 17 None  
Lead 13 - 36 7 - 31 24 - 249 14 - 31 None  
Magnesium -- -- 4,000 - 7,000 2,600 None  
Manganese -- -- 363 - 744 349 100,000 RMEG (adult)
Mercury 0.12 - 0.41 0.1 - 0.37 BDL 0.27 None  
Sodium -- -- 1,300 - 15,000 1,200 None  

a Background samples were taken from on-site locations not expected to have been impacted from site activities
b The -- indicates no data available
c x = matrix interference which may require a dilution
d BDL = below detection limit
e Please refer to Appendix C for information on comparison values.


Table 9.

On-site Pond Sampling Results for 1980-1981
Contaminant Concentration (ppb)
Woods Pond
Concentration (ppb)
Catchment Pond
Concentration (ppb)
Rainwatera
Comparison Valued
Value (ppb) Source
Arsenic 20 --b -- 50 MCL
Chromium 830 - 2,600 NDc 30 100 LTHA / MCL
Cobalt 100 -- -- 2,200 RBC (n)
Copper 10 - 30 20 10 1,300 MCLG
1,000 sMCL
Iron 9,000 -- -- 11,000 RBC (n)
300 sMCL
Lead 50 - 310 100 140 15 MCL
Manganese 500 -- -- 50 RMEG (child)
50 sMCL
Mercury 10 -- -- 11 RBC (n)
Nickel 100 - 2,960 110 120 100 LTHA / MCL
Sodium 1,170,000 -- -- 20,000 DWEL
Zinc 40 - 210 50 220 2,000 LTHA
5,000 sMCL
Phenols 154 - 2,000 -- -- 4,000 LTHA

a Sample listed only as "Rainwater" with no other information<
b The -- indicates no data available
c ND = not detected
d Please refer to Appendix C for information on comparison values.


APPENDIX C - Comparison Values

ATSDR comparison values are media-specific concentrations that are considered to be safeunder default conditions of exposure. They are used as screening values in the preliminaryidentification of site-specific "contaminants of concern". The latter term may be misinterpretedas an implication of "hazard". As ATSDR interprets the phrase, a "contaminant of concern" ismerely a site-specific chemical substance that the health assessor has selected for furtherevaluation of potential health effects. Generally, a chemical is selected as a contaminant ofconcern because its maximum concentration in air, water, or soil at the site exceeds one ofATSDR's comparison values.

However, it must be emphasized that comparison values are not thresholds of toxicity. Whileconcentrations at or below the relevant comparison value may reasonably be considered safe, itdoes not automatically follow that any environmental concentration that exceeds a comparisonvalue would be expected to produce adverse health effects. The purpose behind highlyconservative, health-based standards and guidelines is to enable health professionals to recognizeand resolve potential public health problems before they become actual health hazards. Theprobability that adverse health outcomes will actually occur depends on site-specific conditionsand individual lifestyle and genetic factors that affect the route and duration of actual exposure,and not on environmental concentrations alone.

Listed and described below are the various comparison values that ATSDR uses to select chemicals for further evaluation, along with the abbreviations for the most common units of measure.

CREG = Cancer Risk Evaluation Guides
MRL = Minimal Risk Level
EMEG = Environmental Media Evaluation Guides
IEMEG = Intermediate Environmental Media Evaluation Guides
RMEG = Reference Dose Media Evaluation Guide
RfD = Reference Dose
RfC = Reference Concentration
RBC = Risk-Based Concentrations (RBC)
EPA III = EPA Region III
DWEL = Drinking Water Equivalent Level
LTHA

= Drinking Water Lifetime Health Advisory

MCL = Maximum Contaminant Level
PRG = Permissible Remediation Goal (Action Level)
PEL = Permissible Exposure Limit
TLV = Threshold Limit Value
AWQC = Ambient Water Quality Criteria
ppm = parts per million (mg/L water or mg/kg soil)
ppb = parts per billion (ug/L water or ug/kg soil)
kg = kilogram (1,000 grams)
mg = milligram (0.001 grams)
ug = microgram (0.000001 grams)
L = liter
m3 = cubic meter (used in reference to a volume of air equal to 1,000 liters)

Cancer Risk Evaluation Guides (CREGs) are estimated contaminant concentrations expectedto cause no more than one excess cancer in a million persons exposed over a lifetime. CREGsare calculated from EPA's cancer slope factors.

Minimal Risk Levels (MRL) are estimates of daily human exposure to a chemical (i.e., dosesexpressed in mg/kg/day) that are unlikely to be associated with any appreciable risk ofdeleterious noncancer effects over a specified duration of exposure. MRLs are calculated usingdata from human and animal studies and are reported for acute (< 14 days), intermediate (15-364days), and chronic (> 365 days) exposures. MRLs are published in ATSDR ToxicologicalProfiles for specific chemicals.

Environmental Media Evaluation Guides (EMEGs) are concentrations that are calculatedfrom ATSDR minimal risk levels by factoring in default body weights and ingestion rates.

Intermediate Environmental Media Evaluation Guides (IEMEG) are calculated fromATSDR minimal risk levels; they factor in body weight and ingestion rates for intermediateexposures (i.e., those occurring for more than 14 days and less than 1 year).

Reference Dose Media Evaluation Guide (RMEG) is the concentration of a contaminant in air,water or soil that corresponds to EPA's RfD for that contaminant when default values for bodyweight and intake rates are taken into account.

EPA's Reference Dose (RfD) is an estimate of the daily exposure to a contaminant unlikely tocause noncarcinogenic adverse health effects. Like ATSDR's MRL, EPA's RfD is a doseexpressed in mg/kg/day.

Reference Concentrations (RfC) are concentrations derived from an EPA Reference Dose withassumed body and ingestion rates factored into the calculation.

Risk-Based Concentrations (RBC) are media-specific concentrations derived by Region III ofthe Environmental Protection Agency from RfDs, RfCs, or EPA's cancer slope factors. Theyrepresent concentration of contaminants in tap water, ambient air, fish, or soil (industrial orresidential) that are considered unlikely to cause adverse health effects over a lifetime of chronicexposure. RBCs are based either on cancer ("c") or non-cancer ("n") effects.

Environmental Protection Agency Region III (EPA III) values are risk-based concentrationswhich take into account factors such as body weight, toxicity, and exposure duration andfrequency for non-carcinogens and carcinogens, when applicable.

Drinking Water Equivalent Levels (DWEL) are based on EPA's oral RfD and representcorresponding concentrations of a substance in drinking water that are estimated to havenegligible deleterious effects in humans at an intake rate of 2 L/day, assuming that drinkingwater is the sole source of exposure.

Lifetime Health Advisories (LTHA) are calculated from the DWEL and represents theconcentration of a substance in drinking water estimated to have negligible deleterious effects inhumans over a lifetime of 70 years, assuming 2 L/day water consumption for a 70-kg adult, andtaking into account other sources of exposure. In the absence of chemical-specific data, theassumed fraction of total intake from drinking water is 20%. Lifetime health advisories are notderived for compounds which are potentially carcinogenic for humans.

Maximum Contaminant Levels (MCLs) represent contaminant concentrations in drinkingwater that EPA deems protective of public health (considering the availability and economics ofwater treatment technology) over a lifetime (70 years) at an exposure rate of 2 liters of water perday (for an adult).

Secondary Maximum Contaminant Levels (sMCLs) are EPA drinking water standardsbased solely on the aesthetic qualities (e.g., taste, color) of the water.

Permissible Remediation Goal (PRG) are levels set by EPA under Superfund that trigger aresponse or action when the contaminant concentration exceeds this value. Also genericallyknown as action levels.

Occupational Safety and Health Administration's Permissible Exposure Limit (PEL) for airis an 8-hour, time-weighted average developed for the workplace. The level of exposure may beexceeded (for brief periods), but the sum of the exposure levels averaged over 8 hours must notexceed the limit.

Threshold Limit Value (TLV), according to the American Conference of GovernmentalIndustrial Hygienists (ACGIH), is "the time-weighted average concentrations for a normal 8-hourworkday and a 40-hour workweek, to which nearly all workers may be repeatedly exposed, dayafter day, without adverse effect". Many of ACGIH's TLVs were adopted by OSHA for use asPELs. TLVs and PELs, which were designed to protect healthy workers, are usually muchhigher than the health-based values of ATSDR and EPA, which were designed to protect thehealth of the general population, including the very young and the elderly. Although the ATSDRdoes not base any of its community health decisions on TLVs or PELs, agency health assessorsand toxicologists may sometimes mention such values in Public Health Assessments orconsultations as a means of putting site-specific concentrations of contaminants into some kindof meaningful perspective for the reader.

Ambient Water Quality Criteria (AWQC) are clean water standards established under theClean Water Act. Separate criteria are established for humans and for aquatic organisms. Twotypes of Ambient Water Quality Criteria are established for humans: one based on consumptionof fish alone and another based on both the water and fish living in that water.

Reference

Agency for Toxic Substances and Disease Registry. Health Assessment Guidance Manual.Atlanta: ATSDR, March, 1992.



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