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PETITIONED PUBLIC HEALTH ASSESSMENT

GREAT LAKES CHEMICAL CORPORATION
EL DORADO, UNION COUNTY, ARKANSAS


APPENDIX A


Figure 1. Site Map and Demographics


APPENDIX B

Exposure Pathway Table

Table 1.

COMPLETED EXPOSURE PATHWAYS
Pathway
Name
Source Medium Route
of
Exposure
Exposure Elements Exposure Activities Chemicals
of
Concern
Point
of
Exposure
Receptor
Population
Time
Private Well Unknown Groundwater Ingestion, Inhalation, & Dermal Contact Residential
Water Taps
Off-site
Users of private well past Drinking, Bathing, & Household Cleaning PAHs (See Appendix C, Table 2)


Table 2.

POTENTIAL EXPOSURE PATHWAYS
Pathway
Name
Source Medium Route
of
Exposure
Exposure Elements Exposure Activities Chemicals
of
Concern
Point of
Exposure
Receptor
Population
Time
Ambient Air GLCC Ambient Air Inhalation Off-site Residential Areas
On-site
Residents and GLCC Workers p,c,f Outdoor Activities
Working
Methyl Bromide
Surface Water GLCC Surface Water Incidental Ingestion and Dermal Contact Bayou de Loutre
Little Cornie Bayou
Off-site and On-site
Recreation Enthusiasts and GLCC Workers p,c,f Recreation
Working
See Appendix C, Table 3
Sediment GLCC Sediment Dermal Contact Creeks and
Drainage Ditches
Off-site and On-site
Residents and GLCC Workers p,c,f Outdoor Activities
Working
Bromides and Chlorides
Key: GLCC = Great Lakes Chemical Corporation c = current; f = future; p = past


APPENDIX C

Environmental Sampling Data

Table 1.

Overview of On-Site Groundwater Monitoring Data
Chemical
or Indicator
Number of
Observations
Maximum
Value
Barium 281 36 ppm
Benzene 5,606 55 ppm
Benzoic acid 47 ND
Bromides 5,838 170,000 ppm
Bromoform 5,559 36 ppm
Calcium 281 37,000 ppm
Chlorides 6,100 360,000 ppm
Dichloropropane 21 1.89 ppm
Ethylene dibromide 6,102 4,500 ppm
Ethylene dichloride 6,086 700 ppm
Hexachloroethane 47 ND
Iron 45 32 ppm
Manganese 45 1.1 ppm
Methyl bromide 47 ND
Methylene chloride 47 0.037 ppm
Phenol(s) 92 ND
Sodium 326 65,000 ppm
Sulfates 5,872 3,723 ppm
Toluene 5,606 47 ppm
Tribromophenol 6,102 5,300 ppm
Trichlorobenzene 29 ND

Notes: As described in the text of this attachment, the data in this table should be viewed as an extensive accountof the groundwater sampling at the GLCC Main Plant, but not as a comprehensive account. A maximumconcentration of ND means the chemical was never detected.

Table 2.

Concentrations of PAHs Detected in one Private Well (1991)
Chemical Maximum
Concentration
(ppb )
RBC-c
(ppb)
Benzo[a]pyrene 66 0.0092
Benz[a]anthracene 112 0.092
Benzo[b]fluoranthene 140 0.092
Benzo[k]fluoranthene 47 0.92
Chrysene 94 9.2
*Note* This private well went out of service in 1968 [2]

ppb         parts per billion
RBC-c    Risk-Based Concentration (carcinogenic effects)

Table 3.

Summary of NPDES Monitoring Data for GLCC
Chemical Range of Detection Limits (ppm) Comparison Value
(ppm)
Reference
(refer to cover letter for codes)
Number of Samples Analyzed for the Chemical Number of Samples in Which Chemical Was Detected Number of Samples in Which Concentration Exceeded the CV
1,1,1-trichloroethane 0.003--0.01 0.2 MCL 74 0 0
1,1,2,2-tetrachloroethane a 0.005--0.01 0.0002 CREG 74 0 0
1,1,2-trichloroethane a 0.005--0.01 0.0006 CREG 74 0 0
1,1-dichloroethane 0.004--0.01 NA NA 74 0 0
1,1-dichloroethylene a 0.002--0.01 0.00006 CREG 74 0 0
ethylene dibromide a 0.005--0.01 0.0000004 CREG 16 7 7
1,2-dichlorobenzene 0.005--0.01 0.6 MCL 60 0 0
ethylene dichloride a 0.002--0.01 0.0004 CREG 74 1 1
1,2-dichloropropane 0.005--0.01 0.005 MCL 74 0 0
1,2-trans-dichloroethylene 0.001--0.01 0.1 MCL 74 0 0
1,3-cis-dichloropropylene 0.005--0.01 0.07 MCL 74 0 0
1,3-dichlorobenzene 0.005--0.01 0.6 LTHA 60 0 0
1,3-trans-dichloropropylene a 0.005--0.01 0.003 RMEG (Child) 74 0 0
1,4-dichlorobenzene 0.005--0.01 0.075 MCL 60 0 0
2-chloroethylvinyl ether 0.005--0.01 NA NA 74 0 0
acrolein a 0.01--0.1 0.005 c-EMEG (Child) 27 0 0
acrylonitrile a 0.01--0.1 0.00006 CREG 27 0 0
benzene a 0.004--0.01 0.001 CREG 74 0 0
benzyl chloride a 0.005--0.1 0.0002 CREG 66 0 0
bromoform 0.004--0.01 0.004 CREG 74 3 3
carbon tetrachloride a 0.002--0.01 0.0003 CREG 74 0 0
chlorobenzene 0.005--0.006 100 MCL 37 0 0
chlorodibromomethane a 0.003--0.01 0.0004 CREG 74 0 0
chloroethane 0.01--0.02 NA NA 74 0 0
chloroform 0.001--0.01 0.006 CREG 74 1 1
dichlorobromomethane a 0.002--0.01 0.0006 CREG 74 0 0
dichlorodifluoromethane 0.005--0.01 1.0 LTHA 18 0 0
dichlorofluoromethane 0.01--0.01 NA NA 11 0 0
epichlorohydrin 0.005--0.1 0.07 DWEL 29 0 0
ethylbenzene 0.005--0.01 0.7 MCL 74 0 0
methyl bromide 0.01--0.02 0.01 LTHA 74 4 4
methyl chloride a 0.01--0.02 0.003 LTHA 74 2 2
methylene chloride 0.002--0.01 0.005 CREG/MCL 74 3 1
tetrachloroethylene a 0.004--0.01 0.0007 CREG 74 0 0
toluene 0.004--0.01 0.2 i-EMEG (child) 74 2 0
trichloroethylene 0.001--0.01 0.003 CREG 74 0 0
trichlorofluoromethane 0.005--0.01 2.0 LTHA 75 1 0
vinyl chloride a 0.005--0.02 0.0002 c-EMEG (child) 74 0 0
NA= not applicable (a comparison value has not been developed for these chemicals in this medium)
a Range of detection limits exceeds comparison value

Table 4.

Distribution of On-site Soil Concentrations of Ethylene Dibromide (EDB), by Depth
Maximum Depth
of Soil Samples
Total Number of Samples Distribution of Measured Concentrations Maximum Concentration (ppm)
Non-Detects 1 ppm >1 ppm; 10 ppm >10 ppm
Depth not indicated 74 36 29 2 7 350
Less than 3 feet 57 28 22 2 5 5,800
Greater than 3 feet but less than 10 feet 178 67 55 17 39 8,100
Greater than 10 feet 325 116 111 42 56 6,800
Overall 634 247 217 63 107 8,100

Notes: (1) Shaded cells indicate samples where concentrations exceeded the CREG for ethylene dibromide (or 0.008 ppm).

(2) GLCC monitoring reports generally included a range of soil depths over which each sample was collected. The "maximum depth" in this table refersto the upper end of the depth range for a given soil sample. For example, ERG classified soils sampled over a depth range of 2 to 8 feet in the category of"maximum depth greater than 3 feet but less than 10 feet."

Table 5.

Distribution of On-site Soil Concentrations of Ethylene Dichloride (EDC), by Depth
Depth of soil sampling Number of Samples Distribution of Measured Concentrations Maximum Concentration (ppm)
Non-Detects 1 ppm >1 ppm; 8 ppm >8 ppm
Depth not indicated 31 21 8 1 1 29
Less than 3 feet 24 19 5 0 0 0.5
Greater than 3 feet but less than 10 feet 70 43 18 7 2 43
Greater than 10 feet 132 56 30 25 21 140
Overall 257 139 61 33 24 140

Notes: (1) Shaded cells indicate samples where concentrations exceeded the CREG for ethylene dichloride (8 ppm).

(2) GLCC monitoring reports generally included a range of soil depths over which each sample was collected. The "maximum depth" in this table refersto the upper end of the depth range for a given soil sample. For example, ERG classified soils sampled over a depth range of 2 to 8 feet in the category of"maximum depth greater than 3 feet but less than 10 feet."


APPENDIX D

Evaluation of Environmental Contamination and Potential Exposure Pathways Methodology

Quality Assurance

In preparing this report, ATSDR relied on the information provided in the referenced documents andby contacts with the United States Environmental Protection Agency, Arkansas Department ofEnvironmental Quality, Arkansas Department of Health, Union County Department of Health, andcommunity members. ATSDR assumes that adequate quality assurance and control measures weretaken during chain-of-custody, laboratory procedures, and data reporting. The validity of theanalyses and conclusions drawn in this document are determined by the availability and reliability ofthe information.

Human Exposure Pathway Evaluation and the use of ATSDR Comparison Values

ATSDR assesses a site by evaluating the level of exposure in potential or completed exposurepathways. An exposure pathway is the way chemicals may enter a person's body to cause a healtheffect. It includes all the steps between the release of a chemical and the population exposed: (1) achemical release source, (2) chemical movement, (3) a place where people can come into contactwith the chemical, (4) a route of human exposure, and (5) a population that could be exposed. In thisassessment, ATSDR evaluates chemicals in environmental media that people living in nearbyresidences may come into contact with.

Data evaluators use comparison values (CVs), which are screening tools used to evaluateenvironmental data that is relevant to the exposure pathways. Comparison values are concentrationsof contaminants that are considered to be safe levels of exposure. Comparison values used in thisdocument include ATSDR's environmental media evaluation guide (EMEG) and cancer riskevaluation guide (CREG). Comparison values are derived from available health guidelines, such asATSDR's minimal risk levels and EPA's cancer slope factor.

The derivation of a comparison value uses conservative exposure assumptions, resulting in valuesthat are much lower than exposure concentrations observed to cause adverse health effects; thus,insuring the comparison values are protective of public health in essentially all exposure situations.That is, if the concentrations in the exposure medium are less than the CV, the exposures are not ofhealth concern and no further analysis of the pathway is required. However, while concentrationsbelow the comparison value are not expected to lead to any observable health effect, it should not beinferred that a concentration greater than the comparison value will necessarily lead to adverseeffects. Depending on site-specific environmental exposure factors (for example, duration ofexposure) and activities of people that result in exposure (time spent in area of contamination),exposure to levels above the comparison value may or may not lead to a health effect. Therefore,ATSDR's comparison values are not used to predict the occurrence of adverse health effects.

The comparison values used in this evaluation are defined as follows: The CREG is a concentrationat which excess cancer risk is not likely to exceed one case of cancer in a million persons exposedover a lifetime. The CREG is a very conservative CV that is used to estimate cancer risk. Exposureto a concentration equal to or less than the CREG is defined as an insignificant risk and is anacceptable level of exposure over a lifetime. The risk from exposure is not considered as asignificant risk unless the exposure concentration is approximately 10 times the CREG and exposureoccurs over several years. The EMEG is a concentration at which daily exposure for a lifetime isunlikely to result in adverse noncancerous effects.

Selecting Contaminants of Concern

Contaminants of concern (COCs) are the site-specific chemical substances that the health assessorselects for further evaluation of potential health effects. Identifying contaminants of concern is aprocess that requires the assessor to examine contaminant concentrations at the site, the quality ofenvironmental sampling data, and the potential for human exposure. A thorough review of each ofthese issues is required to accurately select COCs in the site-specific human exposure pathway. Thefollowing text describes the selection process.

In the first step of the COC selection process, the maximum contaminant concentrations arecompared directly to health comparison values. ATSDR considers site-specific exposure factors toensure selection of appropriate health comparison values. If the maximum concentration reported fora chemical was less than the health comparison value, ATSDR concluded that exposure to thatchemical was not of public health concern; therefore, no further data review was required for thatchemical. However, if the maximum concentration was greater than the health comparison value,the chemical was selected for additional data review. In addition, any chemicals detected that did nothave relevant health comparison values were also selected for additional data review.

Comparison values have not been developed for some contaminants, and, based on new scientificinformation other comparison values may be determined to be inappropriate for the specific type ofexposure. In those cases, the contaminants are included as contaminants of concern if currentscientific information indicates exposure to those contaminants may be of public health concern.

The next step of the process requires a more in-depth review of data for each of the contaminantsselected. Factors used in the selection of the COCs included the number of samples with detectionsabove the minimum detection limit, the number of samples with detections above an acute orchronic health comparison value, and the potential for exposure at the monitoring location.


APPENDIX E

Public Comments and ATSDR's Response

This appendix contains the comments received during the public comment period for GLCCand ATSDR's response to those comments. The comments have been numbered and are initalic with the response directly below each comment.

  1. A citizen wrote to ATSDR that they disagreed with the findings and are no longerinterested in this public health assessment.

These comments have been noted and included in ATSDR's official site file.

  1. The official plant name and location are incorrect. The correct title is "Great Lakes Chemical Corporation El Dorado Plant".

This change has been implemented in ATSDR's database and in the public health assessment.

  1. On page 5, insert the following sentence: The Arkansas Department of EnvironmentalQuality (ADEQ) monitored the GLCC property line and Parkers Chapel (a nearbyresidential community) weekly for methyl bromide from June 2, 1995 to May 27, 1996.Most analytical results were below the EPA risk-based concentration for ambient air".

The ambient air sampling event referred to in this comment has been evaluated and included in the public health assessment.

  1. Page 6; page 7;- 16,000 ppm looks high by 10x.

ATSDR re-evaluated the sampling summary and 16,000 ppm is correct.


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