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PUBLIC HEALTH ASSESSMENT ADDENDUM

MOTCO, INCORPORATED
TEXAS CITY, GALVESTON COUNTY, TEXAS


ENVIRONMENTAL CONTAMINATION AND OTHER HAZARDS

The environmental media sampling program at MOTCO began with twoEPA-sponsored studies by Black And Veatch in 1981 and 1982. Additional sampling was conducted by Woodward and Clyde in 1984and 1986, and by CH2M Hill in 1984 and 1985. The types ofenvironmental media sampled included surface and subsurface soil,shallow and deep ground water, surface water, sediments, andaquatic biota (fish and crabs). The pit wastes were alsosampled. The samples were analyzed for Hazardous Substances List(HSL) metals and copper, volatile and semi-volatile compounds(HSL organics), pesticides and polychlorinated biphenyls (PCBs). Appendix C shows the locations of the monitoring wells, borings,and pits. Appendix D lists the chemical compounds that wereanalyzed in the laboratory.

We selected and discussed these contaminants based upon thefollowing factors:

  1. Concentrations of contaminants on and off the site.

  2. Field data quality, laboratory data quality, and sample design.

  3. Comparison of on-site and off-site concentrations withbackground concentrations, if available.

  4. Comparisons of on-site and off-site concentrations withATSDR Health Comparison (HAC) values for noncarcinogenicendpoints.

  5. Community health concerns.

In the data tables that follow under on-site contamination andoff-site contamination, the listed contaminant does not mean thatit will cause adverse health effects from exposures. Instead,the list indicates which contaminants will be evaluated furtherin the Health Assessment. When selected as a contaminant ofconcern in one medium, that contaminant will be reported in allmedia.

The data tables include the following acronyms:

  • EMEG = Environmental Media Evaluation Guide

  • HAC = Health Assessment Comparison value

  • ppm = parts per million

  • RfD = Reference Dose

ATSDR Health Assessment Comparison (HAC) values are contaminantconcentrations in specific media that are used to selectcontaminants for further evaluation. These values includeEnvironmental Media Evaluation Guides (EMEGs) and other relevantguidelines. EPA's Reference Dose (RfD) is an estimate of thedaily exposure to a contaminant that is unlikely to cause adversehealth effects.

We conducted a search of the Toxic Chemical Release Inventory(TRI) for the zip code area containing the MOTCO site. The TRIdid not list any facilities having chemical releases in this areafor 1987-1989. Industries in the zip code area adjacent to MOTCOreported 59 releases in 1987, 55 releases in 1988, and 47releases in 1989. Several chemicals included in these reportedreleases are the same as those identified as MOTCO sitecontaminants.

A. On-Site Contamination

1. Soil Contamination

The on-site soil investigation was divided into three generalareas of sampling: (1) topsoil (0-6 feet); (2) shallowsubsurface (depths to 50 feet); and (3) deep subsurface (depthsbelow 50 feet).

In 1983, 11 surface (0.5-1.0 foot) soil samples were obtained along the northwest, southeast and southwest perimeter dikes at locations that showed visible evidence of dike leakage and five surface soil samples were obtained at locations with no evidence of dike leakage. Woodward-Clyde Consultants screened these samples for volatile and non-volatile organic compounds and metals. Metals, volatile and aromatic compounds were detected in field tests. Metals in the surface soils were further analyzed in the laboratory. Table 1 shows the maximum levels of metals detected in the on-site surface (0.5-1.0 foot) soils. None exceeded available health assessment comparison values.

Table 1.

ON-SITE TOP SOIL
Contaminant Maximum Concentration (ppm) Sample Depth (feet) Reference HAC Values (ppm) HAC Source

Metals (Indicator)
Arsenic NA NA NA 50 EMEG
Barium 87.0 0.5-1.0 WCC 3,500 RfD
Cadmium 0.5 0-2 WCC 200 EMEG
Chromium 7.5 0.5-1.0 WCC 200 EMEG
Lead 25.0 0-2 WCC NONE NONE
Manganese 0.5 0.5-1.0 WCC 5,000 RfD
Mercury NA NA NA 40 EMEG

WCC = Woodward - Clyde Consultants 10/83
NA = Not Analyzed

The major contaminants in shallow subsurface soil samples weresemi-volatile compounds (semi-VOCs). (See Table 2.) Semi-VOCcontamination was detected as far down as 50 feet. ThePolynuclear Aromatic Hydrocarbons (PAHs) fluorene, naphthalene,phenanthrene, and pyrene were detected at depths greater than 50feet.

The highest volatile organic compound (VOC) levels were locatedat depths greater than four feet. Benzene, 1,1,2-trichloroethane, and 1,2-dichloroethane were detected at maximumlevels of 15 ppm, 640 ppm, and 1200 ppm, respectively.

The highest metal concentrations were located at depths greaterthan 33 feet below ground surface (BGS). The shallow subsurfacesoil samples containing the highest levels of contamination werelocated northeast of Pit 7 and east of Pit 2.

Only a few compounds were detected in the deep subsurface soil. (See Table 3.) In general, the highest concentrations ofcontaminants in deep subsurface soil occurred at a depths of53-55 feet. The samples containing the highest concentrations ofcontaminants were located east of Pit 2 and northeast of Pit 7.

Table 2.

ON-SITE SHALLOW SUBSURFACE SOIL
Contaminant Maximum Concentration ppm Sample Depth feet Reference HAC Value ppm HAC Source

Metals (Indicator)
Arsenic 14 48-50 WCEA 50 EMEG
Barium 202 33-35 WCEA 3,500 RfD
Cadmium 8.8 3-6 WCEA 200 EMEG
Chromium 14 6-8 WCEA 200 EMEG
Lead 44.7 48-50 WCEA None None
Manganese 180 22 BVII 5,000 RfD
Mercury ND 10-30 BVII 40 EMEG
Volatile Organic Compounds
Benzene 15 4-6 WCEA 30 EMEG
Chloroform 0.41 4-6 WCEA 1,000 EMEG
1,1-dichlorethane ND 10-50 BVII/MMFS 5,000 RfD
1,1-dichloroethene 66 48-50 WCEA 400 EMEG
1,2-dichloroethane 1200 48-50 WCEA 200 EMEG
1,2-dichloropropane ND 10-30 MMFS 3,000 EMEG
1,3-dichloropropylene NA NA None None None
Methylene Chloride 0.072 10 BVII 2,000 EMEG
1,1,2,2-tetrachloroethane ND 10-30 BVII 10,000 RfD
Toluene 21.0 4-6 MMFS 10,000 RfD
1,2-transdichloroethylene ND 3+ WCEA 1,000 RfD
1,1,2-trichloroethane 640 4-6 WCEA 2,000 EMEG
Trichloroethylene 1.0 4-6 BVII 100,000 EMEG
Vinyl Chloride ND 10-50 BVII/MMFS 50 EMEG
Semi-Volatile Organic Compounds
Acenaphthene 54 48-50 WCEA 3,000 RfD
Acenaphthylene 110 48-50 WCEA 5,000 MRL
Anthracene 55 48-50 WCEA 15,000 MRL
Benz (a) anthracene 0.79 43-45 WCEA 5,000 MRL
Benzo (a) pyrene 0.7 28-30 WCEA 5,000 MRL
Benzo (b) fluoranthene 0.32 43-45 WCEA 5,000 MRL
Bis(2-chloroethyl)ether 610 30+ WCEA 1,000 EMEG
Bis(2-ethylhexyl)phthalate ND 48-50 MMFS 1,000 RfD
Chrysene 0.7 28-30 WCEA 5,000 MRL
Fluoranthene 6.8 4-6 WCEA 2,000 RfD
Fluorene 100 6-8 WCEA 2,000 RfD
Naphthalene 830 6-8 WCEA 66,500 MRL
Phenanthrene 260 6-8 WCEA 5,000 MRL
Pyrene 120 6-8 WCEA 1,500 RfD

ND = not detected
NA = not analyzed
BVII = Black & Veatch Initial Investigation, Dec. 1981
MMFS = Management Migration Feasibility Study, Vol.2, May 1988
WCEA = Woodward & Clyde Endangerment Assessment, May 1989


Table 3.

ON-SITE DEEP SUBSURFACE SOIL
Contaminant Maximum Concentration ppm Sample Depth feet Reference HAC Value ppm HAC Source

Metals (Indicator)
Arsenic 7.6 158-160 WCEA 50 EMEG
Barium 151 158-160 WCEA 3,500 RfD
Cadmium 0.92 63-65 WCEA 200 EMEG
Chromium 18.8 53-55 WCEA 200 EMEG
Lead 27.6 138-140 WCEA None None
Manganese NA NA NA 5,000 RfD
Mercury 0.3 58-60 WCEA 40 EMEG
Volatile Organic Compounds
Benzene 0.01 53-55 MMFS 30 EMEG
Chloroform ND 53-160 MMFS 1,000 EMEG
1,1-dichlorethane ND 53-160 MMFS 5,000 RfD
1,1-dichloroethene 9.2 53-55 WCEA 400 EMEG
1,2-dichloroethane 58 53-55 WCEA 200 EMEG
1,2-dichloropropane ND 53+ WCEA 3,000 EMEG
1,3-dichloropropylene NA NA NA None None
Methylene Chloride 0.016 58-60 MMFS 2,000 EMEG
1,1,2,2-tetrachloroethane ND 53-160 MMFS 10,000 RfD
Toluene 0.053 53-55 MMFS 10,000 RfD
1,2-transdichloroethylene NA NA NA 1,000 RfD
1,1,2-trichloroethane 0.12 53-55 WCEA 2,000 EMEG
Trichloroethylene NA NA NA 100,000 EMEG
Vinyl Chloride ND 53-160 MMFS 50 EMEG
Semi-Volatile Organic Compounds
Acenaphthene ND 53+ WCEA 3,000 RfD
Acenaphthylene ND 53+ WCEA 5,000 MRL
Anthracene ND 53+ WCEA 15,000 MRL
Benz (a) anthracene ND 53+ WCEA 5,000 MRL
Benzo (a) pyrene ND 53+ WCEA 5,000 MRL
Benzo (b) fluoranthene ND 53+ WCEA 5,000 MRL
Bis(2-chloroethyl)ether ND 53+ WCEA 1,000 EMEG
Bis(2-ethylhexyl)phthalate ND 53-160 MMFS 1,000 RfD
Chrysene ND 53+ WCEA 5,000 MRL
Fluoranthene ND 53+ WCEA 2,000 RfD
Fluorene 0.36 53-55 WCEA 2,000 RfD
Naphthalene 1.0 53-55 WCEA 66,500 MRL
Phenanthrene 1.3 53-55 WCEA 5,000 MRL
Pyrene 0.38 53-55 WCEA 1,500 RfD

ND = not detected
NA = not analyzed
BVII = Black & Veatch Initial Investigation, Dec. 1981
MMFS = Management Migration Feasibility Study, Vol.2, May 1988
WCEA = Woodward & Clyde Endangerment Assessment, May 1989

2. Ground-Water Contamination

Eight on-site monitoring wells were sampled. Six of the monitorwells were screened in the shallow aquifer (transmissive zones 1,2, and 3) and two monitor wells were screened in the deeperaquifer (Upper Chicot). Seven of the wells were located in theeastern part of the site, with one well located northeast of Pit1.

The majority of the ground-water contamination in the shallow aquifer consists of VOCs although some semi-VOCs and metal contamination were also detected. (See Table 4.) Contaminants with the highest concentrations were 1,2-dichloroethane (3500 ppm), 1,1,2-trichloroethane (250 ppm), vinyl chloride (116 ppm), and benzene (40.45 ppm). In addition, methylene chloride was detected at a concentration of 0.5 ppm. The highest VOC concentrations were found southeast of Pit 7. Low levels of PAHs were detected in the shallow ground water; however, bis(2-chloro-ethyl)ether was detected at 3300 ppm. The highest levels were found in the well located southeast of Pit 7. The highest ground-water metal concentrations were detected northeast of Pit 7 and close to the plant's main entrance. Metals considered contaminants of concern were manganese (9.2 ppm), chromium (0.56 ppm), cadmium (0.48 ppm), and lead (0.45 ppm).

Only two on-site wells draw water from the deeper aquifer. Bothwells are located northwest of Pit 7. Contamination in the wellsis limited primarily to VOCs, although a few semi-VOCs and metalsare present at low levels (see Table 5). The VOCs with thehighest concentrations are vinyl chloride (0.68 ppm), 1,2-dichloroethane (0.5 ppm), and 1,1-dichloroethene (0.091 ppm). Inaddition, benzene was detected at 0.052 ppm.

3. Waste-Pit Contamination

The majority of the on-site wastes at MOTCO are contained inseven unlined waste pits. The maximum pit depth is between 15and 20 feet, and together the pits cover approximately 4.6 acres. Primary contaminants associated with the waste pits includechlorinated and aromatic hydrocarbons and PAHs. Polychlorinatedbiphenyls (PCBs) and heavy metals are also contained in the wastepits. (See Tables 6, 7, and 8.)

4. Air Contamination

Air quality monitoring was conducted at the MOTCO site inSeptember 1981, to evaluate the necessary levels of respiratoryprotection for initial site remediation work. An organic vaporanalyzer (OVA) was used. No contaminants of concern wereidentified as a result of on-site air quality sampling.


Table 4.

ON-SITE SHALLOW GROUND WATER*
Contaminant Maximum Concentration ppm Reference HAC Value ppm HAC Source

Metals (Indicator)
Arsenic 0.044 WCEA 0.01 EMEG
Barium 0.670 WCEA 0.7 RfD
Cadmium 0.480 WCEA 0.005 EMEG
Chromium 0.56 WCEA 0.05 EMEG
Lead 0.45 WCEA None None
Manganese 9.2 BVII 1 RfD
Mercury 0.002 WCEA 0.008 EMEG
Volatile Organic Compounds
Benzene 40.45 WCEA 0.007 EMEG
Chloroform 0.034 BVII 0.2 EMEG
1,1-dichlorethane 0.267 BVII 1 RfD
1,1-dichloroethene 3.2 WCEA 0.09 EMEG
1,2-dichloroethane 3,500 WCEA 0.05 EMEG
1,2-dichloropropane 0.275 BVII 0.07 EMEG
1,3-dichloropropylene 0.024 BVII None None
Methylene Chloride 0.509 BVII 0.5 EMEG
1,1,2,2-tetrachloroethane 0.291 BVII 2 RfD
Toluene 10.15 BVII 2 RfD
1,2-transdichloroethylene 1.255 BVII 0.2 RfD
1,1,2-trichloroethane 250 WCEA 0.4 EMEG
Trichloroethylene 0.098 BVII 20 EMEG
Vinyl Chloride 116 WCEA 0.01 EMEG
Semi-Volatile Organic Compounds
Acenaphthene 0.054 BVII 0.6 RfD
Acenaphthylene 0.338 BVII 1.0 MRL
Anthracene ND MMFS 3.0 RfD
Benz (a) anthracene ND MMFS 1.0 MRL
Benzo (a) pyrene ND MMFS 1.0 MRL
Benzo (b) fluoranthene ND MMFS 1.0 MRL
Bis(2-chloroethyl)ether 3,300 WCEA 0.02 EMEG
Bis(2-ethylhexyl)phthalate 0.106 BVII 0.2 RfD
Chrysene ND MMFS 1.0 MRL
Fluoranthene ND MMFS 0.4 RfD
Fluorene 0.102 BVII 0.4 RfD
Naphthalene 18.4 WCEA 13.3 MRL
Phenanthrene 0.2 WCEA 1.0 MRL
Pyrene ND MMFS 0.3 RfD

*Transmissive Zones 1,2,&3
ND = not detected
BVII = Black & Veatch Initial Investigation, Dec. 1981
MMFS = Management Migration Feasibility Study, Vol.2, May 1988
WCEA = Woodward & Clyde Endangerment Assessment, May 1989


Table 5.

ON-SITE DEEP GROUND WATER*
Contaminant Maximum Concentration ppm Reference HAC Value ppm HAC Source

Metals (Indicator)
Arsenic 0.003 WCEA 0.01 EMEG
Barium 0.225 WCEA 0.7 RfD
Cadmium ND MMFS 0.005 EMEG
Chromium 0.009 WCEA 0.05 EMEG
Lead 0.051 WCEA None None
Manganese NA NA 1 RfD
Mercury 0.0001 MMFS 0.008 EMEG
Volatile Organic Compounds
Benzene 0.052 WCEA 0.007 EMEG
Chloroform ND MMFS 0.2 EMEG
1,1-dichlorethane 0.039 WCEA 1 RfD
1,1-dichloroethene 0.091 WCEA 0.09 EMEG
1,2-dichloroethane 0.5 WCEA 0.05 EMEG
1,2-dichloropropane ND MMFS 0.07 EMEG
1,3-dichloropropylene NA NA None None
Methylene Chloride ND MMFS 0.5 EMEG
1,1,2,2-tetrachloroethane ND MMFS 2 RfD
Toluene 0.19 WCEA 2 RfD
1,2-transdichloroethylene NA NA 0.2 RfD
1,1,2-trichloroethane ND MMFS 0.4 EMEG
Trichloroethylene ND MMFS 20 EMEG
Vinyl Chloride 0.68 WCEA 0.01 EMEG
Semi-Volatile Organic Compounds
Acenaphthene ND MMFS 0.6 RfD
Acenaphthylene ND MMFS 1.0 MRL
Anthracene ND MMFS 3.0 RfD
Benz (a) anthracene ND MMFS 1.0 MRL
Benzo (a) pyrene ND MMFS 1.0 MRL
Benzo (b) fluoranthene ND MMFS 1.0 MRL
Bis(2-chloroethyl)ether 0.009 WCEA 0.02 EMEG
Bis(2-ethylhexyl)phthalate ND MMFS 0.2 RfD
Chrysene ND MMFS 1.0 MRL
Fluoranthene ND MMFS 0.4 RfD
Fluorene ND MMFS 0.4 RfD
Naphthalene 0.019 WCEA 13.3 MRL
Phenanthrene 0.002 WCEA 1.0 MRL
Pyrene ND MMFS 0.3 RfD

* Upper Chicot Aquifer
NA = not analyzed
ND = not detected
BVII = Black & Veatch Initial Investigation, Dec. 1981
MMFS = Management Migration Feasibility Study, Vol.2, May 1988
WCEA = Woodward & Clyde Endangerment Assessment, May 1989


Table 6.

Pit Surface Water Contaminants
CONTAMINANTS CONCENTRATION (ppm)

aluminum 10,000-130,000
arsenic P
chromium TR-450
copper TR-2420
cyanides TR-12,000
iron 10,000-40,000
lead TR-4300
mercury P
nickel TR-220
zinc 300-1840
sodium 100,000-300,000
calcium 30,000-100,000
magnesium 10,000-50,000
chloroform 65
1,1-dichloroethane 310
1,2-dichloroethane 5400
1,1,2-trichloroethane 1900
vinyl chloride 430
methylene chloride 350
diphenylacetamide 1100
bis(2-chloroethyl)ether 112

P = present
TR = trace


Table 7.

Pit Waste - Inorganic Contaminants
CONTAMINANTS ORGANIC LIQUIDS (ppm) TARS/SLUDGE (MAXIMUM CONCENTRATION) (ppm)

aluminum 2-5,000 12,000
antimony ND-3 -
arsenic ND-3 30
barium ND-10 200
boron ND-5 20
cadmium ND-920 920
calcium 20-800 8,000
chromium ND-100 500
cobalt ND-10 10
copper 3-500 45,000
iron 40-400 > 6,000
lead ND-500 46,000
lithium ND-1.0 55
magnesium ND-220 2,000
mercury ND-5 -
molybdenum ND-5 30
nickel ND-15 150
platinum ND-1 6
potassium ND-500 4,000
silicon 10-30 320
sodium 30-1,350 2,500
strontium ND-10 20
tin ND-20 600
titanium ND-50 200
vanadium ND-5 22
zinc 1-30 750
zirconium ND-3 35

ND = not detected


Table 8.

PIT WASTE - ORGANIC CONTAMINANTS
CONTAMINANTS CONCENTRATION (ppm)

VOLATILES:
benzene ND-5,440
chlorobenzene ND-400
ethylbenzene ND-6,000
chloroform ND-800
1,1-dichloroethane ND-3,200
1,2-dichloroethane 38-41,5000
1,1,2-trichloroethane ND-61,000
1,1,1-trichloroethane ND-220
1,1,2,2-tetrachloroethane ND-4,000
1,1-dichloroethylene ND-10,000
1,2-trans-dichloroethylene ND-11,200
trichloroethylene ND-400
methylene chloride ND-90
toluene ND-3,200
vinyl chloride ND-7,600
1,2-dichloropropane ND-300
1,3-dichloropropylene ND-200
tetrachloroethylene ND-900
2-chloropropane ND-25,700
methyl ethyl benzene ND-16,000
hexane ND-1,800
xylene ND-3,000
PESTICIDE/PCB:
pcb (total) ND-100
dieldrin ND-17
SEMI-VOCs:
bis(2-chloroethyl)ether ND-3,900
bis(2-chloroisopropyl)ether ND-500
naphthalene ND-36,000
2-methylnaphthalene ND-4,000
biphenyl ND-5,000
styrene ND-22,000
methylnaphthalene ND-18,000
phenylnaphthalene ND-7,000
propylenebenzene ND-11,000
ethenylidenebisbenzene ND-8,000
n-nitroso diphenyl-amine ND-4,700
PAHs:
acenaphthalene ND-6,000
fluorene ND-4,500
phenanthrene ND-7,200
anthracene ND-8,430
fluoranthene ND-1,300
pyrene ND-3,000
benzo(a)anthracene ND-3,000
pentachlorophenol ND-670

ND = not detected



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