United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPA/ROD/R06-88/045
September 1988
Superfund
Record of Decision
South Cavalcade Street, TX
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10277-101
REPORT DOCUMENTATION
PAGE
I. HKPORT NO.
EPA/ROD/R06-88/045
3. Recipient's Accession No.
4. Title and Subtitle
SUPERFUND RECORD OF DECISION
outh cavalcade Street, TX
irst Remedial Action - Final
S. Report Date
09/26/88
7. Authors)
8. Performing Organization Rept. No.
9. Performing Organization Name and Address
10. Project/Task/Work Unit No.
11. Contract(C) or Grant(G) No.
(C)
(G)
12. Sponsoring Organization Name and Address
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
13. Type of Report & Period Covered
800/000
14.
19. Supplementary Notes
16. Abstract (Limit: 200 words)
The 66-acre South cavalcade site is located in northeast Houston, Texas.
The
surrounding areas are a mixture of residential, commercial, and industrial properties.
Stormwater, runoff flows to two stormwater drainage ditches, which flow into Hunting
Bayou, a limited aquatic habitat as classified by Texas Water Quality Standards. The
site was used as a wood preserving and coal tar distillation facility from 1910 to
I 1962. The wood preserving facility consisted of an operations area, a drip track, and
Kreated and untreated wood storage areas. The operations area included wood-treating
.Cylinders, chemical storage 'tanks, and a waste water lagoon. Creosote and metallic
salts were used in the operation. Subsequently, the site was sold, divided into smaller
tracts, and resold to the current owners. The site is currently used by three
commercial trucking companies, which have erected four buildings on the northern and
southern parts of the site. In 1983, the Houston Metropolitan Transit Authority
investigated the site for potential mass transit use and found evidence of buried
creosote. Beginning in November 1985, EPA sampled all environmental media and found two
discrete areas of contamination at the site corresponding to the former locations of the
wood treating operations and coal tar plant in the southern portion of the site, and a
pond previously existing in the northern portion of the site. PAHs, VQCs, metals and
(See Attached Sheet)
South Cavalcade Street, TX
First Remedial Action - Final
Contaminated Media: gw, soil, sediments
Key Contaminants: VOCs (benzene, toluene, xylenes,) PAHs, metals (arsenic, chromium,
b. Identlfiers/Open-Ended Termslead) ,
c. COSATI Reid/Group
Availability Statement
19. Security Class (This Report)
None
20. Security Class (This Page)
None
21. No. of Pages
71
22. Price
(See ANSI-Z39.18)
See Instructions on Reverse
OPTIONAL FORM 272 (4-77)
(Formerly NTIS-35)
Department of Commerce
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kEPA/ROD/R06-88/045
'South Cavalcade Street, TX
First Remedial Action - Final
16. ABSTRACT (continued)
components of creosote were detected in the soil, sediments, and ground water. The
primary contaminants of concern affecting the ground water, soils, and sediments are
VOCs including benzene, toluene, and xylenes, other organics including PAHs, and metals
including arsenic, chromium, and lead.
The selected remedial action for this site includes: excavation and onsite washing of
19,500 yd3 of soil, replacing the soil in the excavated areas and capping, and
treating wash water in the ground water treatment system; in situ soil flushing of
10,500 yd3 of soil; ground water pump and treatment of 50,000,000 gallons using
physical/chemical separation, pressure filtration, and carbon adsorption with
re-injection into the aquifer or, if necessary, discharge to the onsite drainage ditch
which flows into Hunting Bayou; offsite incineration or recycling of all non-agueous
phase liquids separated out from the ground water; and ground water monitoring.
Alternatively, in situ biological treatment of soil and ground water will be considered
if a potentially responsible party can demonstrate its equivalent or superior
performance and implementability costs. The estimated present worth cost for this
remedial action is $13,000,000.
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RECORD OF DECISION £ EPA
REGION 6
SOUTH CAVALCADE STREET SITE
HOUSTON, TEXAS
REMEDIAL ALTERNATIVE SELECTION
STATEMENT OF PURPOSE
This decision document presents the selected remedial action for the South
Cavalcade Street site in accordance with the Comprehensive Environmental
Response, Compensation and Liability Act of 1980, as amended by the Superfund
Amendments and Reauthorization Act of 1986; and the National Oil and Hazardous
Substances Pollution Contingency Plan, 40 CFR Part 300, November 20, 1985.
The State of Texas (through the Texas Water Commission) has been provided
an opportunity to comment on the technology and degree of treatment proposed
by the Record of Decision and has no objection to the selected remedy (See
Appendix D).
STATEMENT OF BASIS
This decision is based upon the administrative record for the South Cavalcade
site. The attached index identifies the documents which comprise the admini-
strative record. (See Appendix E).
DESCRIPTION OF THE REMEDY
The selected remedy will treat the health- and environment-threatening
contamination resulting from historical wood preserving operations at the
site. Upon review of the information contained in the administrative record,
EPA has determined that soil remediation using a combination of soil washing
and in situ soil flushing and groundwater remediation using physical/chemical
separation followed by filtration and activated carbon adsorption best ful-
fills the statutory selection criteria. Alternatively, if a potentially
responsible party offers to implement an in situ biological treatment process
for groundwater and can demonstrate that this process can be implemented and
operated at an efficiency equal to or better than activated carbon, then this
method will be used to remediate groundwater. The following is a summary of
the proposed remedy:
Soil Remediation: During the initial stages of the remedial design, contami-
nated soil areas will be sampled to better define areas which require remedia-
tion. All areas will be remediated which either exceed the risk-based or
leaching potential-based remedial goals. The risk-based goals is 700 ppm based
on ingestion and direct contact with soils. The leaching potential-based goal
U.S. Environmental Protection Agency 1445 Ross Avenue Dallas, Texas 75202-2733
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will be determined by the EPA Toxicity Characteristic Leaching Procedure
test. There are approximately 30,000 cubic yards which may need remediation.
In the southeast corner of the site, approximately 19,500 cubic yards of con-
taminated soils will be excavated and transported to the soil washing facility
which will be constructed in the center portion of the South Cavalcade site.
Wash water from the unit will be treated for removal of contaminants in the
groundwater treatment system. The cleansed soils will be placed into the
excavations and capped to maintain soil stability.
In the other parts of the site, contaminated soils will be remediated using
in situ soil flushing. The contaminants which travel into the groundwater
will be extracted and treated in the carbon adsorption wastewater
treatment system.
Groundwater Remediation: Groundwater will be remediated through extraction
and treatment of contaminated groundwater, with reinjection to increase the
hydraulic gradient and flow velocities. Approximately 50 million gallons
of groundwater will need to be processed several times to recover and treat
the non-aqueous phase liquids. Groundwater will be treated to drinking
water standards and no detectable carcinogenic PAHs. Groundwater collection
will continue until the groundwater contaminants have been recovered to the
maximum extent possible. This point will be determined during the Remedial
Action based upon operational experience in using the collection and treat-
ment system. After this point is reached, the groundwater collection will
cease and any remaining contamination be allowed to naturally attenuate to
background levels.
Groundwater will be extracted and re-injected in a series of three groundwater
extraction lines and two groundwater injection lines in the southern part
of the site, and a minimum of one extraction line and reinjection line in
the northern part. These wells will be screened in the shallow aquifer
(approximately 10 - 20 feet below grade) and in the intermediate discontin-
uous sand lenses (approximately 50 feet below grade). The actual number of
lines, locations and spacings of wells and well lines will be refined during
remedial design.
The groundwater will be treated at an onsite wastewater treatment plant
constructed in the center portion of the site. Groundwater will be pumped
into a physical/chemical separator followed by a pressure filter and an
activated carbon adsorption unit. Any non-aqueous phase liquids collected
and separated from the groundwater will be recycled as creosote or incin-
erated offsite. The water will be treated to levels equal to Maximum Con-
taminant Levels and no detectable carcinogenic PAHs. Cleansed groundwater
will be re-injected into the aquifer along with surfactants to help recover
the contaminants. Any excess water will be discharged to the drainage
ditch leading into the off-site Hunting Bayou in accordance with an NPDES
permit.
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Alternate Remediation Plan: If a potentially responsible party can show that
in situ biological treatment of soil and groundwater will provide equal or
better performance and can further ensure that the implementability questions
can be resolved, EPA will consider this remedial method. In this case, the
performance goals and groundwater extraction system will be identical to
EPA's selected remedy, but the actual method of treatment will differ.
Groundwater will be treated above ground in the physical/chemical separator
and injected with nutrients and oxygen (if necessary). The treated ground-
water will be added to the contaminated soil and re-injected to encourage
biological degradation of contaminants under the ground. Any excess water
will be discharged into the city sewer system in accordance with a pretreat-
ment permit and treated in a city municipal treatment plant.
Operation and Maintenance: The need for future operation and maintenance
should be minimized since the primary sources of contamination will be
removed through treatment. Site operation and maintenance will include
installing a well screened in the 500 foot sand, monitoring groundwater
wells and monitoring ambient air during remediation. The groundwater mon-
itoring program will continue for at least 30 years unless it can be shown
during the Remedial Action that some shorter length of time is appropriate.
This sampling program will monitor the effectiveness of the selected remedy
and provide the data necessary. If the monitoring shows leaching from soils
now under existing structures, then the site will need to be revisited to
determine if further remediation is necessary.
Additional site maintenance would include, but not necessarily limited
to, inspections of surface vegetation, ensuring proper drainage, and proper
operation of any actions such as groundwater treatment which may extend
beyond the time required for the source control remedy. The details of
these activities will be defined in the Operation and Maintenance Plan of
the remedial design. The monitoring data will be evaluated during the
Agency's 5-year review, in accordance with CERCLA Section 121 (c), to
determine if any corrective action is necessary.
DECLARATION
The selected remedy is protective of human health and the environment,
attains Federal and State requirements that are applicable or relevant and
appropriate, and is cost-effective. This remedy satisfies the preference
for treatment that reduces toxicity, mobility or volume as a principal
element. Finally, it is determined that this remedy utilizes permanent
solutions and alternative treatment technologies to the maximum extent
practicable.
.
DateRobert E. Layton /r.,
Regional Administrator
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SUMMARY OF REMEDIAL ALTERNATIVE SELECTION
SOUTH CAVALCADE STREET SITE
HOUSTON, TEXAS
SEPTEMBER 1988
U. S. ENVIRONMENTAL PROTECTION AGENCY
REGION VI, DALLAS, TEXAS
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TABLE OF CONTENTS
1. SITE LOCATION AND DESCRIPTION 1
2 . SITE HISTORY 1
2.1 Previous Site Use 1
2.2 Response and Remedial Activities 1
2.3 Enforcement 4
3. SITE CHARACTERISTICS 4
3.1 Geology and Hydrogeology 4
3.2 Surface and Surficial Soils 5
3.3 Groundwater 8
3.4 Surface Water and Sediments 12
3.5 Air ... 12
4. SITE RISKS . 12
4.1 Exposure Pathways 12
4.2 Potential Health Risks ... 14
4.3 Remedial Goals 15
5. COMMUNITY RELATIONS HISTORY 16
6. SCOPE AND ROLE OF ACTION WITHIN SITE STRATEGY 16
7. ALTERNATIVES EVALUATION 17
7.1 Description of Alternatives .......- 17
7.2 Evaluation of Alternatives 23
8. SELECTED REMEDY 30
8.1 Description of the Remedy 30
8.2 Statuatory Determinations 32
8.3 Future Actions 36
APPENDICES
A Responsiveness Summary
B Applicable or Relevant and Appropriate Requirements
C Risk Calculations
D State of Texas Concurrence
E Index to the Administrative Record
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LIST OF FIGURES
Page
1 Site Vicinity Map 2
2 Site Ownership Map * 3
3 Generalized Geologic Profile 6
4 Surficial Soils Quality Map 7
5 Subsurface Organic Quality Map 10
6 Soil Excavation Areas 19
LIST OF TABLES
Page
1 Soil Concentrations 9
2 Groundwater Concentrations 11
3 Surface Water and Sediment Concentrations 13
4 Comparison of Soil Remedial Alternatives 24
5 Comparison of Groundwater Remedial Alternatives 25
i
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1. SITE LOCATION AND DESCRIPTION
The South Cavalcade Street site is located in northeast Houston,
Texas about one mile southwest of the intersection of Interstate
Loop 610 and U.S. Route 59 (Figure l). The site boundaries are
Cavalcade -Street to the north, collingsworth street to the south,
and the Missouri and Pacific railroad lines to the east and west.
The site is rectangular in shape with a base of approximately 600
feet, an height of 4,800 feet, and an area of 66 acres.
The site is generally flat. It is drained by two stormwater
drainage ditches which flank the site on the east and west sides,
and drain water into a flood control ditch which discharges into
Hunting Bayou, a tributary of the Houston Ship Channel. Hunting
Bayou is currently classified in the Texas water quality stan-
dards as a limited aquatic habitat.
i
The site is now used by three commercial trucking companies (Mer-
chants Fast Motor Lines, Transcom Lines, and Palletized Trucking)
which have erected four buildings on the northern and southern
parts of the site. The central part of the site is not currently
used. The surrounding areas are residential, commercial, and
industrial properties. The nearest residential area is directly
to the west. Commercial properties are located along the major
thoroughfares as well as on-site.
2. SITE HISTORY
2.1 PREVIOUS SITE USE
The South Cavalcade site was used as a wood preserving and coal
tar distillation facility from 1910 to 1962. The wood preserving
facility consisted of an operations area, a drip track, and
treated and untreated wood storage areas. The operations area
included wood treating cylinders, chemical storage tanks, and a
wastewater lagoon; this area was located in the southwestern part
of the site. Creosote and metallic salts were used in the oper-
ation. The drip track ran diagonally from the operations area to
the northeast, and ended before the central part of the site.
The coal tar plant was located in the southeastern part of the
site.
In 19,62, the Koppers Company ceased operation of the facility,
and sold the site to Merchants Fast Motor Lines. The site was
later sold, subdivided, and resold to the current property own-
ers. Figure 2 shows current site ownership.
2.2 RESPONSE AND REMEDIAL ACTIVITIES
In 1983, the Houston Metropolitan Transit Authority investigated
the site for potential mass transit use and found evidence of
buried creosote. The Texas Department of Water Resources con-
ducted a further study and determined that the site may pose a
threat to public health and the environment. Based on this
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Houston
Intercontinental
Airport
SOUTH
CAVALCADE
SITE VICINITY MAP
FIGURE 1
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11 / ' // ' SITE OWNERSHIP MAP TAKEN PROM CAMP DflESSER MCKEE REPORT
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BAPTIST FOUNDATION OF TEXAS
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information, TDWR referred the site to EPA for inclusion on the
National Priorities List (NPL). EPA proposed the site to be
added to the NPL in October 1984; the site was formally promul-
gated in June 1986.
EPA began the Remedial Investigation and Feasibility Study
(RI/FS) in November of 1985. The Remedial Investigation included
investigations into contamination in soils, groundwater, surface
water and sediments, and air. The Feasibility Study evaluated
several methods for remediating the site problems including con-
tainment and treatment technologies. The RI/FS ended in August
of 1988 with the publishing of the reports on each.
2.3 ENFORCEMENT
EPA identified four potentially responsible parties (PRPs) in the
initial stages of the RI. EPA issued an Administrative Order on
Consent to the Koppers Company in 1985 to conduct a RI/FS.
EPA mailed copies of the proposed plan of action for this site to
the PRPs on August 19, 1988. EPA will continue its enforcement
activities by sending a Special Notice letter to the PRPs before
the initiation of the remedial design. Should the PRPs decline
to conduct future remedial activities, EPA will either take
enforcement action or will provide funding for these activities
while seeking cost recovery for all EPA-funded response actions
from the PRP.s.
3. SITE CHARACTERISTICS
The Remedial Investigation characterized local geology and hydro-
geology and investigated four different types of environmental
media at the South Cavalcade site: soils, groundwater, surface
water and sediments, and air. The samples collected during this
period were analyzed for substances characteristic of wood pre-
serving and coal tar facilities: polynuclear aromatic hydrocar-
bons (PAHs), volatiles (benzene, ethylbenzene, toluene, and
xylenes) and metals (arsenic, chromium, copper and zinc). The
analytical results from the sampling are described in the Reme-
dial Investigation report dated August, 1988. A brief summary is
presented below.
3.1 GEOLOGY AND HYDROGEOLOGY
The South Cavalcade site is situated on the Quaternary Gulf Coast
Plain of Texas. This region is comprised of a series of sedimen-
tary depositional plains which are composed of channel fill
deposits. The South Cavalcade site is-situated within the sur-
face sediments of the Beaumont Formation, and consists of sandy
to silty clays. Below this is the Lissie Formation which is
composed of fluvial and deltaic deposits.
Regionally, there are three principal aquifers in the Coastal
Plain. These are the Chicot, Evangeline and Jasper. The Chicot
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and Evangeline aquifers are the uppermost units and are approxi-
mately 1800 feet in thickness. Below the Evangeline aquifer is
the Burkeviile Confining System, which in turn is underlain by
the saline Jasper aquifer. Both the Chicot and Evangeline are
fresh water aquifers which are used as water supplies in coastal
areas of Texas.
Locally, in the vicinity of the South Cavalcade site, the upper
five geologic units have been characterized as follows:
Average
Unit Geology Depth (ft)
1 Deltaic Deposits 0-21
2 Fluvial/Deltaic Deposits 21 - 50
3 Deltaic Deposits 50 - 125
4 Fluvial/Deltaic Deposits 125 - 200
5 Pre-Deltaic Deposits below 200
A cross section of the upper three units is shown in Figure 3.
The uppermost water bearing unit at the South Cavalcade site is.
approximately 11 feet in thickness and begins approximately 6 to
10 feet below grade. This unit is continuous across the site.
Horizontal flow velocity in this layer is approximately 16 feet
per year towards the west. Small, localized sand units are
present at approximately 45 feet, but these are not extensive
water yielding units. A thin sand (less than 10 feet) is present
at approximately 115 to 127 feet of depth. A deep aquifer zone
is encountered between depths of 174 and 200 feet; water within
this zone and deeper zones flows to the south. A downward
vertical gradient exists between the uppermost water bearing unit
and the deep aquifer zone. Vertical groundwater seepage rates
should typically be limited by the relatively low permeability of
the clayey confining strata. However, local seepage is greater
due to secondary soil structures (i.e. fissures, silt seams, sand
layers, slickensides). Vertical groundwater seepage rates were
estimated at approximately 1.8 feet per year.
3.2 SURFACE AND SURFICIAL SOILS
Surface and surficial soils comprise the top six feet of soil at
the South Cavalcade site. Surface soils are defined to be in the
upper 0.5 foot. Surface and surficial soils approximately delin-
eate the unsaturated soils of the vadous zone.
Soil staining showing potential residual organic concentrations
was seen at 15 of 139 auger boring locations and at 29 of 82 soil
boring locations. Based on observations at these locations, a
surficial soils quality map was developed to show the approximate
areal distributions of both surface and surficial visual soil
staining. This is shown in Figure 4.
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-------
Visually stained surface and surficial soils in the southern
portion of the site correspond to the former locations of the
coal tar plant and wood treating operations. The stains in the
northern area correspond to a pond observed in the 1964 aerial
photograph of the site. There are approximately 5.5 acres of
visually stained surficial soils on the site with approximately
50% of this in unpaved areas.
A total of four surface/surficial soil samples were analyzed for
semivolatile organic compounds and select inorganics. Total
surficial soil PAH concentrations ranged from below detectable
limits to 8567 mg/kg. Copper, chromium, arsenic, zinc, and lead
concentrations exceeded background levels. Table 1 shows the
maximum concentrations of site contaminants in surface and surfi-
cial soils.
No surficial soil contaminant source areas, such as hydrocarbon-
saturated soils and NAPLs, were disclosed from an electromagnetic
geophysical survey, shallow auger boring program, or soil boring
program.
3.3 GROUNDWATER
A total of 65 groundwater samples including duplicates were ana-
lyzed from shallow and deep water bearing zones for HSL volatile
and semivolatile organic compounds, pesticides and PCBs, and
select inorganics.
As shown in Figure 5, the distribution of subsurface constituents
appears to form two discrete areas, one at the northern portion
of the site and the other in the southern portion of the site.
The northern distribution area generally corresponds to the loca-
tion of a 1964 aerial photograph anomaly. The contamination is
primarily on-site, although there is a small area off-site. The
average attenuation depth of organic compounds in the soils in
the northern site area is about 52 feet.
The southern area encompasses the locations of the former process
areas. Again, most of the contamination is on-site with some
off-site migration to the south and southwest. The average
attenuation depth of organic compounds in the soils in the south-
ern site area is about 58 feet.
/' i
Table 2 shows the maximum concentrations found in the ground-
water. The primary compounds in the shallow aquifer were PAHs,
which ranged in concentration from below detection limits to
observed non-aqueous phase creosote at several wells. Aromatic
volatile organic compounds (benzene, toluene, ethylbenzene, sty-
rene and xylene) were detected in 7 of.18 monitoring wells.
Metals were also detected in the groundwater and were highest in
concentration in the southern area of the site, near the former
coal tar process area. A total of three wells had measurable
concentrations of four pesticides, although no specific pesti-
cide distribution pattern was evident.
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TABLE 1
SOIL CONCENTRATIONS
(1)
Contaminant
Arsenic
Chromium
Copper
Lead
Zinc
Acenaphthy Iene
Acenaphthene
Anthracene
Benzo(a)anthracene
Benzo(a)pyrene
Benzo(b&k)fluoranthene
BenzoCg,h,i)pyrene
Ch rysene
Oibenzo(a,h)anthracene
FIuoranthene
FIuorene
Ideno(1.2,3-cd)pyrene
2-Methyl naphtha Iene
Naphtha Iene
Phenanthrene
Pyrene
Total PAHs
Carcinogenic PAHs
Maximum Concentration
Above 6. fj_ Below 6. fj.
9
10
5
30
3480
nd
440
560
340
210
290
77
310
na
1 ,600
490
nd
68
950
2,100
1,200
8,567
1 ,150
(3)
28
47
20
45
250
nd
570
240
93
nd
61
nd
76
nd
420
440
nd
780
1.900
940
280
5,020
230
Health Based
.(2)
300
>500,000
>500,000
420,000
>500,000
91
(1)
units of mg/kg unless otherwise noted
based on risk calculations for commercial exposure
,-6
equal to the reference dose or 10 cancer risk
na ~ not analyzed; nd = not detected
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//'.'^'v -,-'. >;
LEGEND
SOIL BORMO
SHALLOW ZOm MOHITOHWO WILL
UROANX; COMPOUNDS. MOROANIC CONSTITUENTS AND NON-HSi OROAMC
COMPOUNDS NOT MCIUOEO
O SHALLOW ZONE MOMrroBINO WELL ' ,
(V OTHERS)
i >j»>.«sr"
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tffl uf ULl!^^
a
<
o
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TABLE 2
GROUNOWATER CONCENTRATIONS
(1 )
Contaminant
Arsenic
Ch porai urn
Copper
Lead
Zinc
Benzene
Ethylbenzene
To Iuene
XyIenes
Acenaphthy Iene
Acenaphthene
Anthracene
Benzo
-------
The same contaminants at lower concentrations were observed in
the next lower water bearing zone. However, this contamination
is not continuous across the site.
Groundwater samples from deep zone monitoring wells did not indi-
cate detectable concentrations of either semi-volatile or vola-
tile organics above detection limits of 1 ug/1. PAHs were not
seen above a detection level of l ng/1.
3.4 SURFACE WATER AND SEDIMENTS
A total of 18 surface water samples were collected in drainage
ditches which border the site and are within the property limits.
Data from these samples are shown in Table 3. Surface water data
indicate that no PAH compounds were detected, while volatile
organics (acetone and methylene chloride) were detected at two
sample locations. However, these two compounds are believed to
be due to laboratory cross-contamination. Several metals were
detected in surface water samples (arsenic, zinc, lead, iron,
copper, and nickel), with only arsenic exceeding the maximum
contaminant level (MCL).
Five sediment samples were collected and chemically analyzed from
the drainage ditches. PAH components were detected in each sam-
ple, with concentrations ranging from 2.3 mg/kg to 236 mg/kg.
The highest PAH concentration was detected in the southern end of
the site and is apparently related to trucking activity there.
Volatile organic compounds were also found, but were limited to
acetone and methylene chloride, typical laboratory solvents.
Detected sediment metal concentrations at all of the on-site
sample locations were similar to background condition.
3.5 AIR
Two phenolic compounds were observed upwind of the site at con-
centrations equaling or exceeding downwind levels and at levels
typical of the Houston area. No site related compounds were
found.
4. SITE RISKS
The potential risks from contaminated soil, groundwater, and
sediments were calculated based on present site use and plausible
future development .conditions. Both carcinogenic and non-carcin-
ogenic risks were calculated. The carcinogenic risks are theo-
retical quantifications of the excess lifetime cancer risk, that
is, the incremental probability of cancer comparedto the proba-
bility if no exposure occurred. For example, a 10 excess extra
cancer risk represents an exposure that could result in one extra
cancer case per million people exposed. Non-carcinogenic risks
are determined by comparing potential exposures to contaminant
specific reference doses. The reference dose is an estimate of a
level that would not be expected to cause adverse effects in
sensitive people.
12
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TABLE 3
SURFACE WATER AND SEDIMENT CONCENTRATIONS
(1)
Contaminant
Arsenic
Chroraiurn
Copper
Lead
Zinc
Benzene
Ethyl benzene
To Iuene
Xy I enes
Acenaphthy Iene
Acenaphthene
Anthracene
BenzoC a)anthracene
Benzo(a)pyrene
Benzo(b&k)fluoranthene
Benzo(g.h,i)pyrene
Chrysene
Dibenzo(a.h)anthracene
F I uoranthene
FIuorene
Ideno(1,2,3-cd)pyrene
2-Methyl naphtha Iene
Naphthalene
Phenanthrene
Pyrene
Total PAHs
Care i nogeni c PAHs
56
nd
17
30
140
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
(3)
Drainage
Ditch
Sedi merits
30
360
89
540
3300
nd
nd
nd
nd
nd
nd
nd
5.6
30
59
41
10
nd
32
nd
30
nd
nd
nd
44
236
170
Aquatic
Water
Standards
360
2,450
28
139
167
5,300
32,000
17,500
1,700
(2)
3,980
680
units of mg/kg for sediments, micrograms/l for water
(2) based on Texas water quality standards for acute toxicity,
and federal ambient criteria for those contaminants for
(3)
which there are no state standards
na = not analyzed; nd = not detected
13
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4.1 EXPOSURE PATHWAYS
The principal exposure pathways through which humans might poten-
tially become exposed to contaminants at this site are defined in
chapter 2 of the FS report as:
o inadvertent ingestion, dust inhalation, and direct contact
with surficial soils by utility or construction workers;
o inadvertent ingestion and direct contact with surface soils
by on-site commercial occupants;
o inadvertent ingestion and direct contact with drainage
ditch sediments by trespassing children;
o inadvertent ingestion and direct contact with surface soils
by future residents if the site is ever developed;
o ingestion of groundwater if contamination continues to
migrate of j.f water supply wells are ever installed on-
site.
The first three pathways represent current exposures resulting
from normal commercial activity, likely industrial development,
and occasional trespassing by children. People also could become
exposed on a more frequent basis if the site is ever developed
for residential purposes. This development would destroy the
existing buildings and parking lots which would expose the con-
taminants now under those structures. The actual exposure in
this case is not known because the contaminant levels under the
structures cannot be monitored. Therefore, the exposure caused
by future residential development could be higher.
The groundwater exposure pathway represents only a future sce-
nario. There are no water supply wells in the upper aquifers
within one mile of the site. On-site and neighboring residents
are all served by the city water supply which originates from
either a deeper well located more than 10 miles off-site or else
a reservoir located over 20 miles from the site. The future
groundwater pathway can become complete if migration of dense
NAPLs continues or if an on-site well is installed.
4.2 POTENTIAL HEALTH RISKS
The exposure to site contaminants is of concern because some of
the chemicals are potential carcinogens (ie. benzene, arsenic,
and benzo(a)pyrene) or are otherwise toxic to humans (xylenes,
toluene, and other metals). Some of these exceed health based
reference doses, cancer risks, and drinking water standards
(Tables 1 and 2).
EPA assessed the above pathways and contaminant concentrations
in relation to risks to human health if no remedial action is
14
-------
taken. These risks are reported in the FS report and are summar-
ized below as the aggregate risk to each receptor group from all
site contaminants and pathways. These risks are upper bound
estimates of potential effects on human health based on data
collected during the Remedial Investigation; the true risks are
most likely lower but could be higher if contaminant concentra-
tions in some areas are higher than those sampled during the
Remedial Investigation.
Maximum Maximum
Noncarcinogenic Excess Lifetime
Receptor Group Hazard Index Risk of Cancer
On-site Commercial Occupants <0.01 4xlO~7
Utility Workers <0.0l 2xio~7
Construction Workers <0.0l 4xlO~6
Trespassing Children <0.01 lxlO~6
Potential Future Residents <0.01 lxlO~5
Groundwater Users 5.6 6xlO~2
4.3 REMEDIAL GOALS
EPA concluded from the risk assessment that potential public
health hazards exceeded EPA's maximum level for leaving contami-
nation at a site. Using the exposure scenario which considers
continued commercial use of the site, target remedial levels for
selected chemicals were developed:
Environmental
Medium contaminant Remedial Level
Surface and Carcinogenic PAHs 700 ppm and no
Surficial Soils leaching potential
Groundwater Carcinogenic PAHs no detection
Groundwater Benzene 5 ug/l
Groundwater Ethylbenzene 142 ug/i
Groundwater Toluene 28 ug/l
Groundwater Xylene 440 ug/l
Groundwater Arsenic 50 ug/l
Groundwater Chromium 50 ug/l
Groundwater Copper 28 ug/l
Groundwater Lead 50 ug/l
Groundwater Zinc 100 ug/l
The remedial level for soils was selected to prevent against an
additional risk of cancer from exposure to soils of greater than
1 in 100,000 (10~5) for on-site commercial occupants and also
15
-------
ensure against any non-carcinogenic hazards. The 10 5 cancer
risk level was selected as appropriate for a commercial site
where only a few people may ever become exposed. In addition,
the cancer potency for carcinogenic PAHs may be overstated in the
risk assessment. The actual potencies can be lower by 10 to 100
times; this would reduce the estimated cancer risk by 10 times at
a minimum. The remedial level will also assure that contaminants
will not continue to leach into the groundwater.
The remedial levels for groundwater were selected to comply with
Federal drinking water standards, NPDES BAT requirements, and
Texas water Quality standards which are relevant and appropriate
requirements (see Appendix B for the list of ARARs) or reflect
existing background groundwater concentration levels. The reme-
dial level for carcinogenic PAHs was selected to assure that, in
conjunction with other contaminants, the overall risk to poten-
tial consumers of groundwater will be less than 10" . A higher
risk level was used for groundwater because the aquifers to be
remediated are not being used as water supplies, nor are likely
to be used because there are available water sources in the area.
The actual risk will be lower as natural adsorption reduces the
concentration of PAHs and metals. Levels were developed for
copper and zinc based on the principle of keeping the hazard
index less than 1.
From the Remedial Investigation results, approximately 3 acres of
soil above 6 feet in depth and 50 million gallons of groundwater
exceed these levels. Figures 4 and 5 show the areas of surficial
soil and groundwater where remediation may be needed.
5. COMMUNITY RELATIONS HISTORY
Community concern of either area residents or local officials is
very low at the site. The site is used by three, trucking firms
and is in a light industrial area. Therefore, citizen awareness
and concern about the site is limited.
EPA held the first community meeting on September 11, 1985, to
discuss the reasons for listing the site on the NPL and to pre-
sent the schedule for the site investigation. Fact sheets were
periodically mailed to local residents and interested parties to
describe the field activities.
On August 12, 1988, EPA issued a press release and the Proposed
Plan fact sheet. The press release was mailed to all news organ-
izations in the Houston area; the fact sheet was mailed to 75
residents, the three on-site trucking firms, and local officials.
Extra copies of the fact sheet were provided to the five local
repositories for display.
In accordance with section 117 of CERCLA, both the press release
and fact sheet announced the comment period which began on August
22 and ended on September 19, 1988. A public meeting was held I
on August 29, 1988, at the Ryan Civic Center. Approximately 39
16
-------
area citizens and local officials attended. The Responsiveness
Summary which outlines all public comments and/or questions and
EPA's replies is included in Appendix A.
6. SCOPE AND ROLE OF ACTION WITHIN SITE STRATEGY
The remedial activities at the South Cavalcade site have not been
separated into operable units. Therefore, the site problems,
remedial alternatives, and selected remedy described in this
Record of Decision consider all contaminated media identified at
the site.
7. ALTERNATIVE EVALUATION
In conformance with the National Contingency Plan (NCP), EPA
screened initial remedial approaches to determine which might be
appropriate for this site. The Feasibility Study describes the
details of this evaluation. From these possible remedies, seven
soil and four groundwater alternatives were chosen for detailed
evaluation. The soil and groundwater alternatives are evaluated
separately, and the best alternative from each will be combined
to form the selected remedy. One other alternative, No Action, .
was also evaluated to comply with the requirements of the NCP.
7.1 DESCRIPTION OF ALTERNATIVES
Alternative #1; No Action
The no action alternative consists of continued groundwater and
soil monitoring. Groundwater monitoring of PAHs, volatile organ-
ics and metals will occur twice a year. This monitoring scenario
will be implemented to track the progress of the groundwater
plume in the shallow ground-water zone and, for cost estimating
purposes, will be assumed to continue for 30 years. Replacement
of some monitoring wells may be required. The no action alterna-
tive also includes adding a notice to the deeds of each property.
Under the No Action alternative, contaminants will remain in the
environment and continue to migrate vertically towards drinking
water aquifers. Additionally, shallow groundwater aquifers will
continue to be degraded through leaching of chemical compounds in
the contaminated soils.
The costs are $95,000 capital, $31,000 annual operation and main-
tenance, (0/M), and $384,000 present worth.
Soil Remediation Alternatives
There are several common elements to all soil remediation altern-
atives which include:
o Initial monitoring during the initial stages of the reme-
dial design to more precisely define the areas of contami-
nated soil above the stated remedial action goals;
17
-------
o Soils remediation only in areas which are accessible
(soils under existing buildings or parking lots will not
be remediated); and
o Restrictions on land use by adding a deed notice.
Alternative %2i_ In Situ Stabilization followed by_ Capping
Under this alternative, accessible soils with contamination above
remedial goals will be chemically stabilized to prevent leaching
of contaminants. The stabilization process will mechanically
loosen the contaminated soils, adjust the soil moisture content,
and then thoroughly mix soil with a stabilizing agent. The loos-
ening and mixing would be conducted in place using construction
equipment such as augers. The primary stabilizing agent would be
determined during bench scale tests during remedial design. Once
mixed, the material would be compacted with the top layer sloped
to shed water. The compacted mixture would solidify in place and
mechanically lock the contaminants within the soil. Following
completion of the stabilization, a concrete cap would be built
over the treated area and sloped to drain.
Alternative 2 can be completed in approximately 12 months. The
costs are estimated at $14,300,000 capital, $50,000 annual 0/M,
and $14,800,000 present worth.
Alternative #3; Excavation with Disposal at Off-site Landfill
This alternative would excavate accessible soils containing con-
taminants above remedial action goals. Approximate areas requir-
ing excavation are shown in Figure 6 and will be further deline-
ated during the remedial design. Excavated material, estimated
to be 30,000 cubic yards, would be transported to an off-site
waste disposal facility. Following excavation, fill material
will be placed in the excavated areas, and a minimum of 6 inches
of soil cover would be placed on top of the fill material.
The contaminated soils will be removed and placed in a secure
off-site landfill permitted to receive and dispose of these
materials. The disposal facility will have appropriate state and
federal permits.
Off-site disposal of contaminated soils should take approximately
38 months to complete, costs are estimated at $10,000,000 capital
and $10,000,000 present worth. No O/M would be required.
.Alternative »4; Excavation with On-site Soil Washing
This alternative also involves excavation of contaminated soils
areas as described in alternative #3. In this alternative, the
excavated materials will be hauled to an on-site soil washing
facility for treatment by washing the contaminants from the soil
into a liquid medium. Laboratory results from a soil washing
: 18
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UEKMD
AfffXUJtUTf AX A W
ae
KEYSTONE
FIOURE
5O/C EXC4V41ION AR£*S
SOUTH CAVALCAK. TX
«OPPtRS COMPANY. IMC. f«
-------
study conducted during the Feasibility Study prove the removal
efficiency and the optimum surfactant dosage for the site soils.
In some cases, multiple washings may be required to reduce the
contaminant concentrations to acceptable levels. The decontami-
nated soil will be redisposed in the excavation areas.
The soil washing unit will be constructed on-site within the cen-
tral portion of the South Cavalcade site. After contact with the
soil, the washing solution will be treated for removal of the
contaminants and then recycled for additional soil washing. Wash
waters from the process will be treated in the selected ground-
water treatment system (see alternatives 9 through 12).
This alternative should take approximately 5 years to complete.
The approximate costs for this remedy are $10,000,000 capital and
present worth. No 0/M would be required.
Alternative »5; On-site Incineration of Soils
This alternative would require an incinerator to be transported
to or built in the central part of the site. Contaminated soils
would be excavated as described in alternative #3, and trans-
ported to the incinerator to be burned. There are several ways
to incinerate soils. In general, an incinerator first heats the
contaminated soils to drive off hydrocarbon contaminants and then
thermally destroys the contaminants. Upon completion, the incin-
erator will be removed from the site. The resulting ash, if
shown to be non-hazardous by testing, would be placed back into
the excavation areas and covered by a concrete cap. If the ash
is found to be hazardous, it would be transported to an approved
disposal facility.
This alternative should take between 2 to 4 years to complete.
The approximate costs for this alternative are $10,000,000 capi-
tal and present worth. No 0/M would be required.
Alternative »6; In Situ Bioreclamation
The in situ bioreclamation process for the South Cavalcade site
vadose zone soils would treat the contaminated soil through the
following steps. Water with appropriate chemical additives will
be allowed to percolate though the contaminated soil areas. The
enriched water will provide nutrients for the indigenous micro-
organisms, which will biodegrade the contaminants. The water
will eventually flow into the groundwater where any contaminants
that remain will be handled by one of the groundwater treatment
alternatives. The percolation system will consist of near sur-
face perforated pipe located over the contaminated soil areas to
saturate the currently unsaturated soil zone.
This alternative should take between 5-10 years to complete.
Costs are estimated to be $483,000 capital, $5,000 annual 0/M,
and $530,000 present worth.
20
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Alternative »7; In Situ Soil Flushing
Under this alternative, contaminated soil areas would be remedia-
ted through an in situ soil flushing process. This flushing is a
chemical-physical process of extracting contaminants from the
soil matrix. A water solution, containing surfactants or other
chemicals, is continuously passed through contaminated soil to
release the contaminants. Once in solution, the contaminants are
free to move out of the contaminated soil zone. The contaminants
will in effect be leached out of the soil and travel into the
groundwater. The contaminants which travel into the groundwater
will be handled by one of the groundwater treatment alternatives.
Treatment areas and methods are basically the same as for altern-
ative #6 (In Situ Bioreclamation).
This alternative should also take between 5-10 years to com-
plete. Estimated costs are $483,000 capital, $5,000 annual 0/M,
and $530,000 present worth.
Alternative #8: Excavation and Off-site Incineration
The partial excavation and off-site transportation process will
be identical to that described in alternative f3. However, the"
excavated soils will be contained in 20 gallon plastic containers
which is a requirement of the nearest off-site facility capable
of handling the primary contaminants in the soils.
This alternative should take about 66 months to complete. Costs
are estimated at $62,000,000 capital and present worth. No 0/M
would be required.
Groundwater Remediation Alternatives
There are three common elements to all groundwater remediation
alternatives which are described as follows:
Long-term Groundwater Monitoring
In order to ensure the success of the selected groundwater reme-
dial alternative, long-term monitoring will be required through-
out the 30 year implementation time period. Additionally, due to
the extended remediation period, some monitoring wells may need
to be replaced. Monitoring of potential leaching of contaminants
under buildings and parking lots would also be performed.
Groundwater Extraction and Re-injection System
All groundwater remedial alternatives involve construction of a
series of groundwater extraction and re-injection lines to facil-
itate remediation of shallow water bearing sands (above 50 feet).
The physical arrangement of these lines will be as follows for
all groundwater alternatives. For the southern portion of the
South Cavalcade site, the following components are proposed
(details to be refined during the remedial design):
21
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o A collection system will be located along the southeast
corner of the property, and is intended to collect contam-
inant migration from the former coal tar operation.
o A second collection system will be located on the southern
-property border, located such that it intercepts contami-
nant migration from the former wood treating operations.
In addition, this collection system will be designed to
prevent contaminant migration past the southern portion of
the site.
o A third collection line will be located along the south-
western property boundary, and would be similar in design
to the other two collection systems. This collection
system will intercept groundwater prior to leaving this
portion of the site. West and downgradient from this
extraction line would be two lines of re-injection wells.
For the northern portion of the facility, groundwater will be
collected along a pumping line located on the eastern boundary.
A re-injection system will be located upgradient along the east-
ern property line.
Disposal of Non-Aqueous Phase Liquids
Non-aqueous phase liquids (NAPLs) collected during groundwater
remediation will be separated from groundwater and either sent to
an off-site hazardous waste incinerator with appropriate federal
and state permits, or recycled and used as a creosote product.
Alternative »9; In Situ Biological Treatment of Groundwater
!
With in situ biological treatment, extracted groundwater will be
first treated in a physical/chemical separation treatment unit
which will separate toxic metals and NAPLs from the groundwater.
Most of the groundwater effluent will flow into a nutrient tank
where appropriate additives will be added including oxygen and
nutrients to promote microorganism growth and surfactants to help
release contaminants from soil. This treated water will then be
re-injected into the shallow aquifer through the re-injection
system previously described. Naturally occurring micoorganisms
would biologically destroy residual groundwater contaminants.
The remaining portion of the extracted groundwater not re-
injected would be discharged to the City of Houston's POTW.
This alternative should take approximately 30 years to complete.
The approximate cost for this remedy is $3,500,000 capital,
$325,000 annual 0/M, and .$6,500,000 present worth.
Alternative #10; Carbon Adsorption and Filtration of Groundwater
This groundwater treatment option consists of a chemical physical
separation unit for the recovery of NAPLs followed by a high
22
-------
pressure filter to remove metal contaminants and suspended mat-
ter. Water from the filtration unit would flow to a carbon
adsorption unit. Most of the effluent will be re-injected.
Excess treated effluent from the carbon adsorption unit will be
discharged -to the adjacent drainage ditch which flows into Hunt-
ing Bayou. Surface water discharge will meet NPDES discharge
requirements.
This alternative should take approximately 30 year to complete.
Costs are estimated at $3,800,000 capital, $482,222 annual 0/M,
and $8,300,000 present worth.
Alternative f11; Carbon Adsorption, Air Stripping, and
Filtration of Groundwater
This groundwater treatment option will be identical to option #10
except for the addition of an air stripping column. The air
stripping unit will be installed to more effectively remediate
volatile organic compounds in the groundwater and reduce activa-
ted carbon usage rate.
This alternative should taJce approximately 30 years to complete. -
Costs are estimated at $4,026,000 capital, 480,000 annual 0/M,
and 8,500,000 present worth.
Alternative #12; Aerated Tank Treatment of Groundwater
In addition to physical/chemical separation process for recovery
of NAPLs, this treatment alternative will use an aerobic biologi-
cal treatment system (activated sludge) to remove organic contam-
inants. Following the physical/chemical separation process, the
groundwater will be pumped through the activated sludge system
consisting of an aeration tank followed by a clarifier. Treated
water will be re-injected into the aquifers. Excess treated
groundwater will be discharged into adjacent drainage which flows
into Hunting Bayou. Surface water discharge will meet NPDES
discharge requirements.
This alternative should take approximately 30 years to complete.
Costs are estimated at $4,490,000 capital, $454,000 annual 0/M,
and $8,700,000 present worth.
7.2 EVALUATION OF ALTERNATIVES -
OSWER Directive 9355.0-21 prescribes nine criteria which EPA con-
siders in selecting a remedy for a CERCLA site. These criteria
address the specific requirements of Section 121(b)(l) of SARA.
EPA has assessed the degree to which each remedial alternative
meets the nine selection criteria; Tables 4 and 5 summarize this
assessment. For clarification, soils and groundwater remedial
alternatives are discussed separately. The following values were
used £o compare the remedy selection criteria.
23
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TABLE 4
COMPARISON OF SOU REMEDIAL ALTERNATIVES
SOUTH CAVALCADE STREET SITE
/
COMPLY WITH
ENVIRONMENTAL
LAWS
REDUCE
TOXICITY
MOBILITY
VOLUME
SHORT-TERM
EFFECTIVENESS
LONG-TERM
EFFECTIVENESS
IMPLEMENTABILITY
COST'1'
CAPITAL
0 & M
PRESENT UORTH(2>
COMMUNITY
ACCEPTANCE
PROTECTION OF
HUMAN HEALTH &
THE ENVIRONMENT
ALT
1
-
-
-
'
.
0.10
0.03
0.38
-
-
ALT
2
0
-
0
+
14.3
<0 . 1
14.8
0
-
ALT
I 3
0
-
0
-
-
-
*
10.0
0.0
10.0
0
-
ALT
4
0
0
0
0
0
0
0
7.0
0.0
7.0
0
0
ALT
5
0
+
+
0
0
*
10.4
0.0
10.4
0
ALT
6
0
0
0
0
-
0
o,-
0.5
<0 . 1
0.5
0
0
ALT
7
0
0
0
0
0
o,-
0.5
<0 . 1
0.5
0
0 .
N
ALT
8
0
*
+
0
-
62.0
0.0
62.0
0
0
SymboIs:
+ = Compered to others, alternative exceeds criterion.
0 = Alternative can be designed to meet the criterion.
= Compared to others, alternative will need special efforts
to meet the criterion.
Notes: Units of million dollars, reflects the maximum range of
the cost estimates
Based on 30 years at 10X interest
24
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TABLE S
COMPARISON OF GROUNDUATER REMEDIAL ALTERNATIVES
SOUTH CAVALCADE STREET SITE
/
COMPLY WITH
ENVI RONMENTAL
LAWS
REDUCE
TOXI CITY
MOBILITY
VOLUME
SHORT-TERM
EFFECTIVENESS
LONG-TERM
EFFECT I VENESS
IMPLEMENTABI LI TY
COST<1>
CAPI TAL
0 & M
PRESENT UORTH<2>
COMMUN I TY
ACCEPTANCE
.
PROTECTION OF
HUMAN HEALTH &
THE ENVIRONMENT
ALT
1
-
0.10
0.03
0.38
-
-
| ALT
9
1 . .
I
0
0
0
0
-
0
-
3.50
0.33
6.50
0
0
ALT
10
0
0
0
0
0
0
3.81
0.48
8.30
0
J
0
ALT
11
0
0
0
0
0
-
4.03
0.50
8.50
0
0
ALT
12
0
0
0
0
0
0
4.49
0.45
8.70
0
0
Symbols:
+ a Compared to others, alternative exceeds criterion.
0 = Alternative can be designed to meet the criterion.
a Compared to others, alternative Mill need special
efforts to meet the criterion.
Notes: Units of million dollars, reflects the maximum
range of the cost estimates
(2)
Based on 30 years at 10X interest
25
-------
+ Alternative would exceed a criterion compared to other
alternatives.
0 Alternative can meet the selection criterion.
Alternative would not meet the criterion without special
efforts.
The rationale for the ratings assigned in this table follows:
CONSISTENCY WITH OTHER ENVIRONMENTAL LAWS
Appendix B identifies the Federal and State applicable or
relevant and appropriate requirements (ARARs) for each
alternative.
No Action & Soil Remedial Alternatives;
No Action is rated as "-" because it violates the intent of
SARA Section 121 regarding the selection of a remedy and does
not comply with the National Contingency Plan provisions to
respond to a release.
All soil treatment alternatives are rated "0" since they can
be designed to meet ARARs.
Groundwater Remedial Alternatives;
All groundwater alternatives have been rated "0" because each
can be designed to meet all ARARs.
REDUCTION OF TOXICITY. MOBILITY AND VOLUME
I
No Action & Soil Remedial Alternatives;
No Action is rated as "-" because it does not reduce toxici-
ty, mobility, or volume of the contaminants at the site.
However, natural biodegradation will eventually reduce some
contamination.
Off-site Landfill is rated as "-" for toxicity and volume of
site contaminants, and as "0" for mobility, since the contami-
nants will be placed in a secure landfill. In addition, the
volume may increase if fly ash needs to be added to the soils
to adsorb excess water before disposal.
In Situ Stabilization is rated as "-" for toxicity and volume,
and as "0" for mobility since contaminants will be at least
temporarily prevented from leaching. This alternative will
actually increase the volume of the contaminated soil.
Soil Washing, In Situ Bioreclamation, and In Situ Soil Flush-
ing are rated as "0" because the toxicity and leaching poten-
tial of contaminants at the South Cavalcade site would be
26
-------
reduced, and the contaminated soil volume would be reduced.
On-site and Off-site Incineration are rated as "+" for toxic-
ity and mobility since they will provide the greatest reduc-
tions, and "0" for volume since the volume of contaminated
soils being treated will be the same as for other treatment
alternatives.
Groundwater Remedial Alternatives;
In Situ Biological Treatment and Activated Sludge Treatment
have been rated as "0" because a significant reduction in
organic contaminants can be achieved through biodegradation.
Additionally, the physical/chemical separation will result in
significant reductions in metals in the groundwater. NAPLS
will be separated and either permanently destroyed through
incineration or will be recycled as a creosote product.
Carbon Adsorption and Carbon Adsorption with Air Stripping
are also rated as "0" because a significant reduction in
organic contamination can be achieved through adsorption onto
carbon. Once adsorbed, the carbon will be recycled through
incineration, significant and permanent reductions will also
be achieved in metals and NAPLs as described above.
SHORT-TERM EFFECTIVENESS
No Action & Soil Remedial Alternatives;
No Action is rated as "-" because no existing exposure path-
way will be remediated, and current health risks will remain.
In Situ Stabilization is rated as "+" because the remedy can
be quickly completed (10 - 12 months).
In Situ Bioreclamation and In Situ Soil Flushing are rated as
"-" because of the extended time period to complete (5-10
years).
Soil Washing and On-site Incineration are rated "0" because,
although excavation and materials handling could pose addi-
tional health risks to the health of on-site workers during
remediation, these can be controlled by adherence to health
and safety requirements and dust suppression if required.
Off-site Incineration and Off-site Landfilling are rated as
-" because, as for all alternatives involving excavation,
on-site workers may be exposed to additional contaminants
during excavation and handling, and there is always a
risk for spills with off-site transportation of waste.
Groundwater Remedial Alternatives;
All groundwater alternatives have been rated as "-" due to
27
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the extensive time period of remediation (estimated to be 30
years). Additionally, there is a small potential risk in all
alternatives that on-site workers will become exposed to
contaminants in the extracted groundwater.
LONG-TERM EFFECTIVENESS AND PERMANENCE
No Action and Soil Remedial Alternatives:
No Action is rated as "-" because the potential human health
and environmental risks would not be abated.
Off-site Landfill is rated as "-" because long-term monitoring
and maintenance at the off-site landfill is required to ensure
that contaminants are not released into the environment.
In Situ Stabilization is also rated as "-" due to the uncer-
tainty regarding the permanent fixation of the organic con-
taminants in the stabilized soils.
In Situ Bioreclamation, Soil Washing, and In Situ Soil Flush-
ing are rated as "0" because these alternatives in conjunc-
tion with a groundwater remediation will permanently destroy
organic contaminants to below the remedial action goals.
On-site and Off-site Incineration are rated as "+n because
they could destroy organic contaminants well below remedial
action goals.
Groundwater Remedial Alternatives;
All groundwater remedial alternatives are rated as "0"
because they can all be designed to remediate groundwater to
defined remedial goals through permanent destruction of con-
taminants.
IMPLEMENTABILITY
No Action & Soil Remedial Alternatives;
No Action, Off-site Disposal, and Off-site Incineration are
rated as "+" because they can be implemented without major
capital acquisitions.
Soil Washing is rated as "0" because it can be implemented
with known equipment and has already been tested with site
soils.
In Situ Soil Flushing and In Situ Bioreclamation are essenti-
ally the same as the groundwater alternatives. They are
rated as "0" for remediating soils in the northern and south-
western parts of the site because of the similarities with
the groundwater alternatives, but as "-" in the southeastern
corner because addition of water there can drive site contam-
28
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inants under a railroad line and thereby make them i
ible for remediation.
On-site Incineration and In Situ Stabilization are raj
"-". On-site Incineration requires consultation witl
Texas Air Control Board for design specifications andf?
tion requirements. In Situ Stabilization requires a
cant amount of testing to identify the optimal stabili-j
agent for the site contaminants and soils.
Groundwater Remedial Alternatives:
ess-
as
>
jra-
lifi-
jition
In situ Biological Treatment is rated as "-" due to uni
tainties over the ability to discharge untreated contaminated
groundwater to a City of Houston POTW. Currently the ftty of
Houston prohibits the discharge into its treatment facmities
of any priority pollutants. PAHs and benzene are prioMiy
pollutants and are contained in the groundwater. AddiMppn-
ally, implementation of this alternative would require«|iat a
re-injection line be installed on the southeast side aaloss
the railroad tracks adjacent to the site. It may not
possible to cross the tracks with the treatment systemlRines
due to the railroad's right of way.
Carbon Adsorption with Air Stripping is also rated as
The air stripper presents a potential for air emission^ This
alternative requires consultation with the Texas Air C«trol
Board for design specifications and operation requiremts.
All other groundwater alternatives were rated as "0" bBfeuse
the technologies involved have been used before with
cially available products.
COST
Tables 4 and 5 also list the estimated costs for each me-
dial action alternative including capital, operation
maintenance, and present worth costs. Replacement cosare
factored into the operation and maintenance costs.
Action alternative has the lowest present worth cost
alternatives. The soil alternatives, in increasing ow'-r of
cost, are.ln Situ Soil Flushing, In Situ Bioreclamatio« Soil
Washing, Off-site Landfill, On-site Incineration, In
Stabilization, and Off-site Incineration. The groundwer
alternatives, in increasing order of costs, are In sit«Uo-
logical Treatment, Carbon Adsorption, Carbon Adsorptio^/ith
Air stripping, and Activated Sludge Treatment.
COMMUNITY ACCEPTANCE
Overall, the neighboring residents do not oppose remedi»;ion
of the site unless an on-site incinerator is used. Th^Jefore,
all alternatives are rated as "0" except No Action and
site Incineration which are rated as "-".
29
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STATE ACCEPTANCE
The Texas Water Commission (TWO, the State regulatory agency
for CERCLA sites, was briefed on all remedial alternatives
on July 10, 1988. The TWC notified EPA by letter that the
TWC had no objections to the selected remedy (see Appendix
D).
OVERALL PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT
No Action & Remedial Alternatives;
No Action is rated as "-11 because it does not provide ade-
quate protection from the potential risks involved with leav-
ing untreated soils at the South" Cavalcade site.
Off-site Landfill is rated as "-" because it may not be a
permanent remedy and therefore only offers temporary protec-.
tion to human health and the environment by containment.
In situ Stabilization is rated as "-" due to the uncertainty
with the long-term fixation of organic contaminants, and
therefore, the potential remains for eventual leaching of
these contaminants into drinking water aquifers.
Soil Washing, In Situ Soil Flushing, In situ Bioreclamation,
On-site Incineration and Off-site Incineration are rated as
"0" because contamination in the soils will be destroyed to
protective levels at or below the remedial action goals.
Groundwater Remedial Alternatives;
All groundwater alternatives are rated as "0" because they
will all greatly reduce the concentrations of the primary
constituents of concern in the groundwater, thereby reducing
the possibility of long-term exposure and future site remedi-
ation. These alternatives pose only minimal threats to pub-
lic health and the environment in the vicinity of the site.
8. SELECTED REMEDY
Based on the available data and analyses identified in the admin-
istrative record, EPA is selecting a combination of soil washing
(alternative #4) and soil flushing (alternative #7) as the most
appropriate solution for remediating contaminated soils, and
activated carbon adsorption (alternative #10) as the most appro-
priate solution for remediating contaminated groundwater at the
South Cavalcade site.
8.1 DESCRIPTION OF THE REMEDY
Soil Remediation; During the initial stages of the remedial
design, contaminated soil areas will be sampled to better define
30
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areas which require remediation. All areas will be remediated
where contaminants in soils exceed either the risk-based or
leaching potential-based remedial goals. The risk-based goal is
700 ppm based on ingestion and direct contact with soils as
previously presented in section 4.3. The leaching potential-
based goal will be determined by the EPA Toxicity Characteristic
Leaching Procedure (TCLP) test. EPA believes that the TCLP test
will require removal of total PAHs at levels above 150 ppm
because the leaching test during the Feasibility Study demon-
strated leaching at this level. There are approximately 30,000
cubic yards which may need remediation.
In the southeast corner of the site, approximately 19,500 cubic
yards of contaminated soils will be excavated and transported to
the soil washing facility which will be constructed in the center
portion of the South Cavalcade site. Wash water from the unit
will be treated for removal of contaminants in the groundwater
treatment system. The cleansed soils will be returned to the
excavations and capped with concrete to maintain soil stability.
In the other parts of the site, contaminated soils will be reme-
diated using in situ soil flushing. The contaminants which
travel into the groundwater will be extracted and treated in the
carbon adsorption waste water treatment system.
Groundwater Remediation; Groundwater will be remediated
through extraction and treatment of contaminated groundwater,
with re-injection to increase the hydraulic gradient and flow
velocities. Approximately 50 million gallons of groundwater will
need to be processed several times to recover and treat the
NAPLs. Groundwater collection will continue until the ground-
water contaminants have been recovered to the maximum extent
possible. This point will be determined during the Remedial
Action based upon operational experience in using the collection
and treatment system, and it must be as close to drinking water
standards and no detectable carcinogenic PAHs to the maximum
extent possible. After this point is reached, the groundwater
collection will cease and any remaining contamination be allowed
to naturally attenuate to background levels.
Groundwater will be extracted and re-injected in a series of
three groundwater extraction lines and two groundwater injection
lines in the southern part of the site, and a minimum of one
extraction line and re-injection line in the northern part. These
wells will be screened in the shallow aquifer (approximately 10 -
20 feet below grade) and in the intermediate discontinuous sand
lenses (approximately 50 feet beiow grade). The actual number of
lines, locations and spacings of wells and well lines will be
refined during remedial design.
The groundwater will be treated at an on-site wastewater treat-
ment plant constructed in the center area of the site. Ground-
water will be pumped into a physical/chemical separator followed
by a pressure filter and an activated carbon filter. Any NAPLs
31
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collected and separated from the groundwater will be recycled as
creosote or else incinerated off-site. The water will be treated
to the remedial goals previously listed. Cleansed groundwater
will be re-injected into the aquifer along with surfactants to
help recover the contaminants. Any excess water will be dis-
charged to the drainage ditch leading into the off-site Hunting
Bayou in accordance with an NPDES permit.
Alternate Remediation Plan; If a potentially responsible party
(PRP) can show that In Situ Biological Treatment of soil and
groundwater will provide equal or better performance, and if the
PRP can further ensure that the implementability questions can be
resolved, EPA will consider these alternatives (#6 and #9). In
this case, the performance goals and the groundwater extraction
system will be identical to EPA's selected remedy, but the actual
method of treatment will differ. Groundwater will be treated
above ground in the physical/chemical separator and injected with
nutrients and oxygen (if necessary). The treated groundwater
will be added to the contaminated soil areas and re-injected into
the aquifer system to encourage biological degradation of contam-
inants under the ground. Any excess water will be discharged
into the .city sewer system in accordance with a pretreatment
permit and treated in a city municipal treatment plant.
Operation and Maintenance; The need for future operation and
maintenance should be minimized since the primary sources of con-
tamination will be removed through treatment. Site operation and
maintenance will include installing a well screened in the 500
foot sand, monitoring groundwater wells, and monitoring ambient
air during remediation. The groundwater monitoring program will
continue for at least 30 years unless it can be shown during the
Remedial Design, based on the results of the pilot groundwater
collection system, that some shorter length of time is appropri-
ate. This sampling program will monitor the effectiveness of the
selected remedy and provide the data necessary to trigger future
corrective action, if necessary. If the monitoring shows leach-
ing from soils now under existing structures, then the site will
need to be revisited to determine if further remediation is
necessary.
Additional site maintenance would include, but not necessarily be
limited to, inspections of surface vegetation, ensuring proper
drainage, and proper operation of any actions such as groundwater
treatment which may extend beyond the time required for the
source control remedy. The details of these activities will be
defined in the Operation, and Maintenance Plan of the remedial
design. The monitoring data will be evaluated during the Agen-
cy's 5-year review, in accordance with SARA Section 121 (c), to
determine if any corrective action is necessary.
Protection Achieved; This remedial goal prevents against an
excess lifetime increasedcancer risk of 8x10 for likely on-site
exposure to soil and 4xlO~5 for groundwater users, and keeps
exposure to non-carcinogenic compounds below the reference dose.
32
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EPA is using these cancer risks as a remedial goal instead of
1x10 because of the cancer potency factors for carcinogenic
PAHs and the liklihood for exposure. EPA considered all poten-
tially carcinogenic PAHs to be as potent as benzo(a)pyrene
because the agency has not published cancer potency factors for
the other PAHs. EPA recognizes that the other potentially car-
cinogenic PAHs may be less potent by factors of 10 to 100 times,
and is now in the process of developing cancer potency factors
for other PAHs. In addition, the site is already extensively
developed for use as an industrial areas, and a 10~5 risk level
or less is typically used for industrial areas. Also, the con-
taminated aquifer is not presently used as a water supply, nor
will it likely be used because there are other available sources
of water in the area.
8.2 STATUTORY DETERMINATIONS
Section 121 of SARA requires the selected remedy to be protective
of human health and the environment, be cost effective, use per-
manent solutions and alternative treatment or resource recovery
technologies to the maximum extent possible, be consistent with
other environmental laws, and prefer treatment which signif-
icantly reduces the toxicity or mobility of the hazardous sub-
stances as a principle element. EPA believes that the selected
remedy best fulfills the statuatory and selection criteria as
compared to the other solutions evaluated herein.
Protection of Human Health and Environment
The selected remedy will reduce soil contamination to prevent an
additional risk of cancer of 8xlO~ , prevent any non-carcinogenic
hazards, and prevent continued leaching of creosote compounds
from soils into groundwater. It does this by treating the soils.
For groundwater, it also prevent an additional risk of cancer of
4x10 , prevents any non-carcinogenic hazards, and prevents the
continued off-site migration of contaminated groundwater. It
does this by treatment; therefore, the risks will not increase in
the future due to a failure of the remedy. Short-term risks will
be controlled by suppressing dust, enclosing excavations in temp-
orary domes (if necessary), and requiring the fence around the
site be maintained throughout remediation.
Cost Effective
The present worth of the selected remedy is $13 million and is
the lowest cost of all alternatives which either meet or exceed
the nine evaluation criteria. EPA believes that remedies with
higher costs do not provide any further benefits. EPA also
believes that remedies with lower costs may cause incomplete
remediation. Therefore, EPA believes that the overall effective-
ness of the selected remedy is a reasonable value for the costs.
-------
Permanent Solutions to Maximum Extent Possible
EPA believes the selected remedy is the most appropriate solution
for meeting the remedial goals by providing the best balance
among the evaluation criteria for the alternatives. This remedy
provides effective protection of human and environmental recep-
tors over the short- and long-term, protects against off-site and
deeper migration of groundwater, is readily implemented, is cost
effective, permanently treats those contaminants in soils or
groundwater, and recycles (if possible) recovered creosote.
Soils are treated by desorption, and groundwater is treated by
physical/chemical and activated carbon treatment. However, long-
term monitoring and maintenance of the groundwater collection and
treatment system will be necessary due to length of time neces-
sary to cleanse the groundwater and the unknown potential for
soils under existing structures to leach.
Consistent with Other Environmental Laws
The selected remedy can be designed to attain other environmental
laws. The laws applicable or relevant and appropriate to CERCLA
activities are called ARARs. Appendix B lists all the ARARs
which were initially identified for this site in the Feasibility
Study. The specific ARARs for the selected remedy are described
below:
National Primary Drinking Water Standards ; Groundwater
treatment performance will attain all final Maximum Contami-
nant Levels (MCL). Table 2 listed the MCLs for contaminants
found on the site.
National Secondary Drinking Water Standards ; Groundwater
treatment performance will attain all final secondary drink-
ing water standards. Table 2 listed these for contaminants
found on the site.
Maximum Contaminant Level Goals (MCLGs ) ; This is not an
ARAR, but is another factor to be considered. Groundwater
treatment performance will attain the MCLGs for those con-
taminants where the MCLs have yet to be promulgated.
Underground Injection Control Regulations; The wells through
which treated groundwater will be re-injected into the aqui-
fer will be designed to comply with the Class V well
regulations.
Water Quality Criteria; Discharge of excess treated
water (that not re-injected) will comply with these criteria
for compounds not regulated by state water quality standards.
The discharge, after dilution with Hunting Bayou, must not
exceed these criteria.
National Pollutant Discharge Elimination System; Discharge
of excess treated water will comply with Best Available Tech-
34
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nology (BAT) and water quality standards. The BAT treatment
performance is considered equal to that required for the
Organic Chemical, Plastics, and Synthetic Fibers (OCPSF)
effluent guidelines which were promulgated by EPA for dis-
charges from organic chemical facilities including those
manufacturing creosote-type products. The discharge will not
exceed these criteria. In addition, the discharge, after
dilution with Hunting Bayou, must not exceed the water quali-
ty standards. A permit will be required because the point of
discharge will be off-site.
National Pretreatment Standards; Discharge of excess treated
water will comply with these standards by also complying with
Best Available Technology for OCPSF facilities. Pretreatment
requirements for these facilities are equal to those for BAT.
Occupational Safety and Health Act; Remedial action will be
conducted consistent with the OSHA regulations for personnel
protection and safety.
Hazardous Materials Transportation Act; Off-site transport of
recovered creosote will require handling in a manner consis-
tent with this act.
RCRA Standards Applicable to Generators and Transporters of
Hazardous Waste; Off-site transport of recovered creosote for
incineration or recycling will require manifesting.
Releases from Solid Waste Management Units (40 CFR 264(F)):
Groundwater not recovered will comply with the levels
required by this regulation.
Tanks (40 CFR 264(J)); Tanks temporarily storing recovered
creosote will be designed to comply with this regulation.
Land Disposal Restrictions; Restrictions have yet to be
promulgated for CERCLA soils and debris contaminated with
RCRA wastes. Despite the absence of regulations, the treat-
ment methods used as parts of the remedial action satisfies
the statutory requirement to "...substantially diminish the
toxicity of the waste or substantially reduce the likelihood
of migration of hazardous constituents from the waste so that
short-term and long-term threats to human health and the
environment are minimized.11 .
Texas Allowable Limits of Metals in Drinking Water; Ground-
water treatment performance will attain these levels.
Texas Water Quality Standards for Surface Waters; Discharge
of excess treated water will comply with these standards. The
discharge, after dilution with Hunting Bayou, must not exceed
these standards.
35
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Texas Prohibition of Air Contaminants which Adversely Affect
Human Health; Soil disturbance will be minimized during
remediation to assure compliance with these regulations. .If
necessary, an inflatable dome can be constructed over the
soil areas to contain any release. Air will be monitored
during remediation to observe compliance.
Texas Storage of Volatile Organic Compounds; Tanks tempor-
arily storing recovered creosote and associated volatile
compounds will be designed to comply with this regulation.
Texas Oil/Water Separators; The oil/water separator in the
groundwater treatment system will be designed to control
volatile emissions as required by this regulation.
Texas Vacuum Producing Systems; The groundwater recovery
system uses a vacuum. This system will be designed to pre-
vent emissions requiring incineration under this regulation.
Preference for Treatment as a Principal Element
The principal threats at this site are potential exposure to con-
taminated soils and potential future exposure to contaminated
groundwater. The selected remedy uses treatment for the remedi-
ation of both soils and groundwater. Soil washing and in situ
soil flushing will desorb carcinogenic PAHs and metals from soils
and allow for eventual treatment with the recovered groundwater.
Oil/water separation, filtration, and activated carbon adsorption
will remove contaminants from groundwater.
8.3 FUTURE ACTIONS
The selected remedy completes the remediation of the principal
threats at the site. EPA will send a Special Notice to all
potentially responsible parties to offer them the opportunity to
conduct the Remedial Design and Remedial Action. The proposed
schedule for remediation, assuming that Remedial Design and Reme-
dial Action negotiations were to fail, is as follows:
Approve Remedial Action by Signing
the Record of Decision September 1988
Start Remedial Design December 1988
Complete Remedial Design December 1990
Start Remedial Action March 1991
36
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APPENDIX A
RESPONSIVENESS SUMMARY
-------
South Cavalcade Street
Community Relations Responsiveness Summary
This Community Relations Responsiveness Summary has been prepared
to provide written responses to comments submitted regarding the
proposed plan of action at the South Cavalcade Street Superfund
site. The summary is divided into two sections:
Section I: Background of Community Involvement and Concerns.
This section provides a brief history of community interest and
concerns raised during the remedial planning activities at the
South Cavalcade Street site.
Section II: Summary of Major Comments Received. The comments
are summarized and EPA's responses are provided.
I. Background of Community Involvement and Concerns
Reported citizen concern regarding this site has been minimal.
No known public interest groups have been formed, and concern
about the site is very limited. Media coverage of the site has
been scarce.
In August 1985, EPA held a meeting to announce the start of the
remedial investigation. Thirty-one citizens attended; however,
few attendees lived in the immediate area. Progress reports were
issued in April and July of 1987. These two updates did not
generate any comments, questions or concerns.
II. Summary of Major Comments Received
The press release and Proposed Plan fact sheet announcing the
public comment period and public meeting were released on August
12, 1988. The comment period began on August 22, 1988, and ended
on September 19, 1988. The public meeting was held with area
residents and local officials on August 29, 1988, at the Ryan
Civic Club. The purpose of this meeting was to explain the
results of the Remedial Investigation and to outline the various
alternatives presented in the Feasibility Study. Thirty nine
citizens attended the meeting, and eight people made oral state-
ments or asked questions. Two letters containing written com-
ments were received from potentially responsible parties.
Overall, the residents, on-site businesses and local officials do
not oppose the proposed plan. During the public comment period,
there were comments and questions regarding the following:
Comment tl; What are the current health problems at the site?
EPA Response; EPA conducted a risk assessment using the data
from the site. From this assessment, EPA calculated a maximum
additional risk of cancer of 1x10 5 and no non-carcinogenic
health threats from exposure to soils. EPA also calculated a
risk of cancer of 1x10 and potential non-carcinogenic health
A-l
-------
threats from exposure to groundwater in the upper aquifers^
this water is ever used as a source of drinking water. In;,)
tion, the levels of benzene, arsenic, chromium, and lead i
groundwater may exceed drinking water standards.
Comment #2: Why was this site added to the Superfund list|
EPA Response; EPA was concerned about continued migration^
site contaminants into deeper aquifers which are now used
sources of drinking water.
Comment #3: How will the proposed remedy protect the healt|
the community and minimize the risk to health?
EPA Response; The proposed remedy will achieve the remedial
goals for soils and groundwater. The goals for exposure t
are to prevent an additional risk of cancer from exceeding
and to prevent any non-carcinogenic health threats. The goi
for groundwater achieve drinking water quality in the ground
ter. These goals will be achieved throughout the site.
Comment #4; Will you hold any more meetings about the proj
alternatives or if you decide to use another alternative whi
was discussed at the public meeting?
EPA Response: The public meeting on August 29, 1988, is th<
public meeting which will be held about the proposed remedy?
the alternatives evaluated during EPA's studies. One objed
of the public meeting is to hear the public's opinions about
alternatives. Therefore, EPA will not hold another meeting!
one of the discussed alternatives is selected.
Comment #5: How will you continue to advise people about tl
decision about the site and any future activities or decisi<
EPA Response; EPA will continue to inform all people who hi
shown an interest in the site about the decision and future?
activities. EPA will mail informational fact sheets to all
people who have given EPA their address and will hold publi<
meetings as needed to explain future activities. EPA will
tinue to inform the public until the site has been complete]
remediated.
Comment t6;
this site?
How does EPA know that soil washing will work
EPA Response; EPA has seen this remedy used or selected atj
sites where polynuclear aromatic hydrocarbons (PAHs) are thj
primary contaminants. This shows that soil washing is a pn
which can remove PAHs if site conditions are favorable. Inj
addition, the Koppers Company conducted a test using soils
the South Cavalcade site which showed that site contaminant!
be effectively washed from soils.
Comment #7: Will you continue to conduct studies to determi
if the proposed remedy will work?
Fof
a-
led
m
>nly
id
re
ill
is?
t.her
»ss
m
lean
A-2
-------
EPA Response: EPA will conduct further studies only to refine
the design of the selected remedy. EPA is not proposing to
continue to study the site with the objective of deciding whether
the selected remedy will work.
Comment #8: How likely is it that bioreclamation of the aqui-
fers will be used?
EPA Response; EPA requested comments on bioreclamation because
one potentially responsible party (PRP) has proposed using this
method to remediate the aquifer. This method will only be used
if any PRP offers to construct and operate this method, and if
the PRP can solve the implementation problems of this method.
Comment »9: Creosote needs to heated to 400 degrees to be used.
How will EPA heat the creosote in the groundwater?
EPA Response; The creosote-type contaminants in the groundwater
migrated there without being heated. The Koppers Company was
able to easily collect samples of these contaminants during the
Remedial Investigation. Therefore, EPA believes that these con-
taminants can be removed from groundwater without needing to add
heat.
Comment #10: Did you consider the geology of Houston when you
considered the soil washing and groundwater pump and treat
system? Did you consider that PAHs aren't extremely mobile and
will adhere to soils?
EPA Response; EPA considered the local geology and the nature of
PAHs by requiring tests of soil washing and groundwater pumping.
The Koppers Company during the Feasibility Study conducted a
laboratory test which showed that PAHs can be washed off of
soils. The Koppers Company also conducted a pump test which
showed that groundwater can be extracted.
EPA also recognizes that PAHs are not very mobile in soils.
Typically the PAHs will not migrate very far because clay soils
will prevent migration. However, the soils under the South
Cavalcade site contain small fractures called slickenslides which
offer a path for PAHs to migrate downwards with only a minimum
of adsorption onto soil.
Comment til; Do you intend to implement any type of pump and
treat system to stop contaminant migration in groundwater while
you conduct further studies on the site?
EPA Response; EPA does not believe that the groundwater contami-
nation will significantly migrate during the time the remedy is
designed and installed. The contamination has only 'migrated 60
feet downwards in approximately 70 years. The horizontal ground-
water velocity is less than 20 feet per year. The contamination
should not significantly migrate in one more year.
Comment #12; Can you accurately predict the progress of the
bioreclamation process, and what reassurance do you have that the
A-3
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process itself is not hazardous to the environment? Are there
chlorinated hydrocarbons or pentachlorophenol at the site?
EPA Response: PAHs consist of large molecules containing carbon
and hydrogen arranged in a series of rings. Bioreclamation would
detoxicify PAHs by breaking the rings to form smaller molecules
which are not hazardous. Since there are no chlorinated organics
including pentachlorophenol at the South Cavalcade site, bio-
reclamation would not cause any toxic chlorinated organic com-
pound to be formed.
Comment #13; We want signs posted on the site indicating the
toxic wastes which may be present.
EPA Response; EPA does not believe that signs of this type are
warranted at the South Cavalcade site. The health-threatening
contamination is mostly underground; people will not contact the
contamination unless they dig in the contaminated areas. All
three property owners have been notified of these areas and know
not to dig in these areas without taking reasonable precautions.
The site is already secured by a 10 foot fence which prevents the
general public from going onto the site.
Comment #14; We feel that the area is too highly populated to
have an on-site incinerator there. It would further damage the
air quality around our neighborhoods.
EPA Response; EPA evaluated on-site incineration as one of
several alternatives for remediating soils. However, EPA did not
propose on-site incineration for use at this site, partially
because of the present air quality problems in Houston.
Comment #ij>: We feel that all the soil should be taken out
completely, incinerated off-site, and be replaced with good soil.
EPA Response; EPA did not propose off-site incineration for
two reasons. First, there is always a risk when transporting
hazardous substances to an off-site location. Second, off-site
incineration is more than 10 times as expensive as other alterna-
tives which are just as effective for cleaning soils to levels
which are not health-threatening.
Comment tl6; We feel that if you are going to wash the soil,
there is only so much you can wash out of the soil.
EPA Response; The Koppers Company conducted a study to determine
the ability to wash contaminants out of soils. This study was
reported in the Feasibility Study and showed that contaminants
can be removed to well below the remedial goal for this site.
Therefore, EPA believes that all contaminants posing an unaccept-
able risk can be removed from the soil.
Comment #17.: What alternatives are proposed for the site?
EPA Response; EPA proposed a combination of soil washing and in
situ soil flushing for remediating the soils, and extraction and
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treatment using physical/chemical and activated carbon treatment
for groundwater. These are the alternatives labeled as 4, 7, and
10 in the fact sheet.
Comment #18; Will the remediation be bidded out to a contractor?
EPA Response; Eventually, there will be construction at the site
which will be bidded out. Under the Superfund law, either EPA or
a potentially responsible party (PRP) under EPA's supervision
will conduct the remediation. Therefore, either EPA or a PRP
will request bids sometimes in the future.
Comment #19; When do you anticipate to start remediation?
EPA Response; EPA anticipates making a decision on the site
remedy in September of 1988. After that, the Superfund law
allows for a 120 day period during which a potentially respon-
sible party can offer to conduct the remedy. The design of the
remedy will take about eight to ten months. Therefore, the actual
remediation should not start until about fall of 1989.
Comment #20; Is any of the buildings going to be torn down? Are
you going to tear up any of the concrete?
EPA Response; EPA is proposing to only remediate those soils
which are not under existing buildings or concrete. The soils
under these structures are not- accessible; therefore, there is no
exposure by workers to these contaminants. The concrete and
buildings prevent water from leaching into the soils and re-
mobilizing contaminants. The contaminated groundwater under the
structures can be extracted with wells; therefore, there is no
need to destroy the buildings and concrete at this time.
Comment #21; If there are contaminants underneath the concrete
or buildings, wouldn't they continue to contaminate groundwater?
EPA Response; The contaminants will leach only if rainwater is
allowed to percolate through the soils to re-mobilize the con-
taminants. One way of preventing this is to cover contaminated
soils with an impervious cap such as concrete. The concrete and
buildings provide an effective cap. Therefore, EPA does not
believe that these contaminants will continue to leach.
Comment #22; How long will you continue to monitor to see if
contaminants under the structures will continue to leach? How
soon after you clean up the aquifer will you be able to tell if
contaminants are leaching?
EPA Response; EPA will continue to monitor groundwater through-
out the groundwater remediation so that EPA can observe if the
site contaminants are continuing to migrate. Monitoring could
continue for up to 30 years or even longer. A reasonable esti-
mate of this time cannot be calculated until the extraction and
treatment system is installed and operating. According to the
Superfund law, EPA will review the site data every five years to
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determine if contaminants are continuing to leach and to refine
the duration of continued monitoring.
Comment #23; How much of the contaminated soil is actually under
the concrete?
EPA Response; The site consists of 64 acres. There are 5.5
acres which contain contamination which may need remediation.
Approximately 3 acres of these soils are under the concrete and
buildings.
Comment #24; Is it the cost of tearing down the buildings and
concrete or the concern for destruction of businesses which is
your reason for leaving contaminants on-site?
EPA Response; EPA is not proposing to tear down the buildings or
concrete only because this activity would disrupt the on-site
businesses. Some of the contamination is located under the only
access to the site which the trucking firms need for continued
operation. EPA will tear down the structures to remediate this
contamination only after EPA has solid information showing that
the contaminants under the structures will continue to leach.
EPA will continue to monitor the groundwater during remediation
to determine if the contaminants are leaching.
Comment #25; Has there been any idea of drilling through the
concrete to see whether or not there is contamination in the
groundwater?
EPA Response; As part of the site Remedial Investigation, the
Koppers Company did drill through parts of the concrete to deter-
mine whether there was contamination under the concrete. Only a
few holes were drilled because the drilling activity had to stay
out of the way of trucking operations. This activity did identi-
fy the areas of contamination under the concrete. These areas
were shown on a slide during the public meeting and are also
shown on figure 6-1 in the Remedial Investigation report.
Comment #26; Does your branch of EPA deal with existing operating
plants, or just abandoned plants?
EPA Response; The Superfund part of EPA deals only with those
sites which are abandoned. There is also a part of EPA which
deals with active hazardous wastes sites; this is the Resource
Conservation and Recovery Act (RCRA) part of EPA.
Comment #27; There was a creosoting company on Oliver Street. SP
Railroad had a plant on Wailaceville Road. General American Tank
Farm used to store their creosote at Galena Park. There was a
creosoting plant at Crosstimbers and Hardy. Have you done any-
thing to clean those up?
EPA Response; There is a group inside EPA and the Texas Water
Commission (TWO which investigates all sites for inclusion on
the Superfund list. There are approximately 30,000 sites across
the country which are being or will be investigated, and there
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are roughly 1000 on the Superfund list. If EPA or TWC finds
evidence at these sites that contaminants may pose a threat to
human health, then these sites may be added to the Superfund
list.
Comment #28; At the intersection of Crosstimbers and Hardy, a
company put a lot of creosote-type contaminants under a plastic
sheet under the Hardy Toll Road. Why can't EPA do something like
this at the South Cavalcade site?
EPA Response; The Superfund law requires EPA to select a remedy
with a preference for treatment as a principal element in the
remedy. The law also requires EPA to comply with other environ-
mental laws. The action taken by a company at the Crosstimbers
and Hardy site did not use treatment nor does it comply with EPA
regulations for disposal of hazardous wastes. Therefore, EPA
cannot use the approach taken by that company.
In addition, EPA is now investigating the Crosstimbers and Hardy
site to determine if there is just cause for including that site
in the Superfund program.
Comment #29: The Koppers Company had a site in Texarkana. What-
are you going to do there?
EPA Response; EPA is in the process of determining the remedy
for that site. EPA evaluated several alternatives and proposed
soil washing for contaminated soils with extraction and treatment
using activated carbon for groundwater. This remedy is very
similar to the proposed remedy for the South Cavalcade site.
Comment #30; Are former site owners still responsible if they no
longer own the property?
EPA Response; Under the Superfund law, current property owners
and former owners at the time when hazardous substances leaked or
otherwise were released into the environment can be liable. At
this site, the Koppers Company was the property owner at the time
when hazardous substances could have leaked into the groundwater.
Therefore, EPA identified the Koppers Company as one of the
potentially responsible parties.
Comment #31; What if site owners excavate and remove the contam-
inated soil, add a building, or extend the concrete slab?
EPA Response; EPA has contacted the site occupants to ask them
to keep EPA informed about any activity at the site. EPA noti-
fied the site occupants that, if they developed any area which
needs some remediation, they would be partially responsible for
some of the costs for remediating that area of the site.
In addition, EPA will be requiring the site owners to add a
notice to their deeds expressing that hazardous substances are
located under concrete and buildings. EPA will require this to
notify any potential purchaser of the site about this contami-
nation.
A-7
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Finally, EPA considers part of the soils on the site to be haz-
ardous and therefore subject to EPA regulation. If EPA found
that a site owner excavated and disposed contaminated soil before
the remediation began, EPA would take enforcement action against
that owner. However, EPA does not believe that it is in the
interest of any site owner to do this at this time because the
costs of that action to the site owner could be greater than the
costs of remediating the soils using EPA's proposed remedy.
Comment #32: Have you approached the present owners with your
proposal? What do they say?
EPA Response: EPA mailed information to each site business and
met with them prior to the August 29, 1988, public meeting. Two
of the businesses had no objection to the proposed remedy as long
as it would not interfere with their operations. The other
business feels that a concrete cap would solve the soil problems
at their property.
EPA reassured all three businesses that they would be consulted
in the design of the remedy so that interference with the busi-
ness operations could be minimized.
Comment #33; What can the community do if the owners are not
cooperating in the cleanup?
EPA Response; Under Section 310(a)(1) of the Superfund law,
citizens have the right to file suit against any. potentially
responsible party to require that party to remediate a site. This
section of the law also limits these suits to those sites where
EPA has yet to take any enforcement action. At the South Caval-
cade site, EPA has taken action leading to eventual remediation
of the site.
Comment #34; Koppers re-emphasizes the need to sample the soils
within areas targeted for potential remediation during the Reme-
dial Design phase to determine the actual areas needing remedia-
tion.
EPA Response; EPA will require in the Record of Decision that
the soils in these areas be sampled for this purpose. This was
stated in the Feasibility Study, and it was also discussed in the
Proposed Plan and during the public meeting.
Comment »35; Koppers proposes that some flexibility be included
in the Record of Decision definition of the leaching potential of
these soils to incorporate the results of such sampling.
EPA Response; EPA will require in the Record of Decision that
the Toxicity Characteristic Leaching Procedure (TCLP) be used in
assessing leaching potential. The interpretation of the end-
point of the TCLP test can be developed during the Remedial
Design.
Comment #36: Koppers re-emphasizes that remediation of the upper
aquifer will be achieved to the maximum extent practical as
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stated in the Feasibility Study report. The EPA has suggested
that removal of the non-aqueous phase liquids is a remediation
goal. It is not clear what EPA means by this term and as such it
is uncertain whether this can be practically accomplished. How-
ever, Koppers suggests that the measure by which the parties
determine compliance with the response objective be flexible so
to allow for operational experience to bring practicality to the
decision.
EPA Response; EPA observed, during the Remedial Investigation,
an oily substance in some of the groundwater samples. EPA con-
siders this substance to be a "non-aqueous phase liquid". EPA
believes that this liquid needs to be removed from the aquifer to
prevent the continued downward migration of sinking substances
into aquifers usable as sources of drinking water. EPA will
assess the means for determining when the non-aqueous phase
liquid has been effectively removed during the Remedial Design.
Comment #37; Koppers proposes to investigate bioreclamation of
surface, surficial and subsurface soils at the same time it
considers in situ biological treatment of the groundwater. If
the studies undertaken during the Remedial Design prove to be
effective, Koppers agrees with EPA that in situ biological
treatment should be considered as the remedial action of
preference.
EPA Response; EPA presented this option in the Proposed Plan and
during the public meeting. EPA will include in situ biological
treatment in the Record of Decision as an alternative remedial
action in the case a potentially responsible party elects to
construct and operate this method of treatment.
Comment #38; Koppers further proposes that the selection between
groundwater treatment options be made during the Remedial Design
phase so that the most cost effective option which meets the
discharge criteria and remediation goals can be chosen.
EPA Response; EPA believes that the differences between the
groundwater treatment options (alternatives #10, #11, and #12)
are distinct. Alternative #11, Carbon Adsorption with Air Strip-
ping, has the potential for air emissions of volatile organics.
The air in the Houston area is already over acceptable state and
federal air quality levels. Alternative #12 is approximately
$400,000 more expensive than EPA's selected remedy; EPA believes
that the selected remedy will be less expensive even after fur-
ther studies into the alternatives.
Comment #39; Merchants Fast Motor Lines feels that EPA has not
provided a reasonable opportunity for public comments with
respect to the South Cavalcade Street site, and requests that the
comment period be extended for an unspecified duration. Mer-
chants received a copy of the Feasibility Study on August 23,
1988. The public comment period ends on September 19, 1988.
Merchants feels that the 30 day comment period is insufficient to
review the six volumes comprising the Remedial Investigation and
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Feasibility Study reports. Merchants also believes that EPA
required that the Feasibility Study report to be written in a 30
day period.
EPA Response: EPA provided a 30 day comment period for the
Remedial Investigation and Feasibility Study reports. This per-
iod is in agreement with proposed EPA regulations for public
comment on these reports, and it exceeds the existing regulation
which calls for a 21 day comment period. EPA notes that Mer-
chants had the reports for the full 30 days.
EPA also notes that the four of the six volumes of the reports
are appendices which contain supporting information for the two
volumes which comprise the analysis of the site. EPA feels that
30 days is sufficient for review of the two volumes which contain
the substance of the analyses.
EPA disagrees with the contention that the Feasibility Study
report was written in 30 days. EPA had negotiated a schedule
with the Koppers Company which required that action on the Feasi-
bility Study report begin upon submittal of the draft Remedial
Investigation report in February of 1988. EPA acknowledges that
it required that Koppers take no more than 30 days to revised the
draft Feasibility Study report to comply with EPA's comments.
However, EPA notes that this 30 day requirement was negotiated
with Koppers in March of 1985, and it is also a standard clause
in EPA agreements with potentially responsible parties who con-
duct RI/FS studies for EPA.
Comment #40; Merchants feels that the Record of Decision should
provide for flexibility by requiring re-evaluation of the
selected remedial alternative and consideration of new alterna-
tives following investigations during the Remedial Design. Mer-
chants suggest that the investigations should include additional
soil samples, pump test, and unspecified other investigations.
EPA Response; EPA rejects the suggestion that other alternatives
should be considered during the Remedial Design. EPA believes
that a wide range of alternatives were evaluated during the Feas-
ibility Study, and that further analysis would not result in a
different remedial alternative being selected.
EPA will conduct additional studies during the Remedial Design to
help design the details of the selected remedy. For example, EPA
will resample the soils within the areas of contaminatipn to
better identify the soils needing remediation. Studies of this
type are usually conducted at Superfund sites.
Comment #41: Merchants believes that the soil remediation goal
of 700 ppm carcinogenic PAHs needs to be re-evaluated. Merchants
believes that the goal was based on limited soil data (two sam-
ples), and the value used to characterize the PAHs in the soils
(29 mg/kg) is low by a factor or 40. Merchants also believes
that the soil remedial goal is 70 to 700 times greater than those
used at other similar sites.
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EPA Response; EPA agrees that the quantitative soil data for the
site is scarce and that 29 mg/kg probably does not characterize
the maximum PAH concentration at the site. However, the remedial
goal is not based on the existing soil concentrations. It is
based instead upon assumptions of frequency of exposure, the
potencies of the chemicals, and an maximum incremental increase
in cancer risk of 1 in 100,000 (10~5). EPA required that these
assumptions be consistent with those used at other Superfund
sites investigations.
EPA also notes that the soil remedial goal comprises of two
parts: a health-based level of 700 ppm carcinogenic PAHs and a
leaching potential-based level which is determined by a soil
testing method. The more stringent of the two will apply. EPA
could not establish a numerical criterion for preventing leaching
because the soil and waste characteristics which affect leaching
can vary across the site. Therefore, EPA is requiring within the
Record of Decision that the Toxicity Characteristic Leaching
Potential (TCLP) test be used for this. . EPA expects that the
leaching potential may be the more stringent criterion because a
leaching test conducted during the treatability study in the
Feasibility Study showed leaching at concentrations greater than
150 ppm total PAHs.
The existing soil concentrations were used in the South Cavalcade
risk assessment to estimate the risks to public health if no
remediation were to occur. In risk assessments, EPA's procedures
requires that only valid data be used. In this case, the soil
samples containing PAHs were not valid due to laboratory inter-
ferences. EPA required that the existing risk be estimated using
the available valid data, but EPA did not state that it believed
this risk was correct. In fact, EPA required that the Feasibil-
ity Study report note, within the risk assessment chapter, that
the actual risk.at the site could be higher. For this reason,
EPA stated that soil remediation may be necessary at the South
Cavalcade site, and required the Koppers Company to add soil
remediation alternatives to the Feasibility Study.
EPA also notes that soil remedial goals are site specific because
the characteristics of each site influence the potential exposure
pathways, the location of the wastes, and other factors. For
South Cavalcade, EPA considered the site to be used by operating
commercial enterprises such as Merchants. EPA based the assess-
ment of public health risks on this use. The other sites quoted
by Merchants are in residential areas (united Creosoting and
Bayou Bonfouca), are abandoned and could be developed as resi-
dential areas (Mid-South Wood Products and Midland Products), or
contain RCRA listed wastes which must be treated to a specified
low level (North Cavalcade). EPA notes that the remedial goal
for the Arkwood site has yet to be established.
Comment #42; Merchants requests that the Feasibility Study be
clarified that remediation of the upper intermediate aquifer be
required. Merchants feels that this was intended in the body of
the Feasibility Study, but not clearly expressed in the executive
summary of the report.
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EPA Response; EPA will require, in the Record of Decision, reme-
diation of groundwater contained in the sand lenses located 40 to
55 feet below surface. These lenses were, at one time, called
the "upper intermediate aquifer". However, the lenses are not
continuous, and, therefore, do not comprise an aquifer. The
lenses are part of what EPA labels the "shallow" groundwater.
Comment #43: Merchants believes that the stated groundwater
extraction rate may not be feasible based on model results not
submitted with the comments. Merchants requests that the ground-
water remedial alternatives be re-evaluated after additional pump
tests are conducted. Merchants also request the specifics about
well spacing, the injection rate, radius of influence, and spe-
cific yield be available for public review before completing the
Record of Decision.
EPA Response; EPA agrees that the operational parameters of the
groundwater collection and re-injection system may be changed
after further pump tests are conducted during the Remedial
Design. The parameters stated in the Feasibility Study report
were not intended to be exact values for use in drawing up the
design, but were rather to be used as a reasonable rate for use
in costing the alternatives.
EPA does believe that the selected groundwater remedial alterna-
tive is the correct one for this site. EPA evaluated many
alternatives for groundwater remediation within the Feasibility
Study. The other groundwater collection alternative, trenches,
is not practical because the depth of the sand lenses (40 to 55
feet) is too deep for effective use of trenches. Containment
alternatives such as slurry or grout walls are not practical
because they only halt horizontal migration; the vertical migra-
tion of non-aqueous phase liquids to deeper aquifers would not be
controlled.
Comment #44; Merchants requests that further soil samples be
collected to reassess the maximum contamination concentrations
and re-evaluate the soil remedial goal. In specific, Merchants
requests that some samples be collected close to the existing
underground storage tanks located on the Merchants property.
EPA Response; EPA is requiring in the Record of Decision that
further soil samples be collected during the Remedial Design to
better define the areas needing remediation (see responses to
comments #34 and #41). The soils around the buried tanks can
also be sampled. EPA also reiterates that the,existing soil
concentration has no effect on the health-based remedial goal,
but will affect the leaching potential-based goal which is an
operational test (TCLP test) to be conducted during the sampling
effort.
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APPENDIX B
APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS
-------
APPENDIX B: APPLICABLE OR RELEVANT AND APPROPRIATE REQUIRMENTS
Section 121(d)(2) of CERCLA as amended in 1986 by SARA requires
that the selected remedy attain requirements adopted under Fed-
eral and state environmental laws. These requirements are called
"ARARs" which means "applicable or relevant and appropriate
requirements".
The Feasibility Study for the South Cavalcade site included a
review of these laws, and identified those which could be ARARs
based on the types of wastes at the site, the types of remedial
actions contemplated, and the site location. This appendix lists
all the laws which the Feasibility Study identified as potential
ARARs for this site, and indicates whether each of the final
remedial alternatives can comply with the laws. The appendix
also includes the laws which the Feasibility Study did not iden-
tify as potential ARARs but which EPA now believes are ARARs.
SAFE DRINKING WATER ACT
National Primary Drinking Water Standards: Establishes health
based standards for public water systems (maximum contaminant
levels); an ARAR for all groundwater alternatives because the
groundwater contamination can reach an aquifer used as a drink-
ing water supply.
National Secondary Drinking Water Standards: Establishes
aesthetic based standards for public water systems (secondary
maximum contaminant levels); an ARAR, for all groundwater
alternatives because the groundwater contamination can reach an
aquifer used as a drinking water supply.
Maximum Contaminant Level Goals: Establishes drinking water
quality goals set at levels of no known or anticipated adverse
health effects, with an adequate margin of safety; not an ARAR
but a factor to be considered for those contaminants where the
Maximum Contaminant Levels have yet to be promulgated.
Underground Injection Control Regulations: Provides for protec-
tion of underground sources of drinking water; an ARAR for all
groundwater alternatives because the treated groundwater will
be re-injected.
CLEAN WATER ACT
Water Quality Criteria: Sets criteria for water quality based on
toxicity to aquatic organisms and human health; an ARAR for
disposal of those compounds for which there are no state water
quality standards; applies to the discharge after mixing with
Hunting Bayou water.
National Pollutant Discharge Elimination System: Requires treat-
ment performance for the discharge of pollutants for any point
source into waters of the United States; an ARAR for disposal
of water into Hunting Bayou.
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National Pretreatment Standards: Sets standards to control pol-
lutants which pass through or interfere with treatment pro-
cesses in public treatment works or which may contaminate sew-
age sludge; an ARAR because one possible disposal option from
the groundwater treatment system is to a Houston sewage treat-
ment plant.
OCCUPATIONAL SAFETY AND HEALTH ACT: Regulates worker health and
safety; an ARAR for all site activities.
HAZARDOUS MATERIALS TRANSPORTATION ACT: Regulates transportation
of hazardous materials; an ARAR for the offsite transport of
recovered oil and creosote for burning, and offsite transport
of soil in offsite landfill and incineration alternatives.
SOLID WASTE DISPOSAL ACT
Standards Applicable to Generators of Hazardous Waste: Estab-
.lishes standards for generators of hazardous wastes; an ARAR
for all alternatives except No Action.
Standards Applicable to Transporters of Hazardous Waste: Estab-
lishes standards which apply to transporters of hazardous waste
within the U.S. if the transportation requires a manifest under
40 C.F.R. Part 262; an ARAR for the offsite transport of recov-
ered oil and creosote generated from the groundwater treatment
system, and the offsite transport of soil in offsite landfill.
and incineration alternatives.
Standards for Owners and Operators of Hazardous Waste Treatment,
Storage, and Disposal Facilities: Establishes minimum national
standards which define the acceptable management of hazardous
wastes for owners and operators of facilities which treat,
store or dispose of hazardous wastes. Each subpart follows:
General Facility Standards (Subpart B): Sets siting require-
ments for floodplains; not an ARAR because no treatment or
disposal unit will be located in a floodplain.
Releases from Solid Waste Management Units (Subpart F): Sets
groundwater remediation levels; an ARAR for groundwater
alternatives.
Closure and Post-Closure (Subpart G): Sets standards for main-
tenance of disposal sites; an ARAR only soil alternatives
leaving treated soils at the site.
Use and Management of Containers (Subpart I): Sets require-
ments for storage of wastes in containers; not an ARAR
because containers will not be used in any alternative.
Tanks (Subpart J): Sets requirements for storage of wastes in
tanks; an ARAR for the groundwater treatment system.
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Surface Impoundments (Subpart K): Sets requirements for dis-
posal or treatment of wastes in surface impoundments; not an
ARAR because no alternative uses surface impoundments.
Waste Piles (Subpart L): Sets requirements for storing and
treating wastes in piles; an ARAR for soil alternatives which
store wastes in piles prior to disposal or treatment.
Land Treatment (Subpart M): Sets requirements for treatment of
wastes by placing them in land; not an ARAR because no
alternative uses this method.
Landfills (Subpart N): Sets requirements for disposal of
wastes in landfills; not an ARAR only because no alternative
creates a new landfill.
Incinerators (Subpart 0): Sets requirements for incineration
of wastes; an ARAR for the soil incineration alternatives and
the groundwater alternatives if the recovered creosote will
be incinerated.
Land Disposal Restrictions: Establishes allowable concentration
levels for burial of hazardous wastes; not an ARAR for soil
alternatives because the soils to be remediated were not con-
taminated with a RCRA listed waste (K001 sludge or U051 creo-
sote) and are not subject to these restrictions; an ARAR for
groundwater alternatives for the incineration or recycling of
the creosote collected from the groundwater.
TEXAS DEPARTMENT OF HEALTH
Allowable Limits of Metals in Drinking Water: Sets health-based
standards for public water systems; these set remedial levels
for groundwater alternatives.
Location of Wells used for Drinking Water Supplies:. Restricts
placement of drinking water wells; restricts location of solid
waste disposal sites; an ARAR for groundwater alternatives
because remediation requires a long time for completion.
TEXAS WATER COMMISSION
Water Quality Standards for Surface Waters: Prohibits point
source discharges which cause toxicity in natural streams and
sets maximum levels for selected contaminants; an ARAR for
discharge of treated groundwater into Hunting Bayou; applies to
the discharge after mixing with Hunting Bayou.
TEXAS AIR CONTROL BOARD
Prohibition of Air Contaminants which Adversely Effect Human
Health: Health-based standards for air; only an ARAR for those
alternatives which disturb the soil and may cause a release.
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Control of Air Pollution from Visible Emissions and Particulate
Hatter: Maximum allowable levels of particulates in air; an ARAR
for incinerators.
Storage of Volatile Organic Compounds: Regulates handling of
tanks containing volatiles; an ARAR for the groundwater
treatment system if recovered creosote is stored in a tank.
Oil/Water Separators: Controls volatile emissions from separ-
ators; an ARAR for the groundwater treatment system.
Vacuum Producing Systems: Requires incineration of emmissions
from vacuum producing systems; an ARAR for the groundwater
treatment system
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LIST OF REMEDIAL ALTERNATIVES
Alternative #1: No Action
Alternative #2: Stabilization and Capping
Alternative #3: Offsite Landfill
Alternative #4: Onsite Soil Washing
Alternative #5: Onsite Incineration
Alternative #6: In Situ Biremediation
Alternative #7: In Situ Soil Flushing
Alternative #8: Offsite Incineration
Alternative #9: Groundwater In Situ Biological Treatment with
Physical Separation
Alternative #10: Groundwater Collection; Physical Separation,
Filtration, and Activated Carbon Treatment
Alternative #11: Groundwater Collection; Physical>Separation,
Filtration, Air Stripping, and Activated
Carbon Treatment
Alternative #12: Groundwater Collection; Physical Separation,
Activated Sludge Biological Treatment
NOTE: Alternatives 9 through 12 are actually the ground-
water parts of alternatives 2 through 8. They are
discussed separately within this appendix to help
distinguish the ARARs pertaining to groundwater
actions from the ARARs pertaining to soil actions.
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FEDERAL ARARS
Standard, Requirement,
Criteria, or Limitation
SAFE DRINKING WATER ACT
National Primary Drinking Water
Standards (40 CFR Part U1>
National Secondary Drinking Water
Standards (40 CFR Part 143)
Maximum Contaminant Level Goals
Underground Injection Control
Regulations (40 CFR Part 144-147)
CLEAN WATER ACT
Water Quality Criteria
(40 CFR Part 131)
National Pollutant Discharge Elimi-
nation System (40 CFR Part 125)
National Pretreatment Standards
(40 CFR Part 403)
n/*f*IIBATfntlAI CACCTV Akin UBAI TU Af*Y
OCCUPATIONAL SAFETT AND HEALTH ACT
(29 USC 651-678)
HAZARDOUS MATERIALS TRANSPORTATION
ACT (49 CFR Part 107, 171-177)
SOLID WASTE DISPOSAL ACT
Standards for Generators of Haz-
ardous Waste (40 CFR Part 262)
Standards for Transporters of Haz-
ardous Waste (40 CFR Part 263)
Remedial Alternative
1
A
*
0
A
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2
3
A
A
4
5 6
...
I
7 8
...
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I
A
A
9
A
A
0
A
A
A
A
A
A
10 | 11 | 12
A
A
0
A
A
A
A
^
A
i
A
A
0
A
A
A
....
A
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A
I
A
A
0
A
A
A
A'
A
A"
A
A » ARAR;
other factor to be considered
B-6
-------
FEDERAL ARARS continued
Standard, Requirement,
Criteria, or Limitation
SOLID WASTE DISPOSAL ACT
Standards for Owners and Operators
of Hazardous Waste Treatment,
Storage, and Disposal Facilities:
General Facility Standards
(40 CFR Part 264 B)
Releases from Solid Waste Management
Units (40 CFR Part 264 F)
Closure and Post-Closure
(40 CFR Part 264 G)
Use of Containers
(40 CFR Part 264 I)
Tanks
(40 CFR Part 264 J)
Surface Impoundments
(40 CFR Part 264 K >
Waste Pi les
(40 CFR Part 264 L)
Land Treatment
(40 CFR Part 264 M)
Landf i Us
(40 CFR Part 264 N)
Incinerators
(40 CFR Part 264 0)
Land Disposal Restrictions
(40 CFR Part 268)
Remedial Alternative
1
A
,
2 3
A
A
4 5 6 7 8
1 1 j
A
A
A
A
A
A
,
A
'
A
A
9 10
t
A
A
A
A
.
A
A
A
A
11 12
1
A
A
A
A
A
A
A
A
A ARAR; 0 » other factor to be considered
B-7
-------
STATE OF TEXAS ARARS
Promulgated Standard, Requirement,
Criteria, or Limitation
DEPARTMENT OF HEAtTH
Allowable Limits of Metals in
Drinking Water
Location of Wells used for
Drinking Water Supplies
WATER COMMISSION
Water Quality Standards for
Surface Waters
AIR CONTROL BOARD
Prohibition of Air Contaminants
that Adversely Effect Human Health
Control of Air Pollution from Visi-
ible Emissions and Particulates
Storage of Volatile Organics
Oil/Water Separators
Vacuum Producing Systems
Remedial Alternative
1
2 I 3
f
A
A
...
A
4
A
'
5
A
A
6
7
t
8
...
A
A
9
...
A
A
A
A
A
A.
A
10
....
A
A
A
A
A
A
A
11
12
A
A
A
A
.
*
A
A
A
A
A
A
'
A
ARAR; 0* = other factor to be considered
B-8
-------
APPENDIX C
RISK CALCULATIONS
-------
Potential Risks for Onsite Workers
Selected Remedy
Contami nant
aaaaaaaaaasaaaaaa
Care i nogeni c PAHs
Arsenic
Chromi um
Copper
Lead
Zinc
aaaaaaaaaasaaaaaas
TOTALS
Maximum
Concentration
(ing/leg soi I)
S333333S3333S
700s
8.8
9.5
5.0
30.4
3480
Total
L i fet ime
Intake
(mg/kg/day)
6.66E-07
2.95E-08
3.19E-08
1.68E-08
1.02E-07
1.176-05
Hazard
I ndex
6E-06
5E-07
7E-05
6E-05
1E-04
Excess
Max i mum
Li fetime
Cancer
Risk
8E-06
4E-08
8E-06
Potential Risks for Groundwater Users
Selected Remedy
Contami nant
Carcinogenic PAHs
Benzene
Ethylbenzene
Toluene
xylene
Arseni c
Chromi um
Copper
Lead
Zinc
33S3333S3S3388B3SS
TOTALS
Nax i mum
Concent rat i on
(ug/l water)
ndb
5
470d
1000d
440
50C
50C
28
50C
100
Total
L i f et ime
Intake
(mg/kg/day)
2.86E-06
1.43E-04
1.37E-02
2.86E-02
1.26E-02
1 .43E-03
1.43E-03
8.29E-04
1.43E-03
2.86E-03
Hazard
I ndex
' 333333
0.1
0.1
0.6
*
<0.1
*
<0.1
0.9
Excess
Nax i mum
L i f et i me
Cancer
Risk
333333S3
. 3E-05
7E-06
*
4E-05
Actual concentration may be lower based on leaching potential
(t>> Not detected at normal laboratory procedures (use 0.1 ug/l)
(c> No risk because goal achieves natural background
Represents existing concentration
-------
Potential Risks for Offsite Residents (Sediments)
Selected Remedy
Contaminant
saaaaaaaaaaaaaaaaa
Carcinogenic PAHs
Arseni c
Chromium
Copper
Lead
Zinc
TOTALS
Max imum
Concent rat i on
(mg/kg soi 1 )
5.8
34
360
89
540
3300
Total
Li f et ime
Intake
(mg/kg/day)
7.18E-08
3.83E-07
4.06E-06
1 .OOE-06
6.09E-06
3.72E-05
Hazard
Index
8E-04
3E-05
4E-03
2E-04
Excess
Max i mum
Li f e t i m e
Cancer
Risk
8E-07
6E-07
5E-03
1E-06
(a)
Concentrations reflect present levels;
degradation reflected in intake calculations.
-------
APPENDIX D
ST7.TE OF TEXAS CONCURRENCE
-------
TEXAS WATER COMMISSION
B.J. Wynne, ffl, Chairman ^Y« J D. Head. General Counsel
Michael E. Field, Chief Examin
Karen A. Phillip., Chief Clark
Allen Beinke, Executive Director
*
September 29, 1988
Allyn H. Davis, Ph.D., Director
Hazardous Waste Management Division
U.S. Environmental Protection Agency
Region VI
1445 Ross Avenue
Dallas, Texas 75202-2733
Re: South Cavalcade Superfund Site
Draft Record of Decision
Dear Dr. Davis:
We have reviewed the proposed Record of Decision (ROD) for the
South Cavalcade Site, We have no objection to the selected
remedy of in-situ soil flushing and soil washing (Alternatives 4
and 7) and groundwater treatment (Alternative 10) as described in
the draft ROD of September 20, 1988.
Comments were made by Texas Water Commission staff members on the
initial draft Summary of Remedial Alternative Selection document
and submitted to the EPA RPM on September 14, 1988. These
comments have not been incorporated into this final draft, our
comments, however, would not substantially change our concurrence
with this remedial action selection.
Sincerely,
Allan PT
Executive Director
P 0. Box 13067 Capitol Station « 1700 North Congest As*. Austin, TV)S&787l£ls7 VArM
-------
ADMINISTRATIVE RECORD INDEX
FINAL
SITE NAME: South Cavalcades Street
SITE NUMBER: TXD 980810386
INDEX DATE: 08/25/88
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