United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPA/ROD/R06-86/013
Sept. 1986
&EPA
Superfund
Record of Decision
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TECHNICAL REPORT DATA
(PlelUe read Intlructions on the revene /Hlore completing)
1. REPORT NO. 12. 3. RECIPIENT'S ACCESSION NO.
EPA/ROD/R06-86/013
.. TITLE AND SUBTITLE 5. REPORT DATE
SUPERFUND RECORD OF DECISION September 18, 1986
Sikes Disposal Pits 6. PERFORMING ORGANIZATION CODE
7. AUTHORCSI 8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS 13. TYPE OF REPORT AND PERIOD COVERED
U.S. Environmental Protection Agency Final ROD Report
401 M Street, S.W. 14. SPONSORING AGENCY CODE
Washington, D.C. 20460 800/00
15. SUPPLEMENTARY NOTES
16. ABSTRACT
The Sikes Disposal pits site is located on a 185-acre site, approximately 2 miles
southwest of Crosby, TX. It is bordered by the San Jacinto River on the west, Jackson
Bayou on the north, and U.S. Highway 90 on the south. The site lies in the 100-year
floodplain of the river while portions lie within the 10-year and 50-year floodplain.
The site has been flooded four times since 1969. The area immediately surrounding the
site is largely underdeveloped with numerous active and abandoned sandpits and low lyinr
swamp areas. The area plays host to sport fishermen as well as water sport enthusiasts
on the nearby river and bayou. One family lives onsite. The only residential
development in close proximity is 500 feet southwest. .~tween the early 1960s and 1967,
Sikes Disposal pits operated as a waste depository. Chemical wastes from area
petrochemical industries and numerous drums were deposited onsite in several old sand
pits. A preliminary sampling a t the site in 1982 indicated the presence of phenolic
compounds and other organics. In June 1983 a removal action performed at the site by
the EPA removed approximately 440 cubic yards of phenolic tars from a partially buried
pit. Subsequent studies at the site indicated the need for a total remedial site plan.
Onsite soils and surface wa~er f r oIl! .-the sludge areas as well as Tank Lake were found to
be contaminated. Ground water in the shallow aquifer below the site has been heavily
contaminated ~ no residential wells are currently affected. Neither surface
. (See Attached Sheet)
17. KEY WORDS AND DOCUMENT ANALYSIS
a. DESCRIPTORS b.IDENTIFIERS/OPEN ENDED TERMS C. COSATI Field/Group
Record of Decision
Sikes Disposal pits
contaminated Media: gw, sw, soils, sediment
Key contaminants: phenols, sludges, toluene
organics
1B. DISTRIBUTION STATEMENT 19. SECURITY CLASS (Tills Repo,,) 21. NO. OF PAGES
None 56
20. SECURITY CLASS (Tllis page) 22. PRICE
None .
EPA h,,,, 2220-1 (Rev. ~-77)
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EPA/ROD/R06-86/013
Sikes Disposal pits
16.
ABSTRACT (continued)
water or groundwater contamination has migrated beyond the site boundaries.
The primary contaminants of concern include: organics, toluence, creosote,
benzene, xylene, phenolic compounds, halides, dichloroethane, vinyl chloride.
The selected remedial action includes: onsite incineration of sludges
and contaminated soilsf onsite disposal of residue ash - use as backfillf
ban use of upper aquifer onsite, while naturally attenuating to 10-5 Human
Health Criteria (less than 30 years)f discharge contaminated surface water
to river, treat as necessary to meet discharge criteriaf monitor lower
aquifer and ban its use onsite if site degradation occurs. The estimated
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RECORD OF DECISION
REMEDIAL ALTERNATIVE SELECTION
Site:
Sikes Disposal Pits, .U.S. HWY 90, Crosby, Texas.
DOCUMENTS REVIEWED
I have reviewed the following documents describing the analysis of cost-
effectiveness of remedial alternatives for the Sikes Disposal Pits site:
o Sikes Disposal Pits Site Remedial Investigation
Lockwood, Andrews, and Newnam July 1986.
o Sikes Disposal Pits Site, Remedial Investigation Addendum Report,
Lockwood, Andrews and Newnam, June 1986.
9 Sikes Disposal Pits Site Feasibility Study.
Lockwood, Andrews, and Newnam, July 1986.
o Responsiveness Summary
o Staff Summaries and Recommendations.
. DESCRIPTION OF SELECTED REMEDY
o Onsite incineration of sludges and contaminated soils;
o Onsite disposal of residue ash - use as backfill;
o Ban use of upper aquifer onsite, while naturally attenuating to 10-5
Human Health Criteria (less than 30 years); ~
o Discharge contaminated surface water to river, treat as necessary
to meet discharge criteria;
o Monitor lower aquifer and ban its use onsite if site degradation occurs.
DECLARATION
Consistent with the Comprehensive Environmental Response, Compensation,
and Liability Act of 1980 (CERCLA) and the National Contingency Plan (40
CFR Part 300), I have determined that the selected remedy for the Sikes
Disposal Pits site is a cost-effective remedy and provides adequate
protection of public health, welfare and the environment. The State of
Texas has been consulted and agrees with the approved remedy. In addition,
the action will require future operation and maintenance activities to
ensure the continued effectiveness of the remedy. These activities will
be considered part of the approved action and eligible for Trust Fund
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,
I have also determined that the action being taken is appropriate when
balanced against the availability of Trust Fund monies for use at other
sites. In addition, onsite incineration of sludges and contaminated
soils is the most cost-effective remedial action, since it provides the
best protection to human health, welfare, and the environment.
b1~' \81
DATE
~ ~(,
. LA.
Dick Whittington, P.E.
Regional Administrator
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SUMMARY OF REMEDIAL ALTERNATIVE SELECTION
SIKES DISPOSAL PITS
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TABLE OF CONTENTS
1.
Site Location and Description
...8.."'" ....................
2.
Site History
............................. ....... .... ........
3.
Current Site Status
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . '.' . . . .
4.
Migration
Pathways
................................... ... ....
5.
Target Receptors
................ ...................... .....
6.
Enforcement Analysis
. ........... ........ ............ .......
7.
Alternatives Evaluation
................................... .
8.
Community Relations
..... ........... ....... ............ .....
9.
Consistency with other
Environmental
..................
Laws
10.
Recommended Alternative
............... .....................
11.
Schedule
. . . ". . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page
1
1
5
8
14
14
15
24
24
24
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1
Record of Decision Remedial Alternative Selection
Sikes Disposal Pits
Crosby, Texas
Site Location and Description
The Sikes Disposal Pits site is located on a l85-acre site, approximately
2 miles southwest of Crosby, Texas. It is bordered by the San Jacinto
River on the west, Jackson Bayou on the north, and U.S. Highway 90 on the
south (Figure 1 and 2). The area immediately surrounding the site is
largely undeveloped with numerous active and abandoned sand pits and low-
lying swampy areas. Some commercial timber operations and mineral
exploration have been conducted in the past. The area plays host to
~port fishermen as well as water sport enthusiasts on nearby San Jacinto
River and Jackson Bayou. One family lives onsite. The Riverdale
Subdivision, 500 feet southwest of the site, is the only residential
development in close proximity of the site.
The site completely lies in the 100-year flood plain of the San Jacinto
River, while portions lie within the lO-year and 50-year flood plains.
- The site has been flooded four times since 1969.
The site locations where significant waste deposits have been identified,
and thus, are considered source areas include (Figure 2):
o The main waste pit
o The main waste pit overflow area
o Tank Lake and slough
o Small waste pits (3)
o Drum waste areas
o Suspect waste areas
The approximate volumes of waste at these source areas are listed in
Table 2.
-\
......,.
Alluvial sand deposits, ranging from 17 to 34 feet thick, underlie the
site and form a shallow aquifer. Many of the local inhabitants rely on
this aquifer for drinking water (Figure 3).
Site History
The Sikes Disposal Pits site began operation as a waste depository in the
early 1960's and closed in 1967. During this period, a variety of chemical
wastes from area petrochemical industries were deposited onsite in several'
old sand pits. Numerous drums of wastes were also left on the property.
The dike around the unlined main waste pit was not adequate to withstand
the periodic flooding of the site. Floodwaters have breached the dike
and transported wastes across a large, low-lying area east of the main
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GRAPHIC SCALE
10 MILES
FIGURE I
SIKES DISPOSAL PITS SITE
LOCATION
PrIDor'd for:
TEXAS WATER COMMISSION
SIKES DISPOSAL PITS
CROSBY, TEXAS
ISln
=
-------
JACIfSQ
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RIVERDAlE
SUBDIVISION
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Figure 2
. OVERFLOW AREA
SIKES .DISPOSAl PITS
CROSBY. TE XAS
Prep.red lor: R ,.
TEXAS DEPARTMENT OF WATE ,.
RESOURCES
agn/ESE/ ~
rnOHCT NO. ,~n1l10'11
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NOTE: MAP REFERENCE No. KEYED TO TABLE
3-2
Prep.red lor:
TEXAS DEPARTMENT OF WATER
RESOURCES
~.r /ESE/ B~,~
Figure 3
SHALLOW WATER SUPPLY WELLS
RIVERDALE SUBDIVISION
SIKES DISPOSAL PITS
CROSBY, TEXAS
p"OJFCT NO. Ib1nOO'll
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5
The Sikes Disposal Pits site was one of the original sites ranked under
the Hazard Ranking System and placed on the National Priorities
List in 1983 (score: 61.62).
Preliminary sampling at the site in 1982 indicated the presence of
phenolic compounds, xylene, benzene, creosote, toluene, and other organics.
An Immediate Removal Action was performed at the site by the U.S. EPA
Emergency Response Branch in June of 1983. Approximately 440 cubic yards
of phenolic tars were removed from a partially buried pit near the temporary
living quarters of the Sikes family, immediately north of U.S. Hwy 90.
The Sikes family was temporarily relocated away from the onsite activities
to protect their health and safety, and to reduce their interference with
ongoing operations. Relocation was handled by the Texas Department of
Emergency Management (OEM) using three travel trailers provided by the
Federal Emergency Management Agency (FEMA). Total cost of the relocation,
which ~as completed on May 6, 1983, was $30,000.
The Texas Department of Water Resources (now the Texas Water Commission)
under a Cooperative Agreement signed with the U.S. EPA in June 1982,
contracted with Lockwood, Andrews, and Newnam, Inc., Environmental Science
and Engineering, Inc., and Harding Lawson Associates in January 1983, to
. conduct a Remedial Site Investigation (RI). The preceeding work was
conducted in two phases, one in May of 1983, and a follow-up effort in
February of 1984. The final report was submitted in July 1985, and
contains the results of both efforts.
Following completion of the original RI activities and prior to submission
of the final RI document, work began on the Feasibility Study (FS) (October
1984). Several data gaps were identified in the ~I that were essential
for the development of the FS. The decision was to finalize the RI Report
and conduct a supplemental sampling program. Field work for the supplemental
sampling activities began in July 1985. The final Addendum RI Report for
these field activities was submitted in June 1986, and the draft FS was also
received in June 1986.
Current Site Status
The Remedial Investigation Phase 1 and 2 and the Supplemental Sampling
effort, performed at the Sikes Disposal Pits site, were used to describe the
nature and extent of contamination. Pathways and receptors are described
in detail in the RI/FS Reports.
Several waste areas have been identified as being sources of contamination.
The contamination is broken down as waste or sludges and underlying
contaminated soils. Table 1 shows the estimated waste volumes f~r the site.
Sludges onsite are composed of the wide variety of organics shown on Table 2.
Soils underlying the waste areas appear to be significantly contaminated to
depths ranging from 3 to 18 f~et beneath the sludge/water/soil interface.
Contaminants found in the underlying soils are similar to those found in
the overlying sludg~s (Table 2 gives the highest concentrations for
-------
Tab 1 e 1
Approximate Waste Volu~es at the Sikes Disposal Pits Site,
July 1985
Volume
Medium/Area
I. Wastes
Pits 5,900
Barrels 2,600
Sp i 11 s 43,300
Suspected 16,700
Total 68,500 C.Y.
II. Contaminated 50ils
Main Waste Pit 21,000
Sludge Overflow Area 58,300
Total 79,300 C.Y.
III. Contaminated Sediment
Tank Lake 2,000
Slough 300
Total 2,300 C.Y.
I V. Contaminated Surface Water
Main Waste Pit 4,700,000
Small Waste Pits 417,000
Tank Lake 7 , 071 ,000
Slough 412,200
Total 12,600,000 Gal.
Note:
Volume totals have been rounded to the nearest 100 cubic yards
and the nearest 1000 gallons. For complete volume calculations
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TABLE 2
MAXIMUM CONTAMINANT CONCENTRATIONS IN SOILS AND SLUDGES AT THE SIKES
DISPOSAL PITS SITE
PARAMETER
SO I LS
SLUDGES
Concentration, PPB
Concentration, PPB
Benzene 320,000 400,000
1,2-Dichloro-
ethane 1,000,000 1,400,000
1,2,-Trichloro-
ethane 500,000 290,000
Toluene 93,000 48,000
Ethyl benzene 100,000 52,000
Napthalene 1,200,000 78,300,000
Fluorene 290,000 1,600,000
Pyrene 590,000 0-3,300.000
Lead 370,000 4,150,000
-~
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8
Surface water from the sludge areas as well as a natural surface water
body, called Tank lake, and natural drainage ways were found to be
contaminated. The contaminants.were similar to those found in the
underlying sludge/sediments except at lower concentrations. Table 3
shows the highest concentrations of contaminants found in the surface
water onsite.
Dewatering operations in the local sand pits have altered the ground-
water gradients and subsequently spread contaminants. Groundwater
contamination appears to be moving from the main waste pit to the south,
southeast, and northwest. Groundwater contaminants are shown in Table 3.
Groundwater in the shallow aquifer has been heavily contaminated by the
leaching action of organic wastes deposited in pits and spread on the
surface. At this time, only the shallow aquifer below the site is
significantly contaminated, no residential wells are currently affected.
Neither surface water or groundwater contamination has migrated beyond the
site boundaries.
A second aquifer lies below the first, separated from it by approximately
65 feet of highly plastic clay strata. This lower aquifer appears to
contain trace concentrations of one or more volatile organic compounds
. which seem to be originating from an upgradient source.
Underlying the two aquifers previously discussed and separated by several
hundred feet of clay are the Chicot and Evangeline Aquifers, the primary
drinking water source for metropolitan Houston. These aquifers do not
appear to be in any danger of future contaminatton.
Air quality at the site has not- been measurably degraded, however, if the
wastes were to be disturbed in an uncontrolled situation the air releases
could be substantial.
Migration Pathways
Groundwater in the upper aquifer enters the site area from the east and
northeast. Ultimate discharge of the shallow groundwater flow is to the
San Jacinto River. Onsite there are localized areas of groundwater
recharge from surface water ponds which include abandoned sand pits, the
main waste pit, Tank lake, and possibly the small waste pits. The overflow
area also receives recharge from the north, the east, and the southeast.
The flow of shallow groundwater across the site is intercepted by the
surface drainages in the overflow area, by dewatered sand pits to the
south, by Jackson Bayou to the north, and the San Jacinto River to the
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Tab 1 e 3
Summary of Maximum Conta~inant Concentrations at Sikes
Disposal Pits and Human Health Criteria (All Units in
ug /1 or ppb)
Highest Observed
Human Levels
Parameters Health Ground Surface
Criterion* Water Water
Conventional Analysis
Pheno 1 s, Tota 1 3,500 15,000 23
Metals
Beryllium 0.037 15
Cadmium 10 770
Chromium 50 44 13
Mercury 0.144 0.4
Nickel 13.4 18
Lead 50 46
Thallium 13 93
GClMS Volatiles
Benzene ~ 6.6 10,000 9
Chlorobenzene 488 390 3
Chloroform 1.9 290 2
~ 1,2-DiChloroethane 9.4 2,200 91
T-l, 3-Dichloropropene 87 9
Ethylbenzene 1,400 1,700
1,12,2-Tetrachloroethane 1.7 5
l,l,2-Trichloroethane 6.0 390 4
Trichloroethene 23 44
Toluene 14,300 4,300 2
Vinyl Chloride 20 400 6
GC/MS Base/Neutral 20.01
Acenaphthene 68.0 5
Acenaphthylene 0.028 2
Anthracene 0.028 2
Benzo(A)anthracene 0.028 3
Benzo(B)fluoranthene 0.028 3
Benzo(A)pyrene 0.028 2
Bis(2-ethylhexyl)phthalate 15,000 190 37
Chrysene 0.028 ?
...
1,4-DiChlorobenzene 400 6
1,2-DiChlorobenzene 400 6
Di-N-butylphthalate 34,000 2
Fluoranthene 42 6 2
Naphthalene 5900
Phenanthene 0.028 290
Pyrene 0.028 190
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10
Contaminated wastes within the main waste pit and the overflow area are the
primary sources of shallow groundwater contamination. The groundwater
within this immediate vicinity is heavily contaminated. In addition,
because numerous smaller sources of contamination (i.e., small waste
pits, scattered drum stockpiles, and possibly undiscovered buried wastes)
exist, and because groundwater flow patterns were previously altered by
sand.pit dewatering, groundwater contamination is widespread onsite
(Figure 4). North of Jackson Bayou the shallow groundwater flow is
suspected to be toward the south. Thus, the contaminated groundwater
plume has advanced north of the railroad tracks, based on contaminated
groundwater seeps observed under the railroad trestle, and in some areas
has advanced to Jackson Bayou, based on surface water sampling.
The most rapid advance of shallow groundwater contamination is presently
located around Love Sand Pit south of the main waste pit. Groundwater in .
this area has become heavily contaminated due to extensive pumping of
water from the sand pit. A groundwater seep visible in the pit indicates
that movement of contaminants through the upper aquifer toward the Love
Sand Pit is occurring. Pumping in the pit has resulted in the formation
of a large cone of depression that effectively isolates groundwater in
the western portion of the Riverda1e community from the more heavily
contaminated groundwat~r to the north. If pumping were discontinued, the
groundwater gradient would decrease and the contaminated groundwater
. would disperse covering a larger area. This would increase the risk of
the Riverda1e community's groundwater becoming contaminated. The ground-
water flow would maintain a southwesterly direction but would proceed at .
a reduced rate.
Data from the borings and wells indicate that the upper and lower aquifers
are separated by an aquitard consisting of 64 to 69 feet of low permeability
(less than 10-7 cm/sec) clay which appears to be continuous and relatively
uniform across the site. The estimated vertical groundwater velocity in
the aquitard between the upper and low~r aquifer is approximately 0.2
feet/year.
Groundwater in the lower aquifer has at times exhibited elevated
concentrations of total organic carbon (TOC), total organic halides
and total phenols, as well as traces of benzene, ch10robenzene,
1,1-dich1oroethane, and vinyl chloride.
. 50i1 core samples collected in the aquitard at depths between 31 and 88
feet below the ground surface (elevations -11 feet and -68 feet MSL,
respectively) revealed no apparent vertical migration of the contaminants
mentioned.
(TOX),
Similar contamination in the background monitoring well as in the onsite
monitoring wells indicates that contamination in the lower aquifer is
not from the Sikes site. This assumption is reinforced by the lack of
evidence indicating a mechanism through which contamination of the lower
-------
-~i
o MONITOR WELL
* BORING & MONITOR WELL
. SOIL BORING
)40(50
. ';"',.. 'IV 84"n..
.-.,.... .'.... I....... rVu
RIVERDAlE
. SUBDIVISION
nm DEFIN ITE
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Figure 4
SHALLOW GROUNDWATER CONTAMINATION
SIKES DISPOSAL PITS
CROSBY, TEXAS
P'.p.,.d 10':
TEXAS DEPARTMENT OF WATER
RESOURCES
~n/ESE/ ~
PROJECT N,?~OO1
)
DATE: JIIN.. '985
)
)
-.
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12
The general surface water flow pattern at the site is southwest towards
the San Jacinto River. The drainage of the site is poor and generally
dominated by man-made features such as roads, sand pits, berms, ditches
and cu1 verts.
The main waste pit drains to the east into the overflow area via a ditch
and a 24 inch culvert. The overflow area acts as a runoff detention
area, releasing stormwater to the two drainageways located to the south.
These drainageways join and ultimately discharge to the San Jacinto River
just north of U.S. Highway 90. Contamination is carried along this
surface drainage path to the San Jacinto River. Surface water and sediments
along this drainage pattern exhibit decreasing concentration~ of TOX,
TOC, and total extractable organics (TOE) with distance from the main
waste pit and sludge overflow area.
The northern portion of the site, including the area around the small
waste pits, drains northwest toward Jackson Bayou. The small waste pits
are bermed with no outlet. Tank Lake has no defined outlet but drains
south across the road to the slough during periods of heavy rainfall.
TOE concentrations in sediments from Jackson Bayou indicate that some
transport and deposition of contaminants is occurring along the drainage
. pattern in the northern portions of the site.
Because the site is in the floodplain of the San Jacinto River, it is
frequently inundated by floodwaters. In the past 20 years there has
been flooding, including major ones in 1969, 1979 and 1983. The effects
of flooding on contaminant migration include surficial transport and
deposition of cohtaminants. In the past, floodwaters have deposited
large quantities of waste in various areas of the.-site. Most notable
of these areas is the 8 acre sludge overflow area.
Floodwaters move across the site in the patterns shown on Figure 5.
Several residences in the western portion of the Riverdale Community are
located in the path of the floodwaters. However, soil samples collected
in the Riverda1e area exposed to floodwaters indicate that no significant
deposition of contaminated soils and sediments has occurred.
Two possible pathways exist for airborne contamination at the Sikes site.
Truck traffic travelling along the A and B Sand Company Road across the
overflow area approximately 150 to 300 feet east of the main waste pit
raises dust particles possibly contaminated by wastes. Wind may.
potentially transport dust particles offsite. However, because the dust
appears to settle quickly, the quantity of contaminated dust particles
-------
..
RlVERDAlE
SUBDIVISION
-- - TItANSmCIN MfA:
RON Dnt£CTICH VMI£S
DEPUONG ON CONDITIONS
.
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300 M...,.
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200
Figure 5
ROOD ROW PATTERNS
MAY 24,1983
SIKES DISPOSAL PITS
CROSBY. TEXAS
pr.p.red 'or:
TEXAS DEPARTMENT OF WATER
RESOURCES
~n/ESE/~
)
OAT(: Wf. '''''5'
PRonCT Nr
'JO 0111
'"
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14
The second airborne contamination pathway is by volatilization of organic
compounds in the wastes. Preliminary screening of air quality around the
site indicated that if left undisturbed volatilization of organics is
minimal. However, volatilization may be catalyzed by rainwater in the
hot summer months. Short term rains that evaporate quickly appear to
produce higher than normal readings.
Target Receptors
The following target receptors were identified in the remedial investigation:
o
Members of the Sikes family, who live on the site;
o
residents in the western portions of the Riverda1e community;
o employees of the nearby sand mining operations;
o people who use potentially contaminated sands from the Love Sand Pit;
o sport fishermen that frequent Jackson Bayou and the San Jacinto River;
o persons who make unauthorized or inadvertent entrance to the site;
o Southern Pacific Railroad maintenance personnel; and
o boaters and skiers on the San Jancinto River.
Results of the RI study indicate that remedial action is required to
reduce the potential for pub1tc health exposure through:
o Direct contact with sludges and contaminated soils;
o consumption of contaminated groundwater;
o direct contact with contaminated surface waters; and.
i
I
~
~
~
o
inhalation of toxic organic compounds through uncontrolled disturbance
of the waste.
Enforcement Analysis
Approximately 10 potentially responsible parties (PRPs) have been identified
for the site. PRPs for the Sikes Disposal Pits site consist of t~e
owners, the Sikes family, in addition to several corporations, designated
as either generators or transporters. At the present time, the Sikes
family is the only PRP to indicate inability to fund any portion of the
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15
At the termination of the investigative proceedings, all identified PRPs
will be offered the opportunity to voluntarily implement the preferred
remedy. If anticipated negotiations are unsuccessful, the Fund will be
utilized for cleanup of the site. However, no negotiations have been
initiated to date. If the PRPs decline to implement the remedy, EPA will
seek appropriate enforcement action.
One of the generators identified has acknowledged partial responsibility.
Two of the generators identified have requested additional information
from EPA on their status as a PRP. No task force has been formed yet.
Alternatives Evaluation
The Feasibility Study for the Sikes Disposal Pits site was performed to
de~ermine what actions, if any, would be appropriate as part of a permanent
remedy for the site. Several alternative remedial methods were developed
to mitigate damage to, and provide adequate protection of public health,
welfare, and the environment from past and future releases of contaminants
onsite.
The National Contingency Plan (NCP), 40 CFR Part 300.68(e)(2) states that
- "Source control remedial actions may be appropriate if a substantial
concentration of hazardous substances remains at or near the area where
they were originally located and inadequate barriers exist to retard
migration of substances into the environment." In accordance with the
NCP, and based on the (onclusions of the Remedial Investigation, a source
control remedial action is necessary at the Sikes Disposal Pits site.
The major threats to public health and the environment attributed to
contaminants at the site are:
1.
2.
3.
4.
5.
Direct contact with sludges and contaminated soils;
continued direct contamination of the upper aquifer;
potential contamination of the lower aquifer;
direct contact with contaminated surface waters; and
releases of toxic volatile organic compounds into the air,
uncontrolled disturbances of the waste.
through
Remedial Objectives
The Feasibility Study performed by Lockwood, Andrews and Newnam, Inc., in
July 1986, developed the following objectives and criteria based on the
results of the Remedial Investigation:
1.
Prevent human contact with contaminated soils and wastes.
Criteria: No direct contact with waste containing greater than
-------
16
2.
Minimize impact of contaminated runnoff.
Criteria: Surface Water Quality Criteria: a maximum of 0.1 mg/1
benzene, 0.3 mg/l vinyl chloride, 0.3 mg/l of total phenols, and metals
as per Section 156.19.15.002 of the Texas Water Code.
3.. Prevent human contact with contaminated surface water.
Criteria:
Surface Water Quality Criteria.
4. Minimize site related degradation of the San Jacinto River and
Jackson Bayou.
Criteria:
Surface Water Quality Criteria.
5.
Prevent use of contaminated groundwater (upper aquifer).
Criteria: Drinking Water Standards and Human Health Criteria
(10-4 to 10-7 risk range).
6.
Protect against contamination of the lower aquifer.
Criteria:
Existing background water quality in lower aquifer.
7.
Prevent migration of waste offsite during flood events.
Criteria:
Surface Water Quality Criteria.
8.
Prevent use of groundwater (lower aquifer) contaminated above
background.
Criteria:
Existing background water quality in lower aquifer.
9.
Minimize the potential of any adverse air discharge.
Criteria:
OSHA standards at site boundary, Federal Ambient Air Standards.
Initial Screening of Alternatives and Identification of Potential Remedial
iechnologies
Section 300.68(h) of the National Contingency Plan states that the following
broad criteria should be used in the initial screening of alternatives
and technologies:
j
,
1.
Cost. For each alternative, the cost of installing or implementing
~remedial action must be considered, including operation and'
maintenance costs. An alternative that far exceeds the costs of
other alternatives and does not provide substantially greater
public health or environmental benefit should usually be excluded
-------
17
3.
Effects of the Alternative. The effects of each alternative should
be evaluated in two ways: (i) whether the alternative itself or its
implementation has any adverse environmental effects; and (ii) for
source control remedial actions, whether the alternative is likely
to achieve adequate control of source material, or for offsite
. remedial actions, whether the alternative is likely to effectively
mitigate and minimize the threat of harm to public health, welfare,
or the environment. If an alternative has significant adverse
effects, it should be excluded from further consideration. Only
those alternatives that effectively contribute to protection of
public health, welfare, or the environment should be considered.
Acceptable Engineering Practices. Alternatives must Qe feasible for
the location and conditions of the release, applicable to the problem,
and represent a reliable means of addressing the problem.
2.
Identi.fication of Response Actions and Applicable Technologies
In the screening process, only technologies applicable to the following
objective response actions were considered:
1.
2.
Removing and disposing of sludges and contaminated soils;
removing and treating (if necessary) surface waters; and
3.
groundwater restoration.
Table 4 lists the technologies initially screened and their applicability
to the site.
No air emission control/abatement technologies are presented since air
pollution is not a significant problem at this time. Air emission
control/monitoring technologies will be considered as part of the health
and safety plan for remedial action, since excavation could cause air
releases.
Development of Site Remedial Alternatives
The alternative technologies which were retained after the initial
screening proc~ss were combined into remedial alternatives for a permanent
remedy at the site. Twelve remedial alternatives plus the no-action
alternative were formulated for mitigating the problems at the Sikes
Disposal Pits site. The prescreened alternatives are described in Table 4.
All alternatives listed in Table 5 are composed of the following common
elements except the No Action alternative (FS Alternative 13).
1)
2)
Discharge surface waters to river or treat
as necessary to meet discharge criteria.
Ban use of upper aquifer onsite while restoring
upper aquifer to Drinking Water Standards
or (10-4 to 10-7 range) Human Health Criteria.
-------
TABLE 4
SUMMARY REVIEW OF TECHNOLOGIES
SIKES DISPOSAL PITS
Technology
Applicability (1)
Comments
Removal/Disposal Treatment of Sludges and Contaminated Soils
Waste Removal Technologies
Dragline/Dozer/Backhoe
A
Applicable in combination with
other technologies that treat or
dispose of waste.
Hydraulic Dredging
NA
Would produce large volumes of
contaminated, possibly emulsified
water. .
Waste Disposal Technologies
RCRA Landfill
A
Applicable for onsite and offsite
disposal in combination with
excavation.
Non-RCRA Landfill
(slurry walls and caps)
A
Applicable for onsite disposal
on ly .
Waste Treatment Technologies
Biodegradation
A
Biological land application has a
high potential for surface water
contamination. It is also not
feasible due to the large volume
and type of waste and limited
surface area. Other biodegradation
methods are not considered proven
technologies.
Fixation
A
Applicable to offsite and onsite
treatment in combination with
excavation technology. Rotary
kiln is the most appropriate for
treating solid wastes.
Applicable with excavation and
landfill technologies.
Incineration
(Rotary kiln, fluidized bed,
multiple health)
A
Stabilization
A
Applicable to sludges with onsite
landfilling.
(1) A = applicable major technology
a = applicable minor technology, used in conjunction with major technologies.
-------
TABLE 4 (CONT.)
SUMMARY REVIEW OF TECHNOLOGIES
Technology
(1)
App 1 i cabil i ty
Comments
Surface Water and Groundwater Treatment
Physical Treatment Technologies
Air Stripping
A
Applicable to volatile
contaminants.
Activated Carbon
A
Applicable to non-polar
contaminants.
Fil trat ion
a
Applicable with other treatment
technologies.
Not applicable due to quantities
involved and cost.
Membrane Filtration
NA
Biological Treatment
Activated Sludge
NA
High cost with poor removal of
trace organics.
Aerated Lagoons
NA
High cost with poor removal of
trace organics.
Chemical Treatment
Oxidation
NA
High cost with bench scale testing
required.
.,
..'""
Neutral ization
a
Applicable to some groundwater
contamination with other treatment
technologies. Not suitable for
removal of organic contaminants.
Hydro lys is
NA
High cost with bench scale testing
required.
Produces only a partial treatment
and requires bench scale testing.
Ultraviolet/Ozonation
NA
Natural Flushing
A
Applicable to the upper aquifer
on ly .
(1)
A = applicable major technology
a = applicable minor technology, used in conjunction with major technologies.
-------
20
These twelve alternatives were then screened according to the guidelines
given in the NCP, especially 40 CFR 300.68 (g). The objective of the
screening process was to narrow down the twelve remedial alternatives to
a smaller list of potential remedial alternatives for further detailed
analysis.
Each remedial alternative was evaluated for the following specific criteria
which includes technical feasibility, environmental and public health
factors:
o Performance
o Reliability
o Engineering Implementability/Constructability
o Public Health and Welfare
o Environmental Impacts
o Institutional Factors
o Costs
Cost estimates and brief descriptions of the englneering feasibility, and
effectiveness, as well as screening results are also summarized on Table 5.
The rating system that was used for the non-cost screening of alternatives
is described below:
Rating Symbol
Definition
Extremely negative effects, even with mitigating
measures. Alternative not worth further
consideration in this' category.
Negat i"ve effects, but not- st rong enough to be
sole justification for eliminating an alternative;
or only of moderate negative effects.
o
Of very little apparent positive or negative
effects, but inclusion can be justified for
some special reason; or no change from existing
conditions.
++
A positive or moderately positive benefit.
An extremely positive benefit.
+
Detailed Evaluation of Alternatives
Based upon the screening process, six alternatives were retained for
detailed evaluation in accordance with the HCP, 40 CFR 300.68(h). These
alternatives were selected to demonstrate a reasonable range of remedial'
-------
,>,,..1110..,..._>
TA81.E S
INITIAL At.TERNATIVES SCREENING SUMMARY
SIKES DISPOSAl. PITS SITE
Errectiveness
Shallow Groundwater
F.nj;lnccrlnR
Effectiveness Feaslhll ity
Re 1. Cost
(Sm
Retained for
further Eval.
AllcrnaU YC
Sludges" ContAminated Soils
EnRlneerlnR
Feaslbillty
1. Slud~c9: Offslte RCRA Landfill
Soils: Offsltc RenA Landfill
2. nlu,l~es: Offsite Incineration
SoUs: Fix & backfill
Ash: Offslte RcnA Landfill
3. nludges: Offsite RCRA Landflll
50118: FIx & backfill
4. tiiudgel: On-site incineration
So J Is: On- s Ilc RCRA tand fill
Ash: Fix & backfill
5. nIudp,e: On-sile II1c1neraUon
Snlls: Fix & backfill
Ash: Fix & backfill
6. Sh,d~c9: On-sile Incineration
Soils: Off-site RCRA Landfill
Ash: Fix & backfill
7. SludRe:
5011 s:
On-site RCRA Landfill
On-site RCRA Landfill
8. mlJ(l~es: On-site RCHA Landf111
Solts: Fix & backftJl
9. S\ud~e: On-slt.e Incineration
Solis: Off-site ReRA l.andftl1
Ash: Off-site RCRA l.andfltl
10. nlllll~e: (In-slle Incineration
So 11 s: On-slt.e I nc I nerst Ion
II!;": hackflll
11. S I III I p,c : On-s I t.e "on- HCRA Landi 111
Sui Is: t'lx & hackflll
12. SludRe:
5 t. S:
Slurry walll , Cap
Fix and backfill
11. No Action
+ + + + 93-143
+ + + + 7)-103
+ + + + H-83
+ + ~J-12
Yrs
"0
+ + + + )J-S3 y"s
+ + + + 1)-11) Yrs
+ + H-63 "0
+ + 38-43 "0
++ + ++ + 108-163 "0
+ + + + 43-68 Yes
o
o
))-43
o
+
o + 2J-28 Yes
0-.4 Yes
RaLionaie
"0
C05tly;Risks durlnR transport.
1115(1U581 cApAcity IMY not be avallahlr, ,
Incinerator capacity may not be available.
Hore costly than other eqllttahle altern-
atives. Risks durlnR transport.
Provides protecllon f'qun I to 1I1I.er-
vnt.lve 2 at less cost. Risk durlnj;
10nR transport.
~Iorr cuslly lhan Alternatlv(' 10 vi t.h
no Atld III onR I prot"e lion; f, Itr renvtl n5
closrd. v/lomlflll on-sl t.e IMJor I.pch-
prClblrms; e.g. sl7.e, locnllnn, spll.lr-
""~lIt, subject to floodlllK erosion.
"0
\.Jt:05troys worst contamlllAnts. Imml'hll-
hes rest. HIp-hI. provide equnl clrAllup
('ffeel os lot.ol Inclnrrath'n. Nu transpnrt
r 1!Jks.
1!I'sl.roys worst contaminants. R1!Jk
durlnp; trnnsport, but less than for
Alternative 1, 2, 3.
HnJor technical problems; sl7.e,loca-
tlon, settlrmcnt subject to flo~lln~
erosIon. Hny require lonl': term monl-
torln". RIsk of liner failure.
Greater risks than Alternative 4.
Slmltar technical problems as Alt. 4,1.
tess r1!Jks than AlL 7) No transport risks.
CO!;lIy; 1115posol CRpRC ty IMY not. h..
avo Ilnhle. I,('nl(lhly trRn5rort time
. vi I.h altendnnt exrosure risk!':.
"0
l~stroY5 or rend('rs vnsles ('ffeet.lvely
nun-hn7.Rrdolls. Onlyl.olnl desl.ruel.lnn
nll.prnAlIve. "0 lonl( tcrm mnnl'.r,..llI~
dUP 1.0 d I SpOSR I opll on chosrn. J.onRer
cleanup time. No transport rlsk~
"h,)or t.eehnlcnl probl('m!;; r.p;. 517.('
locntlon, selll"""'lIt, 511b,)...... 1.0 flouls.
"'"sIr ,'('m.'\11I In 11"55 I.hAII 1117 II A frwlJII.Y.
J."nR terlll monltorlllR required.
Contains or Immobilizes wastes.
Requires 10nR term monltorlnK
Inspection and maintenance.
-------
22
All the alternatives retained for detailed analysis, except the No Action.
Alternative, include natural flushing of the upper aquifer as the restoration
technique. Contamination of groundwater in the upper aquifer attenuates
due to the effects of advection, dispersion, and biotransformation as the
distance from the contaminant source increases. Also, approximately
572,000 gallons per day of uncontaminated groundwater flows into the
aquifer under the site (which itself contains about 271 million gallons)
towards the San Jacinto River or Jackson Bayou. The aquifer water entering
the river or bayou meets the Surface Water Quality Criteria because of
significant dilution by the clean groundwater.
To meet the objective of Human Health Standards (10-4 to 10-7 range) or
Drinking Water Quality in the aquifer under the site, removaJ or isolation
of the source of contamination has to be accomplished. With the limited
sources of contamination remaining infiltration and flushing would
effectively attenuate this aquifer to a 10-5 Human Health Risk in less
than 30 years.
Alternative 1 (FS Alternative 13) No Action
Section 300.68(f) of the National Contingency Plan (NCP) specifies that
the "No Action" alternative be evaluated. Under this alternative no
construction activities are implemented. This means the site remains in
. its present state and continues to pose a risk to public health and the
environment.
Periodic monitoring of the upper and lower aquifers is ongoing to
detect changes in upper aquifer contamination and areal extent, and in
lower aquifer water quality.
~
Alternative 2 (FS Alternative 3) Offsite RCRA landfilling of Sludges,
Onsite Fixation of Soils.
Alternatives 2 through 7 contain several supporting work tasks (referred
to as common components) that will not be repeated under each alternative
description. These include:
I
4
f
o Perimeter fence;
o protecting the site against flooding;
o stormwater run-on and run-off collection/disposal
system; and
o pit surface water/infiltration water collection
and treatment system.
It should be noted that for costing purposes the most conservative approach
to flood protection (i .e., perimeter diking) was used, however the exact
nature of flood protection to be used will be determined during the design
phase. Also, for alternatives which involve incineration, fixation of
residue ash was assumed for costing purposes, though this may be eliminated
-------
23
This alternative includes the excavation of sludges to the 100 ppm polynuclear
aromatic hydrocarbon (PNA) criteria level and contaminated soils to the 10
ppm volatile organic aromatic (VOA) criteria level. The sludges are then
trucked offsite to an EPA approved RCRA landfill. The contaminated soils
are chemically fixed with a cement based agent and utilized as backfill
onsite. Use of the contaminated upper aquifer is banned onsite until
restored to drinking water quality through natural flushing. Both the
upper and lower aquifers are monitored following completion of remedial
action and continued for up to 30 years, if needed.
Alternative 3 (FS Alternative 5) Onsite Incineration of Sludges, Fixation
of Soils and Ash
For this alternative, sludges are excavated to the 100 ppm PNA criteria
l~vel and contaminated soils to the 10 ppm VOA criteria level. The sludge
organics are then destroyed by onsite incineration while the ash and
contaminated soils are chemically fixed with.a cement based agent and
utili2ed as backfill onsite. Use of the contaminated upper aquifer is
banned onsite until restored to drinking water quality through natural
flushing. Both the upper and lower aquifers are monitored following
completion of the remedial action and continued for up to 30 years, if
needed.
- Alternative 4 (FS Alternative 6) Onsite Incineration of Sludges, Offsite
RCRA Landfilling of Soils
This alternative includes excavation of sludges to the 100 ppm PNA criteria
level and soils to the 10 ppm VOA criteria level. Sludges are then
incinerated onsite and contaminated soils trucked offsite for disposal at
an EPA approved RCRA landfill.- Incinerator ash is chemically fixed onsite
using a cement based agent. The resulting solid is used as backfill. Use
of the contaminated upper aquifer is banned onsite until restored to drinking
water quality through natural flushing. Both the upper and lower aquifers
are monitored for up to 30 years following completion of the remedial.
action. .
Alternative 5 (FS Alternative 10) Incineration of Sludges and Soils
For this alternative sludges and soils are excavated to the 10 ppm VOA
criteria level, combined and incinerated onsite. The ash is tested, and
if appropriate used as backfill. Use of contaminated upper aquifer water
is banned onsite until restored to drinking water quality through natural
flushing. Both the upper and lower aquifers are monitored for up to 30
-------
24
Alternative 6 (FS Alternative 12) Cap and Slurry Wall
This alternative involves dewatering of the main waste pit and Tank Lake.
Sludges are excavated to the 100 ppm PNA criteria level and placed in
these two pits. Prior to dewatering and excavation, a slurry wall is
placed around both pits and tied into the upper aquitard. Following
transfer of sludges into these pits, a geomembrane and clay cap are placed
over each pit and tied into the slurry walls. Contaminated soils are
then excavated, chemically fixed and the solids utilized for onsite
backfill. Use of the contaminated upper aquifer water is banned onsite
until restored to drinking water quality through natural flushing. Both
the upper and lower aquifers are monitored for up to 30 years following
completion of the remedial action. Information, including cost estimates
on all these alternatives, are summarized in Table 6.
Community Relations
Public interest in the Sikes Disposal Pits site initial project phases
has been minimal, except during periodical flooding of the site.
In May 1983, when the flooded San Jacinto River inundated the site, local
residents voiced their concerns over possible contamination of their
. neighborhoods from the flood waters.
Public interest increased upon completion of the Feasibility Study. The
two week public notice period began on July 14, 1986. This was followed
by a 21-day public comment period from July 30, 1986, to August 20, 1986.
A briefing of local officials, primarily Chamber of Commerce members
from Crosby, Texas, was held August 7, 1986. A public meeting was held
later in the same day, with approximately 120 people attending.
With a few exceptions, incineration (EPAs preferred alternative) appeared
to be acceptable as long as wastes only from Sikes were incinerated at
the site, and adequate controls were used to prevent upsets and pollution.
Responses to the comments received during the comment period are presented
in the IICommunity Relations Responsiveness Summaryll attached to this
Record of Decision.
Consistency with other Environmental Laws
It is EPA policy to give primary consideration to remedial actions that
attain or exceed applicable and relevant standards of other Federal public
health and environmental laws. Environmental laws which will have an
impact on the proposed remedies for the Sikes Disposal Pits site are
summarized on Table 7. Provisions of the applicable and relevant or
appropriate requirements of these laws are summarized in Table 8.
Recommended Alternative
Section 300.68(i) of the National Contingency Plan states that lithe
appropriate extent of remedy shall be determined by the lead agency's
selection of a cost-effective remedial alternative that effectively
mitigates and minimizes threats to and provides adequate protection of
-------
Remedial
AHernat ive
, TAOLE 6
SUMMARY OF DETAILED [VALUATION or REMEOIAL ALTERNATIVES
SIkES DISPOSAL PITS SIT£
Pubtic Health
Considerations
Present Worth Cost ($M)
Implenentat ion O~M
3 - Off-Site RCRA Land-
filling of Sludges.
On-Site Fixation of
Contaminated Soils.
5 - On-Site Incinera-
tion of Sludges.
Fixation of Con-
taminated Soils
and Ash.
6 - On-Site Incinera-
tion of Sludges,
Off -Site RCRA
Landfi11tng of
Contaminated Soils,
On-Site Fixation
of Ash.
10 - On-Site Inciner-
ation of Sludges
and Contaminated
So 11 s .
12 - On-Site 8urial
of Sludges in
Pits with Slurry
Wa 11 s and Caps.
Fixation of Con-
taminated Soi1s.
13 - No Act ion
56.0
53.8
111.3
92.9
23.4
0.4
0.4
Removes direct contact
or ingestion hazard.
low cancer risk. Use
of upper a~uifer banned
until restored. Trans-
portation risks.
Removes direct contact
or ingestion hazard.
low cancer rhk.Use
of uPller aquifer banned
until restored.
,
0.4
Removes direct contact
or ingestion hazard.
Very low cancer risk.
Use of upper a(lui fer
banned until restored.
Reduced transportation
risks than Alt. 3.
0.4
Achieves maximum pro-
tection against direct
contact or ingestion
hazard. Very low
cancer risk. Use of
upper a~uifer banned
until restored.
1.3
Removes direct contact
or ingestion hazard.
low cancer risk. Use
of upper a~ulfer banned
unti I res tored.
0.4
Continued potential
for direct contact on-
site and off-site.
Potential Ingestion
hazard on-sHe.
Environmental
Considerations
------------
Removes or isolates
waste. Promotes
a~uifer restoration.
Potential for leach-
inq from fixed soils.
least time to implenent.
Ren~ves or Isolates
waste. Promotes
aquifer restoration.
Potential for leach-
InQ from fixed soils.
longer Implementat ion
tine than Alt. 3 & 12.
Destroys or removes
waste. Promotes aqui-
fer restoration.
lonqer implementation
tin~ than A H. 3 and
12.
Destroys organic waste
on-site. Provides
greater protection
against potential
aquifer contamination
than Alt. 3. 5 and
12. longer Implenent-
ation time than other
a Herna ti ve s .
Wastes Isolated or
inll10billzed but not
destroyed. leaching
potenlial greatly
reduced, although
sludges left on~site.
Wasles remains in
p I ace. Conl i nlled
pOlential for (on-
tamin.1t ing lower
aqlli fer. Upper
aqulfl'r remains un-
suil.lhle for uSP.
Technical
Considerations
Institutional
Cons id~r!l-.! i.!>I1~_-
Demonstrated tech-
nolo~y effectiveness
if fixation is
effective.
Demonstrated tech-
nology effectiveness
if fixation is
effective.
Demonstrated tech-
nologies. More
rei iable.
Demonstrated tech-
nologies used.
Maximum reliability.
Not totally demon-
strated technology.
System fat1ure
possible. Continued
maintenance required.
Collection and disposal
of leachate required.
Not applicable.
'Oannlng use of llpper
Aquifer continued.
Long term grollndwater
monitoring refluirf'!d.
Longtenn monilorilHI
may affecl sHe use.
Use of Upper Aqui fer
banned. Longlerm
groundwaler moniloring
re~uired. longlerm
monHodng may affect
s He use. .
Use of llpper Aqul fer
banned. Longterm
groundwater monitoring
required. longterm
n~nitoring may affect
site use.
Use of Upper Aquifer
banned. lonQlerm
groundwater n~nitoring
required. Long term
n~nitorinQ may affect
s He use.
Use of Upper Aquifer
banned. lomllerm
monitoring required.
Use of land area
prohibited.
Direct contact and
ingestion hazards
-------
TABLE 7
REMEDIAL ALTERNATIVE COMPLIANCE WITH APPLICABLE
OR RELEVANT AND APPROPRIATE REQUIREMENTS
Remedial Alternative No.
law or Regulation Analysis 3 5 6 10 12
- - -
Federal Water Quality Implementation of this alternative X X X X X
Criteria (FWQC) should result in compliance with FWQC
in groundwater.
Floodplain Management Implementation of this alternative will X X X X X
Executiv.e Order No. 11988 be consistent with Floodplain Management
May 24, 1977 requirements as ,prescribed in Executive
Order 11988.
State
-
Texas Water Commission (TWC) Implementation of this alternative will X X X X X
Surface Water Quality produce a point source discharge. The
Criteria (SWQC) discharge will be treated on-site as
necessary to satisfy' State SWQC.
,
Texas Air Control 80ard Implementation of this alternative may X X X X X
Regulations produce a point source emission from
on-site equipment. Emissions will be
in compliance with State regulations.
Texas Solid Waste Act Implementation of this alternative would X. X
require the transport and disposal of
waste off -s i te. Transport and disposal
wi 11 be in compl iance with State requirements.
Local
Loca 1 Approva 1 S . local agency approval for implementing this X X X X X
-------
TABLE 7
REMEDIAL ALTERNATIVE COMPLIANCE WITH APPLICABLE
OR RELEVANT AND APPROPRIATE REQUIREMENTS
Remedial Alternative No.
Law or Regulation Analysis 3 5 6 10 12
Federal
Resource Conservation and Implementation of th~ source controls X X X X
Recovery Act (RCRA) for this alternative will be consistent
with current RCRA regulations, including
standards for owners and operators of
hazardous waste treatment, storage and
disposal facilities and closure perform-
ance standards for faci11tles located
within a IOO-year f oodp aln.
Department of Transportation Implementation of this alternative does X X X
(DOT) Hazardous Materials not specifically require the off-site
Transport Rules transport of hazardous materials.
Implementation of this alternative requires X X
the off-site transport of hazardous mater-
ials. Transport will be in compliance with
these rules, including use of properly
constructed and marked transport vehicles~
use of licensed transporter, and use of
hazardous waste manifests.
Clean Air Act (CAA) and Implementation of this alternative may X X X X X
National Ambient Air Quality result in the emission of pollutants
Standards (NAAQS) into the air. On-site personnel will
be adequately protected.
Implementation of this alternative will X X X X X
require point source emissions to the air.
Pollution control equipment will be placed
on the on-site treatment facility to
-------
TABLE 8
PROVISIONS OF APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS
Page 1 0 f 3
RCRA Part 264
Subpart B - General Facilities Standards
Requires that facilities located in the 100-year
floodplain be designed, constructed. operated and
maintained to prevent washout of any'hazardous
waste by a 100-year flood.
o Could be applied to anyon-site landfill which would
be constructed in the future to dispose of wastes.
Subpart E - Manifest system, recordkeeping. and reporting
o Hazardous waste manifesting procedures would be required
if any waste is transported to an off-site TSD facility.
Subpart F - Groundwater Protection
o Requires that levels of hazardo~ constituents (40 CFR.
Part 261 Appendix VIII) in the uppermost aquifer at the
point of compliance (generally site boundary) meet
limits set by U.S. EoPA as:
1) Background, or
2) Maximum Contaminant levels (MCLs), or
3) An alternate concentration limit (ACL) posing no
present or future hazard to human health or the
environment.
o
Will be more fully addressed in Upper Aquifer restoration.
Subpart G - Closure and post-Closure
"
Requires closure in a manner that minimizes the need for
further maintenance and prevents future release of
contaminants.
o Could be applied to in-place capping of wastes or closure
of anyon-site landfills constructed as part of the
-------
TABLE 8
PROVISIONS OF APPLICABLE OR RELEVA~T AND APPROPRIATE REQUIREMENTS
Page 2 of 3
Subpart N - Landfills
Requires that RCRA compliant landfill~ be double-lined
and contain leachate collection and leak detection
systems; does not allow placement of liquid, ignitable,
or reactive wastes in landfill; also provides specific
closure requirements.
o
Could be applied to anyon-site landfill which would be
constructed in the future to dispose of wastes.
Subpart 0 - Incinerators
Requires detailed waste analysis and trial burns on
incinerator before operations commence and on-line
monitoring during operation.
o Would apply to anyon-site incineration.
Maximum Contaminant Level for Drinking Water (MCLs):
141.11 - 141.16
40 CFR Section
Sets water quality standards for several metals and
compounds based on health protection.
o MCL values must be met for Upper Aquifer restoration.
Clean Water Act:
40 CFR Section 301 and 403
Requires NPDES permit for discharge of treated water to
natural surface water systems
Occupational Safety and Health Standards:
29 CFR 1910
OSHA sets standards for protection of workers.
o Would be applied to site workers during any remedial
action; some standards may be considered in developing
safe exposure levels (in air for example) for near
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TABLE 8
PROVISIONS OF APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS
Page 3 of 3
Clean Air Act:
42 U.S.C. 7401
Regulates primary air pollutants; does not address volatile
organics or most toxics in air. .
o Application to site limited, possibly applies during
remedial actions involving waste excavation.
D.O.T. Rules for the Transportation of Hazardous Materials:
Parts 107, 171.11 - 171.500
49 CFR
Regulates the transport of hazardous wastes through licensing
of qU3lified transporters.
Regulates hazardous waste manifesting system.
Regulates transport placarding.
EPA Groundwater Protection Strategy
Ranks aquifers in the order to be protected:
Class
Class
Class
I - sole source aquifer
II - usable aquifer, other supplies available
III - water unfit for consumption (due to high
salt content for example), or aquifer
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31
Alternative 5 (FS Alternative 10) is the recommended alternative
for the Sikes Disposal Pits site. Costs for this alternative are summarized
on Table 9. This alternative consists of:
- Flood protection during remedial action;
- Storm water run-on and run-off collection system;
- Excavation of 150,000 cubic yards soils and sludges with greater than
10 ppm VOA's;
- Onsite incineration of excavated sludges and soils;
Onsite disposal of residue ash;
- Backfilling of pits and excavated areas;
- Collection and treatment, if necessary of contaminated surface water;
Natural restoration of upper aquifer; and
Post closure monitoring of upper and lower aquifer.
The rationale for selection of Alternative 5 (FS Alternative 10) is
as follows:
Alternative 1 (FS Alternative 13 - No Action) was eliminated because the
site would remain as it is, continuing to pose a risk to public health
and the environment.
- Alternative 2 and 3 (FS Alternatives 3 and 5 - Fixation of soils on-site)
were eliminated because adequate protection of public health and the
environment would not be provided.
Soil fixation at this site poses several problems. For one, the
effectiveness of soil fixing in preventing contaminant leaching is
questionable when organics relatively high in solvents, such as those
present at Sikes, are involved. In addition cert~in site factors
increase the risk of leaching from any fixated soils. These factors
are a high water table which lies only 10 feet below the surface, and
inundation from frequent flooding.
Taking this into consideration, while direct contact with contaminants
would be eliminated, there is the substantial potential for leaching from
the fixed soils. This~reduce~~he long-term integrity of these remedies.
Because of the high levels of contaminants remaining onsite, this would
not provide adequate protection of the upper aquifer, which needs 30
years to restore itself. This reasoning precludes the use of this
technology.
Alternative 4 (FS Alternative 6) was eliminated because transport and
off-site disposal of soils increases the cost of this alternative
$18,000,000 over the next less expensive alternative (Alternative 5,
EPAs preferred alternative). The increased cost is not justified by a
commensurate increase in protection because the waste is not being
permanently treated. Furthenmore, there is the risk of a transportation
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TABLE 9
COST SUIIMRY
REIIEDIAL ALTERNATIvE 10
ONSITE INCINERATION OF SLUDGES AND
CONTAIIINATED SO!LS,FIXATION OF ASH
SIKES DISPOSAL PITS SITE
!TEll
IIIPLEIIENTATION
CAPITAL 0 ~ II
POST
IIIPLEIIENT A TI ON
o ~ II
PRESENT
!lORTH
10%
-------------------------------------------------------------------------------------------
6ENERAL
"obilization and Delc~ilization 5113,000 Sl13\000
Office Area t $224,000 515,000 1210,000
Security t .500,000 .100,000 $'08.000
Environlental Permitting $300,000 .300,000
Health and Safety Progral ttt 1360,000 .40,000 1363,000
-Air "oni toring
-Report Generating
Dnslte Laboratory ttt S400,000 HO I 000 1350,000
-Operation and "alntenance,
Including Technicians
.
Parking FacilIty t .24,000 S2,000 S22,OOO
SITE PREPARATION
----------------
Road Construction t .83,000 55,500 $78,000
Deccntalination Facility tn $77,000 $13,000 S66,000
-Concrete Pad
-Water Storage Tank
-Steil Sprayer
-SUlp
Storl !later Collection Runo;; '450,000 '20,000 '433,000
and Disposal ttt
Surface !later/Infiltration !later '455,000 870,000 '397,000
Collection and Treatlent ttt
Dike Construction $1,526,000 Sl,526,000
Dike Ruoval $718,000 '718,000
Fencing and Lighting $126,000 5126,000
Clearing and Grubbing 586,000 '86,000
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TABLE 9 CO~T.
EXCAVATIDN,INCINERATION AND DISPOSAL
----------------------------.-.-----
ExCiVit! Wistes
'1,127,000
Sheet Piling
'379,000
Incinerator:
-"obilization and Delobilization of
Onsite Incineration Unit
'1,825,000
-Construct Drying/Holding Pad ttt
'66,000
-Load Incinerator ttt
'1,112,000
'4,000
'278,000
-Annual Op~ration and ~aint. Costs ttf '38,880,000 '9,720,000
D~watering and Storage '25,000
Fixat10n of Incinerator Ash ttt '3,596,000 '899,000
Backfill and R~v~getate $585,000
GROUNDRATER ~ON!TORIN6 tt '58,000
----------
CONSTRUCTION SUBTOTALS " '53,293,000
BID CONTIN6ENCIES 1151) '7,994,000
-
SCOPE CONTIN5ENCIES (251) $13,323",000
----------
CONSTRUCTION TOTALS '74,610,000
PE~~ITTING AND LE6AL SERVICES
DURING CONSTRUCTION (51) '3,731,000
BONDING AND INSURANCE (101) '7,461,000
SERVICES DURING CONSTRUCTION (71) S~122~,OOO
ADDITIDNAL ITE~S (51) '3,731,000
TOTAL I"PLE"ENTATION COST '94,756,000
ENGINEERING DESIGN COST (101) $7,461,000
-------
TOTAL CAPITAL COST $102,217,000
t Annual 0 L " for 5.0 Years
tf Annual 0 L " for 30 Years
ttt Annual 0 ~ " for 4 Years
'1,127,000
'379,000
'1,625,000
'6;,000
'881,000
'30,811,000
'25,000
'2,a50,~00
'585,000
'41,000 '445,000
----------
$41 ,000 $44,385,000
$7,994,000
'13,323,000
----------
'65,702,000
'3,731,000
$7,461,000
'5,223,000
'3,731,000
$85,848,000
$7,461,000
----------
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34
Alternative 6 (FS Alternative 12 - Cap and slurry wall for sludges, soil
fixation) was eliminated because adequate protection of public health and
the environment could not be assured.
The same reasoning as outlined for alternatives 2 and 3 applies here for
soil fixation. In addition to this is the nearly impossible requirement
of maintaining the integrity of a cap in an extremely flood prone area.
This' alternative was eliminated for these reasons.
Consequently, Alternative 5 (FS Alternative 10 - Incineration on-site of
sludges and soils) complies with all applicable and relevant Federal
environmental laws and regulations.
Furthermore, it is the lowest cost permanent remedy that mitigates short
and long term threats to public health and the environment. The greater
protection afforded by this remedy justifies the additional cost.
Operation and Maintenance
Operation and maintenance will consist of post closure monitoring of the upper
and lower aquifers as well as surficial maintenance of the site once closure
is complete. Surficial maintenance includes such items as:
o Fence repair
o Fill replacement and regrading.
Besides the aforementioned, costs also include purchased services such as
sampling and laboratory analysis for groundwater monitoring, administrative
costs, taxes, insurance, labor, and materials.
The State of Texas will assume responsibility for operation and maintenance
of the site for a period of 29 years, commencing one year after the post
closure period begins.
Annual operation and maintenance costs for the recommended alternative is
estimated to be $41,000 and the present worth is estimated to be $445,000.
Schedule
The schedule for the remedial design and construction of the remedy at
the Sikes Disposal Pits site is currently dependent upon re-authorization
of Superfund. The design phase of the project will begin as soon as
funding becomes available, either through re-authorization or a continuing
resolution. When funding is available, the design of the remedy will
take an estimated 18 to 24 months to complete. Remedial construction will
begin as soon as possible after completion of the design, and take
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TEXAS WATER COMMISSION
Paul Hopkins, Chairman
Ralph Romins. Commissioner
John O. Houchins, Commissioner
/.~,;.~ror-A
II;" . ~~..'
/,1:..:"'. "'Jt;\
I'~ \ )" ',\
,~ 'rt:' ,..',
\~~~~~:~~. ii'~:)
Larry R. Soward, Executive Director
Mary Ann Hefner, Chief Clerk
James K. Rourke, Jr., Genera! Co-..nse:
september 15, 1986
Mr. Dick Whittington
u. S. Environmental Protection
Reqion VI
1201 Elm Street
Dallas, Texas 75270
Aqency
Re:
Draft Recor6 of Decision
Sikes Disposal Pits Superfund Site
Dear Mr. whittington:
We have reviewed the proposed Draft Record of Decision (ROD)
and responsiveness summary for the Sikes D1sposal Pits
Superfund Site.
We have no objection to the issuance of a ROD by the
Environmental Protection Agenoy (EPA). Before the State of
Texas can concur by providing its 10\ share of the cost for
the selected remedial alternative, the fiscal impact of this
action must be evaluated and SUbsequently coordinated with
state's budgetary process.
On a related matter, we would like to comment on the
obligation of State monies for a period of 30 years after
the remedial construction activities are complete. Such a
commitment by the State of ~exas may be a violation of
Article VIII, Section 6 of the Texas Constitution which
addresses the appropriation of money beyond a two year
period.
Sincerely yours,
~~
Larry R. Soward
Executive Director
.
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COMMUNITY RELATIONS RESPONSIVENESS SUMMARY
ON PREFERRED REMEDIAL ALTERNATIVE
SIKES DISPOSAL PITS, CROSBY, TEXAS
This community relations responsiveness summary is divided into the
following sections:
I.
Overview - This section discusses EPA's preferred alternative for
remedial action, and likely public reaction to this alternative.
II.
Background on Community Involvement and Concerns - This section
provides a brief history of site background and community interest
and concerns raised during remedial planning activities at the
Sikes Disposal Pits site.
I I I.
Summary of Major Comments Received During the Public Comment
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2
I.
OVERVIEW
In the presentation for the public meeting on August 7, 1986,
, EPA discussed the remedial alternatives which were examined in
the Feasibility Study, for .addressing the contamination at the
Sikes Disposal Pits site.
After the initial screening of the alternatives a detailed
evaluation was performed on the six remaining. Except for the
no action alternative, all met basic criteria for protecting
public health and the environment and all had common components,
including; natural flushing of the upper aquifer as a restoration
technique, a perimeter fence, protection of the site against
flooding, stormwater and surface water treatment (if necessary),
and discharge. The alternatives are:
1. No Action with Monitoring Est. Cost: $ .4 Mill i on
2. Offsite Landfill; Onsite Stabilization
of Soil s Est. Cost: $ 56 Mi 11 ion
3. Onsite Incineration of Sludges; Onsite
Stabilization of Soils Est. Cost: $ 54 Mill i on
4. Onsite Incineration; Offsite Landfill Est. Cost: $111 Mi 11 ion
5. Onsite Incineration of Sludges and Soil s;
Onsite Disposal of Ash Est. Cost: $ 93 Mill ion
6. Cap and Slurry Walls Est. Cost: $ 24 Mill i on
The corrective action proposed. by the EPA was Alternative No.5, Onsite
Incineration. The estimated cost of $93 Million includes annual
operation and maintenance costs of $41,000 ($445,000 over a ten-year
time period). Comments from the Crosby, Texas, Chamber of Commerce
favored this option, provided that the incinerated wastes were only
those generated at the Sikes site and not hazardous wastes brought from
other sites. The comments on the options, along with EPAls response to
each, are presented later in this document.
II. BACKGROUND ON COMMUNITY INVOLVEMENT AND CONCERNS
Site Background-
The Sikes Disposal Pits site is located on 185 acres, approximately two
miles southwest of Crosby, Texas in northeast Harris County. The area
surrounding the site is largely undeveloped with numerous active and
abandoned sand pits and low-lying swampy areas. The entire site lies
within the 100-year floodplain of the San Jacinto River, and portions
of the site lie within the 10-and 50-year floodplains. The dike around
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3
The Sikes Disposal Pits site began operation as a waste depository in the
early 1960s and closed in 1967. During this period, a variety of chemical
wastes from area petrochemical i.ndustries were deposited onsite in the sand
pits. Numerous drums of wastes were also left on the property. The site
was placed on the original National Priorities List in September 1983.
Major Concerns and Issues
Community involvement relating to the Sikes Disposal Pits site has been
relatively low from the time of active operation in the early 1960s to the
present. When the French Limited site located across Highway 90 from Sikes
began operation in 1966, local attention to the Sikes Disposal Pits and
French Limited sites increased. Shortly thereafter, residents in the
nearby Riverdale subdivision sent a telegram to then President Lyndon Johnson
concerning the waste dumping and their fruitless attempts to halt it. There
were fewer community complaints once indiscriminate dumping ceased. In May
1983, the San Jacinto River flooded and inundated the site, and the news
media focused attention on the potential environmental hazards caused by
the flooding. Local residents telephoned the Texas Department of Water
Resources (TDWR) now Texas Water Commission (TWC), District 7 office with
their concerns over the possibility of contaminated flood waters flowing
through the neighborhood. Other than concerns during flooding, community
involvement in the Sikes project has been very low.
Activities to Elicit Input and Address Concerns
The TDWR (TWC) conducted site investigations through a cooperative agree-
ment with the EPA pursuant to the Comprehensive Environmental Response,
Compensation, and Liability Act of 1980 (CERCLA).
In order to accomplish site investigation activities and to provide safety
for the Sikes family who resided on the site, the Texas Department of
Emergency Management moved the family i~ March 1983, to travel trailers
provided by the Federal Emergency Management Agency (FEMA), which were
placed at a location on the property removed from EPA activity.
III. SUMMARY OF PUBLIC COMMENTS RECEIVED DURING PUBLIC COMMENT PERIOD AND
AGENCY RESPONSES
The public comment period on the preferred remedial action alternative
for the Sikes Disposal Pits site extended from July 30 to August 20, 1986.
A public meeting took place on August 7,1986, in the Crosby High School,
Crosby, Texas. Approximately one-hundred thirty (130) people were in
attendance with twenty-two (22) people making oral statements or asking
questions. Eight written statements were received during the comment
-------
4
In addition to the public meeting, a briefing was held for local officials,
primarily composed of the Crosby Chamber of Commerce, on August 7, 1986.
The preferred remedial alternative was presented, and appeared to be acceptable,
provided no wastes, other than those generated at Sikes, be incinerated at
the site.
Comment 1
Will wastes from other Houston area hazardous waste sites be incinerated at
Sikes?
EPA Response
No. This alternative was not a part of the Remedial Investigation and
Feasibility Study (RIfFS), and therefore, no waste from any other site was
considered for incineration or disposal at Sikes.
Comment 2
Opposition to incineration onsite was stated. Citizens were concerned
about adequate protection of their health and safety, and whether the
incinerator would be a permanent fixture. Questions were also asked about
.the type of incinerator and operating parameters.
EPA Response
The design of the incinerator and operating parameters will be established
during the remedial design phase, which is the next step after remedy
selection. The incinerator will be designed to meet all applicable Resource
Conservation and Recovery Act (RCRA) and Toxic Subs~ances Control Act
(TSCA) requirements. The contract for construction and operation will
require the incinerator to meet technical requirements for permitting,
although the incinerator will not have to be permitted. The requirements
include, at a minimum, that a trial burn be conducted to confirm that the
wastes, including PCBs, can be destroyed to required levels. While in .
operation the incinerator will be continuously monitored to ensure compliance
with these criteria.
The incinerator will also be designed with built-in controls, which
will shut down the facility automatically should any burn parameter,
such as feed rate, temperature, or emissions, move out of the optimal
operation range. By designing the incinerator in this way the chances
of an uncontrolled hazardous emission will be minimized. The incinerator
will be a temporary facility and will be removed at the completion of the
Sikes remedial action.
Comment 3
Fumes from an incinerator would be held down by heavy fogs causing local
-------
5
EPA Response
The operation contract for the incinerator will be written such that
during any atmospheric event that would prevent dispersion, feed to the
incinerator will be stopped.
Comment 4
The property values around Sikes will be depressed by incineration at
the site.
EPA Response
Property values around Sikes are already depressed due the presence of
an uncontrolled hazardous waste site. By cleaning up the site permanently
this will no longer be the case. It is hoped that once remedial action
is completed at Sikes the surrounding property values will return to
normal.
Comment 5
Several local residents and three Potentially Responsible Parties (PRP's)
questioned why Alternative 12 (cap and slurry wall for sludges, fixation of
.soil) was not preferred by EPA since it appears to cost much less than the
preferred alternative ($23.4 million versus $92.9 million).
EPA Response
Alternative 12 does not meet the criteria of Section 300.68(i) of the
National Contingency Plan which states that "the appropriate extent of
remedy shall be determined by the lead agency's selection of a cost-
effective remedial alternative that effectively mitigates and minimizes
threats to and provides adequate protection of public health and welfare
and the environment."
A cap is not a viable long term remedy because the area is extremely
flood prone.
The application of soil fixation at this site also poses several problems.
For one, the effectiveness of soil fixing in preventing contaminant
leaching is questionable when organics relatively high in solvents,
such as those present at Sikes, are involved. In addition, the water
table (only 2 to 10 feet below the surface) and inundation from frequent
flooding increases the risk of leaching contaminants.
The above considerations reduce the long term integrity of this remedy.
Also, because of the high levels of contaminants remaining onsite, this
-------
6
On the other hand, Alternative 10 complies with all applicable and
relevant Federal environmental laws and regulations. It is also the
lowest cost permanent remedy that mitigates short and long term threats
to public health and the environment. The greater protection afforded
by this remedy over Alternative 12 justifies the additional cost, and
is therefore, the most cost-effective alternative.
Comment 6
There have been 12 cases of meningitis in the area within a month when
the river flooded. Are these cases linked to pollutants from the Sikes
site?
EPA Response
No. Carl Hickam of the Centers for Disease Control (CDC) contacted
Mark Canfield of the Harris County Health Department on meningitis cases in
the county. Although meningitis cases are elevated in Harris County, data
do not suggest an excessive number of cases for Crosby. Those cases that
have been reported (there have been three in Crosby this year) appear to
be linked to virus/vector borne routes, not flooding of the Sikes site.
Comment 7
Local residents wanted to know if any contaminated sand from the Love
Sand Pit (adjacent to the site) had been sold.
EPA Response
To the Agency's knowledge no contaminated sand has ~een sold. The owners
of the Love Sand Pit have been requested not to sell any sand from an area
in the pit that showed evidence of leaching of contaminants. Mr. Love
agreed verbally with the request and there is no evidence to show that he
has not been complying with this. The Texas Water Commission sampled sand
thought to be bought from this company and found no evidence of contamination.
Comment 8
"
0""'0;
Why doesn't EPA require the county to condemn the land, making access
difficult, and making it unnecessary to remove or treat the waste?
EPA Response
This essentially implies a no action response, which does not adequately
protect human health and the environment. Although direct contact with
contaminants may be minimized for a short while. the long term security
of the site is still questionable. Furthermore. by not removing the waste
you risk further contamination of the groundwater as well as migration of
-------
7
Comment 9
Several commentors stated a strong preference for biodegradation and wanted
to know why it was not considered as an alternative.
EPA Response
Biodegradation techniques were eliminated as a remedial technology for
active consideration in the Feasibility Study's initial screening of
technologies. Biodegradation poses several problems at this site. Heavy
metals present in the waste could prove toxic to the microorganisms. It is
also likely that the desired final soil concentration of 10 ppm of benzene
or 1,2-dichloroethane may be well below the minimum concentration required
to sustain a specialized microbal population. If this were the case, the
soil would not be decontaminated to the necessary level.
Landfarming or in situ treatment may not be applicable because of the siting
requirements for-treatment units set forth in RCRA (40 CFR 264.271(c)).
According to the regulations the maximum depth of the treatment zone must
be more than three feet above the seasonal high water table, as required by
RCRA regulations. Data indicates that the groundwater levels for the upper
aquifer ranges from 2 to 10 feet below the ground surface.
tomment 10
Where does Sikes stand on the priority list to get funds?
EPA Response
The inclusion of Sikes on the National Priorities Ltst allows for funding
of all remedial activities. Once Superfund is reauthorized EPA will proceed
with the design and construction phases.
Comment 11
Have the synergistic effects of the different pollutants in East Harris
County or Sikes been studied by EPA? Have the cummulative health effects
of these pollutants on East Harris County residents been studied?
EPA Response
No. Because of the variety of different pollutants present at Sikes and in
East Harris County it would be very difficult to assess the synergistic
effects. Studies of a similar nature to the ones proposed in the comment
have proven to be inconclusive. Instead, what EPA attempts to do is to
assess the health impacts of individual sites on the nearby populace.
Also, EPA's Office of Research and Development and CDC/ATSDR have begun
studies on the health effects of many individual compounds present at
-------
Comment 12
8
The remedial objectives proposed in the Feasibility Study appear to be .
appropriate for the site, but several criteria to achieve those objectives
require clarification and/or modification:
A.
The definition of waste is proposed as 100 ppm
of polynuclear aromatic hydrocarbons (PAH), based
upon clean-up criteria for a residential area.
A site-specific objective for nonresidential areas
(e.g. 1000 ppm PAH) would be more appropriate for
the Sikes site.
B. The surface water quality criteria are "average
quality" requirements, and should apply to ambient
water quality in the receiving streams (San Jacinto
River and Jackson Bayou).
The alluvial aquifer is not an appropriate drinking
water supply even in the absence of the Sikes Pits,
and the criterion for Objective 5 (prevent use of
contaminated groundwater, upper aquifer) should be
to eliminate the use of that zone as a potable water
supply.
c.
D.
The criteria to satisfy Objective 9 (minimize the
potential of a~ adverse air discharge) should extend
to an assessment of odorous emissions during
remedial action.
EPA Response
The proposed criteria are appropriate for the following reasons (letters
of responses match the comment letter):
A.
The 100 ppm PAH criteria is based on the direct
contact hazard at the Sikes site. This level
reflects the need to protect the many workers
near and around the site and the sports fisherman
that frequent the area.
B.
-
The surface water quality criteria is a maximum
limit that applies to all surface water, not just
major receiving streams.
c.
Whether the alluvial aquifer is an appropriate
drinking water supply is irrelevant and immaterial, since
it is currently being used as a drinking water supply.
D.
Design of the remedy will be such that air emissions
are minimized. After remediation the air at the site's
border must meet OSHA standards at site boundary, and
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9
Comment 13
The volume and characteristics of the wastes at the site have not been
sufficiently defined.
A. The current waste volume estimates could be low by a factor of
~hree. "Miscellaneous" sludge volume estimates could be signifi-
cantly in error, since the aerial extent and depth have not been
fully determined, and no data are available regarding PAH concen-
trations in underlying soils. Also, further investigation may
identify other significant sources of sludge. No current estimates
are available for the volume of additional sludge that might be
found, leaving additional contingency in the total amount of sludge
to be managed under the FS alternatives.
B.
The Tank Lake and Slough sediments should not have been included in
the FS sludge volume because they do not meet the FS definition of
either sludges or contaminated soils.
EPA Response
EPA disagrees. The Remedial Investigation report provides a fully
sufficient evaluation of the waste volume and characteristics needed to
.decide upon a remedy.
A. The FS states, in detail, how waste volumes were calculated.
Sludges were identified as waste containing greater than 100
ppm PNAs. The depth of contaminated soils is equal to the
depth where a single volatile organic is present at a concen-
tration equal to or greater than 10 ppm and where total PNA's
are less than 100 ppm. The concern over the determination of
aerial extent and depth could have arisen from an inaccurate
chemical analysis found in Table 1-2 of the FS. The analysis
presented does fit the definition of sludges given in the FS
and has led to the impresssion that underlying soils of the
main waste pit are really sludges, and that there are addi-
tional contaminated soils beneath the sludges that have not
been accounted for. However, none of the chemical analyses
given in Tables 1-1 and 1-2 representing sludges and
contaminated soils were used to estimate waste quantities,
therefore this would not have changed the numbers.
Sampling and waste quantification were executed on a priority
basis related to known or most probable areas of waste deposits.
Further sampling was not performed because the size of the site
(185 acres) rules out the feasibility of fully determining the
compositions and quantities of all site wastes. This would not
be a cost effective objective for the RI. However, enough
contingency was added into the waste volume estimates that it
should fall into the acceptable range for feasibility cost
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10
B.
The chemical composition of Tank Lake sediments shown in Table
1-1 of the FS indicates as claimed that Tank Lake sediments do
not classify as sludges or as contaminated soils. However, this
is due to an error made in the FS. The concentration shown for
benzene of 1400 ppb was misread as 14 ppm, and not 1.4 ppm as it
. really is. For this reason, this analysis was originally shown
in Table 1-2, as representing contaminated soils in Tank Lake.
None of the chemical analysis for Tank Lake sediments show it
satisfies the FS definition of sludge, but based on the analysis
for a composite sample, Tank Lake sediments do classify as
contaminated soils.
Comment 14
The RI and FS documents characterizing the Sikes Disposal Pits do not
provide sufficient data to conclude that incineration is technically
feasible or cost effective as a remedial action.
EPA Response
EPA disagrees. Sufficient data was developed in the RI to establish
.the technical feasibility of utilizing incineration, either onsite or
offsite, as a remedial technology. Incinerator construction costs,
operating parameters and efficiency are well documented and the type of
waste materials identified have been disposed of by commercial
incineration for years. Sufficient data is presented in the FS to
determine the feasibility of incineration as part of an overall remedial
plan. Additional physical data will be developed during the design
phase to provide the specific needs of a detailed assessment of
incineration. Whether incineration is cost effective or not doesn't
depend only on collecting more waste samples for physical character-
ization, but is determined by blending many factors into a comparative
analysis of alternate technologies. .
Comment 15
The soil decontamination criterion for Objective 1 (prevent human contact
with contaminated soils and wastes) based upon 100 ppm Polynuclear
Aromatic Hydrocarbons will provide more than adequate protection to
human health and the environment for the area. Additional criteria for
soil decontamination based upon the simplified model in Appendix D of
the FS are unnecessary.
EPA Response
The goal of the 10 ppm benzene or 1,2-dichloroethane decontamination
criteria is necessary to restore the upper aquifer to drinking water
quality within 30 years following the completion of remedial action.
Using the site characteristics ~o develop the model, it was determined
that the 10 ppm criteria was the level of cleanup required to attain
the 30 year objective.. If the site were not cleaned-up to this level,
then it is highly feasible that a groundwater remediation would be
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11
Comment 16
A 100-year flood protection dike surrounding the entire site, as .
suggested in the FS, is unnecessary and would cost $5 million. The
flood protection dike need only protect the areas of the site in which
a remedial program could be significantly impacted due to flooding
which results in equipment damage or contaminant dispersal.
EPA Response
Total protection of the area used during remediation is necessary due
to frequent flooding of the site. However, the dike cost estimated in
the FS is approximately $1.5 million, not $5 million.
The costs used to calculate this amount were taken from Average Low Bid
Unit Costs published monthly by the State Department of Highways and
Public Transportation. Costs for District 12, Houston and surrounding
area, in the January 1986 issue were used.
Comment 17
The wastewater treatment system is under-sized for those alternatives
which require excavation of the pits without groundwater migration
.controls. The basis for this argument is a calculated flow rate of 350
gpm for groundwater. The flow rate in the FS is 80 gpm.
If alternative 12 (cap and slurry wall) were performed less groundwater
would need to be treated, making this method even more economical.
EPA Response
EPA disagrees. The expected flow rate of groundwater into Tank Lake
during excavation of sediments was the basis for sizing the water
treatment system. This flow was estimated by two methods. First, the
flow rate was calculated from permeability, differential head, and side
wall area. This method produced a flow rate of 80 gpm. The second
method was to use the flow of groundwater infiltrating Lovels large
sand pit south of the slough (the wall area and depth of this pit was
estimated as being equal to or greater than that of Tank Lake). The
discharge of water from this pit was estimated to be less than 50 gpm.
The 80 gpm flow rate was used so that the worst case cost estimate
would be produced.
The difference between the 350 gpm flow rate mentioned in the comment
and the 80 gpm flow rate calculated in the FS is due to the permeability
values used. The permeability used for the 350 gpm calculation
(2.5X10-3 cm/sec) represents a single point value from a well located
upgradient and in a clean area. An average of well permeabilities
located close to Tank Lake would have yielded a more realistic flow
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12
The same volume of contaminated groundwater was used for costing all
alternatives. Although the volume of water to be treated would probably
be less for Alternative 12 than for the preferred alternative, this
would not make Alternative 12 more cost effective.
Comment 18
The time allocated to environmental permitting, design, procurement,
and construction of incineration facilities in the FS (i.e. one year)
is insufficient.
EPA Response
If the above comment were accurate it would be true. However,
implementation time referred to accounts for only the construction
period, as defined in the FS. It is anticipated that mobilization of the
incinerator would be completed during the one year time period required
for dike construction. The design of the incinerator will have occurred
previous to this. Also, according to CERCLA, 40 CFR Part 300.68 (a) (3),
Federal, State, and local permits are not required for fund financed
remedial action or remedial actions taken pursuant to Federal action
under Section 106 of CERCLA.
"Comment 19
In the event substantial volumes of additional sludge are found, the
onsite incineration option could include two subcategories. These sub-
categories include: increasing the incinerator size (or number of
incineration trains) to incinerate all sludges with)n the designated 3
years; or, extending the implementation schedule to accomodate larger
waste vo 1 umes.
EPA Response
EPA does not feel there will be a substantial volume change from that
estimated in the FS, for the reasons stated in the response to Comment
11. However, if greater. amounts"....of waste are found, it would be the
Agency's choice to bring in more incineration trains to accomplish the
cleanup in the given amount of time.
Comment 20
The implementation schedules for all alternatives considered (except
the no action alternative) should be adjusted to reflect realistic time
requirements. These adjustments to schedule will have a significant
impact upon present value costs of implementing the various alternatives.
EPA Response
The assumption that the time reQuirements are unrealistic is based on
the statements in Comments 13 and 18 regarding volume of wastes and
time allocated for permitting~ design, procurement, and construction of
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13
drastically underestimated, and the comment regarding construction time
was invalid, no adjustment to the schedule is required.
Comment 21
The Feasibility Study states that there appear to be trace quantities
of one or more vac's, including benzene, chlorobenzene, 1,1-dichloroethane,
1,2-dichloroethane, and vinyl chloride in the lower aquifer; however,
Table 1-9 of the FS indicates that none of these substances were detectable
in the lower aquifer. There is also a statement that polynuclear
aromatics (PNA's) are at two times the concentration in the main waste
pit as in the small pit. Analytical results in table 1-1 do not support
this statement.
EPA Response
The data in Table 1-1 of the FS does show that for most individual PNA's,
the ratio is about two times the concentration in the main waste pit as
in the small waste pit. The analysis listed in Table 1-9 of the FS
represents an upgradient water sample, taken in July 1985, for setting
background water quality criteria. The contamination mentioned in the
comment has been detected intermittently in the lower aquifer in concen-
.trations below the Human Health Standards (10-5 risk level) in wells both
upgradient and downgradient of the site. This data indicated the trace
contamination was not from the site, and therefore, was not be considered
in the remedy.
Comment 22
There has not been a consistent approach in assessing feasible remedies
throughout the FS. For example, among the objectives for remediation
established by EPA are: to minimize site-related degradation of the San
Jacinto River and the Jackson Bayou. Another objective is to prevent
use of contaminated groundwater from the upper aquifer. The.Feasibility
Study states in numerous places that there is no evidence of any
degradation of the San Jacinto River and Jackson Bayou from the site and
there is also no evidence of any contaminated groundwater offsite in the
upper aquifer.
EPA Response
EPA disagrees. There is currently no evidence of migration of contaminants
offsite that would lead to the stated degradation. However, this migration
will occur if appropriate actions are not taken to meet the objectives.
Comment 23
An alternate water supply can be provided for the Riverdale subdivision;
this would eliminate human exposure to potentially contaminated ground-
water in the vicinity of the Sikes site. This means the lower aquifer
would not have to be cleaned up and a less stringent soil removal criteria
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14
EPA Response
Even if an alternate water supply were provided, there would be no way to
prevent continued use of the upper aquifer. With some of the wastes still
in place the upper aquifer would continue to be contaminated, possibly
leading to contamination of the lower aquifer. Also, the State of Texas
may not have institutional controls that could prevent the use of the
upper aquifer.
Comment 24
Natural and enhanced soil degassing are proven remediation techniques,
but these alternatives were not thoroughly tested and evaluated for the
Sikes site.
EPA Response
Natural and enhanced soil degassing were not considered because they are
not viable technologies for remediation of the Sikes site. Soil degassing
is usually effective when used on sandy soils that have been contaminated
with volatile organics, such as the case with the Sikes Disposal Pits
site. However, this technology is not effective when water saturated
soils are involved, which is also the case at this site. This method
•cannot be used on sludges, and does nothing to remedy heavy metal
contamination. If this technology were used on the contaminated soils in
spite of the high water table, a separate remedy would still have to be
designed for disposing Qf the sludges and soils contaminated with inorganics
and non-volatiles. This makes it a very impractical remediation technique
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