United States
Environmental Protection
Agency
.Office of
Emergency and
Remedial Response
EPA/ROD/R03-86/019
March 1986
PA
Superfund
Record of Decision:
Tybouts Corner Landfill, DE
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TECHNICAL REPORT DATA
(Pltal rHd l"flfflClions 0" Iht nVlnllNlon com"ltli",)
,. AEPOAT NO. 12. 3. AEC"'ENT'S ACCESSION"NO.
~PA/ROD/R03-86/019
.. TITI.E AND SUBTITI.E 5. REPOAT DATE
SUPERFUND REOORD OF DECIS ION March 6. 1986
Iybouts Corner Landfill, DE 5. PERFORMINO OROANIZATIDN CODE
7. AUTHORIS) 8. PERFORMINO ORGANIZATION REPORT NO.
It. PERFORMING ORGANIZATION NAME ANO ADDRESS 10. PROGRAM ELEMENT NO.
". CONTf'AI;T/Qf'ANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS 13. TYPE OF REPORT AND PERIOD COVERED
p. S. Environmental Protection Agency Final ROD Recort
~Ol M Street, S.W. 1.. SPONSORINO AGENCY CODE
Washington, D. C. 20460 800/00
15. SUPPLEMENTARY NOTES
18. ABSTRACT ,
The Tybouts Corner Landfill site is located in northern Delaware, approximately t$n
niles south of wilmington, in New Castle County. The landfill consists of two fill
~~eas. The main fill is about 47 acres in size and is located near the confluence of
Pigeon Run and Red Lion Creek. A smaller 'fill area, estimated to be about four acres,
is located just west of Pigeon Run.
'!be site was originally a sand and gravel pit. When the landfill began to operate,
plans indicate that no clay liner or other impervious material was placed below the fill
and no impervious cap was placed on top of the fill following abandonment. 'lYbouts
;:orner Landfill was used by the New Castle County Department of Public Works as a
~unicipal sanitary landfill for the disposal of municipal and domestic refuse from
Pecember 1968 until July 1971. In addition, industrial wastes were disposed there
~uring the active life of the landfill. These industrial wastes included:
richloroethylene, vinyl chloride, 1, 2-dichloroethane, benzene and various other organic
and inorganic chemicals.
The main threat posed by 'lYbouts Corner Landfill is that the hazardous substances
:Hsposed of in tfie landfill are contaminating the local and regional aquifers which are
a main source of water for the region. The selected remedial action for this site
ncludes: excavation of all municipal and industrial wastes, as well as contaminated
(See Attached Sheet)
17. KEY WORDS AND DOCUMENT ANALYSIS
a. DESCRIPTOAS . b.IDENTIFIEAS/OPEN ENDED TERMS C. COSA TI Field/Group
Record of Decision
IYbouts Corner Landfill, DE
~ontaminated Media: gw, soil
ey contaminants: VOCs, toluene,
benezene, vinyl chloride, xylenes
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'8. DISTRIBUTION STATEMENT 18. SECURITY CLASS (This Rep!'rtJ 21. NO. OF PAGES
None 73' -
20. SECURITY CLASS (This pqel ;22. PAICE
None
fPA ,- 2220-1 (I... 4-n)
""CYIOU. ;COITIO.,'. O"O~CT&
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INSTRUCTIONS
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REPORT Nua8ER
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RECIPIENTS ACCESSION NUM8ER
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type or otherwISe subordinate it to main title. Whcn II report is rr~'JIa,ed in mo~ thoan "1It.' yulun~. '~'P';JI Ih~' rrull;a,y lill~', ildd Yol:ulI~'
number and indude subtitle for the lpcCiflC," title.
4,
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REPORT DATI
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IIPfI'ONl. dill' o{ ",'ptlfflliolf. 'Ie.j.
PERFORMING ORGANIZATION COOE
Leave blank.
e.
7.
AUTHOR C.»
Give nameb) in o:o)nvcnuonal order (John R. ~, J. Robt." lJot.', c'Ie). Lisl ;Iuthur" ;al'lili.UlulI il" il ,Iifl"~',s !'rum Ih~' 1""l"u'lIIiftj: ...pni.
ution.
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"RFORMING ORGANIZATION REPORT NUMBER
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t.
"RFORMING ORGANIZATION NAME AND ADDRESS
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Use the propam element number under which the report was prepared. Subordinah: numb..'rs lIIiI)' bI: illdU"I.'.11II l'an'lIlh~'\\'"
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Insert contract 01 Jrlnt number under which report WilS prepared.
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Include ZIP code.
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14. SPONSORING AGtNCY CODE
Insert appropriate code,
111. SUPPLEMENTARY NOTEI
Enter information not included elsewhere but useful. such a~:
To be published in. Supersedes. Supplements, ctc.
Prepared in \:aopc:ratian Wllh. 1"'0111',1;1111111 ..I, 1'r"'''''III~''' ;II ""111,'"'''''' ..,.,
1L A8STRACT
Include a brief (100 wonis or ("s) factual summary of the most si.nitit:ant Infarm;alinn ~unlaln~',11II II,,' [<'1'0". IIlh.' "'1'1111, ""la",,,1
si8llificant bibliopaphf or literature survey. mention It here,
17. KEY WORDS AND DOCUMENT ANALYSIS
(a) DESCRIPTORS. ielecl from the Tht'saurus of i::nlinl.ocrir.. ;and Sc.:ientilk Tcrm~ the pruj)\:r ;JUlh..rll~'d I\"IIIS Ih;ll n.ll:nul"y Ihl.' RI;JI'"
concept of the research and arc sufficiently ~peelfic and pre\:I": to be u..:1.1 iI" Inl.l...:\ cnUle~ Iur "illillu~lnl!.
(b) IDENTlrlERS AND OPf.N.ENDED TERMS. Use identiflen for project nanl~'. \:ude lIames, '-'4u1pm...nt d"'''l!nilluf\. ...Ic. I.i~ "''''",
ended terms written in descriptor form for those subjects for which no ck:!lCriptar I:",i~ts.
(c) COSA TI HI:LD GROUP. Field IInd poup assipments ~re to be t;akl:n from the 1965 ("OS" 11 Suhj..cI (';II~'J!"'y I.ht. Sin...... Ihe n'iI'
jority of doc:umenu are multidisciplinary In nature. the Primaty '.itld/Group a'si.nml:lllIs' will b..' 'I"'''''~' U'''''I'line, ar~';J n!" human
endeavor. or type of physi.:al object. The applicationts) will be cross-rcl"erenl.'Cd wUh ~,'unuilr)' I id.lI( ;ruIII' .I"I)!II"''''"ls Ihal '4'.1111111..."
the primary postlnltS),
1L DISTRI8UTION STATEMENT .
Denote releasability' to Ihe public or limitation for rea50ns tUher than ~cuflly far I:~ilmrll: "H.o.:h:iI'C Lllhlllll~'d:' ("110.: all~ iI'ail;,h.hl) ,..
the public. with address ;Ind pm:e.
11..20. SECURITY CLASSIFICATION
DO NOT submit classified reports to the National Teehniciillnformation service.
21. NUMBER OF PAGES
Insert the tow number of pages. includiq 1M one aDd WUlumbered paJ':'. bUI exclude dl\lrlbUliuA "'I, I' iln)'.
. .
22. PRICE .
Insert the. price wt by me National fechaicaUa£orma&ian S\:~ ur ~ Government PrinllllC QfrJ!;~. II knuwa...
! PA ,.,.. 2220-1 (R.... .-n) (R....r..)
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EPA/ROD/R03-86/0l9
Tybouts Corner Landfill, DE
16.
ABSTRACT (continued)
subsoils in the west fill and consolidation with the main fillJ capping of
the consolidated main fill area with a multi-layered RCRA capJ installation
of a subsurface drain or trench systemJ implementation of a health and
safety planJ and establishing a monitoring program. In addition, the
offsite plume of contaminated ground water in the Upper Hydrologic Zone
(UHZ) of the Potomac will be pumped and treated or otherwise disposed of,
either onsite or offsite at a local sewage treatment plant. The goal of the
offsite ground water treatment will be to reduce the level of contaminants
to 100 ppb of total volatile organics, and 10-4 cancer risk level for
cancer-causing contaminants. During the pumping, institutional controls
will be utilized to prevent use of contaminated ground water.
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RECORD OF DECISION
. REMEDIAL ALTERNATIVE SELECTION
SITE:
Tybouts Corner Landfill, New Castle County, Delaware.
Documents Reviewed:
Documents which describe the analysis of cost-effectiveness and
feasibility of remedial alternatives for the Tybouts Corner Landfill
have been reviewed. Meetings to discuss these remedial alternatives
have also been conducted wi th the. State, responsible parties and the
general public. 1 have been briefed by my staff on the documents and
the meetings and they form the principal basis for my decision.
Remedial Investigation/Feasibility Study Report, Volumes I-V,
Tybouts Corner Landfill, New Castle County, Delaware, June - 1985,
prepared by NUS Corporation.
Work Plan for Remedial Investigation/Feasibility Study of
. ,
Alternatives, Tybouts Corner Landfill, New Castle County, Delaware,
August - 1983, prepared by NUS Corporation.
Remedial Action Master Plan and Project Work Statements for
Tybouts Corner Landfill, New Castle County ,Delaware, December -
1982, prepared by R.!. Wright Associates, Inc.
Meetings with Delaware Department of Natural Resources and
Environmental Control.
Meetings with technical and legal staff representing the group of
potentially responsible parties.
-
Public meetings to discuss the alternatives
Letter, dated Nov. 21, 1985, to Judith A. Dorsey from George J.
Weiner, and attached "Preliminary Agreement for Tybouts Corner
Remedial Action Plan".
Description of the Selected Remedy:
1)
The west fill will be excavated and consolidated with the
main fill. Excavation will include all municipal and industrial
wastes as well as contaminated subsoils. The amount o£
contaminated subsoil to be removed will be based on a site-
specific chemical fate and transport analysis. This analysis
will be conducted to ensure that no soil remains in place which
could cause ground water contamination to exceed the standards
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established in- this Record of Decision. The excavated area
wilt be backfilled with suitable clean fill material.
2)
A multi-layered cap that complies with RCRA will be placed
over thi consolidated main fill area to significantly reduce or
eliminate the vertical infiltration of precipitation.
3)
A subsurface drain or trench system will be installed to prohibit
continued lateral migration of ground water through the fill and
to collect existing leachate from the fill. The multi-layered
cap and the subsurface drain/trench system together are intended to
dewater the consolidated fill. This ground water diversion system
and multi-layered cap will be maintained until they are no longer
needed.
4)
The offsite plume of contaminated ground water in the Upper
Hydrologic Zone (UHZ) of the Potomac will be pumped and treated
or otherwise disposed of, either onsite or offsite. During the
pumping, institutional controls will be utilized to prevent use
of contaminated ground water.
The goal of the offsite ground water treatment wiil be to reduce
the level of contaminants to 100 ppb of total volatile organics
with separate standards for cancer-causing c~ntaminants. The levels
for these specific substances are listed in the body of the
Recommended Alternative and are selected to meet a 10-4 cancer risk
level at the boundary of the landfill property. A 10-4 level was
selected because it is not technically feasible to attain the 10-6
risk level. EPA will evaluate ground water contamination levels
after three, six and ten years of pumping and treating. If the
standards are met at any of the evaluation points, pumping will
be disco~tinued. If, after a ten-year pumping period, standards
have still not been met, EPA will evaluate the technical feasibility
. ~f meeting the standards and set new ones if necessary. Pumping
may be terminated if it is shown that no reasonable modification
of-the pumping system would produce significant improvement.
EPA will then examine the need-~r additional monitoring locations
to assure that the influence of any offsite production well
will not cause the remaining contaminated ground water from
Tybouts Corner Landfill to migrate away from the site.
S)"Contaminated water generated by excavation, construction, sub-
surface drainage system collection and ground water pumping will
either be sent to a local sewage treatment plant offsi~e, or
treated onsite. It is possible that a combination of these two
treatment systems and locations will be used. All treated water
will meet NPDES standards before disposal to surface waters,
including any pretreatment requirements if the sewage treatment
is utilized. All waters will be disposed.of in compliance with
local, state. and. federal law. .
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3.
6)
A health and safety plan will be implemented for all activities
described in this Record of Decision. During excavation and
constrUction activities, air monitoring will be conducted to
ensure the safety of the onsite workers as well as to protect
the residents living nearby the excavated areas.
7)
A monitoring program will be established to ensure that ground
water quality, surface water quality, the multi-layer cap and
air quality are maintained.
Declarations
Consistent with the Comprehensive Environmental Response, Compensation
and Liability Act of 1980 (CERCLA) (42 U.S.C. I' 9601-9657) and the National
Contingency Plan (40' CFR Part 300), I have determined that the remedial
action described above, together with proper operation and maintenance,
constitute a cost-effective remedy which mitigates and minimizes damage
to public health, welfare, and the environment. The remedial action
minimizes or eliminates the threat of further contamination to the ground
water and the environment. The Delaware Department of Natural Resources
and Environmental Control has been consulted and agrees with the approved
remedy. These activities will be considered the approved action and
eligible for Trust Fund monies.
I have determined tha~' the action being taken is appropriate.Jwhen
balanced against the. availability of Trust Fu monies for use t ~er
s1te..iflf~
at
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.4..
Summary of Remedial Alternative Selection
. Tybouts Corner Landfi 11
Site Location and Description
The Tybouts Corner Landfill site is located in northern Delaware,
New Castle County, approximately ten miles south of Wilmington and a few
miles west of the Delaware River.
The site was originally a sand and gravel pit. When the landfill began to
operate, plans indicate that no clay liner or other impervious material
was placed below the fill and no impervious cap was placed on top of the
fill following abandonment. The thickness of the fill ranges from
approximately- 5 to 40 feet.
The landfill consists of two fill areas. The main fill is about 47 acres
in size and is located near the confluence of Pigeon Run and Red Lion
Creek, in a triangular area northeast of Pigeon Run, between U.S. Route
13 and State Route 71. A smaller fill area, estimated to be about four
acres, is located just west of Pigeon Run. Figure 1 shows the approximate
limits of the two fill areas.
The main landfill surface is relatively flat, and slopes to
south toward Red Lion Creek. The smaller landfill, located west
Pigeon Run (referred to as the "west landfill" in this document)
flat and also drains to Red Lion Creek. .
the
of
is very
Pigeon Run is a small stream that is a tributary to Red Lion Creek.
Pigeon Run flows along the western perimeter of the main landfill and
intermittently receives surface runoff and leachate from the landfill.
Red Lion Creek is located about 500 feet south of both the main and
western fills and flows from west to east. Red Lion Creek widens
immediately downstream from the .main landfill, forming a broad marsh and
backwater a~a of the Delaware River. The creek enters the Delaware
River approximately 2 miles downstream from the site. Red Lion Creek
receives surface .runoff and leachate from the main landfill.
o
The entire site property is surrounded by privately owned, residential
property and industry-owned property. Six private homes are located
directly adjacent to the site property line along the northeast boundary
of the main landfill. There are two residences on the east side of Route 13,
about 300 to 500 feet from the eastern edge of the site, as shown in
Figure 2. The well for these residences is contaminated. One residence
is located about 150 feet northeast of the site. The well for this
residence is also contaminated. There are approximately 34 other residences
within one-half mile of the site.
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"V XV
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CONTAMINATED
RESIDENTIAL
NELL
CONTAMINA
RESIDENTIAL
NELL
L£fil!lfi
AO SOMCMT MMFIM f
A MFMC WltH SMWltr; p
• ICMMIR MMTUHPCIwr
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TOPOGRAPH»C PLAN ANO LOCATION <
BORINGS AND MONITORING WELLS
TffiOUTS CORNER LAfCOLL SITE NEW CAST
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7~
The landfill is located in an area where extensive development
of ground water resources has occurred for both municipal use and
for large industrial facilities (see Figure 3). The site is located
in Red Lion Creek drainage basin, and the Delaware River is about
two miles downstream from the site. The area along the Delaware
River has been developed by the oil and chemical industries. Facilities
include those operated by Texaco (formerly Getty) Oil, Diamond Shamrock,
Formosa Plastics, Stauffer Chemical, and'Standard Chlorine. all of
which are located within two miles of the site to the east and southeast.
A ~ract of property on the east side of Route 13, directly east of
the landfill, is owned by Texaco. The tract is currently leased for
farm! ng.
Site History
Tybouts Corner Landfill was used by the New Castle County Department
of Public Works as a municipal sanitary landfill for the disposal of
municipal and domestic refuse from December 1968 until July of 1971.
In addition, industrial wastes were disposed there during the active
life of the landfill. These industrial wastes included trichloroethylene,
vinyl chloride, 1.2-dichloroethane, benzene. and various other organic
and inorganic chemicals.
,
The Tybouts Corner Landfill Site is ranked as the Number 2 site
on the U.S. Environmental Protection Agency (EPA) National Priorities
List, and is designated by Delaware as its top priority site. The site
achieved its ranking because of the threat of contamination of the regional
aquifer, which i8 the primary source of water in this region of Delaware.
The first occurrence of contamination of a water well was reported
by the Delaware Department of Natural Resources and Environmental Control
(DNREC) in May 1976 when a private, domestic water well owned by Sarah
Wagner was tested and found to be contaminated by organic compounds.
The Wagner well was located about 400 feet east of the main landfill
perimeter a8 shown on Figure 2. A second private, domestic water well.
located 150 feet north of the landfill and owned by Leo Woytko, was
also found to be contaminated, as indicated by testing performed by
EPA in 1983 and 1984. The Wagner well was abandoned and has since
collapsed. The Woytko well water was treated by the owner at his own
expense prior to its abandonment. No other water supply wells have
been contaminated by the site to date.
The Remedial Investigation (RI) for the Tybouts Corner Landfill
Site was initiated to determine the impact of the landfill on public
health and the environment. focusing on the local and regional ground
water systems. The main concern was that hazardous substances that
were disposed in the landfill were contaminating the ground water
system.
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. - PUMPING WELLS . CE=1NUb
TYBOUTS CORNER LANDFILl SITE. NEW CASTlE ~DELD CUr .~ I
, .. . Figure 3 0 A HaJliburton Company
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9.
The geologic and ground water investigations of the RI were performed
in three phases. The initial phase was to determine the general character
of the geology and ground water at the site and to determine if contamination
could be reachins the regional aquifer. The second. phase was to determine
the detailed geology and potential for ground water contamdnation in the
shallower aquifers that lie above the regional aquifer in the immediate
vicinity of the landfill. The third phase was to determine the character
of ground water contamination, the extent of contamination, and the
potential for the contaminants to spread further in the regional aquifer.
In the summer of 1984, EPA initiated a Focused Feasibility Study to
evaluate possible water supply alternatives for the residences near the
Tybouts Corner Landfill. By July 1984, the alternatives were presented
to the public for comment. On September 13, 1984, the Regional
Administrator signed a Record of Decision to install a public water
supply line for the residences that had contaminated wells, as well as
for the residences whose wells were potentially threatened.
Enforcement History
I~ October of 1980, the United States filed suit against New Castle
County, Stauffer Chemical Company and Wi~liam Ward under section 7003
of RCRA, seeking injunctive relief to abate an endangerment presented by
disposal of wastes at Tybouts Corner Landfill. In March of 1982, the
United States amended its complaint to include a request for injunctive
action under section 106 of CERCLA. The s1 te was 11 sted on EPA' s
National Priorities List, and the Remedial Investigation/Feasibility
Study (RI/FS) process was begun in early 1983. .
,
Having expended considerable investigative funds on the site by
April of 1984, the United States once again amended its complaint,
to include a cost recovery count under section 107 of CERCLA. At the
same time, it joined ICI Americas as an additional defendant. .
Two partial' consent decrees have been signed in the litigation
to date. The first was a consent decree between William Ward and EPA
regarding payment by Ward of money and services to EPA for performance
of the RI/FS. The second was between EPA and three of the defendants
(New Castle County, Stauffer and Ward) for installation of public water
for residences in the vicinity of the landfill. (Because the wells on .
two private properties had already been contaminated and were unusable,
a Focus Feasibility Study was completed and implemented prior to
completion of the remainder of the RI/FS).
In June of 1984, a third-party complaint was filed by Stauffer
against the State of Delaware and two corporations. In April and
Hay of 1985, ICI, New Castle County and Stauffer filed third-party
complaints against over twenty~dditional corporations. The third-
,'party complaints seek; contribution for cleanup costs. :,
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10.
As the third-party search and joinder by defendants was progressing,
EPA and three of the defendants conducted negotiations on a cleanup
remedy for the landfill.' In December of 1985, a preferred alternative
for cleanup was put. out for comment by the public. A preliminary
agreement betWeen EPA and the defendants on implementation of EPA's
preferred alternative was provided to the court. Once the Record of
Decision selecting the final cleanup remedy is signed, negotiations
for a private cleanup by defendants/third-party defendants will begin.
Current Status
The following points summarize the findings of the Remedial
Investigation (RI) regarding geology, hydrogeology, and contamination
levels ip the landfill, ground water, surface water, sediments and wild
life.
Findings of the RI
1) . The main threat posed by Tybouts Corner Landfill is contamination
of local and regional aquifers that are a maln 80urce of water for the
regi on.
,
2) The upperm08t zone of ground w~~e.L.ln the vicini ty of the landfill
i8 called the Columbia Aquifer; the base of the main fill (the landfill Is
unl1ned) sits in this aquifer.
3) . The.t6~of ground water below the Columbia is called the
Upper Hydrological Zone (UHZ) of the Potomac. In the area of the
main fill, .there is a silt layer which'separates the base of the fill from
the UHZ of the Potomac, but this silt layer has some "window8" and the silt
layer "pinches out"" to the north/northeast. The west £111 area si ts .
directly in the URZ of the Potomac.
4) Ground water passing laterally through the fill areas creates a
hazardous leachate which enters the ground water aquifers and.also
creates surface seeps which enter the surface waters around the site.
5) In addition, the surface capping on the landfill does not prevent
rainfall from entering the landf1ll vertically; the rainfall picks up
landfill contaminants as it passes through the fIll and combines with
the ground water that is passing through the landfill.
6) The plume in, the Columbia Aquifer flows to the southeast, with
a small flow towards the north. The southeast portion flows under US
Route 13 and eventually outcrops and seeps into a limited area of the
Red Lion Creek Swamp.
7) The contamination in the.UHZ of the Potomac flows southeast
under US Route 13. 1he.p1ume.baa not yet crossed underdwd:L1on Creek.
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11.
8) The contaminated ground water plumes have migrated between
400-800 ft. from the site.
9) The UHZ Of the Potomac Aquifer is a discontinuous layer of
sandy lenses, separated by clay, that are interconnected. There are
two sand layers within the UHZ, the PI Sand and the P2 Sand. The thickness
of the PI Sand varies, being very thin under the main fill and opening
up and getting thicker toward the southeast. As the PI Sand thickens,
its potential for water production increases, making it an increasingly
valuable resource at greater distances from the landfill.
10) It i5 the PI Sand of the UHZ that the landfill has contaminated.
The PI Sands are the major pathway of environmental concern because of the
potential to reach or become a public water supply in the future.
11) The P2 Sand ~s the major water resource in the region. The fact
that the P2 Sand is hydraulically connected to the contaminated PI Sand
makes the P2 Sand a pathway of environmental concern as well.
Geology
The geology at the site is describe~ by three formations; the
Columbia, the Merchantville and the Potomac. The Columbia Formation is
the uppermost geological unit, which generally lies about 20 feet mean
sea level (MSL). This formation consists of a brown to yellow-brown
silty sand, and sand and gravel. The Columbia was mined for sand and
gravel at Tybouts Corner Landfill and municipal and industrial wastes
were placed in the mined area. The Kerchantville Formation beneath the
site consists of a.dark gray, micaceous, glauconitic sandy silt. The
Kerchantville Formation and underlying silt "pinches out.' north northeast, .
and west of the landfill. The Merchantville Formation is also missing in
the vicininty of well TY-311, where it was removed either naturally, or
by excavation. The extent of the removal at well location TY-3I1 is
unknown, and was estimated for the RIIFS ground water modeling. The
Potomac cond,sts of variegated, red, gray and whi te clay containing
yellow-brown silty sand beds that vary In thickness and lateral extent.
The top of the Potomac ~ormation is a sand bed designated as the Potomac
No.1 sand which ranges from less than 10 feet to about 20 feet thick
,beneath the main fIll and becomes significantly thicker to the southeast.
The Potomac No.2 Sand lies beneath the No.1 Sand with a clay bed,
designated the A clay, which separates the two sand beds. However, the
A clay is not continuous and the Potomac No.1 sand merges with the No.2.
sand where the A clay '.pinches out..' Thi's type of interconnection of
the sand beds is common within the Potomac Formation.
Hydrogeology
The ground water ~low systems beneath and around the Tybouts Corner
Landfill si te include those, iU;',the Columbia and the Potomac Formations,
which are distinct, but at the same time, interrelated. The ground water
.."
-------
12. "
flow system In the Columbia Formation is the uppermost system and intersects
the landfill. 'lbe Columbia Aquifer is sometimes referred to as the "water
table" aquifer. _'lbe ground water flow sY8tem in the Potomac Formation is
often separated from the Columbia Aquifer by a low permeability sandy
silt, the Kerchantville Formation which, impedes but does not totally
eliminate downward migration of ground water. In some areas, the intervening
Kerchantville "pinches out" and two separate aquifers combine to form one
hydraulically continuous aquifer. However, where the Kerchantville i8
present, ground water in the Columbia Formation tends to be perched and
flows laterally. Ground water flow directions in the Columbia Aquifer
were determined from the ground water elevations. 'lbe contours on Figure
4 show that ground water moves laterally from the Columbia Formation into
the landfill from the northeastern side of the fill. Ground water flow
also moves from the landfill into the Columbia Formation in the northern
and southeastern directions.
'lbe Potomac Formation aquifer consists of discontinuous sand beds
" within a silt and clay matrix. The first two sand beds encountered in
the Upper Hydrogeologic Zone of the Potomac Formation, be~eath and around
the site, were evaluated during this investigation, and" are referred to
as the Potomac No.1 Sand and the Potomac No.2 Sand.
t
The Potomac No.1 Sand (PI) exists in a confined 4r semi-confined
ground water condition depending upon the location at and around the site.
The PI Sands occur immediately below and in contact with the Kerchantville
where the Kerchantville exists, or in contact with the Columbia where the
Kerchantville is absent.
Figure 5 shows the ground water "elevations in the PI Sand. The
ground water flow in the PI Sand is different from that in the overlying
Columbia Formation where the Kerchantville separates the two aquifers.
In areas where the Kerchantville 1s absent, the PI Sand an~ the Columb1a
Formation merge, and the Columbia ground water flow becomes the same as
the PI ground water flow. Ground water in the PI Sand flows to the southeast
beneath the main landfill. The west landfill is located within the PI
Sand and ground water flows generally to the south and southeast from the
west fill. # "
Vertical ground water flow occurs from the Columbia Formation to the
PI Sand body along the northern edge of the landfill where the Kerchantville"
Formation 18 absent. Ground water flowing to the north from the landfill
flows downward beneath the edge of the Kerchantville and reverses flow
directions 80 that it flows southeast beneath the landfill.
The Potomac Formation A clay, as referred to in the RI, is a tight
clay that acts as a confining zone between the Potomac No.1 sand (PI)
and the Potomac No~ 2 Sand (P2). The A clay occurs beneath the entire
main landfill area, and beneath the areas to the west, north and east of
the site. The A clay is 'absent"at the southern end of
-------
*•*»
.....,—., . . M
7 ^..:-V. .
A / —-
,.*"—\. \SvC*S
V
:- \
'. \
. V
X \
- A .."
"i"**- -
//
a
it.
•
\
\.
\
'v*
.\
\l
i
• / .«* "I- 1$? -\ \,.L\ ^&. / /. '/
~ r" ^^3^ :;
^Sbi- ' ^ '•"'** "u- '• ~f ^ . LE*E"°
^^S^^^S^^Lr -c>°-^, ' / ./' .... ' ad stMMiirsMwuMiraNi
^f'SS^^^^^^L'y.'^t (r ... *—««-«.
UACMMt
•~> tnr
• ffSTKMMM
• MONITMWM «€LL
\ -
_^v
TT-IW^^II ,«•
, i
GROUNDWATER CONTOURS,
COLUMBIA FORMATION
TVBOUTS CORNER LANDFILL SITE NEW CAS1
o
-------
Ul
^ u '
:--\ .-4 \V4-'
^'""N-k'rA^. :
\
x
v-v>% ' /* ^
-*^? ^/ *-
LIMITS OF MEHCHMITVItLE
--
A MTMX IKUM tAMfLMB
• UAOM1E SMMUNOPOWT
11 i».^'Vi. .*• < 1
•Kv\
ntTMMiiNa
• MOMITOMM WILL
VMTICAL MTUM IS MEAN Sf /
GROUNDWATER CONTOURS.
POTOMAC FORMATION N« 1 SAND
TYBOUTS CORNER LANDFILL SITE NEW CAST!
MO
IN .
-------
10.
The P2 Sand is almost non-existent directly beneath the site, but as
it increases in thickness toward the southeast it has more potential for
ground water production.,
Ground water flow in the P2 Sand is towards the southeast as indicated
by the ground water contour map shown in Figure 7. The general southeast
flow is siadlar to the PI Sand and appears to be the predoadnant direction
of flow in tbe UHZ beneath and around the' site.
Ground Water Cheadstry and Contamination
Chemdcal analyses of ground water from monitoring wells were performed
three times: January-February 1984, May 1984 and January 1985. The
chemical analysis included ErA priority pollutants and hazardous substance
list (HSL) organic and inorganic compounds. The analyses were performed
to deteradne the nature and extent of contamination of groundwater from
the sit~.
The analyses detected volatile organic compounds in all three sand,
beds (Columbia Formation, Potomac Formation No.1 Sand and Potomac Formation
No.2 Sand). The volatile organic compounds detected in offsite monitoring
wells are consistent with the compounds ~etected within the fl1l. The '
organic contaminants most common to both the landfill monitoring wells
and'the offslte monitoring wells within the three sand beds include
benzene, 1,2-dlchloroethane, chloroethane, 1,2-transdlchloroethane,
toluene, vinyl chloride, acetone and o-xylene or total xylenes. Complete
monitoring well analytical data are provided in the RI report. Volume IV;
Tables 1-7 summarize these results.
-'
./
Surface Water, Sediment and Leachate Seep Chemistry and Contamination
Two surface streams receive drainage from Tybouts Corner Landfill.
Red Lion Creek is located about 400 feet south of both landfill
areas. Pigeon Run flows through the site and separates the main and west
landfill areas. Pigeon Run enters Red Lion Creek 400 feet south of the
"toe" of the maIn landfill and Red Lion Creek enters the Delaware River
about two miles downstream from the site.
Surface water and sediment samples were obtained from Pigeon Run and
Red Lion Creek. Sampling was conducted both upgradlent and downgradient from
the main and west landfills. Leachate samples were also collected.
Chemical analyses for surface water samples indicate very little, i£
any, significant contamination of surface water from organic compounds
from the site. Only one positive detection -- of 8 ug/l of 1,2-d~chloroe-'
thane -- occurred at a point downgradient from a leachate discharge.
Sediments also showed little i£ any detectable organic compounds
except at one point where the leachate visibly pools before it dissipates
into the swamp. Table 8 summarizes the organic compounds found in the
sediments.
.'
-------
a\
-•-'•- \ £^<*--\"'\
.,. •-', l^jf -!$&\ \
1 ~*A*'" ' I-* - i/"~V'^ A \
"-?\ \ \ v J^Yr^ \''"\ \
J \ - ^' -
r v;. •
EG END
AQ HDMINT MMTI.MO KMI
* tufta. mn* WMPLMO
MMPUNOPOMT
—Wf Or POTOIMC FDMUTM
Veuw
STRUCTURAL CONTOUR MAP.
.-..._„ - .„— -!-_- j-- --I — i 9
TOP OF THE POTOMAC FORMATION "A" C
TYBOUTS CORNER UUCF1LL SITE
-------
AfmOXHhUTE UMT Of SAND,SANDY SILT
NORTH Of TMS UNC .
t-EGEND
Ad IBMHMT WMMJM6 NMI
* unMCf mam IMMJM
• LMOMTt
• MOMfOWW VCU.
Mi •MOUMBWUM COMTOUM Mf *ffW»ll
•OH • VCNTICM. MTUM It Mf Ml «• UVf I
POfTOMAC FORMATION - qt g
TYBOUTS CORNER LANOFU. SITE NEW CASTLE Ol. t
KET
IMUE|
RXWint •
-------
.
~
VOI.AtU ORGANIC COMPOUNDS DETECTED .. MAIN tANDfIU. _US
plNCEfflRA1IDNS .. IIICROOIIAMSIU1iR8
1YIOUIS CORN(R iANDfI.I. lITE
VoIelll. Orglnlc
ComDOUndl
locldon Columbl. fPnn.tlon - 'Ser.." .i .... 01 Mlln "'ltd.... WIthin 'he fII M"I,.II
W" No. 311 313 "'-2 "'-3 '-1
10"11 181141 111141 nll41 111141 181841 151841 nlMl 111841 111111' III
78 13.1 128.0 M 44 36
10 '.7 IT
4I000O 311000 ' II 18.1 3.. 3080
C11211.
4 2' 33.1 7
32 31.7 " .
IT '.0
880 78.1 42
" 43.' n. '" 37 28
32 4.7,
1.100 1110
30
1& 121 420.1 721 831 12 ..
1'.'
880 48.2 240 118
3200 '04.1e 3.- IS3C Z7 2
" 4720 121.1e 4
'1.11 '''.1 ,3D 36 8
203 ',14.' 20 132.7 27 28 11
It H.1 10 11.&
7.3
314
34.1
"..In.
ChlofObeft..M
, .2-OIchlo,oelhan.
,. '-Olchloroelh8nl
ChIo,o.I"lnl
Chloro'o,m
'.2-1'lnl-OIchloroelhenl
Elhylb.n...e
ChIo,omllhlM
ft.lofOIfIcMo,omeIl\lM
'11,.c_OI"''''' CPCE.
Toluin.
Trlchloro,,".n. CTCEt
VInyl chloride
Ac.lone
2-Bulenon. (MEq
4-M.,"yI-2-p.nllnonl (MIlK)
.-XyI.nl or 10111
J-He.tIIOR8
U Dlcldoroprop.ne
Ok:"lorodlluormllhane
IIYllnl
flol.: C-Corr.CI.d 'or BllnII
"
Table I
-------
I
.
. VOI..ATII.I ORQAMC COWOUNDs D£TECTED" MAIN UUimfI.1 WEU.I
(CONCENJRA11ONS .. ..-.cROORAUSJUTEIQ
TYBOUTI CORNEll 1ANDFI.1SQE ,
,AGE 1WO
: ,"01.1118 Or,.nIc
,', ComDoundl
CoIumI8ta 'orll\8llon-
'Se,.... "low"" 0' MaIn POlomaC. No. 1 18nd-
Loc.11on L.nd"" Avoc. """".nlv",. ,Se,..n ..10. e... Q' Main L.nd... ..10. """"Inlvtll..
W" No. 314 311 30J 310 312 MP-JA '"
IPII.. RIM. fill.. III". iii". (1114. 15114. R/... 11/84) JUI4. 11/84. 11114. 15I84t
31 14 17 24.1 17 7
'.1 10.7
2240 147 LT 21 3.2
LT 4.'
I.' 11 I.'
144 31.4 LT 11
III ".1 220 381 II 4.'
2220 .4 20 1.7 I. 471 I. lilt
0
12 26.4 ., Ii
2010 31.IC '. LT 4110
244
2040 122C 1410 211
11 ".1 4.2 140 112 '
14&0 30.' 43 II. 31 10.'
'.1
"
"n..... '
ChIorob.na....
1.2-Dtehloroel"...
I. . - DtcIltor...Iba..
ChIoro.I"""
Chloroform
1.2- Tr.nl-dIcIIIoroe"'ln.
.."yIIt.n....
Chlorom.",,,,,
fluorolrlclaloo'om."""
T.li.eldoroel"... cPCft
, olu.n.
"k;"'oro,'''.n. (Teft
Vlftyl c"'or'd.
Ac..on.
2-Bu..nOft. CMEICt
4-M.lllyI-2-p.nllnon. (MIlIt)
o-Xylln. or 10111
2-H...no..
NOTE:
LT . LI.. ...... dellcllon Umli. bul "'.'1' lhan 112 dellellon 1Imll,
k . Vllu. I. "'1 "'.n v.'ue glvln.
Table 2
...
-------
VOIATU OIIOANIC COIIPOUNDS DOEC1ID . WEST 1ANDfIJ. WEu.s.
POTOMAC fORMATION. NO. 1 lAND
teonc.....adona In Mlcrogqm8AJIar)
1Y8OUJ1 CORNEIIIMDfU lITE
Volat"
Or.a-
ComDOundI
location
Wa. No.
lDat.,1
Up..adla"l
213
""41 , lien
Non
t212mIC form.llon. "0. 1 SI'"
Up..adI."t Ed.a Wit"'" f.
307 301
"1841 'fiI84l "1141 '11141
Dawn...dla"t Ed...
304
111148 '11148
'....a".
ell'orobe.......
U-Dlchlora8h8n.
II-Dlcblaro.8h8n.
ChIor08t"...
Chloroform
12-Ir...I-Dlchlor08lh1ne
E'''yIb8n.8M
Chloromathan.
fluorOtrlcMoromalhlne
""lChIoromalMne (PCE)
,....
'.lchloro.lhan. (TCEI
VI"yI chlolld.
Acalon.
S.y.a".
J-lut.non. (MEIQ
4-m.."yI- 2-p.nllnon. (MlIIIQ
o-Xyla". 01 to.8I
Dtc:hIorofluorom.than.
Sty.....
31 17CII)
10 47838.
3It
LT 4IC
23
12 28
,LT
13
21C32
4'
31814
, 41
210
327(308
41t 430 '40(8701 1100 832(1188)
81
.
-" . lOG 117 1100 IOII( 1170'
10
41 LT 724(847t
lit 1111121t
12 U 230 ., 838(8&01
41t ", ". '-'" .
40(471 '
NOTE: . LT -l... t"an d.tactlon Imll ..... ..aa... I"a" 112 dat.cllon IImI8
It - Va'u, '8 .... Ihaa value glv.n
. . - indica... labo..tory RepIIc.l.
". "- ....".-
Table 3
-------
VOtATU OROAMC COMPOuNDs PE1ECTED . THE .
COl~ fORMATION AND POTOMAC fORMA..... NO. llANO AND IEI.OW tHE NO. J SAND
CConC....alloal In lIIcrogr8lUJUl8fl
'JYBOUfS CORNER tANDfU IRE
No. 2 SHd POlomlc fo,ml.lon "'Iow
ic»c.,1on ~I formilion - .PoIIWnll..dll'" ',om "'"n fllO POIO"'IC formilioft 1811 No.2 Sind
"0111118 WI. .tv 202 202 203 203 . 214 214 UP-II UP-II MP-11 MP-l1 105 101 101 104 104 "
Or81n1c t-
Comooundl .Oliit JJlI!1. CI!I!8 JJlI!1. JIlU1. J1lUl 1IlW. .ww. J.IlJ!l 11llli JImL JJml JIlI9. JIlU1.. JUI!l '''84t
Ben"nl 74 53 I . 21 11.1 23 12
Chlarobl"''''' I 4.4 2.1
'.2-0Ichlorollhlne 4101 2571 18000 8411 232 1
'.1 Dkhlo,oelMnl 21 11 III 2.21t I 4.'
Chlorollhlne 45 41 50 21.4 8 11.1 1.1
Chloroform
. U-T,.nl-dlchloroelhlne 104 1 7.1
f.hytbln"ne LT 41
Chloroml.h.nl
fluorol'lchlo,omllhlnl '.
T IIf'chlo'~lhlnl .10 18 48 4.11t
T Glulnl II 31( LT 1.2C 1.1 .
Trtc"'O'Ollblftl 140 87 21 11.2
VlnYkhlo'ldl 11 1.4
~..onl .1 IT
2-bu'lnonl (UfK8 10148 '1.1e
4-m""yf-2 penllnone CMIBKI
o-.ytenl Of 10181 . 7.1 11 I' 210 15
,NOlf: L T - L... 'han de'.cllon II""" bu' '''''" 'h.n In d,'.cllon UmI'8
C - COII,c'ld '01 ..link
I - Vilul II I... 'hln Vatul glvln
..
Table 4
-------
VoI8'.e Ort""c
CCNnDouncll
.........
CIIIor".8n8
U-Dlchloroella8...
I. I -Plclllor"""a...
CIIIoroe'b....
Chloroform
1,2-.,.nl-DlcNlwoell88ne
l.hVltian.....
Clllorom........
'8uorol,IcIllorOlR8.h8A8
'e',aeNor......... (PeE)
Toluena
"lchloroe''''''' (TCE)
Wlnyl ehloflde
Aca.one
2-Bu.anafta (MEI)
"-Me'hyl-2-pen,........ (UI.,
.-Xylene Of '0181
DlcIdOfOdilluOfomelhene
I.oca""
W" No.
.8!I!Il
WlLATU 08I0N8C COWOUNoI DOECIED . THi fOTOIIAC fORIM11QN... I 1MB
ICONCEIfIMTIONIIN MlCIIOOIWq PEl UIEIQ
1Y8OUT1 CORNE" 1.ANDfu. III'E .
POleNltae f4Wl'111on. rtc!&..J Sind IDoIl!lUl"dI8n. frCNJI Me" fin
IDJ IOJ 103 103 103 204 204 II.. II.. 114
(Dup)
JJlbL .JIlH. JJm1. .tUI1l Ill! .lliH. JI!I9. JZLH. JIlH. J1lU
II 12.1
LT
21t lit
10 U 12 1.1 422 116.
4. I 2Z
lie II 1".7
7 2.2
..
, "I 31 I
:.
200 1.1 I
II 123.2 17
Table 5
...
-------
VOlATILE ORGANIC COMPouNDs DETEcrm . TtIE POTOMAC fORMAtION NO. ,&AND
=ffJ1IADOHS .. MICROORANI PER UTERI
S CORNER &ANDFIU. lITE
PAGE 1WO
..
" locI'1on Po'oml' form"IIoft. No, 1 ~In. 'Down.ldlent fr0IJl.MI,n fill
WI' 201 205 201 ~ 201 207 207 208 208 208 20. 201
\loIIIU, Orlllnlc fOupl to .. IOup.
ComDounda JI!!JJl .lliH. J1lH. JI!I1l J!lW. JJlH1. .llitil JIM. JJ!H. .JJml JUm JIlI!L ~
"n.lnl II .4 II n
CbIoroblnl"" .0 IT ",
1.2 IMclllotoe.blnl 81 U ".4 72.' 131 1 7.1 IT .88 . l.-
8.8 DkblorOl1b8n8 1 '.7 12.1 '.1 I.'
CbIoroll1l8ne 11 12 I.' 1.8 7.1 350 284
Chlorn'Ofm .
U-arlnl-DichlorOllbln. 12 I.' 24.7 . 18.1 2.3 14 .
E.hytblnJln. 21
CbIoroml.h.n.
fluoro..lclllo.oml"'.nl
'1Iflchlorol.henl CPef.
Toluin. 10 12 '.1 11
trlchlo'OI."'. "Cft i
Vlnyt chlorldl IT IT '1.2 li.3 , \ IT
Ac"4Nl1 "~ .
2-lIManon. I..q
4-M8.hyt-2-pen.lnon. CMlIIq 120
O-~wl1n. 01 TOIII 21 21 11.2 11.1 IT
. ~lcNcNodlnuorom"h.n. " U
.:..
Table 6
...
-------
WJtATU ORCWIC CCJIIIIOt8)S DnECTID It THE POTOMAC fOIIIMT'ION NO. 1 lAm
(COHCENIRATIONS It I8CAOOIWIS PER UTEIQ
1Y8OUTI COINaIIANDfIU. IRE
PAGE TItRfE
locallon '0101lll' form.l8!,n. No. 1 San.fJPownar'''',nl from Me'" fIlA
Wa. 210 210 211 21' 211 282 282 284 284 "I. iii
VoItllle Orlule tOup) CD.
ComDOundl JI!IJt1. J.1lH. JIl.bL JIlbl . JUH. JIlH. JUH. JIM.. JUIJL JI!H. JJlIJl .lli!
.an..n, 7 2.11t 3
Chlorobenl.n. 1
U-Dlc:hIor08lh.... II 1.1 ... 232
1.I-DIchIor08Ib8n. II 7.1 1 2.ZIt
ChIoro.lhane
ChIoro'orm
1.2-lr....-DIcbIoroatban. . 14.1 1 32
Elhvlb8n.8ft8 4
Chlorometbana
fluorolrlchloromelh8n. I
T.lrachloro.lh.ne (PeE) .1 ..1t ..1 4.11t
, Gluen. 17 IIC
Trlehlor08I""', (TCE) 1 4.11t 1 21 11.2 .. ..
Vinyl chlorld. 12.
AceCon. 180 88.1 12 ~
".
2-Bucanon. CMEIC) 230 13.1 21
"-Machyl-2-penlanon. CMIIK)
.-Xvlen. or 10181 1
DlchiorOddluoloIll8Ch..
NOTES:
LT . le.. I..en d.cecllon UmIt. bul ,re.l8I 1188n In o. delICClon IImII.
It . Valu. I. .... Ihan valu. given
Table 7
..
-------
Oenzene
~thylbe"zene
Fluorotrlchloromethane
Toiuene
Acetone
2-but.none (MEIC)
2-hexanone
~-methyt-~-pentanone
1.2-dlchloroethane
Phenol
4-methyl phenol
"
. '
. '
,
'>
(1)
f2)
SUMMARY OF ORGANIC COMPOUNDS(I) IN SEDIMENTS
Upgradlent
00 I 002
Ploeol1 Run
Downgradlent
004 008 012
- --
Red lion Cree~
-»ownnradjent
, 016
003
-
TCl-6
Uporadlent
.mm.
013
014
Table 8
, ,
'.
60
IT (43_2)
l T (262)
17
Include. all organic compounds detected. except methylene chloride. All values In 1191l.
l T (4.3) . lesl than detection limit. but greater than 1/2 detection limit. Number In brackets ( J I. the detection limit.
IT (42.6)
l T (42.61
61
190
9700
,.
51.000 l
l T (650)
,
1200
IT 114001
31.000 '
-------
26.
Table 9 shows the results of chemical analyses for organic compounds
conducted on leachate samples. The results show numerous organic compounds
in the leachate, including benzene, chlorobenzene, 1,2-dichloroethane,
chloroethane, 1,2-trans-dichloroethane, ethyl benzene, toluene, vinyl
chloride, acetone, 2-butanone (HEX), o-xylene, 2-hexanone, and 4-methyl-2-
pentanone. .
Endangerment and Wetlands Assessments
The major potential impact from the landfill on the ecology of
the area is the impact of leachate contamination on Red Lion Creek Marsh
and on Pigeon Run wetlands. Analyses conducted for the RI indicate that
organic contaminants in the creeks and wetlands at and downgradient from
the leachate seeps are not at levels considered harmful to the ecology.
Table 10 lists the range of concentrations for chemicals detected in the
leachate discharges and surface waters of Pigeon Run, Red Lion Creek, and
the unnamed tributar~ to Red Lion Creek, as compared to the acute and
chronic toxicity concentrations for freshwater aquatic life.
The discharge to Pigeon Run contains some organics that may be toxic
but the discharge has not degraded Pigeon Run to the point where metals
and organics are toxic to aquatic life.
The unnamed tributary does not receive visable leachate and contained
no metals or organics that are either acutely or chronically toxic to aquatic
life.
The leachate discharge to Red Lion Creek enters near the Route 13
bridge in an area of marsh vegetation covered by several inches of marsh
water. Some of the vegetation is stressed directly from the reddish
brown leachate seeps. The leachate contains metals (cadmium, iron,
lead, manganese) that may be acutely or chronically toxic to aquatic
life. The discharge also contains some organic compounds at elevated
concentrations, but none exceed the level for acute or chronic toxicity
where values are available.
The sediments collected at the leachate discharge have a higher
concentratiOn of organic compounds than the leachate itself, but the levels
were below reported toxicity values.
The main potential impacts on ecological biota may be degradation of
water quality due to biological oxygen demand (BODS) and chemical oxygen
demand (COD) loadings, and not from the organic or inorg~nic contaminants
detected onsite. The main source of BODS and COD, in some leachates and
ground water, would be the leachate discharged from the site. In addition,
excess nutrients in the leachates may enhance the production of algae
-------
"0, .
~
LEACHATE CONTAMINANTS
1YBOUTS CORNER lANDRU. SITE
- --... "- .
No. 0' Positive Oetecllonsl Rlnoe 0' CQt1centratlon
..ff.L CAS No. Con'amlnant No. 01 Observations (1!JIlD
4V 71-43-2 ebenzene 4/6 13.0 80
7.V 108-90-7 chlorobenzene 4/6 6.3 615
10V 107-06-2 -1,2-dlchloroethane 1/6 29
16V 75-00-3 chloroethane 4/6 7.2 34
30V 166-60-5 1,2-trans-dlchloroethe"e 3/6 8 160
38V 100-41-4 -ethylbenzene 4/6 20 81
44V 16-09-2 .methylene chloride 3/6t 29 280
86V 108-88-3 etoluene 6/6 10 380
.. , 67-64-1 acetone 6/6 160 3,600
18-93-3 '; -2-butanone (MEKt 6/6 680 11 ,000
95-47-6 o-xylene ' 4/6 18 13
o.
'.
.. Critical Contaminant
t Found In blank @ 60 POll
Table 9
-------
,Aid J-J
~
LlACHA1I ..~... AID "ACe WATIII ANALYIE. AID
fllElIIWATBI AQUAtIC IJfE TOXICIIY
1YIOUJI CORNEll iANOfIU. SIll
LI.." DI8cIuqe to lMIe8t L.Ie"", ....... ".ai...,.
fIowlnl 10 ..... ... ..... .. Unnamed TfIbutuy 11M LIo8 CI8III 10 11M UaII CI88k Acluille LNI To.ltv 111111 .
Chlmlcal eo...d8uI'" 111l1li IUAIft lualft 111l1li Iud Acull ' Qronl
aIumIftuftI NO - ,... , NO - '" ' . .08 -'M NO-IS 1.2..
..enIc I NO-" 14 441 40
.......... .I 200 - UIO / NO - 128 101 - 102 NO - 111 uao 10.000
cldmlwa NO-I a. u-u 0.01 - 0
c~""" NO-" 20 UOO-UOO ..~
If- ... - In.'' --148 \01 - 2U 171 - 241 408.- 1..
Ie.. NO-II ,. 7. - 400 0.1' - 2.
manu.n... 411 - ..... /~I .- 331 .7 - 102 131 - 4.. 4.080 1.-
.
nIc~ NO-" "'00 - a. I. " - ,It
'118 / NO - 114
line NO-. NO-at .. 11-14 20 110 - 170 .7
"-m..""".."" / NO-30
ecetonl NO - 1.l1li 2.400
It.....nl NO-4' II ,.- 211,,1.
2-but....... lID - I." 11.-
cIttotob........ ND-" -... 210 10 ....
CIIIaIo."',,,, HO-I4 - 11"000 20.000
'.
1.2-dIcNorOl'" .. - 21 NO-I 11"- 20.000
"".-1.2""""""" NO - 241 IUOO 4*4 ..t.
....,......... 20 - clIO U.OOO 1.210 .'1
t-......... lID - 210
......."... cbIo8NI NO - 210 . lID - I. HO-' 11.- ...0 ....
...,... .. - ci I - '
t.
Table 10
-------
~
UAClIATE DlSClIAIIOE AND IURFAa WATfJI MAlYSE. AND
fRfSHWATEIl AOUAnc UFE TOXICIIY
TYBOUrS CORNEIIIANDfIU. IRE
'AGE 1WO
Ch.rnk.1 Con."'uenl
loIue..., '
Irtcbloro.,,,....
Vlnyt clllorlde
ayten.
l..ch.t. Dbc""" to DI,.
, Flowing '0 PIg.on Run
luall'
. PIgeon Run
lualla
10 - 3.
NO-I
NO -
-------
30.
with concomitant enhancement of the eutrophication process in the Red
Lion Harsh. Dissolved oxygen deficiency can limit the ecological community
in a marsh. Reconnaissance assessment of Red Lion Creek Marsh indicates
that the landfili has not had a significant. visible. ecological impact
on the marsh. The reconnaissance assessment reports by aquatic and
terrestrial ecologists are provided in Appendix N of the RI/FS.
A draft Site Inspection Report (U.S. EPA TOD No. F3-8212-09) prepared
by the NUS Region 111 Field Investigation Team (FIT) for EPA was reviewed
for this RI because the report contained information and data from samples
of the leachate discharge into Red Lion Creek that were taken in October.
1982. prior to the RIIFS Investigation. The report mentions bioassay
tests were performed in the leachate and Red Lion Creek using Fathead
minnows' and Daphnia ("leachate...prBsumably from the Tybouts Corner
Landfill..." and from a "free-flowing section of Red Lion Creek adjacent
to Route 13 bridge..~"). The report indicates the results of testing
were inconclusive since mortality rates of test animals may have been
caused by low levels of dissolved oxygen. by presence of toxic pollutants.
or by abnormally high levels of naturally-occurring chemi~als. The
chemical analytical results from leachate at this location indicates no
significant input of priority pollutants near the Route 13 bridge. although'
significant levels of lead and iron wer~ found in sediment samples near
~~ landfill leachate. paralleling results in the RI. The sediment
data near the leachate indicate that chromium. cadmium. lead and zinc
concentrations do not exceed the reported toxicity values.
The State of Delaware performed chemical analysis on fish from the
Route 13 bridge area on Red Lion Creek on Hay 31. 1983. The location of
sampling is presumed to be upstream from the point where the leachate
discharge in Red Lion Creek 1s located. Twelve white perch and three
brown bullhead were collected at the Route 13 bridge. The analysis
reports 1.3 micrograms per gram PCB and 0.1 micrograms per gram chloro-
benzene in the composite white perch samples. The composite brown bullhead
samples yielded 0.35 micrograms per gram PCBs. and no'chlorobenzenes
were detected. The levels detected are below the FDA standards for
consumptio~ of fish. The analysis indicated no evidence of other purgable
organics. although the data sheets note that all data is qualitative .or
semiquantitative. Since PCBs are not a contaminant detected at Tybouts
Landfill. and chlorobenzene is not detected in Red Lion Creek near Tybouts
Landfill. the origin of these chemicals in the fish is not considered to
be Tybouts. The origin of these contaminants could be other industrial
facilities which border Red Lion Creek downstream closer to the Delaware
River.
.'
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31
ALTERNATIVE EVALUATION
Objectives
The objectives to be achieved by the selected remedial action are:
ra1nf~-
eliminate or appreciably reduce vertical infiltration of
,'~ugh the main and west fill areas;
2. to eliminate or control lateral migration of ground water into
the main and west fill areas; and
3. to eliminate or control the contaminated ground water presently
in the Columbia Aquifer and the UHZ of the Potomac.
Accomplishment of the first two objectives of remedial action at
Tybouts, in combination, will severely reduce or completely eliminate the
, production of contaminated leachate coming from the fill materials and
entering the ground water aquifers (source control).
"
This source control is accomplished in two ways. A cap over the
landfill will prevent rainfall from entering the fill vertically and gene-
rating leachate. A ground water diversion system will prevent lateral
flow of ground water through the fill.
,
The third objective will be accomplished by installing and operating
a system of wells to pump out the existing contaminated ground water
plume in the Potomac No.1 sand. The contaminated water will be treated,
either onsite or off site, to remove the hazardous materials. Monitoring
of ground water quality will ensure that contamination does not migrate
into usable portions of the aquifer.
Review of Alternatives
The following section describes the alternatives reviewed in the
Feasibility.Study, which are divided into four groups:
A.
B.
c.
No Action Alternative
West Fill Alternatives
Main Fill Alternatives (includes surface cap, ground
diversion and excavation)
Offsite ground water Alternatives
water
D.
A.
No Action Alternative
Tbe FS examined theno-action alternative for both landfills,
surface waters, sediment, the Columbia Aquifer, and the Potomac Aquifer.
A moni toring program ,,:would - be implemented to detect further migration of
contaminants. ' - -
.;0:-
.'
-------
32. .
The no-action alternative for the main and west landfill sources of
contamination would result in continued uncontrolled releases of hazardous
chemical compounds to the major, regional aquifer; and in continued
d1.;harges of leachate to the streams and wetlands around the site.
This alternative is unnacceptable because it would not meet the goals
of CERCLA and would not comply with other environmental regulations.
I.
West Fill Alternatives
11)
West Fill Surface Cap, Ground Water Barrier, Pump, and Treat
(Encapsulation)
This alternative involves surrounding the site with a ground water
barrier, such as a slurry wall or sheet pile wall, to prevent lateral
ground water flow through the landfill, and installing a surface cap and
gas venting system to prevent surface water infiltration. These two
actions will essentially isolate the landfill; however, since there may
be some leakage through the barrier and the cap, a pump will be installed
in the fill to pump out excess water. This water will have to be treated
onsite or disposed of properly offsite. Figure 8 is a conceptual diagram
of the cap, barrier, pump and treatment alternative as applied to the west
landfill.
12)
Excavate West Fill, Place on Main Landfill
Excavation and removal of the contaminated waste of the west landfill
is proposed as a method to mitigate the source of ground water contamination.
The depth of excavation required for -this landfill is 30-35 feet, and the
volume to be excavated is approximately 63,000 cubic yards. The exact
vertical and horizontal boundaries of the excavation will be determined
in the design stage and will be based on a site-specific chemical fate
and transport analysis. Backfilling .with clean soils will be required
for all excavate west fill options.
13)
Excavate West Fill, place in RCBA Landfill Onsite
This alternative conisders excavation of the west landfill and
disposal in a RCRA landfill constructed onsite. If only the west fill were
placed in a RCBA fill the dimensions of the required fill are 300 feet x
340 feet x 20 feet high. 1f the main landfill is excavated and placed
in an onsite RCRA fill, a mucb larger landfill is necessary and of course
the west landfill will be placed in the same RCRA landfill.
A preliminary design of an onsite RCRA landfill was prepared for tbe
proposed excavation. Landfill design criteria used are the Resources
Conservation and Recovery Act (RCRA) Subtitle C (40 CFR Part 265)
"".r
..
-------
34.
regulations and the 1984 RCRA reauthorization amendments for caps and
double liners. An example of RCIA landfill construction is shown on
Figure 9.
84)
Excavate West Fill, Offsite Disposal
!bis alternative considers excavation. and offsite disposal west
landfill excavated wastes. Hauling waste to some existing offsite
disposal area is technically feasible, provided that a facility can be
found to accept the waste. The offsite disposal facility would comply
with EPA RCRA regulations, including the proposed amendment for the
RCIA cap and double liner. Unfortunately, there are very few such
facilities operating at this time, and the cost for disposal at such a
facility is very high.
85)
Excavate West Fill, Oosite Incineration
This alternative considers excavation and onsite incineration of
excavated west landfill wastes. This disposal method involves construc-
tion of one or more rotary kiln incineration units onsite. Mobile incin-
erators are not being considered due to their limited capacity and limited
availability. Incinerator residues will. require either onsite or offsite
disposal.
B6) Excavate West Fill, Offsite Incineration
This alternative involves transporting the waste to an existing,
permitted incineration facility for treatment. The use of an offsite
commercial facility is unlikely at this time. Potential facilities have
only limited treatment capacities and presently have a large backlog of
wastes. The estimated 63,000 cubic yards volume of waste in the west
landfill at Tybouts greatly exceeds the annual capacity of the typical
commercial facility.
SUMMARY TABLE
WEST FILL ALTERNATIVES
Cost
(Million) $
Alternative
Surface Cap, Ground
Water Barrier, Pump
5 .2 to 11.7
Excavate, Place on Main Fill
2.5 to 3.8
Excavate, RCIA Fill Onsite
6.5
Excavate, Offsite Disposal
15.2 to 16.5
Excavate, Incinerate Onsite
".'" 20.4 to 21.9
Excavate,. IncinerateOffsite
40.8. to 45.8--.
.:
-------
~
..
f
Q)
.
-
.
.
.
~
\
\
\
\
,
\-
....
J
(
.
ROUTE
13
o
........
800
ICAU . fUT
lIDO
TYBOUTS CORNER LANDFILL SITE
A
_--I
..
'0 '11(1"111'"
_'Ace CU
:r~~f;~?if(:~ftf:,X(;.iti:.
l:~;~~1..~:.
~~
_=::-.~~~
NOr 10 SCAlE
--I- EXISTING
.TER LEVEL
[[]
~
o
LAHDfIU. WASTE
POTOMAC FORMATION
No. I SAND
--2...- ~¥(WfiVEL
POTOMAC FORMATION
CUY...
... -....
CONCEPTUAL DIAGRAM - WEST LANDFILL
SURFACE CAP. GROUNDWATER BARRIER. PUMP. AND TREAT
TYBOUTS CORNER LANDFILL SITE. NEW CASTlE CO.. DE
E!CL~~
'" A . .-....-.
-------
.
(i)
.".... -
."--'
..,..~ fUU'-
.'--
lOa 0\1-' OOC.... ...OOC"-I
""Q.Af18"'II'_--.
....,u .......,....
...... cau..rC'OI- .... ,.pc ... "1IIIIIq
""'."'''''D'..-c .
I... ...... ....
...-.. -.. -'''''104-1
lOa~ M """'~O"-I
-.-.aM .1It""lDJCra~"..........
1O""~~&.-I..II88D.~,
".Q.A..'..~G....,.,. ""'6I8I..IhJ
..,U,U ...... '-
81!!!1!
~.
tv
j'
-
.
.
.anl
\D
ROUTf 15
--~--=--
~~
"..........~..
\
\
\
~-
)
(
,
'1\-j
)
TYPICAL RCRA lANDFILL CROSS SECTION
NOT TO SCAlE
".
MATERIAlS ExCUTEO fROM
MAIN AN) WEST fUS
WEST fill CIHlY
VOlta\[ Of fLL
BASE LENGTH
BASE WOnt ~
~207,III cu. m
52,444 cu. YO.
I :K)()'
340'
700'
300'
o
.....
100
I2IDO
.
RCRA FILL SIZES
~ .. nET
TYBOUTS CORNER LANDFILL SITE
...
lOCATIONS A"O CROSS SECTION OF PROPOSED RCRA FILL~
TYBOUTS CORNER LANDFILL SITE. NEW CASTLE CO.. DE
(--1E... . .
-__L, a...-.:u
,--
-------
36',.
C.
Main Fill Alternatives
Source Control Capping
Several types of surface caps were evaluated in the initial screening
to determine which cap was most effective in reducing surface infiltration,
and subsequent leachate generation, in the main and west landfills. Each
of the caps analyzed would required a gas venting system, a surface
drainage layer, and topsoil layer. The types of surface caps analyzed
include:
C1)
10-6 Surface Cap
o
A surface cap with a thickness of two feet and a permeability
of 10-6 centimeters per second (em/see). Soil materials
that typically have compacted permeability of 10-6 cm/sec
would include silt, clayey silt, and sandy clay.
C2)
10-7 Surface Cap
,
o
A surface cap with a thickne~s of two feet and a permeability
of 10-7 em/sec. Materials for construction would-1,neiude
clay, silty clay, and clayey silt.
C3)
Multi-layer Surface Cap ,
.." ../ ,
A surface cap designed to RCRA closure
minimum amount of infiltration occurs.
requirements 50 that a
o
The multi-layer cap design is considered to be the best design to
minimize surface infiltration into the landfills. One possible design
incorporates a double liner system consisting of a 30 mil PVC membrane over a
two foot thick soil layer, which will be compacted to a permeability no greater
than 10-6 cm/sec. The design also provides for a gas-venting layer beneath
the double ~iner and a protective vegetative cover above the double liner. A
typical cross-section of this proposed cap design is shown in Figure 10.
Source Control Ground Water Diversion
C4)
Main Fill Surface Ca and Subsurface Drain in the Columbia Formation
with or without Ground Water Barrier
The surface cap and subsurface drain alternative involves placing
an impermeable multi-layer surface cap over the main landfill to eliminate,
or appreciably reduce the vertical infiltration of precipitation through
the fill, and construction of a subsurface drain that would intercept
ground water that moves laterally from the Columbia Formati~n into the
I '
.'
-------
.
"II
f
....
o
.
GAS VENT 4.' PVC PIPE
4'" PVC DRAIN
PIPE'
. . . ...-.....-.-.-~.-......-.....-.:......-.-.....-.~..~
:.:.:.:.:.:.:.:.:.: ~.:. :t:-i.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:
..... ............ .................
PROPOSED RCRA CAP
TYBOUTS CORNER LANDFILL, NE :ASTLE -CO., DE
NOT 10 SCALf
2' VEGETATIVE COVER
GtOTfJlTlLE fiLTER fAeRIC
II DRAINAGE LAYER 'SAND)
JO MIL PVC LINER
2' CLAY (10-7 c,./..o PERMEABILITY)
GEOTEJlTILE fILTER fAIRIC
GAl VENTING LAYER"- GRAVEL)
GEOTEJlTILE fiLTER fAIRIC
WASTE
~~-Y~
o A Hallil
.JO CompanV
-------
38.
fill. A ground water barrier, used in conjunction with the drain, could
be used to increase the efficiency of the drain. Figure 11 shows the
surface cap/subsu~face drain (with or without ground water barrier)
:~-." -...'~",'>ve, as applied to the main landfill.
'~rface dratn considered for this feasibility study includes
a pe~.~' .pe system constructed in the Columbia Formation along the
eastern an~ ~o~thern boundaries of the landfill as shown on Figure 11.
The subsurface drain would be constructed in the natural sand and gravel
materials along the perimeter of the landfill and would extend below the
elevation of the base of the fill, into the Merchantville Formation.
The subsurface drain functions as a ground water sink that collects the
ground water and lowers the water table on either side of the drain.
The reliability and efficiency of the drain would be increased by
a ground water barrier on the landfill side of the drain. There will
always be a possibility that clogging of the drain may occur by siltation
or leachate. There should be a monitoring well system in the drain to
determine effectiveness and repair zones. During construction, methane
and other gases would enter the trench. Forced air ventilation is needed
to prevent explosions.
,
. Ground water that enters the drain then enters a perforated pipe
near the base of the drain, and the water is transmitted by gravity
flow, to the discharge point. Since the ground water collected in the
drain originates in either the landfill or contaminant plume of the
Columbia Formation, the discharge from the drains will require treatment
until acceptable levels are obtained at the end of the drain. Any discharge
would comply with NPDES standards.' .
CS)
Main Fill Surface Ca and Ground Water Pum in in the Columbia
Formation with or without Ground Water Barrier
The surface cap/ground water pumping alternative is very similar to
the surface cap/subsurface drain alternative, except ground water pumping
is used to lower the water table and prevent ground water from migrating
laterally into the main landfill. Figure 12 is a conceptual diagram
showing the surface cap/ground water pumping (with or without ground
water barrier) alternative.
The multi-layer surface cap and ground water barrier and treatment
portions of this alternative are described in the previous sections.
The ground water pumping portion of this alternative is to continuously
maintain the water table at or below the base of the landfill. The ,
ground water pumping system would require a water collection and treatment
system before discharging to the local drainage.
. .,.
-------
TYBOUTS CORNER LANDFILL SITE
TYPICAL SECTION A-A'-WITHOUT BARRIER
-MMFACCCAT
+s,i- .• • . •!••-« r
40
SO'
10-
LfCCtfg
J. (MTMtmTENLCVCl
5Z. KMtOMLMIINLtVCL
•O-
MMVfLHMIM - O
TYPICAL SECTION A-*'-WITH BARRIER
s~
~-» * ~" '
CONCEPTUAL DIAGRAM -MAIN LANDFILL
SURFACE CAP. SUBSURFAC
TYBOUTS'CORNER LAN L SITE. NEW CASTLE CO^ DE
IN J
-------
41
Pumping in conjunction with the ground water barrier significantly
increases the capabilitY,and the reliability of the system.
This alterna~ive may not be feasible fc: remediation of Tybouts
Corner Landfill site because the reliability of this system is directly
related to the operation and maintenance of the pumping system since a
failure of a pump or well would lead to resumption of lateral ground water
flow through the landfill. The water level in the fill material will be
immediately affected by a breakdown in the system and leachate production
would resume.
Engineering design of a ground water pumping system to dewater the
landfill and prevent lateral ground water flow from entering the landfill
would require a more detailed design-investigation consisting of several
test and observation wells along the eastern and northern perimeters of
the fill.
C6)
Main Fill Surface Cap/Diversion Trench
The surface cap and diversion trench alternative involves excavating
a diversion trench along the eastern and northern borders of the landfill
that isolates the landfill from the surrounding ground and ground water
syst~m and placing a surface cap over the main fill and side-slopes of
the trench. Figure 13 is a conceptual diagram showing the surface cap!
diversion trench alternative, as app,lied to the main landfill.
.
The diversion trench would be excavated in the landfill materials
to a depth either below the base of the landfill or the depth required
to maintain grade' for drainage, as shown on Figure 13.
The diversion trench can be excavated using co~ventional methods.
The main health and safety concerns are those individuals associated
with excavation of the landfill to constru~ the open trenches. Excavation
may require respiratory and dermal protectio'ft... ".
Construction of the trench will require provisions for controlling,---
collecting, -and treating contaminated ground water that will enter
the trench. Wastewater characteristics and the treatment required are
expected to be the same for all main landfill alternatives.
Source Control Excavation
"
C7)
Excavate Main Fill, RCRA Landfill Onsite
Excavation and removal of the contaminated waste of the main landfill
is proposed as a method to mitigate the source of ground water contamination.
Excavation depths are expected to be up to 36 feet in some areas of the
.'
-------
KI
TYPCAL SECTION A-A'-WITHOUT BARREN
TYPICAL SECTION A-A*-WITH BARRIER
TYBOUTS CORNER LANDFILL SITE
» jo^
KM.C IN fitt
CONCEPTUAL DIAGRAM
SURFACE CAP. GROUNDWATER PUMRNG(WITH AND WITHOUT BARBER)
TYBOUTS CORNER LANDFILL SITE. NEW CASTLE CO, DE
RE.
L—LjOORf-vjrl
-------
TYPICAL SECTION A-A*
-t
M^^j^&mlfe^^^^^^
TYPICAL SECTION B-B1
TYPICAL SECTION C-C1
-f | COLUMU FOMMTMN
UCMCHANTVILIC FOMMTIOM lift*' (LANDFILL
TYBOUTS CORNER LANDFILL SITE
CONCEPTUAL DIAGRAM-MAIN LWDHLL SURFACE CAP. DIVERSION TRENCH
TYBOUTS CORNER LANDFILL SITE. NEW CASTLE CO. PE
J!
OORPORATi
-------
43 -
main landfill. Volume of excavation for the main landfill is nearly 1.5
million cubic yards; it will be assumed that, if the main landfill is
excavated, the west landfill also will be excavated and disposed of in
the RCRA landfilr.
Excavation can be completed using conventional methods. However,
large volumes of water will be generated by the excavation-, and this
water will require treatment. Wastewater characteristics and the treatment
required are expected to be the same for the previous main landfill
alternatives. Also, safety requirements will increase the time and cost
for excavation. The wastes will be compacted before disposal.
Once the excavation of the waste is completed, the main landfill
will be regraded to avoid ponding water. The west landfill will require
a deep excavation to remove the waste, and regrading will not be possible.
The west landfill Will require backfill with clean soils. Both areas
will be revegetated when work has been completed. The location of the
proposed RCRA landfill, and a typical cross-section are shown previously
1 n Figure 9.
C8)
Excavate Main Fill, Offslte Disposal
This alternative is similar to Excavate ODsite Disposal since it
involves excavation of the main and west landfill but presents another
. option for disposal. Here the excavated waste material wouid be loaded
into trucks and hauled to a permitted hazardous waste landfill for
disposal.
C9)
Excavate Main F1l1, Ons1te Incineration
This alternative would involve excavation of both the main and
west landfills, with ons1te incineration as an option for disposal.
This disposal method involves construction of one or more rotary
kiln incinerat~on units onsite. Mobile incineration is not being
considered 'due to limited capacity and limited availability.
A rotary kiln incinerator would decontaminate the wastes by burning
at a temperature in excess of 2,000°F. By-products of incineration are
gases a~d noncombustible particulate matte~ (anlch 18 removed by an
air pollution control device) and bottom ash and fly ash. The bottom
ash and fly ash. approximately 20 ptrcent of the original volume of
waste, will probably be considered hazardous, and will have to be disposed
in a secure RCRA landfill.
The large volume of waste makes this a very costly and time-
consuming alternative. It is estimated that a large capacity rotary
kiln (50 million BTU/hr) can incinerate approximately 7,000 lb/hr. At
.-
-------
44
this rate it would take 65 years to incinerate the entire landfill using
only one incinerator. In order to maintain a reasonable time frame, the
nuober. of incinerators must be increased.
Excavate Main Fill, Offsite Incineration
. This "':..sposal method involves hauling the excavated wastes to an
offsite permitted incineration facility. Since this is such an unlikely
possibility, no costs have been calculated.
SUMMARY TABLE
MAIN FILL ALTERNATIVE
Alternative
*Cost
(Millions) &
Surface Cap, Subsurface
Drainage (with and without
a ground water barrier)
35.8 to 69.0 with barrier
32.9 to 64.4 without barrier
Surface Cap, Ground Water
Pumping (with and without a
ground water barrier)
,
18.1 to 54.9
Surface Cap, Diversion Trench
Excavate, RCRA Landfill Onsite
34.2 to 70.9 (both f11ls)
53.6 (both fills)
Excavate, Offsite Disposal
246.7 (both fills)
370.7 (both fills)
Excavate, Onsite Incineration
Excavate, Offsite Incineration
*
The-costs of these alternatives includes the multi-layer cap
over the main fill area after consolidation of the west and
main fills. Also, the treatment system is included for an
onsite facility which will remove contaminants from the ground
water and will discharge water in technical compliance with NPDES
standards.
D.
Offsite Ground Water Management Aiternatives
Dl)
One Pumping Well at OR-6A
This aquifer remediation alternative involves establishing a production
well for water supply use by Texaco Marketing and Refining Company using
the present well at the location of well OR-6A. The location is approximately
3000 feet away and on'" the 8o.rthern side of Red Lion- Creek ,from, the s1 te.
Texaco would use the water for their operations.
.'
....a - o#.r.
.'
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45
"
I
Pumping of a production well at location OR-6A would draw contaminants
to the well wher~ Texaco would mix the water with water from other wells
for use in their facilities.
This alternative will cause accelerated degradation of water quality
further and deeper in the UBI than currently exists. Ground water use
restrictions will be imposed between Well OR-6A and the contaminant plume.
Also, because of the layering of sand and clay lenses in the UHZ,
there may be areas of the plume which will not be drawn to the production
well.
Ground water contamination could reach this production well within five
years and will requir~ continuous pumping for an extended period of
time, possibly. 20 to 30 years.
A long term monitoring program consisting of periodic sampling and
analysis for organic compounds should be implemented if the well is used
for production. Monitoring on a quarterly basis should be sufficient to
detect plume interception.
,
D2)
for Contaminant Plume Remediation and Water
West and Main Landfills
This alternative involves installation of two new production wells
that will be used to collect the contaminant plumes migrating from the
west and main landfills. One well will be located immediately downgradient
from, and slightly beyond the contaminant plume migrating from the main
landfill; and the other within the contaminant plume immediately downgradient
from the west landfill. Both wells will be be located to optimize contaminant
plume collection and aquifer remediation. The location and a conceptual
diagram of these wells is shown on Figure 14.
An estimate of the pumping rates and effectiveness in remediating
the contamiDant plumes was made using ground water modeling described in
Appendix M of the RIIFS Report. Simulated pumping rates of 110,000
gallons per day for the main landfill well and about 6,000 gallons per
day for the west landfill were estimated for the pumping. The actual
pumping rates required may be different from these simulated rates, and
actual pumping rates should be determined by a design investigation
(pump test) prior to final design of a treatment system. Solute transport
model simulation indicates these rates are sufficient to stop further
migration of the plumes, and to collect the plume for remediation. ~,c
simulation indicates that remediation of the plume from the main lana:ill
may take from 20 to 35 years of fairly continuous pumping.
Ground water pumped from the contaminant plume will have to be
collected and treated before discharge to local surface waters. Technical
~ompliance with all.env1ro~ntal laws will be maintained.
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\ -?
TYBOUTS OWNER LANDFILL SITE
accnoN A-A'
TYPICAj SECTION •-»'
FORMATION
POTOMAC FORMATION
NtlSANO
£o J COUJMHA FORMATION
NENCHANTVILIC FORMATION
NOT TO SCALE
CONCEPTUAL DIAGRAM-MAIN AND WEST LANDFILLS
IHTERCEPTIQfLANILflEMEPIATIQM
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47.
Three pumping wells for the Main Landfill Plume:
Well for the West Landfill Plume.
One Pumping
D3)
The three well system for the main landfill consists of placing
three wells close to the landfill, within the contaminant plume. The
three well alternative was evaluated for comparison to the installation
of one well to collect the plume from the main landfill.
The three-well system involves pumping and treating the aquifer until
contamdnants derived from the landfill are removed to levels that are
acceptable. Pumping wells are located in the plume 80 that only contaminated
water is removed for treatment. Contaminanted ground water pumped from
the wells must be treated and discharged as previously discussed.
The pumping rates for the three wells were estimated by using the
ground water model discussed in Appendix M of the RIIFS report. The
simulated, combined pumping rate was 33,800 gallons per day. The estimated
computer simulated time required for aquifer remediation 1s between 40
and 100 years.
The one pumping well to inte"rcept and remediate the west fill plume
is the same well described for the west till in Section D2.
t
F1gure 15 shows the estimated location and a conceptual diagram for
the three-well system alternative.
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h*-
1
M
Ul
TYBOUTS CORKER LANDFILL SITE
Q
.-•.•.': **-iiis.'.'j?**1
#&3iMg
J5svlji •.;„•.- *»lt\-'v
4*~5;'<:|-*?'v::V
ajKS
TYPICAL SECTION A-A*
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m
:|l|=gl|r€¥5;gr"J
trL"£JSJi*sa>TgLrigjtj&
TREATMENT
POTOIMC
CUV
FOmMTIOM
POTOMAC
N*. ISAMO
COLKMttA FORMATIOM
MENCHANTVN.U FORMATKJN
NOT TO SCALE
CONCEPTUAL DIAGRAM -MAIN LANDFILL
CONTAMINANT PLUME INTERCEPTION AND REMEDIATION
TYBOUTS CORNER LANDFILL SITE. NEW CASTLE CO., DE
IN J£
CORPORATE:
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RECOMMENDED ALTERNATIVE
Section 300.68(j) of the National Contingency Plan (NCP) states
that the appropr~ate extent of remedy shall be determined by the lead
agency's selection of the remedial alternative which the agency determines
is cost effective (i.e., the lowest cost alternative that is technologically
feasible and reliable) and which effectively mitigates and minimizes
damage to and provides adequate protection of public health, welfare and
the environment. In s~lecting a remedial alternative EPA considers all
environmental laws that are applicable and relevant. Based of our
evaluation of the proposed alternatives, the responsible party evaluation
of alternatives, the public comments and the information received from
the Delaware Department of Environmental Control, we recommend the following.
The alternative for source control selected here is B2 in combination
with a variation of Alternative C4, the Main Fill Surface Cap and Subsurface
Drain in the Columbia Formation. The multi-layer cap which complies
with RCRA standards will be used. The difference from the alternative
described in the FS is the location and length of the subsurface drains.
The basis for acceptance of the alternative is how effectively it
can lower the water table in the fill. As part of the Feasibility Study,
the U.S. Geological Survey (USGS) three-aimensional, finite-difference
model developed by McDonald & Barbaugh was used to represent what the
three-dimensional effects would be. The proposed conceptual design of
the subsurface drains consists of an' upgradient interceptor subsurface
drain and a downgradlent contaminated ground water control subsurface
drain as shown on Figure 16. Design modeling showed. that it could effec-
tively lower the water table within the landfill. More dp.tal1ed information
about the ground water modeling can be obtained in Volume V of the RIIFS
report.
The alternative selected for the offsite ground water contamination
is some variation of D2 or D3, pumping wells for the main landfill and
for the west landfill. However the exact number of wells, location and
pumping rates will be determined by a design investigation. . Figure 17
shows possible locations of the ground water recovery wells.
The specifics of the recommended alternative are:
1)' The west fill will be excavated and consolidated with the
main ~ill. Excavation will include all municipal and industrial
wastes as well as contaminated subsoils. The amount of
contaminated subsoil to be removed will be based on a site
specific chemical fate and transport analysis. This analysis
will be conducted to ensure that no soil remains in place which
could cause ground water contamination to exceed the standards
established in this Record of Decision. The excavated area
will be backfilled with suitable clean fill material.
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DIAGRAM 2
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S.-.4-
i '
DRAF
ftflOUMDWATER CONTOURS.
FORMATION N« I SAW
TVBOUIS CORNER UWntlSIIC
KMIMfK
rtOPOSfO SWVttMtNTM.
weu.
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52.
i
;
2)
A multi-layer~d cap that complies with RCRA will be placed
over the consolidated main fill area to significantly reduce or
eliminate the vertical infiltration of precipitation.
3)
A subsurface drain or trench system will be installed to prohibit
continued lateral migration of ground water through the fill and
to collect existing leachate from the fill. The multi-layered
cap and the subsurface drain/trench system together are intended to
dewater the consolidated fill. This ground water diversion system
and multi-layered cap will be maintained until they are no longer
needed.
4)
The offsite plume of contaminated ground water in the Upper
. Hydrologic Zone (UHZ) of the Potomac will be pumped and treated
or otherwise disposed of, either onsite or offs1te. During the
pumping institutional controls to restrict use of the ground
water will be utilized.
The goal of the offsite ground water pumping will be to reduce
the level of contaminants to 100 ppb of total volatile organics
with separate standards for the following cancer-causing
contaminants where HCL's are available. The levels for these
specific substances are listed here.
,
Vinyl chloride
Benzene
1,2-Dichloroethane
1.0 ppb
5.0 ppb
5.0 ppb
These standards are anticipated to meet the goal of a 10-4 cancer
risk at the boundary of the landfill property.
Ground water will be pumped for a minimum of three years, at
which time pumping will be discontinued if contaminant levelR
have been reduced to standards set above. If the standards are
not reached, pumping will continue for another three years. If
after that time the standards have not been met but pumping has
acnieved substantial compliance with the standards and the
levela of contaminants are constant in each well, pumping will
be discontinued. If not, pumping will continue for another
four years. If after the ten-year pumping period, standards
have still not been met, EPA will evaluate the technical feasi-
bility of meeting the standards and set new ones if necessary.
Pumping may be terminated if it is shown that no reasonable
modification of the pumping system or additional years of pumping
would produce significant improvement.
EPA will then examine the need. for additional monitoring locations
to assure that the influence of any offsi te production well wi.ll
not affect the~remainlng contaminated ground. water from Tybouts
Corner Landfill.
....
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53.
The offsite contaminant plume in the Columbia Aquifer will be allowed
to flush itself clean. Once the source control 1s in place, no
further contamination will enter the Columbia Aquifer and we predict
that it-could take between 10 to 15 years for all of the water that
is contaminated to pass through the aquifer and seep into the Red
Lion Creek Marsh. In the area of contaminated ground water, the
Columbia is not hydraulically connected to the Potomac and the
pumping of the Potomac should not influence the path of the Columbia
contaminant plume.
5)
Contaminated water generated by excavation, construction, sub-
surface drainage system collection and ground water pumping will
either be sent to a local sewage treatment plant offsite, or
treated onsite. It is possible that a combination of these two
treatment systems and locations will be used. All treated water
will meet NPDES standards before disposal to surface waters,
including any pre-treatment requirements id the local sewage
treatment plant is utilized. All waters will be disposed of in
compliance with local, state and federal law.
6)
A health and safety plan will be implemented for all activities
described in this Record of Decision. During excavation and
construction activities, air monitoring will be conducted to ensure
the safety of the onsite workers as well as to protect the residents
living nearby the excavation areas.
t
7)
A monitoring program will be established to ensure that ground
water quality, surface water quality, the. multi-layer cap and air
quality are maintained.
Operation and Maintenance
~".
Operation and maintainance will consist of maintaining the effectiveness
"-
o~ the RCRA cap, maintaining the subsurface dra~n system to'~revent clogging
up or overflow, and maintaining the pumps from the drains to the treatment
system. If an onsite treatment plant is constructed operation and mainten8~-
will include the treatment system and proper disposal of contaminants.
Long term monitoring of the offsite ground water plume will be necessary
to ensure the following two things:
"
1. that levels at the boundary do not exceed the standards after
the pumping is discontinued, and;
2. that monitoring wells which are used to ensure no further spread
of contamination remain uncontaminated.
If standards are exceeded at the boundary or if previously clean
monitoring wells become contaminated pumping and treating will be resumed.
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54.
Consistency With Other Environmental Laws
The west fill will be closed in accordance with the RCRA closure
re~uirements of 40 'CFR S264.228(1) by removing all wastes and contaminated
5 "' as discussed in the description of the selected remedy.
f~E multi-layered surface cap will be designed and constructed
in accordance with the RCRA requirements 40 CFR S264.310.
The ground water diversion system will be designed and constructed
to effectively "dewatern the main landfill. During construction the
contaminated water will be disposed of in compliance with all local, state
and federal regulations.
The offsite ground water contaminant plume will be pumped and treated
with the goal of compliance with RCRA through establishment of standards
to be met at the boundary of the facility. The goal is to meet the corrective
action requirements of 40 CFR 1264.100.
EVALUATION OF ALTERNATIVES NOT SELECTED
Alternative A1 was rejected for reasons stated in the no action
alternative description.
~est Fill Alternatives
The Surface Cap, Ground Water Barrier and Pump alternative is techno-
logically feasible but the costs are excessive, when we consider that
the west fill is only the smallest portion of the ent1re site. In addition
it is simply not as effective as removal. The west f11l 1s presently in
the Potomac No.1 Sands where they are connected to the Potomac No.2
Sands. Any breakdown in the barrier .or the pumping system could allow
continued migration of leachate from' the west fill area.
Once the dec1sion 1s made to excavate the cost effectiveness determined
the choice ~o place the excavated material on the Main f111. The other
alternatives (B3, B4, B5 and B6) were millions of dollars more.
Main Fill Alternatives
Source Control Capping Alternatives
Evaluation of the effectiveness of these three caps was based on the
amount of rainfall that each cap would allow to enter the f1ll materials.
The 10-6 cap (alternative C1) allows approximately 60% of the present'
amount of water to enter the f11l (26,000 gallons per day). The 10-7
cap (alternative C2), allows 7% (3,000 gallons per day) and the multi-
layer cap (alternative eJ) allows 2%(800 gallons per' day).. .
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,),)0
Therefore the most effective cap will be the multi layer cap that
allows the least amount of water to pass through the fill. The 10-6
cap and the 10-7 cap would allow too much water to enter the fill an
create more leachate. In addition, Superfund policies require the selected
alterative to be consistent with all environmental laws. In this case,
compliance with RCRA closure requirements (40 CFR Part 264) require a
cap that meets RCRA standards. However, there is a great deal of flexa-
bility in the design and type of materials used to construct such a cap.
Source Control Ground Water Diversion Systems
Alternative C5 consisted of dewatering the fi11 by ground water
pumping in the Columbia Formation. This alternative was not selected
because the effectiveness of the pumping is controlled by the reliability
of the ~umps and the wells to be pumped. Any breakdowns would allow
lateral ground water ~low.
Alternative C6, dependant on divertion of lateral ground water flow
by open diversion trenches, was rejected for two reasons. One, the
local residents had concerns about an open trench with a 40 foot drop.
They felt this would become an attractive playground for local children
and there would be a possibility for accidents.
The seco~eason 1s that this ground water diversion system was
more expensive than the selected alternative and does not provide a
significatly greater degree of protection for public health and the
environment. The higher costs of this alternative are due largely to
the fact that the open trench would have involved much more excavation
of the landfill material, when digging out the trenches.
Alternative C7 proposed excavation of all the fill materials and
placing them 1n a new RCRA landfill on the site. This alternative is
rejected for two reasons. The location onsite is a sand and gravel pit
which has been excavated to the UHZ of the Potomac. Therefore, the
landfill would be built directly on the regional aquifer we are trying
to protect. It is true that witb proper construction, tbe environmental
receptors c~uld be protected. The costs of this alternative would be
greater than the other effective methods.
The remaining Main Fill alternatives (C8, C9, and CI0) are clearly
not cost-effective since they are estimated in the hundreds of millions
of dollars.
Ground Water Management Alternatives
Alternative Dl, pumping at Texaco's well location OR-6A was rejected'
because it will cause the contamination to spread from its present distance
of 400 to 800 feet from the landfill to about 3,000 feet from the fill.
Organic contaadnants could reach the well within 5 years. Concentrations
, '
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56.
of organic contaminants at the well are expected to be very low and
possibly non-detectable, but levels between the production well and site
will probably be high enough to pose a risk to human health 1f the water
were used. -. .
. .~~cific treatment alternative is not selected in this Record of
~~._. :3ecause there are several options available for treatment which
are equally effective. Offsite, a publicly owned sewage treatment plant
may be available or an onsite treatment plant coul~ be built. This
Record of Decision simply establishes that treatment is necessary and that
disposal will comply with local, state and federal law. Any onsite
treatment system may require a treatability study prior to construction.
Responsiveness Summary
The Feasibility Study (FS) and the complete list of alternatives was
presented at public meeting held July 23, 1985. Another FS meeting was
held on December 18, 1985, at which EPA presented the Preferred Alternative.
In response to the December meeting a petition was signed by 192 people
and a response was prepared and sent out. Minutes from the meetings,
the petition and response are included here.
.
Over all, community relations have been on going since the first
meeting held in March 1983. During the course of this Remedial Investiga-
tion and Feasibility Study ten public meetings have been held. Occasionally,
monthly news letters were prepared, other meetings were held with local
citizens in private homes and during the water line construction an EPA
representative was able to talk with most of the homeowners who were
offered the connection to the public water supply.
. ,
Most of the discussion about the recommended alternative focused on
the time period for remedial action. The remedial action includes' main-
tainance of the surface cap and the ground water diversion system for as
long as they are necessary and pumping related to the ground water diversion
will be maintained. However, the pumping associated with the offsite
ground wate~ contaminant plume may be discontinued if the standards set
by this ROD are met.
.,
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A SUtltARY OF
CITIZEN AID IfCTERESTED-PARTY CCMDTS AND CONCERNS
AID Of U.S. ElYIROIOUTAL PROTECTIOI AGENCY RESPONSES
TYBCIITS CORNER LMDFILL SITE
PUBLIC 1&11116
TYBOOTS CORIIER. IEW CASTlE ccum. DElAIIARE
JULY 23. 1985
Public and Enyironlefttal Health
Iss..: .
Response:
Issue:
The site fs affecting the health of co_unft)' resfdents and their
claUd.... A nUliber of citizens belfewe the area has a hfgh naber
of cancer netf.s; one person stated that 60 percent of the deaths
'n the count)' are fro. cancer. Another safd he deyeloped the
disease 8fn 5 .onths.8 These people were certain the T)'bouts
Col"IIer Landfnl Sfte fs responsible for nlnesses fn the area.
The air quality at the Tybouts Corner Landfill Site poses no risk
to the community. Two local wells were affected by the site. Th~
Wagner well has been abandoned, and a.treatment system was
connected to the Woytko well. These are the only wells affected to
date. "0 municipal water supplies have been affected by the
Tybouts Corner Landfill Site. . .
"'n1 people in the area hunt and ffsh near the sfte. Conta.fnated.
groundwater is known to be entering local surface waters. How does
this conta.inatfon affect the .wfldlffe that feeds. in the area and
does the contufnatfon affect the food chain? Can people beco-
i11 fro. eating local1y caught ffsll and ga.?
Response: The Department of Health 01 the State of Delaware has sampTed fish
1n 'areas proximal to the Tybouts Corner Landfill Site, and the'
Department of Health does not consider the fish to be a threat to
huaian health.
Issue:
Shouldn't a health surye)' be conducted?
Response: The purpose of the RI/FS is to remedi ate the landfill and the
groundwater contamination, not to conduct a health survey.
Costs and' Funding
~
Issue:
. ReSponse:
More 1.port&nce is being g1wen to relledfa' costs than to the effect
tile site fs having on hU8lft health. 10 cost should be spared when
h..... health is at state. .
......."""""
All technically feasible alternatives that would utilize known and
proven techn1questo ~mediate the Tybouts Corner Landfill. Site :-
. were. examined: wfttlout;regard.. to. costs. -Costs' were.".erely. reported.
for each alternative. .. The' cost 'effectiveness of each alternative
is considered during selection of the fin~l relledial alternat1'1e
,. .
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that w1ll be implemented, but not at the expense of human health or
of the environment.
Wi11 the potentfally responsible partfes (PRPs) be requfred to pay
for cle",up? If not. where does Superfund get fts lIOIIey?
Response: Yes, the PRPs are responsible for costs. Superfund money comes
from the Comprehensive Environmental' Response, Compensation and
Liab1lfty Act (CERCLA), passed by Congress fn 1980.
Issue:
Technical Questions
Issue:
What is the goal of the RIfFS? Is it total cleanup?
Response: The stated objective is to find the most cost-effective method to
protect the public health and the environment from current
contamfnatiQn and from potential contamination.
Issue:
Response :
Issue:
Haye any of the optf ons proposed for cleanup been done anywhere
else?
All of the technologies evaluated during the feasibility study have
been successfully utilized at.othe~ sites. However, each site 1s-
unique, and technologies that work well at one sfte may not be
app1fcable at other sites. "
When can we expect construction of the final re8ed1al action
.lternatfye to begin? .
Response: Hopefully, construction .will begin by December 1986.
Issue:
Response :
What i8P8ct is the site currently haying on existing .ells?
Currently, the sfte 15 not affectfng any munfcfpal water supply
. wett s. Two private wett s dfd become contaminated; one has been
abandoned, and the other f s now connected to a treatment system.
In addftfon. all local well users have been connected to the
mu~i~fpal water supply.
Is it 8easurable in
How great an area is currently conta.inated7
square .n es?
Response: Presently; contamination of the regfonalaquifer extends 400 to 800
feet east to southeast of Route 13. Contamination has also spread
several hundred feet north of Route 71. .
I.ssue: .
Issue:
110.. do you know that the ColU8bia Aquifer and the Pote.ac Aquifer
are connected?
Response: Drillfng samples and logs show that the 'Columbia . formation 11es:
directly on top of the Potomac formation sand north and northeast
.of the site.' One boring. located within the'lIa1n landfill, showed';:'
as.a11 area,.where there was no intervening. low-permeability layer' .
'. . between conta81nate(t'landf1n 'inaterials and the Potomac' formation
sand.
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. EPA GUide11nes
Issue:
How does Superfund restrict future use of the sfte?
Response: The EPA- w1.11 ask the county and the property owner to restrict the
property deed.
Issue:
10 lluardous ..stes are to be 80Ved on or off tile sfte; yet trucks
have been seen hau1fng sand and gravel fro. the sfte. Why doesn't
anJUH stop thfs?
Response: Sand and gravel are not hazardous was~es.
Re8edial Action Alternatives
Issue:
Isn't incineration considered to be the best .ay to handle
hazardous ..ste?
Response: Yes, it is one of the best methods, but the cost of fnc1nerating
wastes frail the Tybouts Corner Landfill 1 s est1 mated at $350
m11110n. . .
Issue:
Response:
Issue: .
.
t
"astes can be excavated and re80vedto offsfte fncfnerators such a,.
the fncfnerator referred to as the .Blue 600se.. If thfs isn't
possible. an fncinerator can be bunt on site.
. .
The use of an offs.ite commercial facility is not likely at this
time. Approved' facl1it1es have limited treatment capacities and
large backlogs of wastes. The volume of wastes at the Tybouts
Corner Landfill Site is estimated to be 1.5 million cubic yards;
this volume greatly exceeds the annual maximum capc1ty of a typical
commercial facility.
Ons1te incineration would be very costly and t1me consuming because
of the large volume of wastes at this site. The estimated capacity
of a large volume rotary kiln (50 m11110n BTU/hr.) is 7.000 lb/hr.
It would take 65 years, at this rate, to incinerate wastes at the
Ty~outs Corner Landfill Site. To achieve a reasonable schedule for
remediation, several incinerators would have to be built, and the
cost would be prohibitive.
An oftsfte incinerator .ight be the best idea. When the onsfte
contufnated .astes are a11 processed. the fncinerator could be
used to burn .aste fro. other sftes. Using the incinerator to
process .astes fro. other sites would provide .uch needed jobs .nd
revenue for the co_unity.
Response: See res~nse which directly precedes this one.
Issue:
Does fncinerat10n create an air pol1utfon probl.?
Response:....6ases..and.',.vapors generated dur1 ng the.i nc1neratton. process .~are "
destroyed' in an afterburrier" 'chaMber;':" B)1Jroduct gases' and
noncombustible materials are removed from the gas stream by at
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Issue:
60
least one of the numerous air pollution control devices available
on the market.
If an onsfte landff11 1s chosen. .f11 it be used to dispose of any
.astes .other than those fro. the sfte ftself?
Response: Possi bly.
IIIterfal s.
Superfund money woul d only be used for exi sting
If EPA decfdes to pu.p the groundwater. how long wf11 pU8pfng be
necessary?
Response: Dependfng on the pumpfng scheme, tentatfve estimates indicate that
between 10 years and 100 years would be needed to cleanse the
groundwater. .
Issue:
Issue:
Response:
IftIat fs the. yol... of water 8vfng through tile sfte each day?
The volume of leachate generated by the inffltration of
precipitation into the landfill is estimated to be 43,700 gal/day.
The total volume of groundwater movi ng through the landfill each
day is estimated to be 51,000 gallons. '
Re8edf11 Actfon Alternatives Suggested by Citizens
.;
There 1s no need to spend lIOftey on bul1c11ng fncinerators when Sod
has provfded volclnoes that produce enough helt to bum anything
tllat fs put fnto the8. .
Response: The nearest actfve volcano within the United States is Mount St.
Helens. Transportfng hazardous materials would fnvolve interstate
transport and the construction of transfer stations to handle the
wastes at both the point of origin and the destination. Placing the
, wastes into the volacano would be hazardous to workers. These
, ',factors would greatly increase the risks to. the public and to the
environment. The technical aspects involved. as well as the health
an4 safety aspects and the costs. make this option infeasfble at
this time.
Issue:
i
I .
"
"
Issue:
"
Response :
',,-
.
Cont8f nlnts can be frozen fn the ground.
The freezfng option is commonly used on small-scale projects of
short duration to facilitate engfneering activities for civfl
engine~ring works. It is not a proven optfon for hazardous waste
dfsposal, and containing waste materials by this method would
require maintenance in perpetuity. Cost would be extremely high.
IIlIy not dfg I core fnto the [center of the] elrth Ind forc~ 111 of
tile waste fnto ft? .
Response:.: Deep disposal options have been extensively investigated and.
. considered for high-level nuclear wastes but, at present,. there are. :".'.
. nO':.areas'.o1. this' typer.>'ava.i1able... for:. storage' of"'hazardous.: wastes~:'
Issue:
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. '
Underground disposal is not viable at the Tybouts Corner Landfill
Site because of the depths to which the aquifers extend. Since
there are no approved offsite facilities, this option cannot be
considered for the Tybouts Corner Landfill Site at this time.
-
InforwatfOll Repositories
Issue:
Tile current fnfor8atfon reposftorfes are fnconyenient; why not
estOlfs" one at the IInll1ngton City Library?
Response: Fine, we wi11 place copies of the RI/FS in the Wilmington Library.
,
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PRELIMINARY DRA"
. JEETIII8 SlllMRY
TYIaUTS CORIER UlDFILL SITE
':,"."JTIaUtS CGII£R, lEV CAS1U COUIITT. D£1AMAR£
.c ;,-.,..,.,- DECEJ8£R 18. 1.5 .
.. .. ::~. ~.. .
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"' ,
On DeclMber 18. 1985, the U. S. Environment.l Protlction Aglncy (EPA) and t~1
Oehware Dlpartllent of Nat"".l Resollrces and Environm.ntal Control (ONREC)
hlld a pUb1fc meeting at 7:30 pm fn the Gunnfng-Bedford Junior High School.
Represlntfn, th..EPA at thl lIeeting were Ed Sternolis, Sitl RlsponSI Siction
Chilf, Ann Cardi,,,al, Region III Community Relations Coordinator, and Roy
Schrock, Reg1ona1 Site ProJICt 0'f1clr. The DNREC rlpresentatfvls were Mikl
Apgar. Suplrvfsor of the GeohydrOlogy Branch; Bob Picklrt, Environmlnt.l
Engineer, CERCLA Man.gement Brlnch; GusoMIrgantha11r, Environ.lntal Eng1neer,
RCRA Management Brlnch; and Xathy ~amfson, Informitton Officlr. C.rrfe
Deitzll, COII.un1tY~1atfons Specialist, attended for NUS Corporlt10n.
.' !
The ..Iting was opened by Kathy Ja.ison who exp11ined that the 'PU~OSI of thl,
IIllting wal to discuss the preferred remedia1 alternative for thl Tybouts -
Corner Landfill Site. Ms. da.tson strlssed that the choici of remldfa'
al temetives .was not final. Before turning the .eetin, Ov.r. to Mr. Schrock.
she told thl audfenc. that DNREC technical personnel'; Wlrl present. Anyone
wishin, to discuss technica1 mltters after the clos, of the .eeting wis
instructed to contact Ms. Jamison for referr.1 to thl appropr1atl person.
Whln Mr. Schrock .~Qk.th. floo~. h. distributed copies Of the fact sheet
describtng the,p~ef~rred re.ldial alternative. The 'act sh.et had b.en
1118iled. earlie~ ,", the month, to plrsons on th, EPA's intlrlsted partie.
8a111 ng Hit. M". Schrock then proceeded to IXP 181 n the EPA I S purpose 10r
holding the public .eeting. HI a1so outlin'dthe steps of the Superfund
process re.I1n'ng to be taken for thl Tybouts Cornlr Lendf1ll Sitl Ind
rlviewed the preferred rlMedial alternative. Mr. Schrock then announced that
the pub1ic .eeting markld the op,n'n9 of the public comment period which would
be cloSed on January 8. 1986. During this timl. interested parties' commlnts
and concern I would be so1tcited by the EPA. Fol1ow1ng his rlv1'w 01 the
preferrld remedfa' a1tlrnat1ve. Mr. Schrock addrlssed questions fr08 the
.ud1Incl.
Thl preferred rlm.dial alternative descr1bld by Mr, Schrock includld
excavation of th! .Ist fill and conso11datfon of the excavated Bateri.'s w1th
those in the .a'n fi11. The re.u1tfng p1t 1" the west f111 a"'8 would then be
backf111ed with clean fill materi.ls. and the consolidated w.ste matl,,'.ls 0"
the .a1n 1111 would bt COvlred with a multi-1ayered RCRA cap that would reduce
or ettii1nate vertica' inf11trltion 0' precipitation into the landft11. A
subsurfaee dra1n system would bl tnsta118d to prevlnt the 11tera1 .igratton of
groundwater throulh the landf1'1 and a1so to collect llachate flow1n8 fro. the
f11'. In additton, pumping wll1. would be insta1led off,'ta to ...medfatl the
conta.inated groundwater plume in the Upper Hydrolog1c Zone (UHZ) of the ".
Potoaac .qu1fer. Thl.e .ens would be pUlllped for I lIinin. of 3 yearl or.
untU..a 11"1~.of"loar.PJJb .of' tota1 'vol.tne orgufcs "is 'r'HctIed..,: lroUltdwlttr" "
qUll1.t,y wf11,'.b.,~.'.onttO"di" ,'Ind'- contaminated- Wlttr glnerlted durfng
~. ~ ~ . ~.,."'"
..'
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V,J
, '
construction 01 the remedial alternative w111 bed1spoSId '" comp1ianc. with
Federa1, state, and local la.s. Aft agl"eement is .being negotiated with the
City of W11.1ngton. Dell.lre for disposa1 01 any contaminated waters from the
T,ybouts Co",ert~Lanc1t111 Sft..
The question 8ftdo-....".r period was dominated by rep.lted outbursts fl"Oli on.
local Ns1cien\~wh8olL.h.s. I history of sueh behavior at slvel"a' p1"tv1oul 11 tl-
rel.ted ...tings~~~Six' other individuals also asked qu.st10ns, whi1e the othel"
.e.be" 01 th, .udilnce sat qUietly 1fst,ning.
.;,.. ..
-'
Thl most frlquently expressld concern WIS about collected contaminated
groundwlter. Thlre seemed to be confus10n inftta11y about whethlr the
collected water would be stored or treated and, 1f treated, wherl it would be
disch.rgld. There was .1so concern about whether treated watlr cou1d be
sl'.'Y dischlrged into .10ca1 surface waters.
. ..
The subsurfacI drainlge system 1110 rlceivld a great dea' Of attlntion ~rom
plople who wanted to know how it would bl constructed, how deep it wou1d be,
and .hat wou1d~nt tt fro. overflowing during htavy ra1nl.
~.~. ~r-' ~.
5evlra' altlrnative methods of handling hazardous wastes were ~ent1o"ld'
including tot.' Ixcavation Ind of1s1tt storage, .wast' reeye1ing, and offshore.
inciner.to~ ships. The latter tlchno1ogy was addressed by Mr. Sklrno11s. who
infor.ed the audilncI that these shiDS .1... in very 11.1ted opl~at1on in the
United Statls and ~hat, .t this timl, they were bein, USld on1y for one
hazardous subitancl. PCB. One ~ftfzen sugglsted that remediat10n ttChno1ogfes
shou1d not be chosen unti1 the 1lndff11 ..atlria's were actull1y Ixcavated.
This would 1110w the techn01091e, chosen for sfte remediation to be based 1101"1
splcff1cI11y on. what was in the 1andfi11 than 0" wh.t WIS explcted to be
the.... Thfs '.rso,uf.e1t that this practice wou1d '.ad to 110...' efficilnt and
. cost efflctfvecways' 01 dla1ing with wastes than thl current proposld
excavation. .,1oelt10n, and l"ebur1a1 "Ithod.
Re..edie1 Ixplnses Ind who shou1d p.y the. wire a1so mentionld by severl'
residlnts. More than one individua' fe1t that the respons1b11 plrties shou1d
be ...qufrtd to piy not on'y the cost 01 sfte remediation and .aint.nance but
.1.0 the-expenses now being incurred by 10cI1 citizens. such IS the COlt of
water Ind I 8onth1y assess.ent for fire hydrant,.
..
Anothl" questfon ConCIMled .Ita,..tre.tment methods, and concern was. voiced
that'. vol1t11e organics, v01ltf1tzing into thl 111" during wlter treat.lnt,
.'ght cause af.. po11ut10n probl...s. Many plop'e expressed dfsp1e.sure that
. re..d1., a1terfta.t1.v. construction wou1d not begin unt11 late Deciliber 1986,
and so.. peop~.'won~lrld i' it wou1d bl necessary to evacuate residents durin,
thl construction. :Th, 1enlth 0' rl.edi.' 11tlrnat1ve "Iintlnlnel W.S
dfsculsed, and on. resid,nt stated hfs lack of confidence that the propoild
pumpfng we11s could remedi.te the groundwlter effectively. This p.rlon a1so
asked about the interconnection of the aquifers and requested a 'ettel" fl"o.
M~. Schrock stating that there.hsuch . connl~t10n. ."
Ann Cardina' cI1led thl me.ting to a c10se.whln intlrest .,pelrld to be
nagg1ng andc;ulst1ons were becomtng repetitivi. She. stated ..tJ\at the EPA Ind.. .
DKR£Cre,tet."tatives.:.'.ou1d. rnI1n'.an11.b1e..to .disc..I.. aftl addit1ona'
'qulstions w1ttr'1'8O"le 1nd1v1dua11y. Ms. C&rd1n.1 a1 so NII1nded the audience
that the EPA')ub1tc cOII.lnt peMod would re.a1n open unt11 ..Jlnuaf"l 8th. ..
.. .
. .
'. . ..'
-------
Throughout the meeting a reporter for the WilmfnGton News-Jou~ll took not.s.
WHYY-TV and WILM-Radio 1150 COvlred the event and conlucted-;nt8rviews w1th
Mr. Schrock fllll,dilte1y after the close of the meeting.
,
,-" .
;' '":'. ": ~
.
.,.....' 'n. ~
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December 28, 1985
.!
!
Mr. Leo Woytko.
965 Red Lion Road
Route 71
Hew Castle, DE 19720
. '
United States Environmental Protection Agency
ReqioD III
Mr. Roy Schrock.
6th and Walnut Streets
Philadelphia. Pennsylvania 19106
0:
'l'YBOtJ'l'S LANDPILL CLEAN-UP PROPOSAL
We, ~e undersiqned, are located on Bamburg Road, North of
the landfill and in back of Mr. Leo Woytko. We have our own
ring wells which are approximately 20 feet deep.
By pumping approximately 5 million gallons per day from ~
landfill, leads us to be concerned about the drainage of our
wells. We would like to know what can be done for us and if
this plan even concerned or took into aCx9uet SaDe of the other
residents like us who live near the .,landf.ll. We would like to
hear frail you in the very l1eal: future.
. ",; ~ .
Hame
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Address
. ..L.fd~ ~ -728' zv/,: :A,~,.,.f)e.
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:1"': S"~~U,p AJA' ), l!... f).J .
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-------
U.So lnvironmental Protection
Region III
6th & Walnut Streets
Philadelphia, PA 19106
Agency
Attention:
Nr. Roy Schrock
Sir:
Ue, the undersignea, as residents of
New Castle County, DE, , located near the Tybouts
Corner Landfill, wish to go on record as being opposed to the
"Preferred Remedial Alternative for that Landfill", also known
the "Remedial Investigation!Feasability Study", or "RI!FS", as
by the U.S. Environmental Protection Agency.recently.
.
as
presented,
The alternative, or dewatering, as listed above is.~ot a practical
or long range solution to the problem. By way of 'proving the above, in
a similar situation, the Landfill at Llangollen, some two (2) miles
north of the Tybouts Corner site, the dewatering process has been in
progress for thirteen (13) years, having existed since 1972. This
operation has not been successful, and is still pumping:
.
l~e also oppose the dewatering as a solution to the contamination of the
Potomac acquifer at this location because of the lowering of water tables
in the area of this Landfill at Tybouts Corner. ~,
.' '".
In conclusion, we oppose the "RI!FS" as proposed by the U~S. Enviro~ental
Protertion agency recp.ntly a~ ~ Public Hearing in Gunning Bedford Schc~l,
~elaware Gity, Delaware.
It is neither practical, nor efficient as a solution in the long range
context, is a waste financially to the U.S. Government, and the tax-
payer as well as ciamaging individual residential water',supplies.
.
..
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67
"1'O"'4~,,, UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
... A ~ REGION III
l ~ f 841 Chestnut Building .
'c ~~..:" . Philadelphia, Pennsylvania 19107 .
Thank you for your interest in EPA's decision making process for the
cleaaap solution at the Tybouts Corner Landfill lite.
I have reviewed your letter concerning the objections you bave made.
to the Prefeu8d Alterutive presented' to the public on December 18, 1985.
The objectiou qpear to be bued on 818UDderstanditags of the r_edy and
it. effect on local aroUlld nter. /
,
The fir.t aDd 1I08t mport&Dt concern is for tbose of you who have
your ova private wel18 aDd fear that around vater pumping will drain your
...118. .
The fint m8undentaDding i8 the ...ount of water to be pumped. The
proposal i8 to place the v.lla along the landfill 8ide of Route 13. At
mo8t, we are intendi.. to pwap 30,000 - 40,000' gallon8 per day at that
location aDd not the 5 .illion gallonl per day indicated in your December
28, 1985 letter. This pumping il intended to affect only the ground water
Within 300-400 feet east of the lite. There are no private wells within'
this area, therefore the pumping of ground water can not affect existing
local residential vells.
5ecoDdly, the subsurface draiu are part of the ground water diversion.
systea. . The upgradient drain vill stop vater from entenDg the landfill
by collecting the water right before it enters the fill. The raa1D1ng
around vater flow vill go around the landfill. -Dewater- meaD8 to take the
water fro. the laDdf1l1 itself, not all the area around the landfill. The
water alevatiOD around the landfill rill remain at the same levels vbile
th~vater elevation in the landfill itself will drop 2S to 30 feet.
This i. how we can dry out the landfill matenal. The sub8urface drains
will not affect the ground water level in local residential wells.
.'
-------
uo
ne third JI181JDdentaDd.1ng is the objection to EPA' s preferred
altensative beC&U8e it u the s.e -solution- that was carried out at
the LaDaollell, Anay Creek 1.aDdf1l1. site. There are several sig1l1ficant
differellce. betVeen the project. which make the comparis01i inappropriate.
We are prop08ing al1 lIIpermeable surface cap; only soU haa ,beel1 used at
Amy Creak. We are prop08iag to divert groUDd water around the lancif 111
1II&terial to prevel1t further generation of leachate; no groUDd water
diversion has been conducted at Army Creek. We are proposing to collect
and treat the ground water contamination at the site; collection and
treacment have not been carried out at Amy Creek. The pumping wells at
Army creek are intended only 1:0 prevent the contaminated Iround water
from aavilll any further :1D. the groUDd water aquifer. -
A final concem i8 that this proj ect is a waste of U.S. Goverument
funds. We expect a .ettl_81It with the Iroup of re8ponsible parties so
that they can impl...nt aDd pay for the cleanup alternative selected by
ErA. It 1s true that your tue. wiU contribute to thi. cleanup fuqd ,
bec:auae New Cutle County ... the operator of the facility and therefore.
one of the responsible par:1e.. However, there are ..ny other private
companiu vb1ch ..y h&'ge to 8hare 111 the cleanup C08t8.
'-'~-'"'''' --. ./
I have enclosed th& preferred alternative for Y01l to review once
aga1n~ If there are fur'ther questions about what 18 wrttten here, please
/ feel free to call Roy Schrock at 215-597-0913 or Ann Cardinal at
.' ~15-597-9905. In addition' we will plan to be available to discuss the
preferred alternative' with you at DNREC's new office au Grantham Lane
at Route 9, south of New Cutle 011 January 29th. from 3 :00 to 5 :00 1J1Ii. and
fram 7:00 to 9:00 pm. '.
Sincerely,
~ C. ~~~\"
Jloy R. Schrock
EPA project 88nale1'
-.
. .
..
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omc£ 0" TM£
SECRETARY
....I~ ~ g~
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. ,:':..,...;~"I.
~,,!!~.-.::.J,.l'\
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STATE OF OEL.AWARE
DEPARTMENT OF NATURAL. RESOURCES
Be ENVIRONMENTAL. CONTROL.
85 KINGS HIGHWAY
P.O, SOx '401
COva". DELAwA"e 1 9903
( ':;1-f~~/_).
'~,... ,-;;::.r.\lnre1;'
W\~~L-G:'l ~_1: \~1
DEC 2 '( 1S~:)
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H - ' "'. . ~c. :..."'..'
:.... - u- EPi - Re<,&icn ~
~HON~(302)736.4403
December 13, 1985
Mr. Jam.s Seit, R.qion~l
u. s. EPA - Reqion III
841 Chestnut Buildinq
Philadelphia, PA 19107
Administrator
Dear Mr. Seit:
The purpose ot this letter is to inform you that the State ot Delaware supports
the proposed remedial alternative for the 'l'ybouts Corner Landfill Superfund
si te, as described in a memorandum. received by this Department on December
3, 1985.
I request that you keep me infoz:med of your plans to hold a public meetinq
to explain the details of the proposed remedial alternative.
Pinally, please keep me informed of your proqress in neqotiatinq the. consent
a9'reement for remedial cleanup with the responsible. parties involved with
'the 'l'ybouts Corner site.
It you have ,any questions concerninq this letter, please do not hesitate
to contact me directly.
Sincerely,
/~.A'~ /./, ~~ ,~
,:..- fi .~~~~,e-t:-
JohD E. wifson, III
Secretary
JEW,rII:PGR:l.mw
cc: Robert W. Perkins
Robert J. Touhey
Phillip G.' .etallick,
Stephen Wassersu«1, EPA
Re9'ionllI,
..
I{
RECEIVED.
DEC 1 B 1985
EPA, REGION III
GfII[IISIDXAL ~
-------
Alternative Public Health Environmental
Components Costs Considerations Considerations
,A 1) NO ACT.ION Contamination from the Leachate generation
WinI MONITORING landfills will continue will continue to
. , to spread in the UHZ discharge to surface
of the Potomac. which water and ground
. . is a major water sup- water as a result
. , ply aquifer. and the . of rainfall and
COlumbia ~qulfer. ground water Inflow
~ from the Columbia
aquifer.
,- B 1) WEST FI LL Capital This alternative will Leaching of contami-
SURFACE CAP.: $3.8 to $4.1 effectively contain nated materials from
GROUND WATER HU U on contaminated wastes and the west fill will
BARRIER. PUMP Present prevent further conta- be eUmi nated.
AND TREAT. ',: $S.2 to $11.7 mination of the Potomac
HUUon UHZ aquifer. .
"
Technical
COnsidera ti ons
Doea not reduce ver-
tical infiltration.
Does not reduce lat-
eral migration of
COlumbia through the
landfill. Does not
reduce contaminant
plume in COlumbia. or
Potomac aquifers.
Pump and treat system To be most effective.
qust maintain lower this alternative
ground water level should be used In con-
within the barrier Junction ~ith another
than outside the bar- main fill alternative.
rler. 8arrier to be
be keyed Into Potomac
clay layer (approx.
5S ft. depth) and
design investigation
is needed. Treatabi-
lity study should be
performed. Onslte
treatment will gener-
ate residuals which
will require proper
disposal.
Approximately 63.000 Same as 81.
cubic yards will be
excavated. Back-
filling with clean
soils will be re-
quired.
Other' L-
Strict institutional.
controls must be ap-
plied to be sure no
further well permits
are issued in areas
where contaminated
ground water exists.
.....
c
.
Same a9 81.
The source of hazardous
waste will be removed
from the Potomac forma-
tion. Some level of
contaminated soils and
ground water will re-
main.
Same as B2.
82) WEST FILL Capital
EXCAVATE. P~ACE $18 to 2.4
ON MAiN FILL Present
: ' $2.4 to 3.7
MUUon
HI llion
Same as B2.
Same as Bl.
Same as 81.
B3) WEST FILL
EXCAVATE. RCRA
FILL ONSIT~ .
Capital
$5 Hi 1110n
Present
$6 MUUon
Cap. tal
$15 MI11100
Present
$1 6 Htllt on
.'
Same as 82.
Same as 81.
Same as 81.
Same a8 82.
84) WEST FILL
EXCAV~TE. QFF-
SITE DISPOSAL
..
.
.'
...:..
".'
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Alternative Public Health Environmental
Components Cost Considerations Considerations
85) WEST FILL Capital Same as B2. Same as 81.
EXCAVATE, ON- $1.1 to $8.3
SITE INCINERA- M11 lion
, . .
TION " Presf;!nt
$20.4 to 21.9
86) WEST FILL Costs were not Same as 82. Same as 81.
EXCAVATE.' OF'- es tilla ted. ' '
~
SITE INCINERA-
~ . TION "
Cl) SURFACE CAP This alternative The cap alone will not The cap will elimi-
2 FT. OF SLIT was suggested by stop leachate genera- nate some surface
PERMEA8lf~ITY 'OF PRP's and costs tion; contaminant plume seepage areas. Off-
10-6cm'sec. . were not provided. in the ground water site leachate seeps
" ',; I. willrema In. wi 11 con t1 nue.
"
, '
..
.
C2) SURFACE CAP
2 FT. OF (:LAY
PERMEABILITY OF
10-1 cm/~ec
Same as Cl.
Same as CI.
C3) SURFACE CAP Capital
Multi-Layer 15.1 Million
Same a8 Ct.
C41 SURFACE CAP Capl tal
MAIN FILL SUB- 3t.3 to 35.0
SURFACE DRAIN- Million
AGE"IN THE' CO- Present
LUHBIA FORMA- 32.8 to 69.0
TIOM (WITit AND Million
WITHOUT A
GROUND WATER
BARRIER) ~ "
This alternative will
significantly reduce
the release of hazard-
ous substances to the
ground water beneath
and around the site.
It will a190 reduce
surface discharges.
.
Same as ct.
.
The cap will elimi-
nate surface seepage
areas onslte and
will affect offslte
seeps from the Co-
lumbia aquifer. "
The existing landfill
will remain in place;
therefore. this al-
ternative is to
reduce or eliminate
production of leach-
ate coming from the
landf ills.
,
-
This cap will allow Any cap must be used
approximately 60% of in conjunction with
the present amt. of ground water control
water to enter the alternative. Present
fill materials. This amount of water entel
is approximately ing the fill is 44.01
26.000 gallons per gpd (avg. over the
day. (gpd) year)
This cap will allow Same as Cl.
approximately 7% of
rainfall to enter the
fill materials. This
is approximately
3.000 gpd.
this cap will allow Same as Ct.
approximately 2% of
the rainfall to enter
the fill materials.
this is approximately
800 gpd.
This alternative
assumes the surface
cap will meet RCRA
standards. The sub-
surface drainage will
be placed upgradient
on the eastern and
northern boundaries
of the fill and will
be constructed to
allow gravity flow.
Treatment should meet
NPDES standards.
Technical
Considerations
Same as 82.
Same as 81.
Other
Same as 81.
Same as 81.
Space limitations be-
tween highways and.
"
fill materials will
make the drain diffi-
cult to install.
A design stage is
necessary.
A
-
.
.
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Al ter~ 'e
Compo.. ..(8
C5) MAIN FJLL
SURFACE CAP,
GROUND WATER
PUMPING IN: THE
COLUMBIA FORMA-
TION
C6) MAIN F~LL
SURFACE CAP,
DIVERSION
~TRENCH
C1) MAIN FILL
EXCAVATE, ' ~CRA
LANDFILL ONSITF.
C8) MAINF~LL
EXCAVTE, OFF-
SITE DISPO~AL
..
C9) MAIN FILL
EXCAVATE, ON-
SITE INCIN~RA-
.
TION '
CIO) MAIN FILL
EXCAVATE, OFF-
SITE INCINERA-
TION
.
.'.' i.
Cost
Capital
16.2
Ml1 Hon
Present
18.1 to 20.0
, 'MUlion
Capital
33 Million
Present
39 to 71 Million
..
Capi tal
$61 Million
Present
$53 Million
Ca pi tal
$61 Mill ton
Present
$246 MUlion
;
Capital
$106 to $16~ Mill-
Ion
Present
$327 to $370 Mill-
ion
Not calculated.
Public Health
Considerations
Same as C4.
Same as C4.
Excavation will miti-
gate the source of
ground water contamina-
tion and surface re-
leases will be elimi-
nated.
Same as C7.
Same as C7.
Same as C7.
Environmental
A>nsiderations
Same a8 C4.
Tedmlcal
Coris1d.~rati ons
A RCRA cap 1a assum-
ed. Glround water
pumpinu will be done
upgradJient on the
eastern and northern
boundaries.
A RCRA cap Is assum-
ed and vented gases
will be monitored.
The diversion trench
will bE! placed up-
gradient on the
eastern and northern
boundaries of the
fill and will be
constructed to allow
. gravit~r flow.
By removing the land- The exc:avation can
fill, all envi ron- be dOnE! us I ng conven-
mental receptors will tional methods.
be protected when
excavation is com-
pleted. Excavation
will release gases
from the landfill
material.
Same as C7.
Same as C4.
Same as C7.
Same as C7.
Technical compliance
with RCRA regulation
must be met.
Same as C1.
Same as C7.
-
.
.
!
O. ~
The reliability of~
this alternat~ve ~or
t.he long term! Is ma?:-
glnat.
Same as C4.
\. \ ,
~- -',,,-
.., - .-""-4
The estimated t!~e~
completion is 5 Jea~:~
--'
, I
Implementability ts
highly questionable
since there are very
few facilities at
this time aod costs
for hauling and dis-
posal would be high.
The large volume of
wastes make this very
costly and time con-
suming.
Use of an offstte
commercial facility
1s unlikely at this
time due to !fmi ted
capacities and large
backlogs.
-------
Al ter118~1ve
Components'
01) MANAGEMENT None
OF GROUND WATER>
PLUME; ONE'PUMP
ING WELL ATLo-
CATION OF TEXA-
CO REFINING AND
MARKETING ~Ott-
PANY WELL OR-6A
.
D2) MANAGEMENT
OF GROUND ~A1ER
P LUKE 'lW0 PUMP-
I NG WELLS FOR
CONTAMINANT
PLUME REMEDIA-
TION AND ~ATER
RESOURCE ItECo-
VERY
D3) GROUND
WATER PLUME
MANAGEMENT,' '
THRE~ PUMPING
WELLS FOR ruE
MAIN LANDFILL
Costs
Capital
$1,458,200
Present
$3,673,000
Capital
$1,033,500
Present
$2,740,000
"
I
I
Public Health
Considerations
this will cause the
contamination to spread
in the UHZ of the Poto-
mac. Concentrations
of organic cpntamlnants
at the wel)(are antlci-
paged to be very lov
levels but levels bet-
ween t'he well and..the
site viII be hl~'er; ,
probably hlg~enough
to pose a risk to human
health if the water
were used.
..
this alternative will
stop further migration
of the plume; viII col-
lect t~e plume for re-
medlat~on.
.,
Same as D2.
Envi ronmental
Considerations
Th Is al te rns ti ve will
cause the contaminant
plume to spread.
this alternative will
protect the ground
vater resources.
.
Same as D2.
-
.
"
Tt:!chnical
Conl!l1deratlons
Remed:Latlon of the
UHZ hi not conti rllled
by thll! RI. How much
of thli! plume which
vill Illot be drawn to
the plroduction well
I s unl~novn. Th I s
altermatlve vill re-
quire contlnoU9
pumpllllg for an ex-
tended period of
time, possibly 20 to
30 yel1rs. Ground
vater usc restric-
tions must be Impl~-
mented.
This l:tlternative
viII take 20 to 35
years of fairly con-
tinuous pumping,
col1e.~tI ng and
treating. A design
Investigation Is
needed. Institution-
al controls viii be
necesllary until plume
Is rell1edlated.
Same liS 19 except
this alternative
vlll ttake 40 to 100
years..
..
-
.
Other .
The production w~JJ
could, mix the water
with water from
other Texcaco wells
for use In th~ir,
facilities.
..
./'
.. ..
. '
Aqulfeit ,remedl4tt~n
is contingent on
source\~ontrol.
. ;'-,
"
Same a8 D2.
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