United Slates
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPA/ROD/R08-86/010
September 1986
SEP A
Superfund
Record of Decision
-------
!J
TECHNICAL REPORT DATA
(Pftau rt!flu I,UlruCIIOnl 0/1 (ht rtvtnt IHfrNt co,""ltllnlJ
1. AIJlO"T NO. 12. 3. RECIPIENT'S .
site; a soil-bentonite slurry harrier wall constructed throuqh the alluvium and l"Iedror.1(
around the contaminated areas; a reverse-gradient qround water draining and pumpinq
svstem; an activated carbon water treatment plant. 't'he treated water will be discharap~
(See Attached Sheet)
17. KEY wO"DS AND DOcuMENT ANAL.YStS
Ia. DIiSC"'PTOAS b,lOENTIFIERS/OPEII,j ENoeD TERMS c. COSA TI F leld:Gcoup
Record of Decision
U'nion Pacific Railroad, WY
Contaminated Media: gw, soil.
~ey contaminants: VOCs, organics, metals,
PCP, creosote, oils
18. DISTRI8UTION STATEMENT 19. secuRITY CL.ASS, Tills R~pO"1 21. NO. OF PAGES
None S3
20. SEcuRITY CL.ASS ITilis partl 22. PRice
None
I'. 11- 2220-1 (It... 4-77)
"'''.VIOUI 801 TIOH II O.,OIo8T.
-------
. ~ ..,. ,'.....
-~ ~~""""''''_':V.''<'-~ ...,.....1_~'i.""..~..Jf.-::....I- '-"'u.-- ."'. ," .7,' It..
EPA/ROD/R08-86/0l0
Union Pacific Rai~road, WY
16.
ABSTRACT (continued)
~
to the Laramie River under the authority of an NPDES permit issued and
administered- by the State of Wyoming: and ground water monitorina. The
estimated capital costs for this remedy is $7,000,000 with annual O&M costs
-------
u.s. EPA - Region VIII
.
RECORD OF DECISION
UNION PACIFIC RAILROAD LARAMI E TIE TREATING PLANT
LARAMIE, WYOMING
.
-------
I. DECLARATIONS SECTION
DOCUMENTS REVIEWED
.
The following documents contain general and specific information on the
cost and effectiveness of remedial alternatives for the Union Pacific Railroad
Laramie Tie Treating Plant, Laramie, Wyoming, and constitute the primary
record on which I am basing my decision:
- Union Pacific Railroad (UPRR) Remedial Investigation (RI) anci Risk
Assessment.(AA), Final Report, prepared for UPRR by CH2t4 Hill; dated
March 16, 1986 (Appendix A)
- UPRR Feasibility Study (FS), Final Report, prepared for UPRR by CH2M
Hill; dated June 30, 1986 (Appendix B) .
- ~oA Comment~ on the UPRR Rl, RA and FS (Appendix C)
- Agency for toxic Substances and Disease Registry (ATSDR) Comments on
the UPRR RI and RA;
- EPA Community Relations Responsiveness SlII111ary RE:port, Final Report,
prepared by EPA and rCF COrporation; dated September, 1986 (Appendix D)
- Union Pacific Design Documents for the Soil-Bentonite Cutoff Wall,
. prepared for UPRR by CH2M Hill; dated June, July and October, 1985
(Appendix E)
- EPA-Union Pacific Administrative Orders on Consent issued concurrently
in ~vember 1983, under the authori~ of CERCLA Section 106 and RCRA
Section 3008, as amended (Appendix F)
DESCRIPTION OF THE SELECTED REMEDY
The remedy I have selected is an interim source control remedy, a first
operable unit pursuant to 40 CFR Section 300.68(c}. The remedy is a
Contaminant Isolation System designed to mitigate.off-site movement of
contaminated ground water and surface soils during planning and implementation
of more pennanent remedies. The major components of the 1501 ation system are:
- re-a1ignment of the Laramie River channel 150 feet further west from
the site to reduce chances of migration of contaminants to the river;
-
- a soil~entonite slurry barrier wall constructed through the alluvium
and bedrock around the contaminated areas;
- a reverse-gradient ground water draining and pumping system to mitigate
off-site seeping of contaminated ground water through the barrier ~all;
- ...." - .. '[' ...,'" .. -.~,. .- ...,,-, ..;-. ,,-..,
-------
. .:. -- ,-.- ~~.. ~ ....\. .-.... .-:~J' .. ~1. H ~-,.- ....... r: "'._.".'-~ ~ _'t~.... '1,- ~.~
,. -r- ..~ 1.<-." ....I........
~
- an activated carbon water treatment plant to remove contaminants from
the ground water that is withdrawn from inside the barrier wall; the
treated water will be discharged to the Laramie River under the
authority of an NPDES permit issued and administered by the state of
Wyoming; and
- a ground water monitoring system to measure the integrity of the system.
DECLARATIONS
Consistent with the Comprehensive Environmental Response, Compensation, "
and L1a~i1ity Act of 1980 (CERCLA), and the National Contingency Plan (40 CFR
Part 310), I have determined that Contaminant Isolation System at the Union
Pac i fk La rami e Ti e Treati n9 Pl ant si te is a cos t-effecti ve remedy (fi rst
oper,ab' e unit). that is cons1Stent with a permanent remedy [40 CFR Section
300.68(c)]. I have also determined that the action being taken is a
cost-effective a1 ternative when compared to the other remedi al options
revie~(. The State of Wyoming has been consulted and concurs with the
approvl'(' remedy.
The remedial action selected will require future operation and maintenance
acti vi ti es to _.'.:iure the conti nued effecti veness of the remedy. These
activities will be considered part of the approved action.
.
I have further determined that the Contaminant Isolation System selected
herein is only an interim remedy. The responsible party (Union Pacific
Railroad) recognizes that more permanent remedies are required, and has
identified and partially evaluated some of these i" the June 30, 1986
Feasibility Study. Union Pacific will undertake additional feasibility
studies and pilot and field tests to evaluate these remedies more fully.
These studies will be conducted pursuant to the authori~ of the Resource
Conservation and Recovery Act (42 U.S.C. Section 6901, et seq.). Additional
remedial actions will be implemented pursuant to a post-closure care permit or
other actions under the Resource Conservation and Recovery Act.
.~~~;
16, I fit-'
.
~(~..J. - ~. t;;.,~
John 'G. e es, Jrvt
Regional Administrator
.
Appendices:
A. Union Pacific Remedial Investigation (RI) and Risk Assessment (RA)
B. Union Pacific Feasibility Study (FS)
C. EPA Comments on the Union Pacific RI, RA and FS
D. EPA Community Relations Responsiveness Summary Report
E. Union Pacific Design Document for the Soil-Bentonite CUtoff Wall
-------
,".-~, ~~.... .--.'- .&._.'_~4........~'..._.. - . :- ".
"
u.s. EPA-Region VIII
Union Pacific Laramie Tie Treating Plant Record of Decision
List of Figures and Tables
Page # Figure/Table # Figure/Table Title. or Subj~
2
3
4
5
7
12
13
14
15
3Q
37
38
42
11
18
1 9, 20
21
29
30
Figure A-1
Fi gure A-2
Fi gure A-3
Fi gure A-4
Fi gure B-1
Figure C-1
Fi gure C-2
Fi gure C-3
Fi gure C-4
Fi gure H-1
Figure H-2
Fi gure H..3
Fi gure 1..1
Laramie, Wyoming
Four aquifers underlying the site
.Ground water.flow patterns (dry)
. Ground water flow patterns (wet)
Historical waste disposal areas at th~ UPRR site
Oily contamination in the alluvium
3-d view of oily contamination in the alluvium
Three bedrock formations subcrop, aerial extent of
bedrock contamination
Schematic of vertical contamination in the formations
Map of Soil Bentonite Slurry Wall
Location of Interior and Exterior Drains
Schematic of Water Treatment Plant
CIS GW monitoring system map, location of wells
Table C..l - Representative contaminant levels
Table C..2 .. Summary of Risk Pathw~s/Scenarios
Table C..3 .. Health Effects of contaminants found at the site
Table C-4 .. Toxici~ of contaminants found at the site
Tabl e E..l .. SUlllllary of Al ternatives Eval uation
-------
EPA
DEQ
UPRR
C ERe LA
NPL
NCP
RCRA
NPDES
U~
CFR
FR
RI
RA
FS
CIS
PCP
PNA or PAH
NO
COD
M:L
RM:L
ACL
u.S. EPA-Region VIII
Union Pacific Laramie Tie Treating Plant Record of Decision
List of Abbreviations and Acronyms
Environmental Protection Agency
(Wyoming) Department of Environmental Quality
Union Pacific Railroad
Comprehensive Environmental Response, Compensation, and Liability
Pet (Superfund) .
National Priorities List
National Conti ngency Plan
Resource Conservation and Recovery Act
National Pollutant Discharge Elimination System
United States Code
Code of Federal Regulations
Federal Register
Remedial Investigation
Risk Assessment
Feasibility Study
Contaminant Isolation System
~ntachlorophenol
PolyNuclear Aromatics or Polynuclear Aromatic MYdrocarbons
Not detected; below minimum detection limit
Chlorinated Dibenzodioxin
Maximum Concentration Limit
Recommended Maximum Concentration Limit
-------
II. SUMMARY OF REMEDIAL ALTERNATIVE SELECTION PROCESS
A.
SITE LOCATION AND DESCRIPTION
The Union Pacific Railroad (UPRR) Tie Treating Plant is located southwest
of Laramie, Wyoming (population 25,000) (Figure A-1). The approximately 700
acre site is bordered on the east by the UPRR right-of-way, on the north by
Interstate Highway 80, and on the west by the Laramie River. The plant site
is located less than one-half mile from the nearest residential area and
approximately 1.5 miles from downtown Laramie.
The surface of the UPRR site is relatively flat and drains gently to the
Laramie River on t~e west. In 1983, the area was removed :~c~ the historic
100 year flood plain by raising and reinforcing the existing levee along the
ri vera
There are four aqui fers il11i1edi ate1y under1yi ng the si te' (Fi gure A-2):
1. Alluvium - approximately 10 to 15 feet thick;
2. Morrison - uppermost bedrock ,formation, about 125-320; feet thick:
si 1 tstones and shales; ',."'..
3. Sundance - next lower bedrock formation, about 125 feet thick:
sandstones; and
4. Chugwater - lowest bedrock formation, about 600-1400 feet thick:
siltstones and shales;
All three bedrock formations subcrop to the bottom of the alluvium for at
least some of the site. The average dip of the three formations is 40 West
and the strike is North SO East. Of the three formations, the Sundance is
the most important in that it immediately underlies the alluvium for much of
the heavily contaminated parts of the site and is hYdraulically connected to
domestic water supply wells in the area.
The alluvial ground water flow patterns for the site are shown in Figures
A-3 (dry weather pattern) and A-4 (wet weather recharge pattern). The flow is
generally towards the north west corner of the site.
As will be presented in greater detail in section C of this report, the
soils and ground water at the Laramie Tie Treating Plant site are generally
characterized by gross contamination from creosote oils and pentachlorophenol
wood treating wastes.
-------
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Figure A-2
Ref:
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I.
1986
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flGUllE 1-'
ICHlIlATIC Of' GfOl.DGIC CRO'. UCTION
AT 'HI ""1111 TII TMATING "-ANT
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EAST
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8.
SITE HISTORY
UPRR began operations at the Laramie site in 1886 and treated' rail road
ties and other wood products until 1983. Wood preserving agents used by UPRR 0
or its contractor (the J. H. Baxter' Company) in the treatment process included
zinc chloride (1886-1931), a creosote oil and asphalt-based petroleum/residuum
oil mixture (1928-1983), and pentachlorophenol or PCP (1956-1983). Creosote,
some creosot~ constituents and PCP are hazardous substances under the
Comprehensive Environmental Response, Compensation, and Liability Act of 1980
(CERCLA). UPRR closed the wood treating operation in May 1983.
During the first 70 years of operation, process wastes from the plant were
disposed of in various locations on the site (Figure B-1) including low areas
and sloughs. immedi ately north and west of the phnt. In 1958, UPRR .
construrted four unlined waste collection ponds near the center of the site, .
and routed liquid wastes to these impoundments until 1983. Solid wastes from
cleaning the retorts were reportedly buried south of the plant (Area G).
From 1980-83, waste sludges from another UPRR tie treating plant in The
Dalles, Oregon were also disposed of in the Laramie waste collection ponds.
These sludges were wastes from' wood treating operations that used creosote,
pentac/: 1 uropheno 1, and ammoni aca 1 copper arsenate.
The recent history of the site has included numerous investigations of
on-site contamination in response to regul.atory and legal actions by the U.S.
Environmental Protection Agency (EPA) and the Wyoming Department of
Environmental QJality (DEQ):
1. In August and November 1980, UPRR submitted notification and a Part A
application as required under Sections 3005(e) and 3010 of the Resource
Conservation and Recovery Act (RCRA), thereby qualifying for interim
status for the four waste collection ponds.
2. Contamination outside of the collection ponas was initially discovered
in October 1981 as a result of RCRA interim status ground water
monitoring requirements (40 CFR Sections 265.90 - 265.94).
3. In October 1981, the State of Wyoming filed suit against UPRR under
Wyoming Statute Sections 35-11-301(a)(;), (11), and (iii). In October
1982, the State and UPRR reached a litigation suspension agreement and
formalized a more thorough investigation through an "Investigative
Research and Remedial Action Plan" that included the following four-
phase program:
- Preliminary Investigation
- Remedial Investigation
- Feasiblity Study
- Implementation of Remedial
Action and Monitoring
-------
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WIS'.t..
FIGURE 2-2
WASTE DISPOSAL AREAS
AT THE UPRR TIE TREATING PLANT l~tt:1
LARAMIE, WYOMING
--- ~----
!-'igure 8-1
Hd: CII:?~lIlill,
-------
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B.
SITE HISTORY (cont'd)
4. In September 1983, EPA listed the portions of the site not specifically
regulated under RCRA at the time (those areas other than the four waste
impoundments and the associated"contamination) on the CERCLA National
Priorities List (NPL) (48 FR 40658, September 8, 1983).
5. In November 1983, EPA entered into an Adminstrative Order on Consent
with UPRR under Section 106 of CERCLA (Docket No. CERCLA VIII-83-Q5).
The order required UPRR to perform a Remedial Investigation and
Feasibility Study consistent with the four phase program required by
Wyoming's litigation suspension agreement and EPA guidance.
UPRR has submitted its final reports on the first three phases of the
four-phase investigation/remec;:al action program.
6. Concurrently with the CERCLA AO, EPA also entered into an Adminstrative
Order on Consent with UPRR under Section 3008 of RCRA (Docket No. RCRA'
(3008) VIII-83-25), which required closure of the waste impoundments,
and, if necessary, post-closure care of the RCRA-regulated areas.
As requi red by tne RCRA order (paragraph 29), UPRR pa rti ally closed the
four waste ponds in the summer and fall of.:l984 by removi n9, treati ng, '.
and/or disposing of offsite the contents of the ponds. This partial
closure was the subject of litigation between EPA and UPRH [Union
Pacific Railroad Company v. William D. Ruckelshaus, et ale (Civil No.
84-0190, D. Wyoming, 1984)], and resolved in a Consent Decree in July
19B4. .
7. On October 20, 1983, the State of Wyoming issued a permit to construct
a pilot industrial wastewater/oil product recovery well system (Permit
Nu. 83-549). The system is currently in place, although its
effectiveness has not met expectations.
8. UPRR is currently constructing an industrial wastewater collection and
treatment system pursuant to the authority of a construction permit
(Permit No. 84-77RR), issued on August 1, 1984 by the State of Wyoming.
9. In October 1985, UPRR relocated a 3000 foot reach of the Laramie River
bed about 150 feet further west from the site. This action was
performed under the authority of a dredge and fill permit issued to
UPRR on September 13, 1985, by the U.S. Army Corps of Engineers
pursuant to Section 404 of the Clean Water Act.
10. On March 20, 1986, the WY DEQ issued a National Pollutant Discharge
Elimination System (NPDES) permit to UPRR,.authorizing a discharge from
UPRR's proposed ground water treatment plant to the Laramie River. The
plant is currently ur1er construction.
-------
1
,
. - . ,+.- , - 'I
B.
SITE HISTORY (cont'd)
11. As noted above or in the supporting record,UPRR has already completea
some preliminary remedial actions. These actions include:
a. relocation of the Laramie River 150 feet further west from the site
(completed in the fall of 1985);
b. construction of a flood levee four feet above the 100 year flood
level for the site (first constructed in 1983, completed in 1985);
c. construction of a temporary cutoff barrier in the fall of 1983 to
mitigate oil migration to the Laramie River~
The ~lternative selection process presented in this document focuses on
additional interim remedial actions rather than a. f~nal remedy. EPA views the
combination of these new interim remedial actions as the first part of Phase 4
(Implementation) of the UPRR program under the Wyoming litigation suspension
agreement. Under CERCLA and the NCP, the new interim remedies constitute a
first operable unit pursuant to 40 CFR Section 300.68(c).
..
- 9 -
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C.
CURRENT SITE STATUS
Approximately 140 acres of the 700 acre site are contaminated. The
contamination ranges from soil saturated with free oil to ground water
containing parts per billion levels of dissolved contaminants.
Representative ranges of contaminant levels are presented in Table C-1.
Many of the analytical data are represented as NO (not detected or below
detection limit). In many cases, however, analytical results were qualified
by very high detection limits.' Thus, the designation of ND does not
necessarily mean that the contaminants were not present for a given area.
...
Much of the contamination remains .:-, the alluvium, where the
heavier-than-water creosote oils lie 1t the bottom of the alluvium (10-15 feet
deep) on top of the bedrock. However. extensive contamination of the bedrock
formati ons has occurred in a fracturel i zone in the Morri son formati on and in
other bedrock locations as deep as 70 feet.
4
1. Alluvium
~'.,....-
The bulk of the contamination at the site is made up of alluvial sands
and gravels that are saturated or nearly ~~~urated with oils containing
creosote constituents and PCP. It has been estimated that over 700,000
cubic yards of alluvium are contaminated, of which more than 300,000 cubic
yards are saturated or nearly saturated. It has also been estimated that
the volume of oil in the alluvium is as much as nine million gallons, of
which about one million gallons of IIfree oil II (oil that would flow freely
from the soil) could be recovered.
The main body of the oily contamination in the alluvium is centered
around the locations of the former retort building and the four waste
impoundments, including a shallow depression in the bedrock surface west
of the ponds. Figure C-1 shows the extent of measured alluvial contami-
nation (solid line) and the extent of oily contamination greater than one
foot thick (broken line). Figure C-2 is a three-dimensional depiction of
the thickness of the oily and oil-saturated alluvium as viewed from north
and west of the si tee
Several soils samples were collected and analyzed for chlorinated
dibenzo dioxins (COOs) and chlorinated dibenzo furans (COFs). Although
some COOs (hexa-, hepta- and octa-) were detected, none of the tetra- or
penta- varieties of CD Os or COFs were measured above detection limits.
,
2. Bedrock
--
A'il three bedrock formations underlying the alluvium at the site
(Morrison, Sundance and Chugwater) have been contaminated by wood-
preserving wastes to some extent (Table C-l). Figure C-3 depicts where
the three bedrock formations subcrop and the areal extent of contamination
within each formation. Figure C-4 presents a schematic of vertical
contamination in the formations.
-------
~
.
Table C-l
Representative Levels of Contaminants Found at the UPkR Laramie Tie Treating Plant Sitea
Fonuation: Alluvium Horrison Sundance Chugwater Laramie Hi ver
. Parameter HediwII: Soil Water Water son Water Water Water
'Units: ii97£g iij7L iij7L . iii9lkg iij7l iij7l ~
VOLATILES:
Benzene 0.30-0.65 NO-O.56
Toluene 1.9-18 0.59-18
MHALS:
~enic 1.2 NO-35
Chromium 2.1 5-39
Copper 1.7 10-40
1inc 19 N0-80
POL Y IU;CLEAk AI«WJH ICS:
Acenaphthene NO-7200 NO-6700 NU-57oo 150-110u NO-35 NO-5 NU-J7
Acenaphthy1ene NO-250 NO NO-460 37-250 NO ND NO-3.3
Anthracene "0-3700 NO-bOOO NU-l3UO 49-540 NO r.U NU-1.8
Uenzo(a)anthracene NO-340 NO NO-1700 23 -180 NO NIJ
8elozo( a )prrene NO-98 NO NU-96O 15-92 N1) NIJ
8enzo(b)f uoranthene NO -99 NO
~enzo(9hi)perlene NO-23 ~O NO NLI-23 NO NU
8enzo(k)f1uoranthene N0-65 1m NO-860 NO-67 NO NO
Chrysene NO-11 00 NO NU-12oo 22-1t.1.1 NO NIJ
Oibenzo(a.h)anthracene NO tm NO NO NO liD
Fluoranthene NO-6700 NO-87oo NO-130C 18-5~jO NO NIJ Nu-2.5
n uorene N0-6900 NO-4100 NO-450LI 85-110 NO-9 NO NIJ-14
Indenoll.2.~-cd) pyrene NU-24 till NIJ NU-24 NO NU
tiaphthalene NO-22.oo0 NO-41.5oo NO-16.oo0 660-6200 NO-1600 NO-21 11-150
1 .1etlIY 1 t4aphthal ene J.8-42
2 ~~thY1 Naphthalene (;.1-26
Phenanthrene NO-18.0oo 14.100-11.300 NO-9300 290-1900 NU NU 1.9-16
Pyrene NO-5300 1600-7100 NO-5300 75-460 NO NO NO-I. b
PHE..OU:
Phenol NO-52 NO-102 NO NU NO-2.1 NU
Pentachlorofhen01 NO-37oo N0-65oo NO NO NO-22 NO
2.4 -Oimettl)' phenol NO-1. 4 NO ND NU NLJ-b NU
CHLORINATED OIBENZOOIOXINS (units Ire ug/kg):
Tetra- NU
Penta- NO /
HeXi- 0.15-715
Hepta- 35-14.200
Oct a- 124-28.000
.
Key:
ii - source for data 15 Phase 11 RSlledial InvestigaUon Report by Clt2HHil1. Harch 17. l~tlL
-------
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Figure C-l
Ref: Cll2MIIUl,
1986
tic
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.- CION1_11OOI
-'w"".-
- , Of OIlY AUUWIAL
- --="'1....-...1111-
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CON~AlllHAnoNAJLAIWIUI ~J:7!I
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Figure C-2
"GUIUII..
laOMETilIC "'10- VIIW '"0M THE NORTHWIIT
tHOWING THI OILY .,.0 OIL.aATUIIA TED ALLUVIUM
AT THI uPfIlI TII TllEATING PUNT.
LAIIAMIE, WYOMING
Ref; Cl
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r
Figure C-3
Itd: CII2t-UI ill J
I (JH6
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,
,
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-.... --s
.....
. "" ..
. ~---
..
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;,
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.
~AflA_I_MU.
'1UHIIAHCI_IOIIIHOWtLL
. __10IIIHQ1ftU
. MOIIIIlSOHl'IUOMnEII
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II CONf_UDCHUOWAfEII
trJID"~f 'DllMAIIOHCOIofACf
~.
. "
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'IOURI a,l
MAP 'HOWINO fHl AIIUL IIUNT 0'
UOROCII CONTAMINATION
AT THI """R TIlIREATINO PLANT
URAMIE. WYOMINO
-
-
~
-------
WEST
LARAUIE
RIVER
(OLD CHANNEL.
EAST
APPROXIMA IE SCALE; 1 VERYlCAllNCH . acr
1 HORIZONT -'LINCH' 250'
. flOUlI1 a.1
IC..IIATIC Of CONTAIlINANT
DIITIIIIUYlON
UPIIII TIE TIIEAYlNG PlAMT
LARAlllE, WYOMINO
Figure C-4
Her:
....-fill i1 I .
IIJH()
-
-
. E"?/mI
-------
". .. .'..-.' "'.......";;....8'':-."
4:'! (..' -." ..', . .' .::'.n_"-"::-......,.... .;..~... .....-~~..1......,!:..J~ ~'.t.1~.,.~.::... ~,.~..' -,:. ,~t..;."" - ,~ ~'..
.~ . '; " .
C. CURRENT SITE STATUS (conti d)
3. Laramie River
Contamination of the Laramie River by the site has been indicated by
visual observation and the analysis of water and sediment samples (Table
C-l). Data presented by UPRR in the Remedial Investigation Report show
contamination in samples collected before installation of the sheet metal
barrier (fall 1983). Visible contamination ceased after the barrier was
installed, and subsequent downstream water and sediment samples collected
and analyzed by UPRR did not show detectable levels of site relatea
contaminants.
EPA has, however, received ;esults from downstream sediment sample~
collected in September 1985 which indicate continued presence of
contaminants related to wood treating wastes in river sediments. In
addition, during the July-August 1986 public comment period, EPA received
reports from citizens of the continued presence of contaminants in
alluvial back waters downstream from the site. At a minimum, further
sampl i ng of downstream ri ver sediments is indicated before the matter of
off-site contamination is laid to rest.
4. Potential and Actual Risks
Table C-2 presents potential and actual pathways and scenarios for
contaminants to leave the site. Most of the pathways or scenarios
presented involve either a high likelihood of occurrence (some have
already occurred) or a release posing significant risks to public health
or the environment. For the present, none of the pathways includes the
combination of both high likelihood and significant impacts.
Some of the more immediate or likely pathways "for the contaminants to
threaten pUblic health or the environment involve the movement of the
contaminants off-site. Public health or environmental threats for which
there is already documented evidence include the migration of the gross
contamination through the alluvium to the Laramie River; migration of
contamination through the bedrock to off-site aquifers; and deposition of
contaminated surface soils further downstream by flood or wind erosion.
1he most severe threats to public health or the environment are more
potential than immediate, and are based on future, rather than present,
scenarios. 1hey include the potential for contamination to spread far
enough in off-site bedrock aquifers to contaminate wells which might
become a source for drinking water, stock water, or agricultural
purposes. Other future scenarios could include either industrial use or
residential use of tl.~ site. The pUblic hed1th risk from either of these
scenarios is significantly heightened by the increased likelihood that
on-site workers or residents would be exposed to airborne or surface soil
contamination. A less likely pathway associated with these scenarios
involves the use of the on-site alluvial or bedrock aquifers, either for
industrial or residential purposes.
-------
..._-..:.:.."Io:..,,-~..;;........o.a.-'--..aL L.:.. 8..&.._-=-"- ,. .'.-..:....'. -". -_. ."~...:. ..I,,~,.,... ~.... r... . i"
. .- - \ -.' ...
C. CURRENT SITE STATUS (cont'd)
Local officials have indicated the City.s intention to include at least
that portion of the site adjacent to the Laramie River as part of a green-
belt along the river. Users of that greenbelt could be exposed to
contaminants from the site that either migrated off-site previously (flood
or wind erosion) or are continuing to migrate off-site, either as
contaminated soil particles or organic vapors.
Tables C-3 and C-4 present a summary of the health effects and EPA
health standards for many of the contaminants found at the Laramie Tie
Treating Plant site. A comparison between these data and the data
presented in Table C-l shows that several EPA Health Related Standards are
exceeded for many $i te contami nants', i ncl udi ng arseni c, acenapthene,
benzo(a)pyrene, fl';!)ranthene, and pentachlorophenol.
-------
...-...~.........I':'~.
~~.~.... -----. ............~--"................_......_~..._-_...~--_.._----- ~~ ---
..
Tab1 e C-2
Summary of " Scenarios and Risk Pathways
for the UPRR Laramie Tie Treating Plant Site
Source
A. contaminated bedrock
ground water
B. gross contamination
in alluvium and
underlying bedrock
c. contaminated
surface soil s
Scenario/Pathway
1. installation of on-site wells into contaminated
formations, use of contaminated ground water for
drinking water, stock water, agricultural,
industrial or commercial purposes.
2. migration of contaminated ground water to offsite
receptor wells, use ~f ;ontaminated ~round water
for drinking water, stock water, agr1cu1tura1,
industrial or convnerc; a 1pu rposes.
1. use of contaminated a~luvia1 ground water for
drinking water, stock ~ ater, agr;c~ltura1,
industrial or commerc.,1 purposes.
2. seepage of oily waste to Laramie River:
- toxicity to aquatic life;
- contaminant bioaccumu1ation in fish;
- human consumption of fish;
- recreational use contact, direct human
exposure (swimming).
3. contaminants spread through bedrock aquifers,
migrate to receptor wells, use of contaminated
bedrock ground water (A-1, A-2).
1. direct contact with or ingestion of soils on-site
(future use or cleanup worker scenario).
2. migration of contaminated surface soils off-site
through flood and/or wind erosion:
~ transport to the Laramie River, toxicity to
aquatic life and human health (B-2)
- deposited as surface soils off-site (green-
belt or other riverside areas), direct human
contact from recreational use;
- air entrainment of contaminated soil particles
or organic vapors; direct inhalation,
absorption or ingestion by humans or animals;
3. leaching of contaminants from surface soils to
alluvium and/or bedrock, contamination of
alluvial, bedrock ground water (B-3)
-------
Tabl e C-3
Health Effects of Contaminants Found
. at the UPRR Laramie Tie Treating Pl ant Site
Parameter
VOLATILES:
Benzene
Toluene
METALS:
Arsenic
Chromium (hexavalent)
POLYNUCLEAR AROMATICS:
Creosote
Acenaphthene
Anthracene
Benzo(a)anthracene
Benzo(a)pyrene
8enzo(b)fluoranthene
Benzo(ghi)pe~lene
8enzo(k)fluoranthene
Ch~sene
Dibenzo(a,h) anthracene
Fl uoranthene
Indeno(1,2,3-cd)pyrene C
Naphthalene
1,2-Methyl Naphthalene
Phenanth rene . D
Py re ne
PHENOLS:
Pentachlorophenol
EPA
Carcinogen Potential Health
Category (a) Effects (Reference)
A - headache, dizziness, nausea, convulsions, coma,
death, birth defects, certain forms of
leukemia, blood disorders, nervous system
depression, liver and kidney damage (1)
" "ervous system depression, 1 her and ki dney
d~age (2)
A - interferes with certain metabolic processes (3)
D
Bl
~ mutageilj", (4)
- skin carcinogen (mice) (5), mutagen (4)
B2 - animal carcinogen (5), mutagen (4)
82
82 - co-carcinogenic data (1)
- co-carcinogenic data (1)
D
82 - co-carcinogen (1)
82 - tumorigen (5)
- co-carcinogen (with pyrene) (4)
- co-carcinogen or initiator with negative
carcinogens or in-vivo mutagen (1)
- inhibitor (4)
- inhibitors (4)
- co-carcinogen (with fluoranthene) and mutagen
~4), co-carcinogen or initiator with negative
carcinogen or in-vivo mutagen (1)
- teratogen, toxicity (4)
CHLORINATED DI8ENZODIOXINS:
-Tetra- ( not found )6
Penta~ (not found) 8 (b)
Hexa- B (b)
Hepta- 8 (b)
Octa- 8 (b)
- 19 -
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~ -.".'. ""., , ~., ~ .
. .'r. '-. .."
-------
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. .
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~
Table C-3 (conti d)
Health Effects of Contaminants Found
at the UPRR Laramie Tie Treating Pl"ant Site
Key:
a - EPA Carcinogen Catego~ Explanations:
A
HUman Carcinogen - sufficient evidence from epidemiological studies to
support a causal association between exposure and cancer
B1 Probable Human Carcinogen - limited evidence of carcinogenicity in
humans from epidemiological studies
82 Probable Human C:.'rcinogen - sufficient evidence of carcinogenicity in
animals, inadequcte evidence of carcinogenicity in humans
C
Possible Human Ca~inogen - limited evidence of carcinogenicity in
animal s
D
E
Not Classified -".;nadequate evidence of carcinogenicity in animals
No Evidence of Carcinogenicity in Humans - no evidence for
carcinogenicity in at le.., ,. two adequate animal tests or in both
epidemiological and animal studies
b - CDD carcinogenicities based on equivalence factors relative to 2378 TCDD
References:
rene and Other Pol c lic
20, Ju y 982.
(2) - ~ Water Quality Criteria for Toluene, U.S. EPA, Washington, D.C.,
EPA-440/5-80-o75, October 1980.
. .,
C. F. Cramer, et a1.,
-------
Tab1 e C-4
EPA Standards for Contaminants Found at the UPRR Laramie Tie Treati ng P1 ant Site
EPA Pmbient 10~
Water Quality Criteria Cancer Ri sk
Pa rameter Drinking Drinking Water Level a For Levels of
Water + Aquati c Dri nki ng Proposed Contami nant
~ orga/~ sms Water RftI: L at UPRR site
Uni ts : ug ug L ug/L ug/L ug/L
VOLA TI LES:
Benzene 0.6b 0.67 0.78 0 ND-0.65
To 1 uene 1 0,800 1 4,300 2000 ND-18
METALS:
Arsenic 0.0022 0.0025 0.0028 50 0-35
CJ1romium (hex) 50 50 120 5-29
Copper 1000 1000 1300 1 0-40
POLYNUCLEAR AROMATICS:
Acenaphthene 20 20 ND-6700
Benzo( a)pyrene 0.0029 0.0031 0.0029 ND-960
F1uoranthene 188 42 0 -8700
PHENOLS:
Pheno 1 3500 3500 ND-102
Pentachlorophenol 30b 1010 0.22 ND-6500
2,4-Dimethylpheno1 400 400 ND-5
No tes :
a - 10-6 Risk Level assumes 70 kg adult drinking 2 liters of water per day.
b - Pentachlorophenol standard based on odor.
- 21 -
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. ". .. ..... .~.,.. .,' '. . '. .,;.~. ,"', .. ::.-" '," ?;';': ":" "., - ". ... ".? '. ", . . :.
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-,.',-,'..' ..... .
-------
. '..:.;' !~"10;..: ... ...f:'"J...}..L,.'-'':'''','': ,.:'I....'-,JP_:.;.r.,.,,; ":..~:....J.~".J;1.. ~I"':~r'"-'~''::''~'"'''' ....'.~~:. -",I.. ......,-~'..:._.. ~ ~ ~~."~' "'-..'.. .r........ .\ .. -....-1- .-' (..,. ~ 1-.-...-.<:-.. ~_.to .~.J'.._,.",.....~- - ....... .. ".'O6."'"&.
D . ENFORC EMENT
(The Enforcement Section is confidential and is included only in Agency copies
of thi s report)
-------
... . .~ ".1...> ~: :.' ....:. --::...: ! ~:... ,:. .~.. ..::.~:;'.~.'"3.t:)~';-L ~:...~.~;:1.,.~....~:...r;i"'J;~ w-:L ..~~.: ~..~f-..:..I i:~ ,."U. :~- .'-.
','.:: . -
-
~
E. ALTERNATIVES EVALUATION
The primary objectives of remedial action at UPRRls Laramie -Tie Treating
Plant are to mitigate the adverse environmental impacts of the site and to
protect human health, welfare, and the environment. The remedial action must
also comply with CERCLA, the National Contingency Plan (40 CFR Part 300), the
requirements of the EPA CERCLA Administrative Order on Consent, and the
litigation suspension agreement with the State of Wyoming.
Specific objectives for remedial action(s) at the site involve mitigation
of the following risks or pathways summarized from Table C-2:
- installation of on-site wells into contaminated formations, use of
contaminated ground water for drinking water, stock water,
agricultural, industrial or commerCial purposes;
- migration of contamination to off-site wells, use of contaminated
ground water;
- seepage of alluvial contamination to Laramie River, causing toxicity to
aquatic life, contaminant bioaccumulation in fish, and possible human
exposure throl.!9h consumption of fish or recreational use contact; f'.~.
- direct human contact with or ingestion of on-site surface soils (future
use or cl eanup worker scenari 0); .
- off-site migration of contaminated surface soils through flood and/or
wind erosion:
- transport to Laramie River, risk to aquatic life and human health;
- deposition of contamination as surface soils off-site (greenbelt or
other riverside areas), direct human contact from recreational use;
- air entrainment of contaminated soil particles or organic vapors;
direct inhalation, absorptiOn or ingestion by humans or animals;
The RI/FS process has identified several major remedial action measures
(in addition to no further action) for consideration as solutions to the above
listed risks or pathways. These measures may be divided into two categories,
those that are interim or partial in nature, and those that have at least the
potential to be final or permanent remedies:
I. No Further Action
I!. Interim Remedi es:
A. Contaminant Isolation/Source Control
B. Primary 011 Recovery
III. Permanent Remedies:
A. In-situ Remedies:
(1) Solidification
(2) Enhanced 011 Recovery or In-situ Suil Washing
(3) In-situ Bioreclamation
(4) Pump and Treat Selected Bedrock Ground Water
B. Excavation and:
(1) Soil Washing
(2) On-site Incineration
(3) Off-site or On-site Land Treatment
-------
,:",;~,:,,",~'~~h...K::'~.""::''\'I,),~~~}...t'-.!~......Z;'''..,.:tt,;.~...,.....h\~ ._~_:c:r.J;..c4.oc:. "fi1~..,1.~~_~.;"~'~ ~....-l."..':-.' ....~,.~.- _._~ ~....,..J,-.'..-~-..!._..~~~:....:.._-~ '."...~........_,
. . ..-... ~ ......~.. .~_...... .. .. -
"
E.
AlTERNATIVES EVALUATION (cont'd)
In its FS, UPRR evaluated these remedial action alternatives based on
technical feasibility, short term environmental effectiveness, and long term
environmental effectiveness. UPRR's evaluation placed a heavier emphasis on
long term environmental effectiveness than the other two factors.
In the preliminary screening process for these remedies, UPRR judged the
no action and in-situ solidification alternatives to be inadequate to address
the contamination and eliminated them from further evaluation. EPA concurs
with this evaluation.
EPA has reviewed UPRR's evaluation of the remat ling remedies, and has
concluded that the record documents the effectivene~s of only certain interim
remedies thoroughly enough to support a decision on their adequacy to mitigate
environmental and public health risks. Thus, the only remedy evaluations
fully discussed here are those for the interim remedies.
Slnce UPRR's RI/FS did not evaluate all of the final remedies adequately
enough to support selection of a final remedy, especially for the in-situ
remedies, the final remedies identifed by UPRR are discussed he,t-c:-,,:far
. informational purposes only. As discussed elsewhere 1n this do~ument, UPRR
wlll perform further evaluation affinal remedies pursuant to RCRA authority.
1. Interim or Partial Remedies:
a. Contaminant Isolation:
A Contaminant Isolation System (CIS) was the only interim remedy
documented adequately in UPRR's FS. The CIS is intended to mitigate
off-site movement of contaminated ground water and surface soils. As
proposed by UPRR, the major components of an isolation system for the
Laramie Tie Treating Plant could include:
(1) re-alignment of the Laramie River channel 150 feet further west
from the site to reduce chances of migration of contaminants to
the river and provide a Ic1ean" area for installation of a
barrier wall between the site the river channel; this remedial
action was accomplished in.October 1985;
(2) a barrier wall constructed through the alluvium and bedrock
around the contaminated areas; the wall would penetrate the full
thickness of the Morrison formation on the north, west and south
sides; barrier wall alternatives evaluated were:
- grout curtain
soil-bentonite
- vibrating beam
- sheet piling'
- cement-bentcnite
- ground freezing
-------
_..~....._...:..~,..-.'l.....t~.."""~"",,,, '"~~'''
. ..~-..........yr- ".!.. .-....}....
~- .- ~ .. ... - .-
E.
ALTERNATIVES EVALUATION (conti d)
(3) a reverse-gradient ground water draining and pumplng system to
mitigate off-site .seeping of contaminated ground water through
the barrier wal I;
(4) a water treatment plant to remove contaminants from the ground
water withdrawn from inside the barrier wall; the treated water
would be discharged to the Laramie River under the authority of
an NPDES permit; water treatment options considered included:
- activated carbon
- air stripping
- biological treatment
- UV-Ozone
(5) placement of caps over areas where heavily contaminated surface
soils are exposed;
(6) reliance on a slight updip hydraulic gradient in the Sundance
and Chugwater formations to mitigate downward migration of
contaminants into the bedrock;
(7) institutional controls (deed restrictions) on ground water use
at the site; and
(8) a ground water monitoring plan to measure system integrity.
b. Evaluation of Contaminant Isolation System options:
(I) The barrier wall options were evaluated against three criteria:
- technical feasibility
- applicability to long term (5+ years) scenario
- assurance of wall continuity
The results of that evaluation were that only the soil-bentonite
and cement-bentonite walls met all three criteria. Further
evaluation of these two options showed soil-bentonite to be more
cost-effective. Pilot tests were performed with soil-bentonite
to assure its effectiveness for this type of waste.
(2) Water treatment options were evaluated against three criteria:
- demonstrated technical feasiblity
- high removal efficip~cy for low levels
chlorinated phenols
reliability and ease of operation
of PNAs and
The results of that evaluation were that only the activated
carbon option met all three criteria. The other three
alternatives were eliminated from further consideration.
-------
. :.' ,. '... .. . '':'' .... -~~'...,. -::. ';...::.:.
. ",,~: ..;.~ 'L'L!"~';/":. ,._,......"Y..t'" ~~ :':':::=,.!-.~:,:""~,:,~,,'~l,,,';'~:.t:~'J\'!'':..~.\. ..7,. , . '\. ~. '.'. .:.<.. .....',
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~
E.
ALTERNATIVES EVALUATION (cont'd)
c. Prima ry Oi 1 Recovery:
This alternative may De implemented in at least two ways:
(1) the "passive" method of installing parallel trenches through the
alluvium into the first few inches of bedrock and letting the
011 drain into the trenches; EPA's consultant proposed a method
of digging the trenches twenty-seven feet apart and removing one
million gallons of recoverable oil in one year.
(2) the II acti veil method of i j,c;ta IIi ng and opera ti ng a dua 1 pump oil'
recovery network in the oIl-saturated alluvium; based on this
type of system, UPRR is projecting a three to five years oil
recovery program;
In UPRR's FS, Primary Oil Recovery is considered a necessary
preliminary action before implementation of any final remedies. The
process would remove a significant portion of the free or drainable oil
in the alluvium in preparation for bioreclarrlt~L:n, soil washing or any
of the final remedies discussed below.
2. Final Remedies:
As notea above, the RI/FS perfonned by UPRR did not completely evaluate
all of the final remedies, and further evaluation is to be accomplished
through a RCRA 3008 Consent Order (see Section K). Therefore, only a
cursory discussion of the final remedies 1spresented below.
a. In-Situ Treatment Alternat1ves:
(1) Enhanced Oil Recovery or In-situ Soil Washing
This alternative consists of cycling a contaminant extraction solution
through the contaminated zones via an injection/withdrawal system'. The
withdrawn contaminated solution would be treated above ground for oil
removal prior to reinjection. The process would continue until the
withdrawn ground water containea acceptable concentrations of contaminants.
. (2) 8ioreclamation:
This methOd consists of enhancing conditions for microbial degradation
of surface and subsurface contamination. The mLst important factors in
implementing this type of treatment are the teMperature and pH in the area
of treatment and the availability of oxygen and nutrients.
-------
E.
ALTERNATIVES EVALUATION (conti d)
The feasibility of the Bioreclamation alternative was not evaluated in
detail by UPRR other than to identify some of the key factors and some
pilot and field tests that would have to De completed before implementing
the a1 ternati ve.
(3) Pump and Treat Selected Bedrock Ground Water
This method would be designed specifically to remove the "stringers" of
contaminants from the fractured zone at the Morrison-Sundance interface.
or at least mitigate the movement of the contaminants further off-site.
These "stringers" are located outside the proposed boundclr1~s of the 50il-
bentonite barrier wall and will require special remedial 'action.
The goal of the method would be to provide a "boost" to the natural
slight updip gradient in the Sundance formation. A line of pumping wells
could be installed on the outside of the north end of thE! west barrier
wall. creating a cone of depression in the lower Morrison formation. To
assure that these wel Is doni t generate pressure on the 1nsi.de of the wall
in that vi ci n i ty. correspondi ng'. i4e 11 s wou I d be i nsta lIed ths i de the wall.
D. Excavation/Treatment/Disposal Alternatives:
(1) Excavation and Soil Washing:
This alternative would consist of the construction of a s011 washing
system on-site and the subsequent excavation and treatment of the
contaminated alluvial and bedrock materials. After treatment. the
materials would be considered for de1isting as a hazardous waste and
may be used to back fill the excavation.
(2) Excavation and On-site Incineration:
This alternative would consist of incineration of the excavated
contaminated alluvial and bedrock materials 1n a rotary kiln
incinerator that would be constructed on-site. Incineration would have
ta. designed to result in 99.9999 percent destruction of the principal
organic hazardous contaminants. The incinerated material would be
returned to the excavated area.
(3) Excavation and Off-site Land Treatment
This alternative would consist of treating excavated contaminated
alluvial and bedrock materials in a land treatment facility constructed
in the Laramie area.
-------
E.
ALTERNATIVES EVALUATION (cont'd)
- (4) Excavation and On-site Land Treatment
This alternative is the same as b-(3)~ except that land treatment
would take place at the site inside the contaminant containme~t system.
Because of the limited area, this alternative could take conslderably
longer than the off-site alternative.
c. Final Remedy to Meet or Exceed A11 Federal Requirements:
AccorCling to the recorCl established thus far by UPRR, the
a! ternative most likely to meet or exceed all applicable or relevant
ar~ appropriate federal requirements is #b-~~), Excavation and
Incineration (99.9999\ destruction) of all alluvial and bedrock
contamination, followed by on-site disposa" of residues that did exceed
site cleanup objectives. This is a proven technology that would best
be able to achieve a final remedy.
3. Results of Eva111,".;on, Coordination of Remt-des:
-- .1..-
One of the most important conclusions to be derived from the UPRR RI/FS
process was that all of the final remedies evaluated ;,'-1y on contaminant
isolation as a source control first operable unit. The principle is that
all of the final remedies will involve some sort of disturbance of the
waste mass in order to treat or destroy it. This disturbance could
mobilize significant amounts of the hazardous substances, increasing risks
to public health or the environment. Also, each of the final remedies is
likely to take an extended period of time, i.e., more than five years.
Each of these facts points to the conclusion that some partial remedy is
needed to mitigate the risks of the contaminants moving off-site before or
while the more permanent remedies are developed, evaluated and implemented
under RCRA authority.
A contaminant isolation system (as described earlier) is fully
consistent with each of the final remedies presented. The barrier wall
and the rest of the contaminant- isohtion system were judged to be the
only effective interim remedy, and the individual components of the system
were selected on the basis of cost effectiveness.
- 28 -
.. ~ ~ ..' ..,. 3' - "'''''...-.~~~ .. - .
-------
. . --... ~4' ., -.. ~ -.:
.
~
Table E-1
Summary of Alternatives Evaluation
Criteria
A1 ternati ve A B C D E F G
-------
No Further Action N N N N 0 0 0
Interim Remedies:
Contaminant Isolation 1 2 2 2 2 1 l( N)
Primary Oil Recovery 2 1 1 2 2 . 1 l(N)
Pennanent Remedies:
In-situ Solidification 1 1 0 1 1 1 1
Enhanced Oil Recovery/In-situ Soil Washing 2 2 1 1 2 1 1
Biorecl amation 2 1 1 1 2 1 1
Pump and Treat Bedrock Ground Water 2 2 2 1 .2 1 1
Excavation/Soil Was";ng 1 1 1 1 1 1 1
Excavation/On-site Incineration 2 2 2 1 1 2 2
Excavation/Off-site-On-site Land Treatment 2 1 1 1 1 1 1
Cri teri a:
A - Prove~ Technology with potential to treat this type of waste
B - Demonstrated Reliab1ity
C - Technical Feasibility at the Laramie Site
D - Cost Effective
E - Mitigates short tenn environmental risks at the Laramie Site
F - Mitigates long tenm/environmental risks at the Laramie Site
G - Meets Applicable or Relevant and Appropriate Requirements
Rati ngs:
o - fail s to meet CM teri on
1 - may meet cri teri on partially, may
2 - meets criterion
N - not applicable
have some unknowns
-------
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L
Tabl e E-2
Summary of Cost Evaluations
Alternative
Costs (in millions of $)
Annua 1 Present
Capital O&M Worth
No Further Action
a
a
a
Interim Remedies:
Contaminant Isolation
Primary Oil Recovery
7.5
9.6
0.57
0.75
15 a
13 c
:.......
Permanent Remedies:
In-situ Solidification
Enhanced Oil Recovery/In-situ Soil
Bioreclamation
Pump and Treat Bedrock Ground Water
Wc.:shing
not computed
~ .5 2. 1
3. 8 1 .2
'. /"lot computed
11 a
11 b,c
Excavati :;rtl::- oil Washi ng
Excavation/On-site Incineration
Excavation/Off-site Land Treatment
/On-site Land Treatment
8.2
78
8.4
1.1
15
32
8. 1
0.46
150
38
6.7
Notes:
Costs do not include pre-1986 expenditures of $6,000,000.
Capital and O&M costs from UPRR FS (by CH2~~il1); Present Worth costs from
Table 6-21, adjusted to reflect only costs for each particular remedy:
a - $6,000,000 subtracted for pre-1986 costs.
b - $11,900,000 subtracted for Primary Oil Recovery.
c - $17,500,000 subtracted for pre-1986 costs and contaminant isolation.
,
-------
F. COMMUNITY RELATIONS
..
The Laramie Tie Treating Plant site has generated a high level of
community interest, with citizens and environmental groups commenting
extensively on the RI and FS reports prepared by UPRR. These groups have
included local, state-wide and national organizations, such as the
Environmental Defense Fund, and have demonstrated an extraordinarily hi~h
level of expertise in the issues and problems at the site. The process of
citizen involvement and EPA responsiveness to that public involvement is
presented in greater detail in the Community Relations Responsiveness Summary
Report, Appendix D.
During the remedial planning stage of the project (prior to July 1986),
comments addressed the broad issues of remedial alternatives, technical and
cost questions, application of other laws, and community impact issues. In
general, the comments ~rd questions from citizens and environmental groups
advocated very similar positions. While the public strongly opposed UPRR's
earlier proposal of the contaminant isolation system as a final remedy, they
generally concurred that the system should be part of an interim solution.
Commenters generally saw the slurry wall as inadequate to contain the
contamination for more than 10 or 20 years, and said that the contaminants are
too heavy to be affected significantly by the reverse-gradient pumping.
Commenters also:
.
- questioned-the effectiveness of UPRR's proposed oil recovery system,
especially because of the general ineffectiveness of the pilot system;
- disagreed with irrigation of the land with untreated ground water as an
unproven technology that may lead to air contamination;
- called for an improved ground water monitoring plan;
-- criticized the scoring system used by UPRR in the alternative selection
process;
- expressed concern that the contamination would adversely affect a
proposed 'Igreenbel tll recreation area in Laramie, as wen as
socio-economic growth of the area.
In general, EPA agreed with these comments and asked UPRR .to revise its
Feasibility Study to address these concerns. EPAls detailed comments and
concerns were presented to UPRR in a major position letter dated April 8,
1986. EPA agreed that the contaminant containment alternative was inadequate
as a final cleanup remedy and asked UPRR to revise its evaluation in order to
develop more permanent remedies.
.
- 31 -
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-------
F. COMMUNITY RELATIONS (cont'd)
Comments received during the July-August 1986 pUblic comment period on the
final Phase III FS report were generally supportive of the revision that
contaminant containment would an interim remedy, provided it was followed by a
thorough and timely cleanup. Citizens continued to express strong concern,
however, that no specific remedy and no specific timetable for establishing a
remedy had been set. The community also asked for information on the schedule
and protocol for the pilot and field test program.
EPA agrees with these concerns and intends to use RCRA authority to
institute a specific schedule of pilot and field tests. Negotiations with
UPRR on this issue are under way, and the schedule is expected to be in place
by early October 1986. Although EPA will not require further revision of the
Phase III FS report at this time, we will require selection of a more specific
permanent and final remedy after completion of the pilot and field tests. The
selection o~' the remedy will take place under the procedures of developing and
issuing a RCRA post-closure care permit. EPA intends to coordinate the steps
in this prJcess to maximize overlapping studies and minimize the overall time
required to reach a conclusion.
.
Some s';~nificant public concerns remain unresolved, but will be addressed
under RCRA ~uthority (see Sections D, K). These concerns pertain to two basic
questions:.'~o what level of contamination will EPA require the site to be
cleaned and how quickly can the cleanup process be implemented.
EPA recognize~ ~hese concerns as the most significant for the site and has
stated for the record that EPA will determine the final cleanup levels during
the issuance process for the RCRA post-closure permit. In our determination,
we will consider input from various sources including public comment on the
draft permit. EPA's basic position is that the levels will be set such that
they assure the protection of pUblic health and the environment within a
reasonable time period.
-------
:_,..._'.:~...,~~.~~:::"::c,.:.~J'~..":;;".::."=. ':1,"':-~"',.:_'~,~~-~, }7."." :':....:~. '~'''....:.... -... ~ -
G. CONSISTENCY WITH OTHER ENVIRONMENTAL LAWS
.
The NCP generally requires that a final remedy selected under CERCLA
authority attain or exceed applicable or relevant and appropriate requirements
that have been identified for the site [40 CFR 300.68(i)(1)]. However, the
remedy selected in this document is an interim remedy (first operable unit),
not a final remedy. Therefore, as provided for at 40 CFR 300.68(i )(5)(i), the
NCP does not require that the remedy selected herein meet the requirements
discussed below.
In accordance with the CERCLA Compliance Policy found in the preamble to
the revised NCP (50 FR 47946, November 20, 1985), EPA has reviewed the list of
potential applicable or relevant and appropriate Federal requirements for a
final scl'ttion at this site, and has detennined that the following would be
selected:
- the requirements of the Resource Conservation and Recovery Act, as
amended, especially the requirements of Sections 3008(h), 3004(u) and
3004(u); and the regulations promulgated at 40 CFR Parts 264 and 265;
- Th~ Safe Drinking Water Act (Maximum Concentration Levels at 40 CFR
Section 141. 11.-141 . 16; Recommended Concentrati on Level s) ;
- The Clean Water Act as amended, especially the requirements of Sections
301, 302, 303, 306, 307, 309, 403 and 404.
EPA would also consider the following state requirements:
- The Wyoming Environmental Quality Act - Article 3, Statute 35-11-301;
- Wyoming Water Quality Rules an~ Regulations, especially Chapters 3, 4,
~, 9, and 11, including Wyoming's Ground Water Protection Policy.
.
After consideration of these potentially applicable Or relevant and
appropriate requirements, EPA concludes that the selected interim remedy for
the Laramie Tie Treating Plant site is fully consistent with these
requirements:
1. EPA has long intended that final cleanup of the RCRA regulated unit and
the associated contamination be implemented under RCRA authority. The
1984 amendments have expanded RCRA jurisdiction significantly, and EPA
is moving to strict, direct application of RCRA requirements rather
than the NCP. In addition, even if portions of the site were to remain
under CERCLA jurisdiction for final remedy, RCRA requirements would
still be the most appropriate for the site. In many instances, the
older wastes have commingled with the RCRA regulated wastes, and are
also amenable to treatment through similar technologies.
-------
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G. CONSISTENCY WITH OTHER ENVIRONMENTAL LAWS (cont'd)
Based on the findings of the CERCLA RI/FS process, EPA concludes that
any permanent remedy for the RCRA regulated areas (now the entire site)
will rely on the Contam1nant Isolation System as a means of preventing
off-site migration of contaminants during implementation. Thus, the
CERCLA first operable unit will be consistent both with full closure of
the regulated unit and with any post-closure corrective actions.
2. In compliance with the Clean Water Act, the Wyoming Environmental
Quality Act, and associated regulations, UPRR has applied for and
receiVed an NPDES permit (No. WY-0032590, signed March 20, 1986) from
WY DEQ for the discharge from the Water Treating Plant that is part of
the Contaminant Isolation System. The limits in the permit, ~re
developed on a flow-weighted/water quality basis to assure that the
discharge would not result 1n any violat10ns of water qua11ty standards
for the adjacent reach of the Laramie River.
3. On September 13, 1985, U.S. Army Corps of Engineers issued to UPRR a
'dredge and fill permit pursuant to Section 404 of the Clean Water Act
to authorize the relocation Jf about 3000 feet of the Laramie River bed
about 150' futher-west from the site. Negotiations over the permit
resulted in a condition that any wetlands that might be filled in
during the rechannelling operation must be replaced. UPRR has complied
with the conditions of the permit. .
-------
.. ..'. :!........:"":"'...
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H.
RECOMMENDED ALTERNATIVE
1. First Operable Unit
.
EPA 1S selecting a source control interim remedy (first operable unit)
pursuant to 40 CFR Section 300.68(c}. This remedy is a Contaminant
Isolation System designed to mitigate off-site movement of contaminated
ground water and surface soils during planning and implementation of more
permanent remedies. The major components of the isolation system are:
- re-alignment of the Laramie River channel 150 feet further west from
the site to reduce chances of migration ~f contaminants to the river;
this activi~ was completed in the fall O? 1985.
- a soil-oentonite slurry barrier wall constructed through the alluvium
and bedrock around the contaminated areas;
- a reverse-grad1ent ground water draining and pumping system to mitigate
off-site seeping of contaminated ground water through the barrier wall;
"': an acti vated careon water treatment pl ant to remove cl)"ntami nants from
the ground water that is withdrawn from inside the barrier wall; the
treated water will be discharged to the Laramie River under the
authority of an NPDES permit; and
- a ground water monitoring system to measure the effectiveness and
i ntegri ty of the system.
EPA has determinea that the Contaminant Isolation System is a
cost-effective remedy in accordance with the NCP and 1s consistent and
compatible with all the final remedies considered. The other source
control systems considered in the evaluation of alternatives were not as
cost-effective as the selected remedy.
EPA stresses that the contaminant isolation system selected as a first
operable unit 1s not a final remedy 1n that it does not permanently
address the most likely potential risks to public health,welfare, or the
environment. More permanent remedial action will be required to minimize
these ri sks.
EPA notes, however, that this Contaminant Isolation System 1s
consistent with any permanent remeay for this site.
The estimated cost of the selectPd remedy is as follow~:
.
Capital expenses:
Annual O&M:
Present Worth:
$7,000,000
57,000
15,000,000
-------
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FIGURE 8-1
APPROXIMATE LIMITS OF
ALLUVIAL CONTAMINATION AND
CUTOFF WALL ALIGNMENT
UPRR TIE TREATING PLANT
LARAMIE, WYOMING
Figure H-l
-------
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fiGURE 8-3
IN ERIOR AND EXTERIOR
DRAINAGE SYSTEM
UPRR TIE TREATING PLANT ==
LARAMIE. WYOMING ~
~
..
"
"
"
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Fjgure "-2
.
Ref.
~2~1II i '11. 1986
-------
UGHJ
OIL
auaMERli18U
PUMJI
HEAVY OIL
.
.ABa COLUCJIOII
AND
fIIUMAA' OIL MIIOVAL
(IiDAllAJIOM)
TO
. ADOITIONAL
.ABa TUATIIIIIIT
-- .ABa COLUCTEO
ININTIAIOA.
MAINAU ...TEII
8ECOHOAR' Oil
REMOVAl (UIiO"JION)
Figure H-)
Hd; CII2NII ill. t "I/HI
.
ACTIVATED CAR80N
UaO-TiON IYITUI
(NIUII OPIRAJION)
DIIiCHAROI
TO LARAMIE
RIVER
-
-
fiGURE 6-5 '.:I~l:II"
-------
~
H. RECOMMENDED ALTERNATIVE (cont'd)
2. Other Interim Remedies:
a. other contaminant isolation remedies:
The FS developed by UPRR includes other interim remedies under the
category of source control contaminant isolation techniques. These
remedies include the following:
- capping of highly contaminated surface soils (such as in the pond
bottom areas);
...
.
- institutional controls (deed restrictions) on ground water use at
the site; and
- reliance on an upflow gla:ient in the Chugwater and Sundance
fonnati ons.
EPA is not including these other interim contaminant isolation
alternative remedies in its remedy selected under CERCLA for the following
reasons:
a the capping of the RCRA pond areas and other highly contaminated
areas is a process that clearly falls under RCRA jurisdiction at
this site; UPRR has already sub~!ted a closure plan for the ponds,
and that plan is currently under review at EPA and has been
circulated for public comment.
- UPRR did not adequately address EPA concerns that the effectiveness
of the institutional controls identified in the FS couldn't be
assured; and .
- UPRR places undue confidence in the upgradient ground water flows in
the Chugwater and Sundance fonnations; those upgradient flows are
slight rather than strong, and could be influenced by off-site
pumping in the Sundance fonnation.
b. Primary Oil Recove~:
As discussed in Section E-1-b of this document, prima~ oil recovery is
considered a likely preliminary step before any of the final remedies that
would be implemented at this site. However, as discussed elsewhere in
this document (SectionsD, K), all further remedies at this site beyond
the source control first operable unit will be implemented under RCRA
authority.
.
- 39 -
. ,- """~'.. ,': -';'--"';:' "-',"';'.': ";...",
-------
H.
RECOMMENDED ALTERNATIVE {conti d)
c. Pump and Treat Morrison Bedrock Contamination:
This method is listed as a final remedy in Section E, but could also be
considered an interim remedy. Because this contamination is located
outside the soil-bentonite slurry wall, it will likely require a different
remedy from the bulk of the contamination that is located inside the wall.
3. Final Remedy
EPA is not, at this time, selecting a final remedy for cleanup of
contamination at the UPRR Laramie Tie Treating Plant site. The record
developed by UPRR in the RI/FS process was not adequate to support such a
selection.
...
.
.( ~~
-
The final remedial action best documented by UPRR's studies to
on-site incineration Gf the contaminated soils. This is the only
i denti fied in the eva1 .ation that has an establi shed record as an
effective final remeqy. .
EPA has serious concI rns that thJ effectiveness of all the remedies
evaluated in the FS wa..:not adequately demonstrated. Even in the case of
incineration, EPA is cc;;',:erned with some of the possible short term risks
involved in excavating and managing the on-site material.
date is
remedy
EPA acknowledges that perman£~t remedy for the site will be selected
under RCRA rather than CERCLA authority. The application of RCRA
authority to the entire site is imminent, and that authority will be
exercised in the short tenn through development and implementation of
pilot and field scal~-tests to measure the effectiveness of two remedies
that have significant potential as a final remedy, namely free oil
recovery and in-situ bioreclamation.
.
- 40 -
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t
I. OPERATION AND ~~INTENANCE (O~I)
UPRR has developed basic operation and maintenance (O&M) procedures for
the selected source control first operable unit, as follows:
1. Soil-Bentonite Slurry Cutoff Wall:
The wall will be inspected on a weekly basis by the site operator for
erosion, damage, and visible contamination. Erosion will be repaired
by backfilling and rip-rap, if required, and wall damage will be
repaired using soil-bentonite, cement-bentonite, or other impermeable
barrier material.
.
2. Reverse Gradient Water Management System:
Maintenance of the water management system will include routine
equipment calibration, maintenance for the pump station components, and
periodic checks of the manholes and sumps. Each manhole and sump will
be checked at least semi-annually for unobstructed inlet flow and the
presence of oil and or sediment. If necessary, drain lines, manholes
and sumps will be cleaned.
3. Water Tn.idtment System:.
The three carbon columns will be monitored for evidence of contaminant
breakthrough biweekly. At the first sign of phenol breakthrough on the"
second column, the first column will be taken out of service, filled
with virgin carbon, and placed back in service as the third column.
The effluent of the preliminary klensorb column will also be analyzed
biweekly for oil breakthrough. An on-line turbidity meter will
continuously monitor the influent to the klensorb column to detect high
levels of oils or suspended solids.
4. Post Containment Monitoring Plan, including monitoring of:
a. the NPDES discharges from the north and south sumps;
b. alluvial water levels inside and outside the slurry wall;
c. bedrock water level and water quality (Figure I-1);
d. Laramie River water quality.
.
A more detailed OIM plan will be developed by UPRR pursuant to the
pro vi si ons of the CERCLA Admi ni.strati ve Order on Consent after approval of
the first operable unit. The litigation suspension agreement with the
state requires development of an O&M manual by the time construction of
the system is 5~ complete.
-------
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UGINO
. CHUGWArER~"ORIHGWEU
. SUHDANCE MOfoIfOAIHQ W£l.l
. MOAAI$Ote MOHtrOAiHQ Will.
Q MOR'USOH PIEIOWE f(A
fiGURE 2
LOCATION OF 8EDROCK
MONITORING WELU
THE UPRR TIE TREATINO PLANT
LARAMIE, WYOMING
-
-
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-
1-1
-------
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J.
SCHEDULE
Some of the key milestones for implementing the selected remedy have
already been accomplished. In the spring of 1986, UPRR initiated planning and
design of the slurry wall. Construction of the wall was initiated in June
1986.
The key future milestones and dates for project implementation of the
CERCLA first operable unit (Contaminant Isolation System) are as follows:
Milestone
Date
..
.
Approve Remedy (sign Record of Decision)
comflete Construction of Contaminant
Iso ati on System .
September, 1986
To be deciaed pursuant to paragraph
30 of the 1983 CERCLA consent order
(about Apri 1 31, 1987)
.
.
-------
K. FUTURE ACTIONS
As noted previously, this record of decision selects only a "first.
operable unitll or interim partial remedy for the site. EPA has detennined
that the contaminant isolation system alone is not adequate as a pennanent
cleanup remedy and would not be sufficient to comply with the NCP. EPA
intends that more permanent and effective remedies be developed and
implemented for this site. EPA has also detennined that some of the other
remedies identified in the CERCLA FS need to be evaluated further through
pilot and field tests to measure their effectiveness more thoroughly.
As also noted earl i er, EPA has determi ned to apply RCRA authori ties rather
than CERCLA for implement~~g final remedial action at this site. EPA is
currently negoti ati ng wi tl. UPRR on the detai 15 and schedul e of the pil ot and
field test program to aSSUt'e the effectiveness of the final remedies under
consideration, and this program (expected to last about one year) \tiill be
included in a' new RCRA Administrative Order on Consent. EPA anticipates that
these negotiations will be completed by ,early OctQber, 1986, and that the RCRA
Consent Order will signed soon thereafter. EPA also anticipates th~t the new
RCRA order will also cover development and implementation of furthei' interim
remedies, including primary oil recovery and/or Morrison bedrock grmmd water
treatment in preparation for permanent ,N>, adia1 action. The CERCLK;f)rogram
will be involved in these negotiations and programs to provide comments and
ensure continuity of approach.
~.
.
Sometime during the pilot and field test program, EPA will be requesting
UPRR to submit its post-c10sure care plan. Submittal is required within 180
days of the request from EPA. EPA plans to use the results of the pilot and
field tests to when developing the requirements of UPRR's permit for
post-closure care.
As discussed in Section C of this document, some questions remain
unresolved about off-site contamination. These questions should be fully
resolved before final selection of remedies by RCRA.
4
.
- 44 -
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