United States
Environmental Protection
Agency
Off ice of
Emergency and
Remedial Response
EPA/ROD/R10-91/029
September 1991
&EPA Superfund
Record of Decision:
Union Pacific Railroad Yard,
-------
REPORT DOCUMENTATION T 1. REPORTNO. I ~ 3. RecIpient's Acc:eaaion No.
.
PAGE EPA/ROD/R10-91/029
4. TItle and SW1IIIe 5. Report Date
SUPERFUND RECORD OF DECISION 09/10/91
Union Pacific Railroad Yard, ID
6.
First Remedial Action - Final
7. Aulhor{s) 8. Perfonnlng Organlz81lon Rept. No.
I. PIIrfonning Orgalnlzatlon N8me and Add.... 10. Ptojec1lT uklWork UnI1 No.
11: ContraC1(C) or Grant(G) No.
(C)
(G)
1~ SponaorIng Organization N8me and Adchaa 13. Type of Repor1 & PerIod Covered
U.S. Environmental Protection Agency 800/000
401 M Street, S.W.
Washington, D.C. 20460 14.
15. SupplemenWy No....
16. Abatract (UmIt: 200 words)
The Union Pacific Railroad Yard site is an active rail yard located in Pocatello,
Bannock County, Idaho. Land use in the area is mixed commercial and light
industrial, with some residential areas. Site features include sludge pits along the
northwestern edge of the site, and Portneuf River, which is located 1,000 feet from
the pit. Ground water in the vicinity of the sludge pit occurs in two distinct
water-bearing deposits, the Upper and Lower Aquifers, which appear to be
hydraulically connected. Union Pacific Railroad (UPRR) began operations around the
turn of the 20th century. Site operations have included maintenance and repair work,
train assembly, and refueling, which involved the use of various fuels, cleaning
agents, detergents, and degreasers, including halogenated and non-halogenated
hydrocarbon-based solvents. UPRR constructed a treatment plant in 1961 to receive
indu~trial wastewater and surface stormwater runoff from the railyard. Until 1983,
sludge from the treatment plant's oil/water separator and from a dissolved air
flotation unit was disposed in the onsite sludge pit. . Currently, the sludge pit
contains approximately 2,500 cubic yards of sludge and 1,700 cubic yards of
contaminated soil beneath the sludge. In 1983, EPA determined that seepage from
(See Attached Page)
17. Document Analyaia .. Deacripto..
Record of Decision - Union Pacific Railroad Yard, ID
First Remedial Action - Final
Contaminated Media: soil, sediment, sludge, gw
Key Contaminants: VOCs, other organics (PAHs), metals (arsenic, chromium, lead),
oils
b. IcIentlfleralOpen-EncIed Terms
Co COSA 11 FleldlGroup
18. AYlilabilty SIatement 19. Sec:urIty CI... (ThIa Report) 21. No. o' Psges
None 166
20. Sec:urIty CIua (ThIa Page) n PrIce
Nnno
212(4-77)
I
~
.;
.)
:..
'..
50272.101
(See AJ$.Z3I18)
s.. ImItructiOM on RsllefIMI
(FormeJty NTlS-35)
-------
/
EPA/ROD/R10-91/029
Union Pacific Railroad Yard, ID
First Remedial Action - Final
Abstract (Continued)
~
~
UPRR's sludge pit, and from a nearby area where an oil tie treating facility was located
were contributing to Upper Aquifer ground water contamination. In 1985, UPRR, the only
identified potentially responsible party, conducted an investigation of the railroad
yard, and the sludge pit was determined to be the principal source of onsite
contamination. This Record of Decision (ROD) addresses contamination of the Pocatello
Sludge Pit located at the UPRR property. The primary contaminants of concern affecting
the soil, sediment, sludge, and ground water are VOCs, other organics including PARs and
petroleum-based hydrocarbons (oils), and metals.
~
The selected remedial action for this site includes implementing a comprehensive soil,
sediment, sludge, and ground water sampling effort prior to remedial activities to
determine background levels and to. set final remediation goals; excavating to the maximum
extent practicable up to 4,200 cubic yards of visibly-contaminated soil, sediment, and
sludge; testing these media for compliance with land disposal restriction treatment
standards, followed by disposal at an approved offsite landfill; treating soil remaining
beneath the excavated area using in-situ soil flushing as part of the Upper Aquifer
ground water treatment system, backfilling, grading, and capping the entire pit boundary;
extracting and treating nonaqueous phase liquid contaminants from the Upper Aquifer
ground water using an onsite oil/water separator and a dissolved air flotation unit;
discharging effluent offsite to a publicly owned treatment works (POTW); placing skimmed
oil in an onsite holding tank for sale to a recycler; disposing of residual sludge from
ground water treatment offsite; conducting quarterly sampling and analysis of ground
water to ensure remediation goals are met; constructing a fence around the sludge pit;
providing advanced funding for design and installation of an alternate water supply
system to be implemented if monitoring indicates that ground water contamination has not
been adequately remediated; .monitoring ground water, surface water, 2nd air; and
implementing administrative and institutional controls including deed, land, and ground
water use restrictions. The estimated present worth cost for this remedial action is
$3,797,550, which includes a present worth O&M cost of $1,657,900 for 30 years.
PERFORMANCE STANDARDS OR GOALS: Chemical-specific remediation goals have not been
finalized, with the exception of lead 500 mg/kg for soil and 0.015 mg/l (MCL) for ground
water, as a result of incomplete data regarding background concentrations of contaminants
in soil, sediment, sludge, and ground water. Final clean-up goals will be based on
background concentrations, lowest practical quantitation limits, ground water ARARs
identified in the FS, or target concentration values, whichever is highest. Health-based
cleanup goals include a 10-6 cancer risk for carcinogens and an HI
-------
~
.
'1
I.
II.
III.
IV:
V.
VI.
VII.
VIII.
IX.
X.
XI.
~
~
RECORD OF DECISION
for the
UNION PACIFIC RAILROAD SLUDGE PIT
POCATELLO, IDAHO
TABLE OF CONTENTS
Declaration of the Record of Decision
Decision Summary
Introduction
site Name, Location, and Description
site History and Enforcement Activities
Community Relations
Scope and Role of Response Action within site Strategy
Summary of Site Characteristics
Summary of S~ = Risks
Description 0: Alternatives
Summary of Comparative Analysis of Alternatives
The Selected Remedy
The Statutory -Determinations
Documentation of Significant Changes
Responsiveness summary
Administrative Record Index
Page
8
8
9
10
12
13
18
27
38
44
50
-------
DECLARATION OF THE
RECORD OF DECISION
SITE NAME AND LOCATION
.
Union Pacific Railroad Sludge Pit
Pocatello, Bannock County, Idaho
.
"
STATEMENT OF BASIS AND PURPOSE
This decision document presents the selected remedial action for
the Union Pacific Railroad Sludge Pit site in Pocatello, Idaho.
This action was chosen in accordance with the Comprehensive
Environmental Response, Compensation, and. Liability Act of 1980
(CERCLA), as amended by the Superfund Amendments and
Reauthorization Act of 1986 (SARA), and, to the extent
practicable, the National Oil and Hazardous Substances Pollution
Contingency Plan (NCP).
This decision is based on the Administrative Record for this
site. The attached index identifies the items that comprise the
Administrative Record upon which the selection of the remedial
action is based.
The state of Idaho concurs with the selected remedy.
ASSESSMENT OF THE SITE
Actual or threatened relea~es of hazardous substances from
site, if not addressed by implementing the response action
selected in this Record of Decision (ROD), may present an
imminent and substantial endangerment to the public health,
welfare, or the environment.
this
DESCRIPTION OF THE SELECTED REMEDY
The selected remedy for the Union Pacific Railroad Sludge Pit
addresses contaminant threats at the site by excavating and
disposing of contaminated slud~e,silt and soil; by removing
nonaqueous phase liquid (NAPL) contaminants from the Upper
Aquifer groundwater surface, and by flushing residual
contamination from the soil. The remedy is designed to .
significantly reduce exposure to the contaminated sludge, silt
and soil, and contaminated groundwater. The goal of the selected
remedy is to remediate the sludge, silt and soil, and the
contaminated groundwater to levels that are protective of human
health and the environment.
w
The major components of the selected remedy include:
. Excavating contaminated sludge, silt and soil to the maximum
extent practicable, followed by disposal at an approved offsite
~
-------
~\
Resource Conservation and Recovery Act (RCRA) landfill; excavated
areas will be backfilled with clean fill and graded.
. Testing of contaminated sludge and soil prior to disposal to
demonstrate compliance with land disposal restriction (LDR)
treatment standards at a frequency specified in the receiving
facility's waste analysis plan, .including Toxicity Characteristic
Leaching Procedure Extraction (TCLP); treatment, if necessary,
prior to disposal. Test results indicate that the sludge and
soil are not RCRA characteristic waste, and therefore, no
problems are anticipated with disposal at the facility. However,
if unforseen circumstanc~s arise, a treatability variance for the
wastes is requested should the wastes fail TCLP and the Paint
Filter Test at the disposal facility.
~
. Placing and maintaining a low permeability cap over the entire
pit boundary following excavation, backfilling and grading.
Areas outside the pit that are excavated will be backfilled with
clean fill and graded. . .
. Treating soils and nonaqueous phase liquid (NAPL) contaminated
Upper Aquifer groundwater via soil flushing, an onsite oil/water
separator, and a dissolved air flotation unit in order to prevent
migration of NAPL to the Lower Aquifer and to reduce NAPL and
other contaminant concentrations which exceed proposed maximum
contaminant levels and maximum contaminant level goals; effluent
discharge to the Pocatello publicly owned treatment works;
residual sludge resulting from groundwater treatment tested and
disposed in an approved, offsite landfill; potable water obtained
from Batiste Springs for use in the infiltration galleries for
washing contaminated soils.
. Providing advance funding for design and installation of an
alternate water supply system to serve potential future onsite
businesses and/or residences, in the event that the system is
determined to be needed. . Since businesses and. residences. do not
exist onsite, installation of a new water supply is not
immediately required.
. Constructing a six-foot-high chain .link fence around the entire
sludge pit to ensure site security and to restrict public access
to the site.
.
~
. Implementing administr~tive and institutional controls in the
property deed such as air monitoring, groundwater monitoring, and
land and water use restrictions, that supplement engineering
controls and minimize exposure to releases ~f hazard6us
substances during and following remedial activities.
. (
. Conducting quarterly sampling and analysis of. groundwater from
all onsite wells, at a minimum, for the first three years
following completion of remedial activities. If deemed
-
-------
appropriate, the sampling rate will be reduced to a lesser
frequency for the remaining 27 years. Monitoring of the
groundwater and the pump/treat system during groundwater
remediation activities will be conducted to ensure that
groundwater remediation goals are achieved. If cleanup goals are
not met, modifications to the groundwater treatment system will
be necessary. . .
~
. Implementing a comprehensive, onsite and offsite, soil and
groundwater sampling effort, prior to initiation of remedial
activities, to determine background levels in these media and the
extent to which onsite concentrations exceed background levels.
Preliminary target concentrations/remediation goals for
contaminants of concern have been established for the site and
are provided in the Record of Decision. Final remediation goals,
target concentrations and performance standards will be
identified following the determination of soil and groundwater
background concentrations.
~.
STATUTORY DETERMINATIONS
The selected remedy is protective of human health and the
environment; complies with Federal and state requirements that
are legally applicable or relevant and appropriate to the
remedial action; and is cost effective. This remedy uses
permanent solutions and alternative treatment technologies or
resource recovery technologies, to the maximum extent
practicable, and satisfies the statutory preference for remedies
that employ treatment that reduces toxicity, mobility, or volume
as a principal element.
While the risk assessment appears to indicate that the
contaminated sludge and soil in the sludge pit may present an
imminent and substantial endangerment to public health, welfare
and the environment, EPA has determined that it does not pose a
principle threat at this site.
Existing analysis of railyard and wastewater treatment plant
operations, applicable governmental regulations, and the results
of sl:dge chemical analyses indicate the sludge is not a
hazardous waste as defined by RCRA, pursuant to 40 CFR
261.4(b) (7); therefore, the RCRA Land Disposal Restrictions do
not apply.
The selected remedy for addressing contaminated sludge and soil
within the sludge pit is excavation, to the maximum extent
practicable, and offsite disposal. This portion of the selected
remedy is not considered to be treatment. However, physical
extraction of contaminants from soils (underlying the sludge and
soil removed by excavation) using in-situ soil flushing is
considered an innovative treatment technology. Treatment
technologies including solidification and incineration were
.
r.
-------
considered but were determined to be technically infeasible for
. the following reasons:
,8\
Solidification: Because of the oily consistency of the
sludge, the ability to ensure successful implementation and
maintenance of this remedy is highly uncertain.
~~
Incineration: Elevated contaminant levels of metals
in the sludge present significant uncertainty in the
technology's ability to achieve target cleanup
concentrations.
found
Because this remedy will result in hazardous substances remaining
onsite within the groundwater, above health-based levels, a
review will be conducted within five years aftercornrnencement of
remedial action to ensure that the remedy continues to provide
adequate protection of human health and the environment.
~t)(V (j~~1Wr.JL
DAN A. RASMUSSEN.
Regional Administrator, Region 10
U.S. Environmental Protection Agency
.I'".
') 1 '-
Date
.,)
/!
-------
DECISION SUMMARY
INTRODUCTION
The Union Pacific Railroad Sludge Pit was nominated to the
National Priorities List (NPL) in September 1983. The nomination
was based on a Hazard Ranking System (HRS) score the pit received
from a site assessment performed by EPA in June 1983. The site
was placed on the NPL in September 1984 (49 Federal Reqister
37083, September 21, 1984) under the Comprehensive Environmental
Response, Compensation, and Liability Act of 1980 (CERCLA or
Superfund), as amended by the Superfund Amendments and
Reauthorization Act of 1986 (SARA).
Pursuant to Executive Order 12580 (Superfund Implementation) and
the National Oil and Hazardous Substances Pollution Contingency
Plan (NCP) , the Union Pacific Railroad performed a Remedial
Investigation/Feasibility Study (RI/FS) for the Union Pacific
Railroad Sludge Pit. The Remedial Investigation (RI) (1990)
characterized contamination in the sludge, silt, soil, surface
water and groundwater. The Baseline Risk Assessment (1990)
evaluated potential effects of the contamination on human health
and the environment. The Feasibility Study (FS) (1991) evaluated
alternatives for remediating contamination.
{'f..
~
I.
SITE NAME, LOCATION, AND DESCRIPTION (Maps 1 and 2)
The Pocatello Sludge Pit is located on Union Pacific Railroad
(UPRR) property in the southern half of Section 16, Township 6
South, Range 34 East of the Boise Merid~an, Bannock 'County,
Idaho. The property is on the northwest edge of the city of
Pocatello, Idaho, a few hundred feet south of U.S. Highway 30.
The Pocatello Sludge Pit is in a mixed commercial and light
industrial setting, with residential areas approximately 0.3 mile
to the north and east of the site. The MCCarty's/Pacific Hide
and Fur Superfund site abuts Union Pacific Railroad property to
the northeast and is upgradient of the UPRR site.. .
There are no major structures or yard facilities located on UPRR
property near the sludge pit. The land surface surrounding the
pit slopes gently to the southwest towards the river. The area
is sparsely vegetated with wild grass and sagebrush.
The sludge pit is 620 feet long (along the nort~western edge) by
58 feet wide, covering approximately one acre. Sludge thickness
ranges from 1.5 to 4.4 feet. The pit contains approximately.
2,500 cubic yards of sludge. The sludge consistency ranges from
desiccated to oily. Approximately another 1,700 cubic yards of
contaminated soil underlies the pit.
,.,
Two concrete retaining walls, each approximately 450 feet long,
run longitudinally through the pit and rise about two feet above
~
-------
'~
~.
STUDY AREA
SLUDGE PIT
'.
IDAHO
POCA TEU.O.
~
HAP 1
I
N
SeAL t: ... Ft:'(T
~
::::::/
I~
o
4000
-------
~
15.. Z...
~
"
a
a
o
()
CDnAn AUf.
o
---==--.--
legend ,
industrial wel
o 1ftdic8tes ~tic or
.
.
-------
~
. the sludge bed. The pit is bermed along the north and east sides
with soil varying in height from one to two feet. The pit is.
surrounded by a barbed wire fence.
~
Groundwater in the sludge pit vicinity occurs in two distinct
water bearing deposits (Upper Aquifer and Lower Aquifer)
separated by a less permeable clay layer. The Lower Aquifer is
very productive and is used as a water source by local, private
residents, businesses, and the city of Pocatello (Supply Well No.
32). No water supply wells in the area have been found to
utilize the Upper Aquifer, which is c_ntaminated with chemicals
that have migrated downward from the sludge, through the silt and
soil, to the groundwater surface. Contaminants have also been
identified in the Lower Aquifer but are below Safe Drinking Water
Act standards. .
The Portneuf River is 1,000 feet from the pit and is frequented
by a variety of fish and wildlife species. Land surface at the
sludge pit is approximately 35 feet above the average river
level. To date, no adverse affects to environmental resources
from the site have been reported.
II.
SITE HISTORY AND ENFORCEMENT ACTIVITIES
Union Pacific Railroad (UPRR) has operated a railroad yard in .
Pocatello, Idaho since approximat~ly the turn of the century.
Operations have included maintenance and repair work, train
assembly, and refueling. Railroad operations have involved the
use of various fuels, cleaning agents, detergents, and
degreasers, including halogenated and non-halogenated hydrocarbon
based solvents.
UPRR constructed a treatment plant in 1961 that receives
industrial wastewater from the railyard as well as the yard's
surface stormwater. The wastewater is treated in a process that
recovers free oil and yields treated effluent and residue sludge.
The effluent, discharged to the Portneuf River between 1961 and
1978, has been discharged to the city of Pocatello's sewer system
since 1978. Sludge from the wastewater treatment plant's'
oil/water separator and from a dissolved air flotation unit was
placed in the sludge pit until 1983. '.
Historical and .current ind~strial operations in the surrounding
vicinity that provide potential additional sources of
environmental contamination are discussed below.
~
~
The Pocatello Timber Treating Plant, owned by the Oregon Short
Line Railroad, occupied approximately 15 acres immediately
northwest of the sludge pit. UPRR records indicate the plant
began operation in 1917, primarily treating railroad ties. A
zinc chloride based solution was the original treating medium;
-------
creosote .was used after' 1927.
d~molished in 1948. .
The plant closed in 1942 and was
Neighborhood industrial sites that historically performed a
variety of manufacturing and process activities included the
nearby H. o. Miller Distributor Company, which stored bulk
petroleum products in the 1950s; the Phillips Petroleum Refinery
which is suspected of operating sludge ponds from 1941 to 1956;
the Patton Gravel Pit processed batteries from the late 1960s to
early 1970s and backfilled the pit with demolition debris from
1968 to 1980; and, the Pacific Hide and Fur Company, which
operates a metals recycling business and historically, in
conjunction with McCarty's Inc., salvaged transformers and
capacitors, discharging coolant oils. t~ the ground surface.
In 1983, an EPA site investigation found that seepage from UPRR's
sludge pit, and from an area in the vicinity of the ~ludge pit
where an oil tie treating facility was located, were'contributing
to Upper Aquifer (and to some extent, Lower Aquifer) groundwater
contamination. Samples from private wells, completed in the
Lower Aquifer in the vicinity of UPRR's property, contained low
levels of organic compounds consistent with the wastes discharged
to the pit. .
~
~
Following the site's placement on the NPL on. September 21, 1984,
UPRR retained Applied Geotechnology, Inc. (AGI) in 1985, an
independent contractor, to conduct a limited investigation of the
UPRR site and to evaluate the nature and extent of the suspected
contamination. UPRR and AGI presented the results of ~hat
investigation to EPA in November, 1986.
On January 8, 1988, a General Notice Letter/Request For
Information was sent by EPA to UPRR, the only identified
potentially responsible party (PRP) for the sludge pit. A
Consent Order (No. 1088-01-03-106) was signed by EPA and UPRR on
June 21, 1988. In compliance with that order, 'UPRR was directed
to supplement the data in the preliminary report and to prepare
an RI/FS as outlined in CERCLA. AGI began the RI in July, 1988,
and completed activities in April, 1989.
A Risk Assessment and FS for the site were also prepared by UPRR
contractors and were completed in November,' 1990 and April, 1991,
respectively.
III. COMMUNITY RELATIONS
,
Throughout the UPRR Sludge Pit site's history, community concern
and involvement has been low. EPA has kept the community and
other interested parties apprised of site activities through fact
sheets and published notices.
~
-------
r
~
. In June, 1988, EPA released a community
outlined a program to address community
opportunities for community involvement
activities.
relations plan which
concerns and provide
during remedial
.
The speci.fic statutory requirements for public participation at
the Union Pacific Railroad Sludge Pit under CERCLA include the
release of the RI/FS results and the Proposed Plan to the public.
In accordance with Sections 117 and 113(k) (2) (B) of CERCLA, the
public was given the opportunity to participate in the .remedy
selection process. The Proposed Plan, which summarized the
alternatives evaluated and presented the preferred alternative,
was mailed to approximately 130 interested parties in June 1991.
Concurrent with distribution of the Proposed Plan, EPA made the
Administrative Record available for public review at EPA's
offices in Seattle, Washington, and at the Pocatello Public
Library. Notice of the Proposed Plan availability and public
comment. period was placed in the June 6, 1991, Idaho State
Journal. The public comment period was held June 7, 1991, to
July 8, 1991.
On June 18, 1991, EPA held a public meeting to accept oral
comments on the Agency's Proposed Plan. During this meeting, the
Agency gave a presentation on the cleanup alternatives and
answered questions from the public. The public was encouraged to
.submit any written comments on the alternatives presented in the
Feasibility StUdy and the Proposed Plan and on the other
documents which were a part of the Administrative Record for the
site. A transcript of the public meeting and comments and the
Agency's response to comments are included in the attached
responsiveness summary.
The following is a summary of EPA community relations activities
to date at the site:
September 1983 - Site proposed for NPL.
September 1984 - site listed on NPL.
June 1988 - Interview conducted with local officials
and citizens to develop Community Relations Plan.
June 1988 - Community Relations Plan was published.
.
June 1988 - Information repositories established at the
Southeastern Idaho Health District office, and the
Pocatello Public Library.
~
August 1988 - EPA distributed a fact sheet providing
information on the start of the field work for the
Remedial Investigation.
-------
July 1989 - EPA distributed a fact sheet on findings of
the RI and announced upcoming activities related to the
cleanup of the site.
~
January 1990 - EPA distributed a fact sheet to update
the public on site work.
~
June 1991- Proposed Plan was published.
June 7, 1991 to July 8, 1991 - Public comment period
for Proposed Plan.
IV. SCOPE AND ROLE OF RESPONSE ACTION WITHIN SITE STRATEGY
June 18, 1991 - Public meeting on Proposed Plan.
Approximately 20 people attended this meeting. Meeting
was announced in Proposed Plan and local newspaper.
The selected remedy for final action is intended to address all
of the concerns originating from the contamination at the Union
Pacific Railroad Sludge Pit. The principal source of
contamination, based on the RI sample results, is the sludge.
Contaminants have migrated from this media to the surrounding
soils and leached into the Upper Aquifer resulting in
concentrations above applicable or relevant and appropriate
requirements (ARARs) and health-based risk values.
The primary purpose of the selected remedy is to remove the
source of contamination by excavating and disposing of sludge,
silt and soil in and around the pit, followed by backfilling,
grading and capping of the excavated area to meet cleanup goals.
During the RI, the groundwater in the Upper Aquifer was found to
be contaminated with nonaqueous phase liquids, pOlycyclic
aromatic hydrocarbons, metals and other chemicals such as
chlorinated solvents. Under the selected remedy, pump and
treatment of the Upper Aquifer and cleansing of soils beneath the
excavated material, using soil flushing, will be employed to meet
groundwater cleanup goals. This treatment will be employed to
prevent migration of nonaqueous phase liquids (NAPL) and other
contaminants to the Lower Aquifer and to reduce contaminant
levels which exceed proposed maximum contaminant levels (PMCLs)
and goals (PMCLGs).
Union Pacific Railroad will perform additional field work prior
to implementation of the remedy to determine whether contaminants
found in the soil and groundwater occur at "background" levels.
Cleanup goals will be established for those contaminants where
none had previously been set; preliminary target concentrations
identified in the ROD will be refined and finalized along with
performance standards. Once treatment begins, a long-term
~
~
-------
l
monitoring program will be implemented to evaluate performance of
the selected remedy.
-
..
v.
SUMMARY OF SITE CHARACTERISTICS
~
The following discussion summarizes data from the sampling and
analyses performed as part of the RI.
A.
Sludge Contamination
The pit contains approximately 2,500 cubic yards of sludge.
Another 1,700 cubic yards of contaminated soil underlies the pit.
The sludge pit was investigated and sampled from 1985 to 1988.
The initial sampling data provided a basic understand~ng of the
sludge pit's geometry and contents. Further analyses provided
data to evaluate physical and chemical characteristics of the
sludge. .
The sludge within the pit has been characterized as generally
brown to black, oily, and of varied consistency. Much of the
sludge's initial fluid content has evaporated, leaving a dry,
relatively firm crust. Hydrocarbons, including chlorinated
volatile organic compounds, polycyclic aromatic hydrocarbons, and
metals (arsenic, cadmium, chromium, lead, nickel, and zinc) are
the compounds of most concern associated with the sludge pit.
Figure 1 indicates the estimated extent of soil contamination
based on a summary of all data from 1985-1989.
The silt underlying the sludge has a grayish appearance. It is
rather hard and resilient and ranges from dry to moist. In most
subsurface borings, the silt was extremely difficult to penetrate
and appeared to be cemented by chemical compounds leached from
the sludge. The gravel underlying the remainder of the sludge
pit could not be penetrated. Consequently; the degree to which
the gravel received conta~inants from the sludge could not be :
evaluated. Figures 2A and 28 depict the plan view of the sludge
pit investigation and the cross sections of the north and south
sides of the sludge pit, respectively.
..
The bulk physical composition of the sludge is approximately 65
percent solids and 35 percent water; this ratio changes'
. seasonally. The solid fraction yields approximately 70 percent
ash and 30 percent volatile solids. The bulk sludge (solids and
liquid phases) is composed of approximately 26 percent oil and
grease and 0.5 percent total sulfate.
Chemical analyses perfor~ed on sludge samples resulted in the
identification of the following contaminants:
~
1. Metals- The pri~ary inorganic constituents in the
sludge are common soil metals, including calcium, aluminum,
-------
UPRR. PROPERTY UHf
lCALE IN fEET
.
o
100
. .
300
t
N
flGUIIE
SLUDGE PIT INVESTIGATION PLAN
II[HIIENCE'
UNION PAC If IC IIAILIiOAD I fO"MEIIU OIlEOON
1"0111 LINE I WES1 rocArnlO IIUIO" IIAP.
C[ 0llAWIN8 NO. Izrll. DArED AUGUsr 18, ..n
UNION PACifiC RAILROAD - POCATELLO SLUDGE PIT
POCATELLO, IDAHO
2a
:.
.
~,
-------
...
.
.1
...~.
_.
A
e
2N
T
3N
T
A.
. OEPTH 8ELOW
PIT SURfACE
IfEU)
e
8
..
S'
\
e
PIT SECTION 8-8"
.
.
. . . .
. . . . .. .... . . . .
. . . . . . . . . . . . , . . .
. . . . .. .....,... . . . I .
. . . . . . . . . . " "" . . . . . . . .
. . . . .. ............ ........ .
. . . . . . . . . . .. ..................
. . . . .. ............ ..... .....
. . . . . . . . . . .. .................
. . . . .. ............ ..... .....
. . . . . . . . . . .. .................
. . . . .. ..... ............ .. f . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
tIt.,..,.........,. ,..., ....
. . . .. . . . . . . . . . . . . . . . ..
1 '.'.'. .'.'.'.'.
.. ... ?
. . . I .
. . .
SOUTH SI DE
2
DEPTH 8UOW
PIT SURfACE 3
(fEn)
II
~
~
BROWN SIL TV SANO I fiLL I
btJI--
''''..0- -"''''--P_of____.
~.............................. ..~.......... of doIo~.... ......,...
-.. -... ..........., -. --.... -1Iot*Iod.......
''''Y bo- boolngl.
AOI clot. not '.......... Ih8 - ...It..,.. ..Iet. bwI 'MiOVftI,..
.... v.d811on1 .....
LEGEND
OESICCATED
SLUDGE
SEE flOURE
FOR CROSS' SECTION LOCATIONS
SCALE IN FEn
.
o
lIII1IIJJ
~
.0
pgg
~
OIL Y SLUDOE
VERT ICAL
.
711 150
EXAOOERATION . 20,1(
SILT IRECENT ALLUVIUM)
SLUDGE PIT CROSS SECTIONS
"QURE
BROWN SANDY ORAVEL
10LDER ALLUVIUM I
UNION PACIFIC RAILROAD - POCATELLO
POCATEllO, IDAHO
SLUDGE
PIT
-------
r
~j
irpn, magnesium, and potassium. The sludge also contains
cadmium, chromium, copper, lead, mercury, and zinc at higher
concentrations than adjacent soils. A third group of metals
which includes antimony, arsenic, cobalt, manganese, nickel,
and vanadium, are present at low but detectable
concentrations. Metals sampling results are presented in
Table 1.
-
.
Soil leaching studies [EP-Toxicity, EPA-Toxicity
Characteristic Leaching Procedure Extraction (TCLP), and a
deionized water leach test] were performed on sludge
samples. These studies indicate metals in the sludge are
generally not available for leaching and are not mobile
unless an acidic leaching solution is used. Table 2
presents the sludge TCLP data and TCLP standards.
2. Volatile and Semivolatile Organic Compounds- Eight
target compound list (TCL) volatile organic compounds were
detected in the 1985 sludge samples: ethylbenzene, toluene,
xylenes, trans-1,2-dichloroethene, trichloroethene,
tetrachloroethene, acetone, and methyl. ethyl ketone. Only
four of these compounds were detected in the 1988 sludge
samples: ethylbenzene, xylenes, trans-1,2-dichloroethene
and tetrachloroethene. The 1988 samples contained lower
concent~ations of these compounds. This may be due to
differences in sampling p~ocedures or to actual changes in
the sludge during the intervening years. Oily sludge which
is expected to be the most contaminated is the most
difficult to retain in the sampling tubes, and complete
recovery was not possible. The differences may also reflect
an actual decrease in the concentration of volatile organic
components. Possible causes of the decrease include
migration and volatilization of compounds from the sludge
pit.
Semivolatile TCL organic compounds detected in 1985 sludge
samples include polycyclic aromatic hydrocarbons (PAHs), .
nitrosamines, a phthalate, .and dichlorobenzene. Tha sludge
samples also contained a substantial number of non-TCL
hydrocarbons. The 1988 sludge samples contained PAHsand
dichlorobenzene. Tables 1 and 3 list the semivolatile and
volatile compounds found in the sludge.
~
TCLP extractions for volatile and. semivolatile compounds
indicate several chlorinated volatile and semivolatile
organic compounds leach from the sludge under moderately
acidic conditions.
~
The existing analysis of railyard and wastewater treatment plant
operations, applicable governmental regulations, and the results
of chemical analyses indicate the sludge is not a characteristic
waste as defined by the Resource Conservation and Recovery Act,
-------
TABLE
'"
1
SUMMARY OF METAL AND SEMIVOLATILE ORGANIC COMPOUNDS
IN SLUDGE (mq/kg) (a)
Concentration
~ Maximum
Metal. - ~tal
,---,
Antimony
Arsenic
Beryllium
Cadmium
Cobalt
Chromium
Copper
Lead
Manganese
Mercury
Nickel
Selenium
Silver
,Thallium
Vanadium
Zinc
1.9
21.5
Not Detected
24.9
10.8
92
184
1036
226
0.68
26
Not Detected
1.5
Not Detected
36.1
1129
Seaivolatile Organic Compound.
Anthracene
Benzyl Alcohol
1,2-Dichlorobenzene
1,4-Dichlorobenzene
2,6-Dinitrotoluene
Fluorene
2-Methylnaphthalene
Naphthalene'
N-Nitro8odiphenylamine
Phenanthrene
Pyrene
11
46
16
5.6
40
6
1051
8
43
22
6.9
3.3
27.4
40.2
12.1
136
242
1460
261
0.96
35.8
2.7
45.8
1530
26
67
38
10(c)
51
14
2600
14
54
64
10(c)
Detection
Limits
1.0
--(b)
0.5,1
1.0
2.5
1.0
2.5,16,20
20
2.5,16,20
2.5,16,20
20
20,2.5,1.7
2.5,16,20
20,2.5
10
20,2.5
2.5,16,20
rf'
No. of Detects/
tio. of Sarnt)les
4/6
.6 / 6
0/6
6/6
J / J
6/6
6/6
6/6
4/4
6 I 6
6/6
0/6
1/6
0/6
J / J
6 / 6
2/6
J / J .
4/6
1/6
J I J
1/6
4/6
4/6
J / J
4/6
2/6
#
(a)
(b)
(C)
"
From surface sludge samples and sludge composite samples in Tables
4.5, 4.9 and 4.10 in Remedial Investigation report (RI) (ACI, 1990a).
---- indicates that detection limit was not provided with data.
Indicates value is one-half the highest detection limit.
-------
.~
TABL8 2
SLUDGB TCIoP DAD AND TC:I.P SDIIDARDs'
'1\
TCLP Data
for Sludge'
(mall )
.TCLP Standard'
(mall)
Arsenic
Cadmium
Chromium
Lead
Mercury
Selenium
Silver
<0.3
<0.1
<0,1
<0.3
<0.0005
<0.3
<0.5
5.0
1.0
5.0
5.0
0.2
1.0
5.0
Benzene
Carbon Tetrachloride
Chlorobenzene
Chloroform
l,2-Dichloroethane
l,l-Dichloroethene
2-Butanone (KB1t)
Tetrachloroethene
Trichloroethene
Vinyl Chloride
<0.002
<0.002
<0.002
0.005 B
<0.002 B
<0.002
<0.020
<0.02
0.002
<0.002
0.5
0.5
100.0
6.0
0.5
0.7
200.0
0.7
0.5
0.2
Notes:
(1) Thi. table lists only tho.e parameters
(2) Data is from AGI, 1990a.
(3) FR Karch 29, 1990.
B - Analyte pre.ent in Method Blank.
which ',ave TCI.P .tandard..
.
-------
TABLE 3
50HMARY or VOLATILE ORGANIC COMPOUND5
IN 5LUDGE. (mg/kg) (a)
!>
Vol.~ile Organic eoapoUAds
Acetone
2-Butanone
Chlorobenzene
Chloroform
Chloromethane
1,1-Dichloroethane
c-1,2-Dichloroethene
Ethylbenzene
Meehylene Chloride
Toluene
1,1,2,2-Tetrachloroeehane
Tetrachloroethene
Trichloroethene
Total Xylene.
Concentraeion
~ Maximum
1.43
1.86
0.248
0.201
0.605
1.52
34.1
35.2
24.2
1.61
0.378
15.4
19.9
99.0
2.5(b)
3.7
0.66
0.38
2.5(b)
8.30
107.0
100.0
86.0
7.4
0.99
56.0
51.0
370.0
rf.
Deteceion
Limits
No. of Deteces/
No. ot Sam1)les
5,2,0.5,1.0 1 / 5
5,2,0.5,1.0 2 / 5
0.5,0.25,0.2 1 I 6
0.5,0.25,0.2 1 I 6
5,2,1,0.5 1 / 6
0.5,0.25,0.2 1 / 6
0.5,0.25,0.2 4 I 6
0.5,0.25,0~2 4 / 6
3,1.2,0.5 3 /6
0.5,0.25,0.2 3 I 6
0.5,0.25,0.2 4 I 6
0.5,0.25,0.2 4 / 6
0.5,0.25,0.2 3 / 6
0.5,0.25,0.2 4 I 6
.
(a)
(b)
From sludge samples 51, 52, 53, 5P-1, 5P-2, and sludge composite in
Tables 4.7 and 4.8 in Remedial Investigation report (RI) (AGI, 19904).
Indicates value is one-half the highest detection limie.
-------
r
~
pursuant to 40 CFR 261.4(b) (7). However, incorporated in the
selected remedy is the requirement for testing, and treatment if
necessary, of contaminated sludge and soil prior to disposal in
the landfill to demonstrate compliance with land disposal.
requirement (LDR) treatment standards.
B.
Soil Contamination
'''1
During the RI, soil samples were collected from around and below
the sludge pit. Soil directly adjacent to and beneath the sludge
pit is contaminated with petroleum hydrocarbons, TCL volatile and
semivolatile organic compounds, and heavy metals. Tables 4
through 7 provide summaries of the contaminants found in
subsurface soils and silt underlying the sludge pit.
Mean and maximum metal concentrations detected in soil samples
were typically less than those in sludge samples except for
beryllium and manganese.
Concentrations of volatile organic compounds detected in soil
were generally less than those detected in sludge, with the
exception of carbon tetrachloride and 4-methyl-2-pentanone
(MIBK). Semivolatile organic compound concentrations were
generally less in soil than sludge. However, the following
polycyclic aromatic hydrocarbons were detected in subsurface soil
samples but not in the sludge: benzo[a]anthracene,
benzo[k]fluoranthene, benzo[g,h,i]perylene, benzo[a]pyrene,
chrysene, fluoranthene, and indenO[1,2,3-cd]pyrene. It is
hypothesized that these either originated in the sludge or were
in the sludge but not detected due to higher laboratory de~ection
limits or matrix interferences.
C.
Groundwater Contamination
'. ..
Petroleum hydrocarbons (as nonaqueous phase liquids- NAPL) have
migrated from the sludge through the surrounding soils and are
floating on the surface of the water table (Upper Aquifer) below
the pit. This NAPL layer is similar in composition to a medium
weight fuel or lubricating oil and is approximately 2 inches
thick. Borehole.information suggests that some of the
contaminants have adhered to soil particles and other material as
they migrated through the surrounding soil layers. Hydrocarbon-
contaminated soil appears to lie primarily beneath the sludge
pit, based on soil sampling, visual observations and a strong
hydrocarbon odor observed during the RI. Tests indicate that the
NAPL does not contain high concentrations of metals. No
polychlorinated biphenyls (PCBs) were detected.
,.
The NAPL is estimated to cover approximately two-thirds to three-
quarters of an acre, and underlies and extends past the
northwestern half of the sludge pit. Figure 3 indicates the
-------
TABLE 4 t
SOMMARY OF METAL AND SEHIVOLATILE ORGANIC COMPOUNCS
IN SUBSURFACE SOIL (mq/kq) (a)
tf'
CQncentration Cetection No. of Cetects/
Mull Maximum Limits No. of Sam'Oles
..etal. - 'rotal
Antimony Not Cetected 1.5 0 / 18
Arsenic 7.9 21.9 1.0 18 / 18
Beryllium 0.6 1.2 0.5 9 / 18
Cadmium 0.9 5.3 0.5 8 / 18
Cobalt 4.5 7.3 1.0 17 / 18
Chromi.um 10.1 19.1 0.5 17 / 18
Copper 14.9 42.1 1.0 17 / 18
Lead 10.0 74.8 1.5 17 / 18
Manqane.e 215 717 0.5 17 / 18
Mercury Not Cetected 0.25,0.40 0 / 18
Ni.ckel 11 21 1.0 17 / 18
Selenium Not Cetected 1.0 0 / 18
Silver Not Detected 2.5 0 / 18
Thallium Not Detected 1.0 0 / 18
Vanadium 10.5 19.5 0.5 17 / 18
Zinc 86 1110 0.5 17 / 18
S..ivolatile Orqanic Compounds
Anthracene 0.6 10.0 0.17 ,1 / 18
Benzyl Alcohol No~ Analyzed
Benzo(a)Anthracene 1.36 23.0 0.17 1 / 18
Benzo(k) Fluoranthene 2.15 33.0 8.5, 0.17 1 / 18
Benzo(q,h,i)Perylene 0.75 12.0 0.17 1 / 18
Benzo(a)Pyrene 1.02 17.0 0.17 1 / 18
Chry.ene 1.36 23.0 0.17 1 / 18
1,2-Cichlorobenzene Not Analyzed
1,4-Cichlorobenzene Not Analyzed
2,6-Dinitrotoluene Not Analyzed
Fluorene 0.35. 4.25(b) 8.5, 0.17 2/ 18
Fluoranthene 2.48 43.0 0.17 2 / 18
Indeno(1,2,3-cd)Pyrene 0.75 12.0 0.17 1 / 18
2-Methylnaphthalene Not Detected 8.5, 0.17 0 I 18
Naphthalene Not Detected 8.5, 0.17 0 / 18
N-Nitro8odiphenylamine 0.62 4.25Cb) 8.5, 0.17 3 / 18
Phenanthrene 1.09 18.0 0.17 2 / 18
Pyrene 3.09" - 54.0 0.17 2 I 18
.
~
Ca)
Cb)
From Tables 8.2 and 8.6 in Remedial Investiqation report car) (AGI,
1990a) .
-------
ft'
TABLE 5
St1MHARy or VOLATILE ORGANIC COMPOUNDS
IN SUBSURFACE SOIL (mg/kg) (a)
~)
Concent:ation
Mean Max ilnum
Detection
~
No. ot Detects/
No. of Samcles
Vola~il. Organic eompounds
Acetone Not Detected 12,0.1 0 / 36
2-Butanone Not Detected. 0.25,0.1 0 / 36
Carbon Tetrachloride 0.003 0.006 0.005 1 / 18
0.013 (b) NO 0.025 0 / 18
(weigh~ed average) 0.008 0.013(b) NA 1 / 36
Chlorobenzene Not Detected 0.005,0.025 0 / 36
Chloroform Not Detected 0.005,0.025 0 / 36
Chloromethane Not Detected 0.25,0.1 0 / 36
1,1-Dichloroethane Not Detected 0.025,0.005 0 / 36
e-1,2-Dichloroethene Not Detected 0.025,0.005 0 / 36
Ethylbenzene Not Detected . 0.025,0.005 0 / 36
Methylene Chloride NOt Detected 0.3,0.005 0 / 34
4-Methyl-2-Pentanone 0.025 (b) NO 0.050 0 / 18
0.156 0.69 0.25 1 / 18
(weighted averac;e) 0.091 0.69 NA 1 / 36
Toluene 0.003 0.003 0.005 2 / 18
0.:J21 0.13 0.025 2 / 18
(weighted ave:3ge) 0.012 0.13 NA 4 / 36
1,1,2,2-Tetrach1cr~e~~a~e Not Detected 0.005,0.025 0 / 36
Tetrachloroethene O.0025(b) ND 0.005 0 / 18
0.015 0.05 0.05 1 /18
(weighted a':~:-1:;'!) 0.009 0.05 NA 1 / 36
Trichloroethene No': De':ected 0.005,0.025 0 / 36
Total Xylenes Not Detected 0.005,0.025 0 / 36
.
,.
( a)
(b)
NO
NA
From samples i~ ~~~:es 8.3 and 8.4 in Remedial Investigation
(RI) (AGI, 199Ca). .
Indicates value ~s one-half the highest detection limit.
Not detected.
Not applicable.
report
-------
TABLE 6 !
SUMMARY OF METAL AND SEMIVOLATILE CHEMICALS
IN SILT UNDERLYING THE SLUDGE PIT (mq/kq) (a)
(f'
Concentration Detection No. of Detects/
~ Max imum Limits No. of Samcles
Netal. - Total
Antimony Not Detected 1.0 0 / 1
Arsenic (b) 10.8 (c) 1 / 1
Beryllium Not Detected 1 0 / 1
Cadmium (b) 2.8 (c) 1 / 1
Chromium (b) 14.2 (C) 1 / 1
Copper (b) 17.1 (c) 1 / 1
Lead (b) 72.5 (c) 1 / 1
Manqanese 382 395 (c) ,2 / 2
Mercury Not Detected 0.20 0 / 1
Nickel (b) 11.1 (C) 1 / 1
Selenium Not Detected 1.0 0 / 1
Silver Not Detected 2.5 ' 0 / 1
Thallium Not Detected 1.0 0 / 1
Zinc (b) 467 (c) 1 / 1
Seaai.volatile OrqaDic COlDpouads
Anthracene Not Detected 20 0 / 1
Benzvl Alcohol Not Detected 20 0 J 1
1,2-~ichlorobenzene Not Detected 20 0 / 1
1,4-Dichlorobenzene Not Detected 20 0 / 1
2,6-Dinitrotoluene (b) 32 20 1 / 1
Fluorene Not Detected 20 0 / 1
2-Methylnaphthalene (b) 758 20 1 / 1
Naphthalene Not Detected 20 0 / 1
N-Nitrosodiphenylamine (b) 14 10 1 / 1
Phenanthrene (b) 20 20 1 / 1
pyrene Not Detected 20 0/1
.
"
(a)
From silt sample in Tables 4.5 and 4.9 in Remedial Investigation
report (RI) (AGI, 1990a).
Indicates mean was not calculated because only one result was
available. ,
Indicates detection limit was not provided with data.
(b)
-------
~
TABLE 7
SUMMARY 01 VOLATILE CONSTITUENTS
IN SILT UNDERLYING THE SLUDGE PIT (mq/kq) (a)
.~;
Concentration
Mean Maximum
Vol.~ile Org8Al.c COumpoUAds
Acetone
2-Butanone
Chloroeenz8ne
Chlorotorm
Chloromethane
1,1-Dichloroethane
t-1,2-Dichloroethene
Ethyleenz8ne
Methylene Chloride
Toluene
1,1,2,2-Tetrachloroethane
Tetrachloroethene
Trichloroethene
Total Xylenes
~
Not Detected
Not Detected
Not Detected
Not Detected
Not Detected
Not Detected
(b)
(b)
(b)
(e)
(b)
(b)
(b)
Not Detected.
0.05
2.8
0.05
0.20
0.02
1.5
1.2
Detection
~
0.01
0.01
0.005
0.005
,0.01
0.005
0.005
0.005
0.01
. 0.00.5
0.005
0.005
0.005
0.005
. No. ot Detects/
No. ot Samoles
0/1
0/1
- 0 / 1
0/1
0/1
0/1
1/1
1 / 1
1/1
1 / 1
1 / 1
1 / 1
1 / 1
0/1
( a)
(b)
'"
From Table 4.7 in Remedial Investiqation report (RI) (AGI, 1990a).
Indicates mean ~as not calculated because only on8 result was
available.
-------
..
~
..
l.~'
SCAI.E IN FEET
I~O
,
300
r
o
, .'
!
........
"-
'~
"-
'~
LEGEND
,':.,;:,~,\ INFERRED MAXIMUM EXTENT OF NAPI.,
'c'...::,::':',::) OF AI.l. OBSERVATIONS 198~-89
...~
.
5011. BORINO OR MONITOR WEl.l. WHERE NAPI. OR
OIU SHEEN HAS BEEN OBSERVED
o
SOIl. BORINO OR MONITOR WEl.l. WHERE NAPI. OR
OII.Y SHEEN HAS NOT BEEN OBSERVED
REfERENCE:
UNION PAc,nc AAI LROAO I fORNERLY OREGON
SHORT LINEI WEST POCAULLO STATION NAP.
CE OUWING NO. 821", OUEO AUGUST 18, "n
UNION PACIFIC RAILROAD - POCATELLO SLUDGE PIT
POCATELLO, IDAHO'
-------
r
~,
.estimated extent of NAPL floating on the surface of the
groundwater, based on observations made from 1985 through 1989.
The sludge pit is located along the southern edge of the Portneuf
River Valley where the valley opens to the Snake River Plain.
The valley is filled by unconsolidated river sediments and lake
deposits that overlie bedrock of primarily volcanic origin.
~:
During subsurface investigations, six distinct stratified,
sedimentary rock deposits of common physical character
(lithostratigraphic units) were encountered. From youngest to
oldest, they are: Fill- loose black cinders, and cinders mixed
with silt; Recent Alluvium- stiff, brown silt; Older Alluvium-
dense, brown sandy gravel, and dense. gray gravel with some sand;
Michaud Gravel- dense, brown unsorted mixture of gravel, cobbles,
and boulders; American Falls Lake Beds Clay- stiff, iight brown
silty clay; Pleistocene Gravel- dense, brown sandy gravel.
The relationship between the lithostratigraphic unit (from
youngest to oldest) and water bearing deposits
(hydrostratigraphic unit) is as follows:
Lithostratiqraphic Unit
Hvdrostratiqraphic Unit
Michaud Grave.l
American Falls Lake Beds Clay
Pleistocene Gravel
Upper Aquifer (Cla.ss lIB).
American Falls Lake Beds Aquitard
Lower Aquifer (Class I)
A discussion of the aquifer classification (i.e. Cla~s I and
Clas~ lIB) requirement can be found in the groundwater ARARs
section of the ROD.
Groundwater occurs within the Michaud Gravel between 34 to 38
feet below ground surface (bgs). During the RI, no water supply
wells were identified as having been constructed within the
Michaud Gravel. The Michaud Gravel does not appear to be of .
sufficient saturated thickness to be used as a major groundwater
source.
The American Falls Lake Beds Clay comprises a major aquitard, a
less-permeable layer, which, in many places, hydraulically
separates the Upper and Lower Aquifers.
:'\
Groundwater occurring under semiconfined conditions in the
Pleistocene Gravel comprises the Lower Aquifer. The Lower
Aquifer is the shallowest deposit developed extensively for water
supply purposes. Most do~estic and small. commercial wells are
completed within the Lower Aquifer, 60 to 150 feet bgs.
Groundwater recharge does not differ significantly between
aquifers and probably occurs from direct infiltration of snow
melt, irrigation water and precipitation, from potential leakage
"..'
-------
from aquifer to aquifer, and by infiltration through intermittent
streams and the Portneuf River. Groundwater beneath the sludge
pit in the Upper Aquifer flows to the northwest, and west to .
northwest in the Lower Aquifer, down valley toward the American
Falls Reservoir. Hydraulic gradients within both aquifers are
between 10 to 15 feet per mile. As applied to an aquifer, the
hydraulic gradient is the rate of pressure change per unit of
distance. Groundwater velocities range from 6.8 to 11 feet per
day. Lower Aquifer transmissivity (the rate at which water moves
through a unit width of aquifer under a unit hydraulic gradient)
is approximately 2,000,000 gallons per day per foot.
During the RI, several sampling events took place from 1985-
1989. Both aquifers were sampled for inorganic, organic and
other TCL compounds. The wells which were evaluated included
seventeen (17) new wells put in by UPRR- nine (9) shallow and
eight (8) deep~ twenty-four "(24) existing wells including six (6)
monitor wells installed for the McCarty's/Pacific Hide and Fur"
Superfund site investigation~ five (5) monitor and four (4)
production wells on the adjacent Great Western Malting property~
and, nine (9) local domestic or industrial supply wells. Table 8
summarizes groundwater sampling results from all RI sampling
events and lists current and proposed maximum contaminant levels
(MCLs, PMCLs) and maximum contaminant level goals (MCLGs, PMCLGs)
for contaminants found.
~
~
Upper and Lower Aquifer water samples ~rom 1985 and 1986
samplings contained low concentrations of the heavy metals found
in the sludge. All detectable metals had concentrations below
primary drinking wat~r MCLs. A contaminant of concern in the
groundwater is manganese with maximum concentrations ranging from
0.2-1.82 mg/l. These concentrations exceed the secondary
drinking water standard for manganese of 0.05 mg/l. .
Various TCL semivolatile compounds were detected in 1985, 1986,
and 1988 in Upper Aquifer wells near the sludge pit. No TCL
semivolatile compounds were detected in 1989. Semivolatile
compound occurrence and distribution indicate the presence of a
small, seasonal contaminant plume associated with the NAPL.
Several chlorinated volatile organic compounds, primarily
trichloroethene (TCE) and tetrachloroethene (PERC), were detected
in most Upper and Lower Aquifer monitor wells and in several
water supply w~lls in Septembe~ 1988 and April 1989. These.
compounds were not detected in the 1985 and 1986 sampling rounds.
These compounds were, however, detected in a 1983 EPA sampling of .
area water supply w~lls.
r
April 1989 sampling results indicated the presence of PERC at
concentrations of less than 1 part per billion (ppb) in both the
Upper and Lower Aquifers near the sludge pit.
~.
-------
(
f.I
}
..,..
TABLE 8
Chemical Lower Aquiler (c)
Concenlrallon Propoeed
CI..a Mean Maximum ..CUh
Melal. - ToCal
AnUmon~ 0.0044 0.0213 0.0035 0.0086 NO NO None 0.01l0.oo6(g) None 0.00.1 (g)
Ar..nlc 0.0088 0.0283 0.0033 0.0059(J) 0.0018 0.002 0.05 NP None NP
Beryllium 0.0025 0.0026(h) 0.002 0.0026(h) 0.0023 0.0026(h) Non. 0.001 (g) None o (g)
Cadmium 0.0003. 0.0008. NO. NO. 0.0003. 0.0000. 0.0011 0.0011
Chromium 0.008 0.02 0.0139 0.0268 O.ooee 0.0145 0.1 0.1
Coball 0.0108 0.0133 0.0084 0.01(h) NO NO Non. NP Non. NP
Copper 0.018 0.03 0.0097 0.01(h) 0.0251 0.08 1.0 (S). 1.3(1) Non. 1.3 (e)
Lead 0.0048 0.010 0.004 0.0079(J) 0.0077 0.0282(J) 0.06 0.005(1) 0.05(1) 0.015
Mangane.. 0.71 1.82 0.107 0.2 0.141 0.65 0.05(S) NP Non. NP
Mercur~ 0.00015 0.00042(J) 0.00003 O.OOOI(h) 0.0002 0.0007(J) 0.002 0.002
Nicke' 0.022 0.011 0.018 0.03 0.0088. 0.01.(h) None 0.1 (g) None O.1(g)
Selenium 0.0011 0.0014(R) 0.0011 0.0014(R) 0.001. 0.0012.(R) 0.05 0.05
54I\18r 0.0044 O.OO6(h) 0.0055 0.01 NO NO 0.05 0.1 (S)(d) Non. NP
Thallium 0.0013 0.0028(R) 0.0018 0.0028(R) 0.0012 0.0023(R) None 0.002lO.oo1(g) Non. 0.00011 (g)
Vanadium 0.012 0.02211 0.0077 0.0132 0.0082 0.0121 None NP Non, NP
Zinc 0.082. 0.12. 0.08. 0.12. 0.0825. 0.111. 11(6) NP Non. NP
Volatile Organic ComDOund. .
Benzene NO NO NO NO 0.0011 0.0042 0.0011 NP 0 NP
Chlorobenzene NO NO NO NO 0.00084 0.0026(h) 0.10 NP 0.10 NP
Chloroform NO NO 0.001 0.0026(h) NO NO 0.1 NP NP NP
1.1-0Ichloroelhane 0.00055 0.0026(h) NO NO NO NO None NP None NP
1.1-0Ichloroelhene 0.00052 0.0026(h) NO NO NO NO 0.007 NP 0.007 NP
Iran.-1.2-0Ichloroelhene 0.0008 0.0026(h) 0.00128 0.003 NO NO 0.10 0.10
cl'-1.2-0Ichloroelhene 0.0002 0.0003 NO NO' NO NO 0.07 0.07
Melhytene Chloride NO NO 0.0017 0.005 NO NO None 0.005 (g) None o (g)
TeUachloroelhene 0.00080 0.0026(h) 0.0011 0.0026(h) 0.00182 0.0026(h) 0.005 0
Toluene NO NO NO NO 0.00084 0.0026(h) 1 1
Trlchloroelhena 0.00082 O.0026(h) 0.0008 O.0026(h) O.oooet O.0026(h) 0.005 NP 0 NP
Tol., Xylene. NO NO NO NO 0.001. 0.0078 10 10
SemlvoiaUle Organic.
NO 0.0058 0.021 0.0024 O.OI(h) None NP None NP
NO 0.0050 0.018 NO NO None 0.0001 (g) None o (g)
NO 0.0043 0.01(h)' NO NO Non. 0.0002(g) None o (g)
NO 0.0037 O.OI(h) NO NO Non. NP None NP
0.01(h) 0.0043 0.01(h) NO NO None 0.0002(g) None o (g)
NO 0.0042 0.01(h) NO NO None NP Non. NP
NO 0.0068 '0.028' NO NO None NP None NP
NO 0.0158 0.11 NO NO None NP None NP
0.01(h) 0.0054 0.012(J) 0.0070 0.053 Non. NP None NP
0.01(J) 0.0048 0.014 0.0031 0.012(J) None 0.004 (g) Nor... -0 (g)
e ec e - a u. agge .. e ma n
(I) 53FR 311118 NP NoC Propo88d R - V.lue n.gged .''')ecled In RI (1.01. 1880a); h_ver
(g) 55FR 30370 S Secondary Standard value wa. u..d 10 con..rvaUvel~ .8I'male rlek..
(h) Value I. one-hallihe hlgheat delecllon limil. . Indlcale. 1888 dalator dl.eoIved melal. exceed. 1888 (8hown)
-------
The distribution of TCE in the April 1989 sampling indicates low
concentrations (less than 1ppb) in the Upper Aquifer and none in
the Lower Aquifer near the sludge pit or in the residential water
supply wells northwest of the pit.
,.J
D.
Surface Water
Several sUrface water bodies are present in the study area.
Those identified in the RI included the' Portneuf River, an
irrigation canal, intermittent ponds in the gravel pit southwest
of the sludge pit, and water observed in the sludge pit.. The
Portneuf River appears to be 'perched above groundwater in the
study area. The nearest springs are close to the Portneuf River,
. approximately two miles northwest of the sludge pit.
Based on City of Pocatello Flood Potential maps, the sludge pit
is not located within the 100-year flood plain of the Portneuf
River.
/'r
No surface water bodies transect the sludge pit, however, surface
runoff occurs during storm events and snowmelt. No significant.
drainage rills were observed onsite indicating predominant
drainage patterns. The pit is protected from runon and runoff by
a surrounding berm. The sludge pit surface is generally level
and is depressed approximately one to two feet below the
surrounding land surface. The sludge pit appears to be capable
of retaining rainfall from significant storm events without,
overflowing. Additionally, based on characteristics of surface
soils on the site property, surface water likely infiltrates
rapidly into areas wher~ the stiff, brown silt (Recent A1luvium)
is absent.
VI.
SUMMARY OF SITE RISKS
A Human Health Risk Assessment (HHRA) (AGI, 1990a) and an
Environmental Risk Assessment (ERA) (AGI, 1990b) were performed
to estimate the potential for adverse human health and .
environmental effects from exposure to contaminants associated
with the site. The Human Health Risk Assessment followed a four
step process: 1) identification of contaminants which are of
significant concern, 2) an.exposure assessment which identified
current and potential exposure pathways and exposed populations,
and quantified current and potential exposure, 3) identification
of the type of toxic effects associated with contaminant exposure
and identification of toxicity constants to estimate these
effects, and 4) a risk characterization, which integrated the
three earlier steps to summarize the potential and current risks
posed by hazardous substances at the site. The results of the
Human Health Risk Assessment and Environmental Risk Assessment
are discussed below.
,
...
-------
.,
.Analyses of' the sludge, soil, and groundwater indicate that
exposure to these media may pose a threat to onsite workers, the
community and the environment at the Union Pacific Railroad site,
particularly if, during remedial activities, sludge, silt and
soil are removed but dust control measures are not implemented or
fail. Available data indicates that surface water flow is not a
primary contaminant pathway.
i
Current land use is strictly industrial and has been since before
the turn of the century. The likelihood of a change in current
land use in the foreseeable future is extremely low. However,
the closest residential area is 0.3 mile from the site. --
Therefore, reasonable maximum exposure (RME) 'was calculated for
both residential and industrial scenarios.. A combined exposure
scenario was used to calculate risk-based goals. A detailed
discussion of this procedure can be found in the section' entitled
Human Health Risks.
Current groundwater use indIcates that the Lower Aquifer is very
productive and is used as a drinking ~ater source by local,
private residents, businesses, and the City of Pocatello (Supply
Well No. 32). No water supply wells in the area have been found
to utilize the Upper Aquifer, which is contaminated with
chemicals that have migrated downward from the sludge, through
the silt and soil, to the groundwater surface.
Figures 4 and 5 depict exposure points for an onsite worker and
an offsite resident using the current land use scenario and a
potential future land use scenario, respectively.
Potential future onsite residential and industrial worker
populations are at risk from ingestion and dermal exposure to
cpntaminants in the sludge pit, and secondarily from exposure
through ingestion of contaminated groundwater if used as a
drinking water supply.
HUMAN HEALTH RISKS
...
Identification of contaminants of Concern. A total of 58
contaminants (19 volatile organics, 23 semivolatile organics, and
16 metals) were identified in sampling of sludge, soil, water,
and NAPL. At least 20 additional compounds were also tentatively
identified. All chemicals positively identified and for w~_ch
toxicity constants exist were included in the risk assessment.
Tables 3-5, 3-8, 3-9, )-10, and 3-11 in the HHRA list, for each
media, the chemicals quantitatively evaluated in the risk
assessment with their mean and maximum concentration.
..,
Exposure Assessment. Potential human health effects resulting
from exposure to' site contaminants were estimated for each of
several known and potential exposure pathways. These pathways
were developed based on current industrial and residential
-------
!:b
(
\0
}
--------
----.-
'----.-
<
rREVMUNG WI~ .
.~
\\.
rUG IT I VE OUST
/\
UPPER AQUifER
AQUI TARD
\{ \ (
._~~._u_~~-~~--~I~l[i'm. ..... ...
c!!,lli'iI~~l.~lfEfI~1
lOWER AQUifER
~rwJ6I~1
-
. '
LEGEND
~ ON-SITE WORKUI
1,r OFF-SITE RESIUENT
UNION PACIfiC RAILROAD
POCAT£llO, IDAIIO
CURRENT LAND U8E 8CENARIO
..---.-.--..--..--.. ... . --.-.-...
. "..- - ....-. --.
.. .... --'.._.h
. - ..... - .. - ou- --.
.. ".- -- -,"
.... . .. ---- '''00. ".-.- ..
------.---- -.---
..-..-- -.- _.. -----.------...---.--- '--'--...-.. ~.-
-------
--.-'-.------..-.-.. ..------ -.-----.-
<
PREVAILING \'t;~ .
- 1\
\\ \\ A A FUG'j'V\ DUST
- ~ ~ VDlallt~ON / \
- - r ~~II~~A~tDN ) {)1 DIRECT CONTACT/
~ EXPOSURE INAOVERTENT INGESTION
~ -I__W 'HH, H'.HH ...iB~ POI NT OF EXPOSURE
SOURCE
( (UPPER AQUifER
. \ \
- - . ~ .. - WNfR AQUIFER
II' I~~~- ' ~ggam
DRINKING WATER-
INGESTION
S I fE BOUNDARY
DRINKING WATER
DIRECT CONTACr
INIiAlATION
. INHALATION' ~ -
'" fi'RECT CONTACT
"'. INADVERTENT INGEST
.~R '\:- t. POINT OF EXPOSURE
. ..-- --' 1- -'*'11.1.--- -
.
- ----
----
!~~1_~' f
.-
LEGEND
~
- ~ ON-.S lYE RES IDENT
ON-SITE WORKER
~
-
-
UNION PACIfiC RAilROAD
POCATEllO, IDAIIO
POTENTIAL FUTURE
LAND USE SCENARIO
Figure 5
...-----.-------.--.--- -..__. - ---------.--------------
.-
f
'~..
.-------
,
-------
activities in the vicinity of the sludge pit, and likely future
uses given the nature and location of the site. The fOllowing is
a brief summary of exposure pathways evaluated and assumptions
used in the assessment. A more thorough description can be found
in Section 3.3 of the Human Health Risk Assessment (pp. 3-3 to 3-
5) .
~
. Soil Ingestion. It was assumed that both children and
adults inadvertently ingest soil (0.1 and 0.2 gm/day,
respectively) over exposure periods from one day to a lifetime
(75 years), at varying frequencies (1 to 365 days/year).
.....
Dermal Contact. Absorption of contaminants via dermal
contact with soil was evaluated for both children and adults
u~ing the same exposure periods arid. frequencies as. for soil
ingestion, adjusting for age-specific differences in body surface
area.
Water Consumption. It was assumed that groundwater at the
site is used as a drinking water source. Consumption of
groundwater from both the Lower (deep) and Upper (shallow)
Aquifers (separately for NAPL and non-NAPL containing wells) was
estimated for children and adults using age-specific consumption
rates (0.83 - 2.0 liters/day) at varying frequencies.
Inhalation of Particulates and Volatiles. Air
concentrations of particulate matter and volatile organics
originating in the sludge pit were estimated using emissions and
dispersion modeling in the HHRA. Exposure to particulates and
volatiles was subsequently reassessed ~y EPA as described in the
Administrative Record for the ROD. The document appears in
Section 6.0 Enforcement/Subsection 6.4 Risk Assessments- Human
Health, Environmental/sub-subsection 6.4.2 Air Pathway
Reassessment and Supporting Documentation. Inhalation exposures
to children and adults were considered using varying inhalation
rates (20-30 m3/day) and exposure frequencies.
Inhalation of Volatiles from Drinking Water. . Inhalation of
volatile organic contaminants which could volatilize from
drinking water during showering or bathing was estimated ~or
children and adults using a conversion factor to predict
inhalation exposure from estimated drinking water exposure.
Ingestion of NAPL. Exposure to contaminants in NAPL was
estimated assuming a child was to inadvertently ingest 0.53 to
1.0 liter of NAPL a single time.
,
Vegetable Consumption. Contaminants in sludge could
accumulate in vegetables grown in sludge or sludge-amended
Cadmium uptake in vegetables and subsequent exposure via
ingestion was estimated assuming contaminated, homegrown
soil.
.,.
-------
~
vegetables were consumed during both child- and adulthood.
Exposure via contaminated vegetable consumption to other
'contaminants in sludge (which are less likely to accumulate in
vegetables) is discussed qualitatively.
~,
For each pathway evaluated, an average and reasonable maximum
exposure (RME) estimate was generated for short-term (subchronic)
and long-term (chronic) exposure. Average estimates are based on
average media concentrations and exposure parameters, and
reasonable maximum exposure estimates are based on maximum media
concentrations and RME exposure parameters. Standard default
exposure parameters developed in 1990 by EPA Region 10 were used
to develop estimates of exposure for current and future site
uses. 'These are slightly more conservative than national default
values which were established following completion of this
assessment. Default assumptions may not accurately reflect
current site exposures, as discussed further in the Uncertainties
section.
Toxicity Assessment
Cancer Risks. Excess lifetime cancer risks were determined for
each exposure pathway by multiplying the exposure level by the
chemical-specific cancer slope factor. Tables 5-2 and 4-2 in the
HHRA summarize carcinogenic effects and cancer potency factors,
respectively, for site contaminants. Chemical-specific cancer
potency (slope) factors have been developed by EPA from human
epidemiological or animal studies. This information was obtained
from the Integrated Risk Information System (IRIS) and the Health
Effects Assessment Summary Tables (HEAST). Risk estimates
calculated from these potency factors reflect a conservative
"upper bound" of the risk posed by potentially carcinogenic
compounds. That is, the true risk is very unlikely to be greater
than the risk predicted. The resulting risk estimates are
expressed in scientific notation (i.e. 1 x 10.6 or 1.0E-06 for
1/1,000,000; indicating that, in this example, an individual is
not likely to have greater than a one in one million chance of
developing cancer over his/her lifetime as a result of site-
related exposure). Current EPA practice assumes carcinogenic
risks are additive between chemicals when assessing exposure to a
mixture of hazardous substances. Therefore, cancer risks have
been summed across chemicals and across exposure pathways.
-
Noncancer Risks. Tables 5-1 and 4-1 in the HHRA summarize
noncarcinogenic effects and reference doses for site
contaminants, respectively. A hazard index was calculated for
each pathway as EPA's measure of the potential for
noncarcinogenic he~lth effects. The hazard index is calculated
by dividing the human dose by the reference dose (RfD) or other
suitable benchmark for noncarcinogenic health effects. Reference
doses have been developed by EPA to protect sensitive individuals
~
-------
over varied exposure durations {subchronic: up to 7 years, and
chronic: 7 years to a lifetime). They reflect a daily exposure
level that is likely to be without an appreciable risk of an
adverse health effect. RfDs are derived from epidemiological or
animal studies and incorporate uncertainty factors to help ensure
that adverse health effects will not occur. This information was
obtained from IRIS and HEAST. The hazard index is often
expressed as a single value indicating the ratio of the estimated
human exposure to the reference dose value (i.e. 0.3 in this
example, indicating the exposure is approximately one third of
the reference dose for the given compound). Adverse health
effects are not expected to occur if the hazard index is . ~ss
than 1. As the hazard index increases above, 1, adverse e_~ects
become more likely. The hazard index is only considered additive
for compounds that have the same or similar toxic endpoints. For
example, the hazard index for a compound known to produce only
liver damage would not be added to another compound whose toxic
endpoint is predominantly nerve damage.
~
('!"
Risk Characterization. Carcinogenic risks from current and
future exposure assuming residential 'and industrial land use are
listed in Tables 5-3 to 5-10, and 5-13 to 5-17 in the HHRA. '
Noncarcinogenic risks from current and future exposure, assuming
residential and industrial land use, are listed in Tables 5-3 to
5-8, 5-11 to 5-13, 5-15, 5-18, and 5-19 of the HHRA.
Table 9 summarizes risk by scenario"and toxicity endpoint for the
reasonable maximum exposure. Cancer and noncancer (subchronic
and chronic) risks are high (i.e. greater than 10" cancer risk
and hazard index greater than 1.0) in all scenarios. Risks are
greatest assuming future residential land use, however,
differences in risk between scenarios are not great, and vary by
a factor of 0 to 7.
Table 10 displays cumulative risk by medium and pathway. Risk
from exposure to each media (soil/sludge, Lower Aquifer wells,
Upper Aquifer NAPL wells, Upper A~ifer non-NAPL wells) is
significant (e.g. greater than 10' cancer risk; hazard index
greater than 1.0) for cancer and noncancer endpoints. Exposure
to soil/sludge appears to present, the greatest risk [e.~. cancer
risk of 4 x 10-2 vs. 2 X 10-2 (Upper Aquifer) to 5 x 10. (Lower
Aquifer)] and ingestion'pathway risks are the highest, about an
order of magnitude greater than dermal contact and inhalation.
Table 11 identifies chemicals of qreatest risk in each media for
both cancer and noncancer effects. Metal contaminants present
the highest noncancer risks for the contaminated sludge and soil,
primarily arsenic, cadmium, and chromium; although this may
reflect the relative lack of reference doses for organic
contaminants identified at the site. Far more contaminants
(organics and metals) present a significant cancer risk. The
ii'
''('
-------
;
TABLE 9.
TOTAL RISK BY SCENARIO AND TOXICITY ENDPOINT (a)
Future
Current Future Current Future Residential and
'Risk Endpoint Residential Residential Industrial Industrial Industrial
Cumulative Cancer Risk 2.6E-06 2.0E-02 4.3E-02 4.5E-02 6.6E-D2
Chronic Cumulative Hazard Index 0.006 5 8 12 17
Subchronlc Cumulative Hazard Index 0.02 10 0.2 3 13
(a) Totals are based on the reasonable 1T\d.'mum e.posure case Groundwater r'lsks are based on
cumulative cancer risks anll halM!J .n,Jlles of Upper AQuI fer Non-NAPL wells;
risks are essentially equivalent for Lower Aquifer and Upper AQuifer-NAPL water sources.
.'
~
.. .~.
-------
TABLE 10. CUMULATIVE RISK BY MEDIUM AND PATHWAY (a)
SOil/SLUDGE I GROUNDIlt\lfR I
I 1
I. I
Inhalation I lOWER AQUIFER I UPPER AQUIFER, NON-NAPl WEllS I UPPER AQUIFER, NAPl WEllS I
Dem I (Volatiles + I I I I
Ingestion Contact Part. TOTAL I Ingest ion Inhalation TOTAL I Ingestion Inhalation TOTAL 1 Ingestion Inhalation TOTAL I
I I I I
Cancer Risk 3.8E-02 2.0E-02 1. 4E -05 3.8E-02 I 6.6E-04 3.2E-05 6.9E-04 I 7.9E-03 9.5E-06 7.9E-03 I 2.3E-02 6.0E-05 2.3E-02 I.
I. I I. I.
Chronic 1 I. I I
Noncancer 8 0.4 0.04 8 I 3 0.5 4 I. 9 0.003 9 I 5 0.001 5 I
Hazard Index I I I I
1 I I I
Subchronlc I I I. I
Noncancer 0.5 0.1 2 I 0.06 2 I 11 0.001 " 111 4 0.003 4 I
Hazard Index I I 1 I
(a) Based on combined future residential and Industrial risks, for the reasonable maximum exposure case.
,"',
.,'
~
'"
-------
,
.;
. a:.
.
TABLE II. CHEMICALS OF GREATEST RISK BY MEDIA (a)
CANCER RISKS:
-------------
Soil/Sludge
Compound
Benzo(k)Fluoranthene
Benzo(a)Anthracene
Chrysene
Benzo(a)Pyrene
Indeno(I,2,3-cd)Pyrene
2,6-0lnltrotoluene
Arsenic
Beryllium
Tetrachloroethene
1,l-Dlchloroethane
Methylene Chloride
Trlchloroethene
n-Nltrosodlphenylamine
1,4-Dlchlorobenzene
1,I,2.2-Tetrachloroethane
Chloromethane
Cancer
Risk (b)
Lower Aquifer Upper Aqut fer, Non - NAPL We lis Upper Aquifer, NAPL We 11 s
Cancer
Cancer Cancer Compound Ri sk (b)
Compound Risk (b) Compound Ri sk (b)
Benzo(a)Anthracene 9.65£-03
Bery 11 I urn 5.00£-04 Chrysene 5.35E-03 Chrysene 5.35£-03
Arsenic 1. 42£ -04 , Arsenic 1. 98£ -03 Benzo(b)Fluoranthene 5.35£-03
Benzene 2.elE-05 Bery11 i um 5.04£-04 Methylene Chloride 1.21£-03
Trichloroethene 9.28£-06 1,l-Dichloroethene 6.99£-05 Beryllium 5.04£-04
bls(2-ethylhexyl)Phthalate 7.88£-06 1,l-Dlchloroethane 1. 07£ -05 Arsenic 4.15£-04
Tetrachloroethene 7.44£-06 Trichloroethene 9.28£-06 1,3-Dichlorobenzene 1.23£-04
Tetrachloroethene 7.44£-06 Chloroform 3.81£-05
bis(2-ethylhexyl)Phthalate 6.53£-06 Trichloroethene 9.24£-06
bls(2-ethylhexyl)Phthalate 9.19£-06
Tetrachloroethene 7.48£-06
I . 6£ - 02
1. 2E -02
1. 2£ -02
8.6£-03
6.lE-03
1. 5£ -03
1. 2£ -03
1.5£-04
1. 3£ -04
3.4£-05
3.3£-05
3.1£-05
1. 2£ -05
1.1£-05
8.8£-06
-------
TABLE 11 (contd). CHEMICALS OF GREATEST RISK BY MEOlA (a)
CHRONIC RISKS
-------------
Soi 1 Sl udge '
Cheml ca 1
Cachlum
Chromium
Arsenic
Antimony
Tetrachloroethene
Zinc
t-l.2 dlchloroethene
Vanadium
SUBCHRONIC RISKS
----------------
So11 Sludge
Cherni ca 1
Arsenic
Lower Aquifer
Upper Aquifer. Non-NAPL Wells Upper Aqui fer. NAPL We 11 s
Chronic Chronic
Hazard Hazard
Compound Index (c) Compound Index (c)
Antimony 3.19E+00 Thallium 2.40E+00
Thallium 2.40E+00 Antimony 1.27E+00
Arsenic 1.70E+00 Arsenic 3.54E-Ol
Manganese 5.46E-Ol Chromium 3.07E-Ol
Chronic
Hazard
Index (b)
Compound
Chronic
Hazard
Index (c)
2.2E+00
1.5E+00
1. 4E +00
4.3[-01
4.2[-01
4.0E-Ol
3.9E-Ol
3.4E-Ol
Thalli um
Benzene
1.97E+00
4.37E-01
Lower Aquifer Upper Aquifer. Non-NAPL Wells Upper Aqul fer. NAPL Wells
Subchronlc Subchronlc Subchronic Subchronic
Hazard Hazard Hazard Hazard
Index (b) Compound Index (c) Compound Index (c) Compound Index (c)
5.3E-Ol Thall ium 3.68E-Ol Antimony 5.96E+00 Antimony 2.38E+00
Arsenic 3.17E+00 Arsenic 6.60E-Ol
Thallium 4.48E-Ol Thallium 4.48E-01
Manganese 4.07E-Ol
Vanadium 3.60E-Ol
(a) This table presents cancer risk greater than or equal to -1[-06 and hazard indices greater than
or equal to 0.3. based on combined risks for the future residential and industrial scenarios
for the reasonable maximum exposure case.
(b) Represents the total of inhalation, ingestion, and direct contact..
(c) Represents the total of inhalation and ingestion.
<:
.~
"
-------
~
. largest number of contaminants of concern are in soil/sludge,
followed by Upper Aquifer wells (NAPL, then non-NAPL) and
finally, Lower Aquifer wells. Arsenic and beryllium have cancer.
risks greater than 10.4. Several PARs and 2,6-dinitrotoluene
have cancer risks greater than 10.4 .
~
Uncertainties. In general, the uncertainty associated with these
results is large, spanning an order of magnitude or more.
Specific factors which contribute to the uncertainty in this
assessment are as follows.
Analvtical data. site risk is estimated based on limited
sampling of soil, sludge, and groundwater (e..g. metals are
evaluated based on a single round of sampling). Interferences in
highly contaminated samples may have precluded identification of
some contaminants. A number of tentatively identified compounds
(TICs) were present in some samples, but could not be
definitively ide:-tified and were, therefore, not included in the
quantitative ass~ssment. .
Exposure Assessment. Two key factors contributed a great deal of
uncertainty to the exposure assessment. First, few studies are
available from which to estimate exposure to contaminants by
dermal contact, especially in soil. Second, chemical-specific
absorption rates have only been developed for a few compounds
(e.g. PARs), therefore, conservative default values were used.
This leads to significant uncertainty in the exposure assessment
results, particularly .for metals, which are generally poorly
absorbed. EPA belie"es that dermal pathway exposure and risk
estimates are, there:ore, quite conservative. Since the basis
for these estimates is so uncertain and conservative, and since
guidance for conducting dermal assessments is just now being
developed, this exposure pathway will not be included in
developing risk-based cleanup goals as discussed later in this
document.
Another major area of uncertainty arises from the use of other
default exposure parameters. The most obvious effect of using
these assumptions is on estimates of current onsite exposure.
Pathways contributing most to current onsite exposure are
inadvertent ingestion and dermal contact with sludge. Whil~
site-specific data regarding the frequency of time people are in
contact with the sludge/soil is sparse, information gathered
during the Remedial Investigation and during EPA site visits
indicate that:
~.
there are no buildings, facilities, work-related or
other activities in the immediate vicinity .of the
sludg~ pit, other than the railroad tracks,
-------
the terrain is essentially level and there are no
topographic or other features nearby (e.g. ponds)
would encourage recreational or other types of
exposure,
which
.
the pit is surrounded by a barbed wire fence.
~
This information indicates that exposure to sludge/soil is
infrequent. The standard default assumption used to estimate
exposure from soil ingestion and dermal exposure is 131 days/year
(36%) for 40 years. This frequency could be more than an order
of magnitude above actual exposures, and these uncertainties must
be carefully considered when interpreting current exposure and
risk estimates. .
other factors in the exposure assessment which contributed to
uncertainty include the absence of data to validate exposure
modeling (e.g. particulate and volatile emissions; showering
exposure), limited exposure point concentration data, and the use
of standard default exposure parameters in general.
Risks associated with consumption of groundwater from both NAPL
and non-NAPL contaminated Upper Aquifer wells appear to be
relatively high. However, no drinking water wells in the area
are in place ,in the Upper Aquifer and the likelihood of future
wells completed in the Upper Aquifer is low. The 'area's reliance
on the Lower Aquifer for drinking water is primarily due to the
low productivity of the Upper Aquifer. Even though NAPL has not
been identified in the Lower Aquifer, the Upper and Lower
Aquifers appear to be hydraulically connected, consequently,
migration of the NAPL to the Lower Aquifer could be possible and
could affect water quality.
Toxicitv. Toxicity constants were not available for many,
contaminants (e.g. TICs; RfDs for many organics)' nor for the
dermal exposure route (e.g. oral toxicity constants were used
.instead to estimate dermal pathway risks). As a result, risk
estimates presented here represent a subset of site risks.' In
addition, noncancer risks have not been separated by toxic
endpoint, resulting in a conservative noncancer risk estimate.
The results could be different if chemicals are grouped by toxic
endpoint prior to calculating the hazard index.
The degree of over- or underestimation and magnitude of these
combined uncertainties is difficult to determine. Therefore,
results of the assessment should be viewed as order of magnitude
estimates (e.g. 10-3 vs. 10'.) at best.
~
ENVIRONMENTAL RISKS
-------
r
..
.Exposure Assessment. wildlife habitats near the sludge pit are
limited in extent and of low quality because of current and
historical land use. However, contamination in surface water or
groundwater may pose potential risks to aquatic and terrestrial
wildlife.
.~,
Birds and small mammals may be attracted to the sludge pit during
periods of standing water after heavy rains or snowmelt. It
appears unlikely that contaminants from the sludge pit would
enter the Portneuf River via overland flow. Two potential
release pathways were identified: (1) ephemeral surface water
within the sludge pit that may contain contaminants leached from
the sludge, and (2) groundwater transport of contaminants via the
Upper Aquifer to the Portneuf River.
EPA contacted the U.S. Department .of the Interior (001) which
includes the U.S. Fish and Wildlife Service, requesting that they
conduct a preliminary natural resource survey of the site. The
survey enabled them to determine whether their natural resource
trust responsibilitie~ were involved. Their assessment concluded
that neither releases from the site nor the site itself affect
any lands, minerals, waters, plants, animal species or Indian
resources managed or protected by 001. Concomitantly, EPA
determined that no critical habitats, nor any endangered species
or habitats of endangered species are known to be affected by
site contamination. .
..
Exposure Point Concentrations. Exposure to surface water and
groundwater was estimated using average and maximum values, found
in Tab.1es 2-3 and' 2-10 in the ERA, respectively. Surface water
exposure concentrations were assumed equivalent to toxicity
characteristic leaching procedure (TCLP) test data for sludge
samples. These values were used when estimating risks associated
with ingestion or direct contact with pooled water. Upper
Aquifer water quality data were used to represent exposure point
conceritrations for aquatic life. No dilution or differential
flow rates were assumed to occur between source and point of
exposure.
Toxicity Assessment. Indicator species of animals were
identified to assess effects on small mammals and avian ,species
due to contacting or ingesting contaminants. Data included a
broad range of exposure effects on as many life stages as
possible in both the short~ and long-term. A detailed discussion
can be found in Chapter 4 of the Environmental Risk Assessment.
wo.
....
Potential phytotoxicity was not evaluated quantitatively due to
the physical and chemical unsuitability of the sludge as a
substrate to support plant growth. Plants were not identified as
potentially important environmental receptors at this site.
-------
Aquatic toxicity' endpoints were selected to give a broad
characterization of potential adverse effects on the life stages
of each organism. Species were selected to represent fish,
insects, crustaceans, and plants. Table 12 summarizes the
potentially adverse aquatic effects of site contaminants.
Bioconcentration is reported to occur in some classes of
organisms for most metals detected onsite. At higher trophic
levels, volatile and semivolatile organic compounds are the most
likely to bioconcentrate.
Risk Characterization. Hazard indices (HIs) were calculated by
dividing the exposure intake values by their respective toxicity
endpoint. Potential adverse aquatic effects were assessed by
comparison of average and maximum contaminant concentrations with
available toxicity endpoint data. Table 13 summarizes the
aquatic HIs.
~
~
The greatest potential for adverse environmental effects are
expected from exposure to high concentrations of metals. .Silver
has the greatest potential for adverse environmental effects due
to estimated concentrations onsite. Copper has the greatest
potential for ecosystem damage due to its. effects across all
trophic levels examined in the assessment. Semivolatile
constituents pose a threat to the aquatic ecosystem.
Benzo[a]anthracene and pyrene are suspect for effects across
trophic levels. .
Contaminant concentrations were compared with Ambient Water
Quality criteria (AWQC). Average concentrations were compared
with chronic freshwater criteria and maximum concentrations were
compared with acute freshwater criteria, as listed in Table 14.
Chronic criteria were exceeded by average concentrations of
copper, lead, mercury, and silver. Acute criteria were exceeded
by maximum concentrations of chromium, copper, silver, and'zinc.
Uncertainties. The results of this assessment must be
interpreted cautiously due to the general lack of toxicological
data for threatened species, and the conservative assumptions
used given the lack of surface water concentration data.
Likewise, a potential threat to wildlife and aquatic species is
indicated, but these results should not be interpreted as
predictive.
CONCLUSIONS
Current and potential future residential and industrial worker
populations are at risk primarily from ingestion and dermal
exposure to contaminants in the sludge pit, and secondarily from
exposure through ingestion of contaminated groundwater if used as
a drinking water source. Carcinogenic risks which exceed 10-~
and noncarcinogenic hazard indices which exceed 1 are estimated
~
~
-------
"',
TABLE. 12
.'
SUMMARY OF POTENTlAll. Y AOVERSE AQUA TIC EFFECTS
FISh Insects Crustaceans Plants"
Cadmium Chronic Toxicity
Chr',)mium (VI) Growth
Copper Lethality Lethality Lethality Physiological
Manganese Photosynthesis,
Enzymatic
. Mercury Chronic Toxicity
Nickel tethality . Chronic Toxicity
Silver Chronic Toxicity Chronic Toxicity
.
Zinc Lethality Lethality Lethality
bis{2-Ethylhexyl) Mortalityl Mortality
Phthalate Morphology
Chrysene Physiological
t ,3-Dichlorobenzene Photosynthesis
Benzo(a)Anthracene Lethality Lethality Growth
Pyrene Lethality Lethality ReprOduction Biochemical
. Includes blue-green algae
~
-------
...
TABLE 13
/f-.
SUMMARY OF AQUATIC H"-ZARD INDICES
Hazard Hazard
Index@ Index @
Chemical Species Type Av:g COne. Max Cone.
Cadmium Water Ilea J.8E.OO 1.0E+01
Chromium Algae 1.0E.OO 2.6E+OO
Chromium Blue-green Algae S.OE.OO 1,3E+01
Copper Trout 8.4E-OI 1.6E+OO
. Copper Water Ilea 6.4E.01 1.2E+02
Copper Water Ilea 1.1E.01 2.1 E.01
Copper Midge 9.8E-01 1.8E+OO
Copper Green Algae 3.1E.OO S.9E+OO
Manganese Water Weed 1, 1 E.01 4.0E+OI
Manganese Algae 9.3E-OI J.3E+OO
Mercury Fathead Minnow .S.7E-Ot 1.8E+OO
Mercury Trout ~.5E-01 1,4E+OO
Nickel Trout ~.2E-01 l,OE.OO
Nickel Water Ilea 2.1E.OO 4.9E+OO
Silver Fathead Minnow 1.3E+OO 2.6E+OO
Silve: Trout 9.4E-OI 1.9E+OO
Silver Trout 5.6E.01 1.1E+02
Silver Waler Ilea 2.0E.01 ~.OE+OI
Silver Waler flea 3.1E.QO 6.3E.OO
Zinc Trout o.9E-'01 1.3E.OO
Zinc Water Ilea 5.7E.OO 8.6E.OO
Zinc Water flea 1.6E.OI 2.4E.OI
Zinc Midge 2.2E.OO 3.2E.OO
1.3-Dichlorobenzene Algae ~.OE-OI S.OE+OO
8enzo(a)Anthracene Fathead Minnow 1.9E.OO I .OE+01
8enzo(a)Anthracene Water Ilea 3.SE-Ol . I .8E.OO
8enzo(a)Anthracene Water flea 1.9E.OO 1.0E.01
8enzo(a)Anthracene Blue-green Algae ~.2E.Ol 2.2E+02
8enzo(a)Anthracene Blue-green Algae 7.0E-Ol 3.6E+OO
8is(2 -Ethylhexyl)Phl "alal e Fathead Minnow 4.3E-01 1.3E+OO
8is(2 -Ethylhexyl)Phthal al e Trout 9.4E-Ol 2.8E.OO
8is(2 - Elhylhexyl)Phlhalal e TrOut 1.3E.OO J.8E.OO r-:
8is(2 -Ethylhexyt)Phl halal e Water flea 1.5E.OO 4.4E+OO
Cnrysene Blue-green Algae t.5E.02 4.5E+02
Chrysene Blue-green Algae S.2E.OI 1.6E+02
Pyrene Fathead Minnow I.SE-OI UE.OO ;0<
Pyrene Waler Ilea 9.5E-Ol 7.0E.OO
Pyrena MOSQuito 1.9E-OI 1.4E.OO
-------
r
...
TABLE 14
COMPARISON OF COMPOUND CONCENTRATIONS
IN THE UPPER AQUIFEA WITH
NATIONAL AMBIENT WATER QUALITY CAITEAIA (mg/l) °
.t'
Concentration
Mean
Metals - Total
Antimony
Arsanic
Beryllium
Cadmium
Chromium
Cobalt
Copper
Lead
Manganese
Mercury
Nickel
Selenium
Silver
Thallium
Vanadium
Zinc
Volatile Oraanics
Chloroform
1,1-Dichloroethane
1,1-Dichloroethene
t-1,2-Dichloroethene
C-1,2-Dichloroethene
Methylene Chloride
Tetrachoroethene
Trichloroethene
0.0041
0:0069
0.0023
0.0003
0.01
0.0098
"';i;i!~r.II!11,
0.51
t.O:OOOj3t~
..... """""'-",','.".".".
0.021
0.0011
O..9Q?:I
0.0014
0.011
0.08
0.0006
0.00066
0.00064
0.0009
. 0.0002
0.0014
0.00098
0.00074
~
Semivolatile Oraanics
Acenaphthene
Benzo(a)Anthracene
BenZo(b)Auoranthene
Benzo(g,h,l)Perylene
Chrysene
Fluoranthene
Pyrene
1,3-Dichlorobenzene
di-n-Octylphthalate
bis(2-ethylhexyl) Phthalate
00036
00035
o 0037
00031
0.0032
00033
00038
0.0089
0.005
0.0047
~,
AWQC
Freshwater
Chronic
1.6
0.048 (v)
0.0053
0.0011
0.011
NP
0.012
0.0032
NP
0.000012
0.16
0.035
0.00012
0.04
NP
0.11
1.24
NP
NP
NP
NP
NP
0.84
21.9
0.52
NP
NP
NP
NP
NP
NP
0.763
NP
NP
Metals assume a hardness 01 100 mg CaC03
NP Not Promulgated
J Value lIagged as estimated in AI.
R Value flagged as rejected in AI.
(a) Value is one-hall the highest detection limit.
Shaded values indicate the value exceeds an ARAR.
From Table 5-32 Environmental Aisk Assessment (AGI, 199Oc).
Concentration
Max
0.0213
0.0283
0.0025 (a)
0.0008
~:1~:::'::~1m~~1~:
0.0133
;:::::::H::::i:tg~~:;:i:
0.01
1.82
0.00042 J
0.05
0.0014 R
ili:~'imI:11Pi.mU
0.0028 R
0.0225
..:-:-:-:.;-:.;.:..,.:.;../.-:.;.;-:.:.;.~:-:.;.
t???/m~lg:I
0.0025 (a)
0.0025 (a)
0.0025 (a)
0.003
0.0003
0.005
0.0025 (a)
0.0025 (a)
0.021
0.018
0.010 (a)
0.010 (a)
0.010 (a)
0.010 (a)
0.028
0.11
0.012 J
0.014 J
AWQC
Freshwater
Acute
9
0.36 (III)
0.13
0.0039
0.016
NP
0.018
0.082
NP
0.0024
1.4
0.26
0,0041
1.4
NP
0.12
28.9
NP
11.6
11.6
11.6
NP
5.28
45
1.7
NP
NP
NP
NP
NP
NP
1.12
NP
-------
for all exposure
and semi volatile
contaminants may
organisms.
scenarios from exposure to metals and volatile
organic compounds. In addition, sludge
pose a threat to wildlife and/or aquatic
~
Actual or threatened releases of ha~ardous substances from this
site, if not addressed by implementing the response action
selected in this ROD, may present an imminent and substantial
. endangerment to public health, welfare, or the environment.
~,
VII.
DESCRIPTION OF ALTERNATIVES
This section presents a narrative summary of each alternative.
Additionally, a description of the major applicable or relevant
and appropriate requirements (ARARs) and other standards to be
considered (TBCs) utilized for the specific components of the
waste management process is provided. A detailed assessment of .
each alternative can be found in Chapter 4 of the FS.
Several alternatives were eliminated early in the screening
process because it was readily apparent that they would not
effectively address contamination, could not be implemented, or
would have had excessive cost compared to an alternative that
would achieve the same degree of protection or level of
effectiveness. Table 15 lists each of the proposed alternatives
and identifies the elements of each.
The remedial alternatives consider four treatment options for
sludge/soil:
--excavation and offsite disposal
--excavation, offsite disposal and capping
--onsite solidification
--onsite and offsite incineration
Two alternatives were considered for treatment of contaminated
groundwater:
--oil/water separation and dissolved air flotation (DAF)
--oil/water .separation and carbon adsorption
All alternatives, except Alternative 1 (No Action) and
Alternative 2 (Institutional Controls), have the following
features in common:
~
--soil flushing
-------
.f
,
~
.. ,.
~b~15 ..
Elements of Proposed Alternatives
Proposed Alternatives
Remedy Elements 1 2 3 4 5* 6 7 8 9 10 11 12
Groundwater (GW) Monitoring ,/ ,/ ,/ ,/ ,/ ,/ ,/ ,/ ,/ ,/ ,/
Institutional Controls ,/ ,/ ,/ ~ ,/ ,/ ,/ ,/ ,/ ",/
Dust Control and Air Monitoring ,/ ,/ ,/ ,/ ,/ ,/ ,/ ,/ ,/
Backfilling 01 Pit with Clean Material ,/ ,/ ,/ ,/ ,/ ,/ ,/ ,/ ,/
Alternative Drinking Water Supply ,/ ,/ ,/ ,/ ,/ ,/ ,/ ,/ ,/ ,/
GW Extraction & Soli flushing ,/ ,/ ,/ ,/ ,/ ,/ ,/ ,/ ,/
GW Treatment by OlllWater Separation
& Dissolved Air flotation (DAF) ,/ ,/ ,/ ,/
GW Treatment by OlllWater Separation
& Carbon Adsorption ,/ ,/ ,/ ,/ ,/
Off-Site GW Discharge ,/ ,/ ,/ ,/
On-Site GW Discharge ,/ ,/ ,/ ,/ ,/
Low Permeability Cap ,/ ,/ ,/
Soli excavation Off-Site Disposal ,/ ,/ ,/
Soli excavation Solidification ,/ ,/
On-Site Soli Incineration ,/ ,/
Off-Site Soli Incineration ,/ ,/
-------
--air monitoring and dust control measures during
construction
--alternate onsite drinking water supply, if necessary
--post-construction institutional controls maintained by
UPRRand operation and maintenance (0 & M)
..
Contaminants found in groundwater, although currently below both
maximum contaminant levels (MCLs) and maximum contamina~t limit
goals (MCLGs), but above ambient water quality criteria (AWQC),
will be closely tracked. Monitoring of the groundwater and the
pump/treat system during groundwater remediation activities will
be conducted to ensure that groundwater remediation goals are
achieved. If cleanup goals are not met, modifications to the
groundwater treatment system will be necessary.
Additional soil and groundwater sampling will also be conducted
prior to commencement of remedial activities in order to
determine background concentrations. Preliminary target
concentrations/remediation goals for contaminants of concern have
been established for the site and are provided in the Record of
Decision. Final remediation goals, target concentrations and
performance standards will be identified following the
determination of soil and groundwater background concentrations.
~,
A.
ARARs and TBCs:
CERCLA Section 105 required the NCP to include "methods and
criteria for determining the appropriate extent of removal,
remedy, and other measures authorized by the Act..." In
response, EPA developed the applicable or relevant and
appropriate (ARARs) concept. The 1985 NCP revisions and
Compliance Policy (50 FR 47946) required that remedial actions
"attain or exceed applicable or relevant and appropriate Federal
public health and environmental requirements." Since that time,
SARA codified and expanded the ARARs concept, OSWER provided
Interim Guidance on ARARs published on August 27, 1987 (52 FR
32496) and EPA published the ."CERCLA Compliance with Other Laws
Manual" which provides additional guidance on the Agency's.
interpretation of the SARA provisions and their implement~tion.
The principal federal and state regulations which were considered
in evaluating the groundwater component of the remeqial .
alternatives are:
Federal Water Pollution ~ontrol Act (Clean Water Act)
(CWA) (33 USC 1251)
Safe Drinking Water Act (SDWA) (40 USC 300)
.
...
Underground Injection Control (40 CFR Part 144)
-------
I
~
Idaho Solid Waste Management Regulations and Standards
Manual (Section 16.01.6005,01, 16.01.6008,07)
Idaho State Well Construction Standards (Idaho Code Title
42-238(4»
~
Idaho Construction and Use of Injection Wells (Idaho Code
Title 42, Chapter 39- Rule 8,1,1, Rule 8,2,1,a., Rule
8,3,1)
Idaho Water Quaiity Standards and Wastewater Treatment
Requirements (Section 16.01.2200, 16.01.2250,06,
16.01.2302, 16.01.2460, 16.01.26~0)
Idaho Regulations for Public Drinking Water Systems.
For Offsite Only:
City of Pocatello Municipal Code- Non-Residential.
Wastewater Discharges (Sections 13.20.030 N.3, 13.20.040
D.1)
Other non-promulgated, non-enforceable guidelines or criteria EPA
considered in selecting a preferable alternative were TBCs, or
"To Be Considered". TBCs included OSWER Interim Final Directive
9283.1-2 "Guidance on Remedial"Actions for Contaminated Ground
Water at Superfund Sites" dated December 1988; the proposed
maximum contaminant levels (PMCLs) and proposed maximum
contaminant level goals (PMCLGs) for. contaminated groundwater;
ambient water quality criteria (AWQC) which were developed for
the protection of human health and aquatic life; and, drinking
water health advisories which provide health-based guidance
levels for contaminants in drinking water.
Groundwater
~
CERCLA section 121(d) (2) (A) requires onsite CERCLA remedies to
attain standards or levels of control established under the Safe
Drinking Water Act (i.e. MCLs or MCLGs). According to the NCP
(55 FR 8848), where MCLGs are set ,at zero, the remedial actions
shall attain MCLs for ground or surface water that are current or
potential sources of drinking water. Either MCL~, non-zero
MCLGs, risk-based levels or lowest quantitation limits will be
the groundwater remediation goals for the UPRR sludge pit.
Further discussion is provided later in the section entitled,
Remediation Goals.
.
Under the CWA, State Antidegradation Requirements/Use
Classification require every state to classify all the waters
within its boundaries according to intended use. There are two
aquifers (Upper and Lower) beneath the sludge pit. EPA has
-------
designated the Upper Aquifer as Class IIB since it is potentially
available for drinking water, agriculture or other beneficial
uses. The Lower Aquifer is Class I (i.e. drinking water) as it
is the primary drinking water source for the community.
The CWA section 301(b) requires that, at a -minimum, all direct
discharges meet technology-based limits for conventional
pollutant control technology. Because there are no national
effluent limitation regulations for releases from CERCLA sites,
technology-based treatment requirements are determined on a case-
by-case basis using best professional judgement. Oil/water
separation, dissolved air flotation, carbon adsorption and soil
flushing were the types of pollutant control technologies
evaluated for the groundwater alternatives. All of these
techniques are proven technologies for treatment of groundwater
contaminated by NAPL ahd other compounds. -
~
~.
The various Idaho state standards listed above primarily address
solid waste management, groundwater well construction, and
protection of state groundwater against unreasonable
contamination or deterioration. These standards are designed to
control and regulate the public drinking water system in order to
protect the health of consumers.
The -City of Pocatello Municipal Code provides uniform regulations
and requirements applicable to dischargers into the city
wastewater collection and treatment system. UPRR's current
wastewater discharge limit with the City of pocatello will
require an increase in volume in order to dispose of treated
groui!~water in excess of the current]! permitted amount.
Sludqe/Soil
The principal regulations which were considered in evaluating
remedial alternatives for sludge and soil were:
Occupational Safety and Health Act (OSHA)
1910.12)
(29 USC, CFR
Clean Air Act (CAA) (42 USC 7401, 7410, and 7411)
Rules and Regulations for the Control of Air Pollution in
Idaho (Citations: 16.01.1011. 16.01.1201, 16.01.1501-
16.01.1550, 16.01.1957)
Idaho Soiid Waste Management RegUlations and Standards
Manual (Sections 16.01.6004,01, 16.01.6005,01, and
16.01.6008,16) .
~
TBCs for sludge/soil included OSWER Directive #9355.4-02 entitled
"Interim Guidance on Establishing Soil Lead Cleanup Levels at
Superfund sites", dated September 7, 1989, Memorandum re:
.
-------
r
"Cleanup Level for Lead in Groundwater" from H. Longest, OERR and
B. Diamond, OWPE to P. Tobin, Region IV Waste Management
Division, and American Conference of Governmental Industrial
Hygienists Threshold Limit Values.
'.'
OSHA requirements (1910.12) pertain to workers engaged in
response or other hazardous waste operations. Excavation of the
sludge pit, installation of a soil flushing treatment system,
backfilling and grading of the pit are considered hazardous waste
operations at this site.
CAA requirements pertain to national ambient air quality
standards (NAAQS), and state implementation plans for compliance
with the NAAQS. Rules and Regulations for the Control of Air
Pollution in Idaho pertain to state air quality standards,
process emissions, visible emission standards and fugitive dust
standards. The State of Idaho ambient air quality standards are
based on total suspended particulates (TSP). pocatello is a '
federal, nonattainment area for particulate matter (PM,o).
Onsite dust control measures must be implemented to prevent
activities at the sludge pit from causing or contributing to a
violation of the NAAQS or the state TSP standards. '
A detailed assessment of the extent to which various remedial
alternatives meet ARARs and TBCs can be found in the Threshold
Criteria and statutory Determinations sections ,of the ROD.
B.
Description of Alternatives:
The following twelve remedial groundwater and sludge/soil
remedial alternatives were evaluated.
Alternative 1: No Action (Groundwater Monitoring).
Estimated
Estimated
Estimated
Estimated
Estimated
Time for Construction:
Time for Operation: 30
Capital Cost:
o , M:
Total (Present Worth):
years
-0-
(monitoring)
-0-
$635,300
$635,300
'.
The NO-Action Alternative is required by law to be developed and
acts as a baseline for comparison with the cleanup alternatives.
Under this alternative, no action would be taken to clean up
contaminated sludge, silt, soils or groundwater, consequently
this alternative is not protective of human health or the
environment and does not meet ARARs. However, a long-term
groundwater monitoring program would be implemented to monitor
movement of the contaminant plume. Since this alternative does
not change contaminant concentration or exposure, the risk
remaining at the site after remedial activities have been
~,
-------
completed (residual risk) is equivalent to the current, estimated
site risks based on the risk assessment results (baseline risk).
Alternative 2: Institutional Controls/Groundwater Monitoring.
.,
Estimated
Estimated
Estimated
Estimated
Estimated
Time for Construction:
Time for Operation: 30 years
Capital Cost:
o , M:
Total (Present Worth):
2-6 months
(moni.toring)
$33,150
$636,700
$669,850
/t-
This alternative involves surrounding the sludge pit with a six-
foot chain link fence. Land and water use restrictions would be
added to the property deed to prohibit current and future
landowners from disturbing the. site. and from using. the site
groundwater resources. If necessary, an alternate drinking water
supply system would be provided to serve potential future
businesses and/or residents moving onto the site property. This
alternative does not reduce contaminant concentrations and only
. nominally reduces exposure, therefore, residual risk is
equivalent to baseline risk. In addition, this alternative does
not meet ARARs.
Alternative 3: Excavation' Offsite Disposal/Groundwater
Treatment (with Oil/Water Separation and Dissolved Air Flotation
(DAF»/soil Flushing/Offsite Discharge/Institutional Controls/Air
Monitoring' Dust Control/Groundwater Monitoring.
Estimated Time for Construction:
Estimated T~me for Operation:
4-6 months
5 years (treatment)
30 years (monitoring)
(up to) $4,894,208
$1,624,300
(up to) $6,518,508
Estimated Capital Cost:
Estimated 0 , M:
Estimated Total Cost (Present Worth):
. .
This alternative is designed to reduce potential human and
environmental exposure to contaminants contained in the sludge.
By removing the sludge, the source of contamination to
groundwater beneath the pit will be significantly reduced. In
addition, this alternative is designed to prevent offsite
migration of groundwater from the Upper Aquifer contaminated with
NAPL, prevent migration of NAPL and other contaminants from the'
Upper to the Lower Aquifer, and to treat NAPL and other
contaminants in the Upper Aquifer which exceed PMCLs andPMCLGs.
The alternative consists of excavating sludge and soil, and
transporting it to a RCRA approved landfill. Testing of
contaminated sludge and soil will occur prior to disposal in the
landfill to demonstrate compliance with land disposal restriction
(LDR) treatment standards. If the contaminated sludge and soil
fail the RCRA tests, they will be treated, as appropriate, prior
to disposal. The pit and other excavated areas will be
,r
-------
~
backfilled with clean fill. Because the vertical and horizontal
extent of this contamination is presently unknown, sampling of
the underlying and surrounding soil would be performed
periodically during excavation, with the results determining
whether to excavate further in order to meet cleanup goals (site-
specific remediation levels that define the extent of cleanup
required by federal, state and local law).
~
Excavation of the Michaud Gravel will likely be limited since the
formation is extremely coarse in nature. The Michaud Gravel
consists of a poorly sorted mixture of gravel, cobbles, and
boulders ranging up to 9 feet in diameter, ranging from dense to
very dense. Current estimates indicate that approximately 4,200
cubic yards of sludge and soil could be removed from the pit and
surrounding areas. However, the maximum extent of excavation
could extend down to the existing level of the water table (i.e.
the top of the Upper Aquifer) .
Although it is intended that all contaminated sludge and soil
which exceed cleanup goals will be excavated, this may not be
feasible due to subsurface conditions as mentioned above.
Therefore, soil flushing, using uncontaminated water from Batiste
Springs, would be used to flush contaminants beneath the
excavated area to the groundwater Surface via infiltration
galleries. By using a system of perforated drains, the water
would infiltrate into and through the unsaturated soil down to
the Upper Aquifer where it would be captured with groundwater
extraction wells and pumped to the surface for treatment.
-
Since the technical feasibility of excavating through soils (as
described above) is uncertain, it is assumed that 4,200 cubic
yards will be the limit of removal. Therefore, additional
protection is necessary. Unlike Alternatives 5 and 6, this
alternative (and Alternative 4), does net include the placement-
of a low permeability cap over the backfilled pit. Without the
low permeability cap, risks associated with the volatilization of
wastes, direct contact, and infiltration of water that could -
leach contaminants into underlying soil, potentially
recontaminating treated groundwater may not be adequately
addressed.
~
Treatment of groundwater and nonaqueous phase liquids (NAPL)
would involve using an oil/water separator to skim off floating
oil. The wastewater would then be run through an onsite
dissolved air flotation unit (OAF) for removal of primarily
emulsified oil, semivolatile organic compounds, and metals in the
NAPL before discharge to the Pocatello publicly owned treatment
works (POTW). Organic contaminants remaining in the wastewater
will receive biological treatment at the POTW. Skimmed oil will
be kept in an onsite holding tank for sale to a recycler;
residual sludge will be disposed in an approved, offsite
landfill.
.
-------
Air monitoring and dust control measures will be implemented
during site cleanup activities to reduce emissions and to ensure
the protection of site workers, nearby workers and residents.
The dust control measures may include spraying the ground surface
with clean water or an approved chemical dust suppressant. Long-
term groundwater monitoring and deed restrictions would be
required. If monitoring indicates that groundwater contamination
has not been adequately remediated, an alternate drinking water
supply system would be provided to serve potential future
businesses and/or residents moving onto the site property.
Alternative 4: Excavation' Offsite Disposal/GrOundwater
Treatment (with Oil/Water Separation and Carbon Adsorption)/soil
Flushing/Onsite Discharge/Alternate Drinking Water
Supply/Institutional ControlS/Air Monitoring, Dust
Control/Groundwater Monitoring.
~
~
Estimated Time for Construction:
Estimated Time for Operation: 5 years
4-6 months
predicted (treatment)
30 years (monitoring)
(up to) $5,689,163
$4,130,400
(up to) $9,819,563
Estimated Capital Costs:
Estimated 0 , M:
Estimated Total (Present Worth):
Treatment of the sludge and soil contamination in Alternative 4
is identical to the treatment discussed in Alternative 3. The
groundwater treatment and disposal method in Alternative 4,
however, would involve carbon adsorption and onsite discharge,
rather than dissol~~ed air flotation and offsite discharge. The
carbon adsorption system would enhance groundwater cleanup by
specifically removing organic contaminants. .
The extracted groundwater would be pumped from the oil/water
separator to the carbon adsorption unit for further treatment.
The carbon adsorption system brings the contaminated groundwater
into direct contact with activated carbon by passing the water
through carbon containing vessels. The activated carbon
selectively adsorbs hazardous organic particles. The treated
water would then be routed to the infiltration galleries for use
in the soil washing process. Used carbon would be recycled
offsite through combustion at an approved regeneration facility.
Institutional controls, air monitoring, dust contro~, groundwater
monitoring and an alternate drinking water supply system are also
included in this alternative as described in Alternative 3.
~
Alternative 5: Excavation" Offsite Disposal/Low Permeability
Cap/Groundwater Treatment (with Oil/Water Separation and
DAF)/Soil Flushinq/Offsite Discharge/Alternate Drinking Water
Supply/Institutional Controls/Air Monitoring' Dust
Control/Groundwater Monitoring.
4
-------
r
~
Estimated Time for Construction:
Estimated Time for Operation: 5 years
10 months
predicted (treatment)
30 years (monitoring)
(up to) $2,139,650
$1,657,900
(up to) $3,797,550
~
Estimated capital Costs:
Estimated 0 , M:
Estimated Total (Present Worth):
This alternative is designed to reduce the primary source of
contamination at the site by excavating contaminated sludge an~
soil to a depth that is technically practical, disposing at an
approved offsite landfill, backfilling the excavated area with
clean fill and covering it with a low permeability cap.
Excavation of soils beneath the sludge may be difficult due to
the subsurface conditions. These soils consist of a poorly
sorted mixture of gravel, cobbles, and boulders up to 9 feet in
diameter, ranging from dense to very dense. Therefore, it is
assumed that only visible sludge (i.e. material that is
discolored or noted to have the consistency of sludge) and
underlying silt, up to a maximum of 4,200 cubic yards, would be
removed.. .
since the technical feasibility of excavating through soils (as
described above) is uncertain, it is assumed that 4,200 cubic
yards will be the limit of removal. Therefore, additional
protection is necessary. A low permeability cap will be placed
over the backfilled pit to reduce volatilization of wastes,
direct contact, and infiltration of water that could leach.
contaminants into underlying soil, potentially recontaminating
treated groundwater. The cap will protect, not interfere with,
the soil flushing component of the remedy by preventing the
potential introduction of contaminants into the perforated drains
via percolating rainwater, snowmelt, etc., from the ground
surface. Soil flushing is intended to operate in a closed loop
system. By using a system of perforated drains, the water would
infiltrate into and through the remaining unsaturated, .
contaminated soil down to the Upper Aquifer where it would be
captured with groundwater extraction wells and pumped to the
surface for treatment.
~
Testing of contaminated sludge and soil will occur prior to
disposal in the landfill to demonstrate compiiance with land
d~sposal restriction (LOR) treatment standards. If the
contaminated sludge and soil fail the RCRA tests, they will be
treated, as appropriate, prior to disposal.
~
Soil flushing and ground~ater extraction and treatment using an
onsite oil/water separator and OAF unit, infiltration galleries,
institutional controls, dust control, air monitoring, groundwater
monitoring, and an alternate drinking water supply system are
also included in this alternative as described in Alternative 3.
-------
Alternative 6: Excavation & Offsite Disposal/Low permeability
Cap/Groundwater Treatment (with Oil/Water Separation and Carbon'
Adsorption)/soil Flushinq/Onsite Discharqe/Alternate Drinkinq
Water Supply/Institutional Controls/Air Monitorinq & Dust
Control/Groundwater Monitorinq. .
~
Estimated Time for Construction:
Estimated Time for Operation: 5 years
,..;:,
10 months
predicted (treatment)
30 years (monitorinq)
(up to) $2,820,750
$4,164,000
(up to) $6,984,750
r~~
Estimated Capital Costs:
Estimated 0 & M: '
Estimated Total (Present Worth):
Alternative 6 combines the contaminated sludge/soil excavation,
offsite disposal and capping remedial activities described in
Alternative 5 with the carbon adsorption groundwater treatment,
system described in Alternative 4. Institutional controls, dust
control, air monitoring, groundwater monitoring and an alternate
drinking water supply system are also included in this
alternative as described in Alternative 3.
Alternative 7: Sludqe Solidification/Low permeability
Cap/Groundwater Treatment (with Oil/Water Separation and
DAF)/Soil Flushing/Offsite Discharge/Alternate Drinking Water
Supply/Institutional Controls/Air Monitoring & Dust
Control/Groundwater Monitoring. -
Estimated Time for Construction:
Estimated Time fc,~ Operation: 5 years
12-14 months
predicted (treatment)
30 years (monitoring)
(up to) $6,410,850
$1,643,500
(up to) $8,054,350
Estimated Capital Costs:
Estimated 0 & M:
Estimated Total (Present Worth):
This alternative is designed to treat the contaminated sludge and
soil in, around and below the pit. Because the likelihood of
success of this process is unknown, a bench scale treatability
study would be performed to determine the suitability of this'
remedial alternative. If this alternative was found to be
feasible, sludge and contaminated soils would be excavated to a
depth that is technically practical (approximately 4,200 cubic
yards)4and mixed with stabilizing agents such as fly ash, lime,
cement or proprietary chemicals to immobilize contaminants. An
onsite landfill will be constructed for disposal of the
solidified sludge and soil. To prevent possible future leaching
of contaminants from the solidified mass to the groundwater, the
landfill cell will be double lined and contain a leachate
collection system. The entire landfill will be covered with a
low permeability cap.
#
~
-------
f
-a'
Soil flushing and groundwater extraction and treatment using an
onsite oil/water separator and DAF unit, infiltration galleries,
institutional controls, dust control, air monitoring, groundwater
monitoring, and an alternate drinking water supply system are'
also included in this alternative as described in Alternative 3.
,y\
Alternative 8: Sludge SOlidification/Low Permeability
Cap/Groundwater Treatment (with Oil/Water Separation and Carbon
Adsorption)/soil Flushing/Onsite Discharge/Alternate Drinking
Water Supply/Institutional Controls/Air Monitoring' Dust
Control/Groundwater Monitoring. '
Estimated Time for Construction:
Estimated Time for Operation: 5 years
12-14 months
predicted (treatment)
30 years (monitoring)
(up to) $7,195,950
$4,149,600
(~p to) $11,345,550
Estimated Capital Costs:
Estimated 0 , M:
Estimated Total (Present Worth):
This alternative combines the sludge solidification and its
onsite disposal in a specially constructed landfill as described
in Alternative 7 with the carbon adsorption groundwater treatment
system described in Alternative 5. .
Institutional controls, dust control, air monitoring, groundwater
monitoring, and an alternate drinking water supply system are
also included in this alternative as described in Alternative 3.
Alternative 9: Onsite Incineration/Groundwater Treatment via
Oil/Water Separation and DAF/Soil Flushing/Offsite .
Discharge/Alternate Drinking Water Supply/Institutional
Controls/Air Monitoring' Dust Control/Groundwater Monitoring.
.' -i~.
Estimated Time for Construction:
Estimated Time for Operation: 5 years
10-14 months
predicted (treatment)
30 years (monitoring)
(up to) $23,240,950
$1,624,300
(up' to) $24,865,250
Estimated Capital Costs:
Estimated 0 , M:
Estimated Total (Present Worth):
~.
This alternative is designed to treat contaminated sludge and
soil in the pit which is the potential source of groundwater
contamination. A test burn(s) to assess if incineration meets
air quality standards will be required prior to implementation of
this remedial alternative. Soil exceeding cleanup goals and
sludge within the pit would be excavated and incinerated in an
onsite incinerator. Ash would be transported and disposed in an
approved landfill. Procedures for 'determining the extent of
contamination of the underlying and surrounding soil and
commensurate excavation, backfilling and grading are identical to
those described in Alternative 3.
!O
-------
50il flushing and groundwater extraction and treatment using the
existing onsite oil/water separator and DAF unit, infiltration
galleries, alternate drinking water supply system, institutional
controls, dust control and air monitoring are also included in
this alternative as described in Alternative 3. .
.
Alternative 10: Onsite Incineration/Groundwater Treatment via
Oil/Water Separation and Carbon Adsorption/soil Flushing/Onsite
Discharge/Alternate Drinking Water Supply/Institutional
Controls/Air Monitoring' Dust Control/Groundwater Monitoring.
~
Estimated Time for Construction:
Estimated Time for Operation: 5 years
10-14 months
predicted (treatment)
30 years (monitoring)
(up to) $23,786,250
$4,130,600
(up to) $27,916,850
Estimated Capital Costs:
Estimated 0 , M:
Estimated Total (Present Worth):
This alternative combines the carbon adsorption groundwater
treatment system remedial action described in Alternative 4 and
the onsite incineration of contaminated sludge and soil described
in Alternative 9. The remaining remedial features of this.
alternative are also described in Alternative 3.
Alternative 11: Offsite Incineration/Groundwater Treatment via
Oil/Water Separation and DAF/Soil Flushing/Offsite
Discharge/Alternate Drinking Water Supply/Institutional
Controls/Air Monitoring' Dust Control/Groundwater Monitoring.
Estimated Time for Construc~ion:
Estimated Time for Operation: 5 years
10-14 months
predicted (treatment)
30 years (monitoring)
(up to) $38,662,850
$1,624,300
(up to) $40,287,150
Estimated Capital Costs:
Estimated 0 , M:
Estimated Total (Present Worth):
This alternative is designed to treat contaminated sludge and
soil in the pit which is the potential source of groundwater
contamination. 50il exceedi~g cleanup goals and sludge within
the pit would be excavated and incinerated in an offsite
incinerator. Ash would be disposed in an approved landfill.
Procedures for determining the extent of contamination of the
underlying and surrounding soil and commensurate excavation,
backfilling and grading are identical to those described in
Alternative 3. .
50il flushing and groundwater extraction and treatment using an
onsite oil/water separator and DAF unit, infiltration galleries,
institutional controls, dust control, air monitoring, groundwater
monitoring, and an alternate drinking water supply system are
also included in this alternative as described in Alternative 3.
-
~
-------
I
,k
Alternative 12: Offsite Incineration/Groundwater Treatment via
Oil/Water separation and Carbon Adsorption/Soil Flushing/Onsite
Discharge/Alternate Drinking Water Supply/Institutional
Controls/Air Monitoring' Dust Control/Groundwater Monitoring.
~
Estimated Time for Construction:
Estimated Time for Operation: 5 years
10-14 months
predicted (treatment)
30 years (monitoring)
(up to) $39,208,150
$4,130,600
(up to) $43,338,750
Estimated Capital Costs:
Estimated 0 , M:
Estimated Total (Present Worth):
This alternative combines the carbon adsorption groundwater
treatment system remedial action described in Alternative 4 and
the offsite incineration of contaminated sludge and soil
described in Alternative 11. The remaining remedial features of
this alternative are also described in Alternative 3.
VIII.
SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
For the purpose of remedy selection,' the relative performance of
each remedial alternative was evaluated in relation to three
categories of criteria: (1) threshold criteria [a required level
of performance]; (2) primary balancing criteria; and, (3)
modifying criteria. The nine evaluation criteria and the results
of the evaluation are discussed below. A summary of the relative
performance of the alternatives based on these criteria is
included in Table 16.
A.
Threshold Criteria
The remedial alternatives were first evaluated in relation to the
threshold criteria: overall protection of human health and the
environment, and compliance with ARARs. The threshold criteria
are statutory requirements and must be met by all alternatives
that remain for final consideration as remedies for the site.'
1. Overall Protection of Human Health and the Environment. This
criteria addresses whether or not a remedial alternative provides
adequate protection and describes, how risks are eliminated,
reduced, or controlled through treatment and engineering or
institutional controls. '
~
All of the alternatives except Alternative 1 (no action) and
'Alternative 2 (institutional controls) are protective of human
health and the environment and meet preliminary cleanup goals.
Preliminary target concentrations/remediation goals for
contaminants of concern have been established for the site and
are provided in the Record of Decision. These preliminary
remediation goals are concentrations of contaminants for each
exposure route that are believed to provide adequate protection
of human health and the environment based upon available site
.
-------
TABLE 16
SUMMARY OF REMEDIAL ALTERNATIVES DETAILED ANALYSIS
CRITERIA. I 2 1 4 5 6 7 8 9 10 II 12
Overall protection of
human health and Low Low Medium Medium High High High High High High Ifigh High
environmenl
Compliance with Low Low High High High Ifigh High Ifigh Medium Medium Medium Medium
ARARs
Long-term erfectiveness Low l.ow Medium Medium Medium Medium Ifigh Ifigh High High lIigh High
and permanence
Reduction of toxicity, '(1.. I.." \tnllUm \te,lllIm \tedlum \Iedlum lIi,.:h lIigh lIigh High lIigh Iligh
mobility, or volume -
Short-term n/a" n/a" lIigh lIigh Ifigh lIigh Medium Medium Medium Medium Medium Medium
errectiveness
Implementability n/a" n/a" Ifigh High High Ifigh Low Low Medium Medium Medium Medium
State acceptance - - - - - - - - - - - -
Community a'cceptance - - - - - - - - - - - -
" n/a = not applicable, assumes no remedial action
Cost comparisons for each of the alternatives can be found on pages 31-38
:.-
..
..
-------
~
information. Before final remediation goals are established,
further refinement may be necessary after consideration of, for
example, exposure factors, uncertainty factors, technical factors
including the determination of soil and groundwater background
concentrations.
~
Alternatives 3 through 6 (sludge/soil removal and offsite
disposal) primarily treat the contaminated Upper Aquifer
groundwater by pumping it to the surface, removing NAPL and other
contaminants before discharge to the Pocatello.publicly owned
treatment works (POTW). Sludge and soil will be excavated to
practicable depths, removed and disposed offsite in an approved
landfill, and the pit area backfilled, graded and capped. A soil
flushing treatment system will be i~stalled and used to remove
contaminants in remaining soils.
Alternatives 7 and 8 (solidification) and Alternatives 9 through
12 (i~cineration) treat both the contaminated sludge and soil, .
and the contaminated Upper Aquifer groundwater. Alternatives 7
and 8 include solidifying sludge/soil and placing it in a lined
landfill cell onsite. These alternatives provide protection
similar to offsite disposal and capping of the sludge pit
(Alternatives 5 and 6) by eliminating inhalation, ingestion, and
dermal contact exposure routes. Alternatives 9 through 12
(incineration) like offsite disposal, remove the contamination
source, therefore, eliminating exposure routes. Incineration can
destroy organic contaminants, but the ash byproduct will likely
contain increased concentrations of heavy metals. Metals may
become more mobile in the ash, necessitating solidification or
stabilization before being landfilled.
Excavation, removal and offsite disposal of the contaminated
sludge and soil will significantly reduce the threat of exposure
from ingestion, dermal contact and inhalation. A baseline risk
for the combined industrial/residential scenario associated with
these exposure pathways is estimated at 6 x 10-2 for carcinogenic
risk with a HI=8 for chronic, noncarcinogenic risks. By
excavating and removing the contaminated sludge/soil to target
concentrations, the cancer risk will be reduced to 2 x 10-5 and
the chronic HI will decrease to 0.8.
~
Soil flushing, extraction and treatment of the contaminated
groundwater will eliminate the threat of exposure from ingestion
or inhalation of contaminated groundwater. The highest baseline
risk for the combined industrial/residential scenario associated
with these exposure pathways is estimated at 2 x 10-2 (Upper
Aquifer NAPL wells) for carcinogenic risk with a HI=9 (Upper
Aquifer non-NAPL wells) for chronic, noncarcinogenic risks. By
excavating and removing the contaminated sludge/soil and lowering
groundwater concentrations to target concentrations, the cancer
risk from groundwater exposure will be reduced to 9 x 10-6 (Upper
~
-------
Aquifer NAPL wells) and the chronic HI will decrease to 0.7
(Upper Aquifer non-NAPL wells).
Both groundwater treatment systems are equally protective for
this site. Under the dissolved air flotation (DAF) treatment
scenario, biological and inorganic treatment at the Pocatello
POTW is further expected to remove organic and metal contaminants
that the DAF unit alone does not remove. If modifications to the
groundwater treatment system are necessary following evaluation
of the system's effectiveness, carbon adsorption could be used to
enhance groundwater cleanup by specifically removing organic
contaminants. .
~
.
The combined effect of the groundwater extraction and soil
flushing system will prevent the offsite migration of
contaminated Upper Aquifer groundwater, prevent migration of NAPL
and other contaminants from the Upper to the Lower Aquifer, and
treat NAPL and other contaminants which exceed PMCLs and PMCLGs.
It will also provide additional protection to aquatic species by
reducing the potential for contaminant migration to the Portneuf
River.
2. Comcliance with ARARs. This criteria addresses whether or
not a remedial alternative will meet all of the applicable or
relevant and appropriate requirements or provide grounds for
invoking a waiver.
Alternatives 3 through 12 comply with the applicable, or relevant
and appropriate requirements (ARARs) for this si~e and are
discussed further in section XI entitled statutory
Determinations.
Tests performed on the sludge and soil indicate it is not a
Resource Conservation and Recovery Act (RCRA) waste. Therefore,
land disposal restrictions do not apply nor do RCRA landfill
closure requirements. However, under Alternatives 3 through 6,
the contaminated sludge and soil will be tested again, prior to
disposal, and stabilized at the landfill, if necessary.
Alternatives 3 through 12 will meet state and federal air quality
standards for visible emissions and fugitive dust, as each
alternative includes dust control measures.
Alternatives 3 through 12 include groundwater extraction,
treatment, and discharge process options that will meet both
federal and state water quality ~s for groundwater, drinking
water, and leaching. Alternatives 3, 5, 7, 9 and 11 will require
an increase in volume to UPRR's current wastewater discharge
limit with the City of Pocatello. All of these alternatives use
offsite discharge of treated wastewater to the Pocatello publicly
owned .treatment works (POTW).
.
~
-------
B.
Primary Balancing Criteria
~
Once an alternative satisfies the threshold criteria, five
primary balancing criteria are used to evaluate the technical and
engineering aspects of the remedial alternatives.
~
3. . Lonq-term Effectiveness and Permanence. This criteria refers
to the ability of a remedial alternative to maintain reliable
protection of human health and the environment once remediation
goals have been achieved. The magnitude of residual risk is
considered as well as the adequacy and reliability of controls.
Alternatives 3 through 12 effectively and permanently reduce the
risks associated with the inhalation, dermal contact, and
ingestion of contaminated sludge and soil at the site. The
magnitude of the residual risk remaining from untreated
contaminants (or the risks remaining at the conclusion of
remedial activities) is expected to be below preliminary cleanup
goals. Alternatives 3 through 12 should maintain reliable
protection of human health and. the environment once these goals
are met.
Additionally, capping included in Alternatives 5 through 8
reduces the amount of water available for leaching contaminants
into the subsurface after soil flushing has been completed. The
potential for leaching is further reduced in Alternatives 5 and 6
because sludge and contaminated sdil are excavated and disposed
offsite in an approved RCRA landfill. Leaching potential is also
reduced in Alternatives 7 and 8 because solidification is
designed to resist leaching and the solidified sludge and soil is
placed in a lined, capped, onsite landfill. With regard to
adequacy and reliability, caps require frequent inspection and
possibly frequent maintenance. 0 & M costs associated with cap
maintenance have been calculated for a period of 30 years. The
adequacy and reliability of solidification depend on the process
used. Because of the oily consistency of the sludge, the ability
to ensure successful implementation and maintenance of this.
remedy is highly uncertain.
-
The groundwater extraction and treatment systems and the
alternate water supply included in Alternatives 3 through 12
address groundwater threats by remediating the Upper Aquifer and
by providing a clean drinking water source, if necessary, for
potential future onsite users. The groundwater treatment system
will further reduce the potential for any contaminants to reach
the Portneuf River.
.
4. Reduction of Toxicity. Mobilitv. or Volume. This criteria
refers to the anticipated performance of treatment technologies
which will be used in the various remedial alternatives, such as
solidification and incineration, etc.
-------
Alternatives 3 through 12 reduce toxicity, mobility or volume
through treatment to the maximum extent practicable.
The capping alternatives (Alternatives 5 through 8) will help to
reduce the contaminant mobility by limiting surface water
infiltration and subsequent leaching. Similarly, the offsite
disposal alternatives (Alternatives 3 through 6) restrict
contaminant mobility (although no treatment of the contaminated
sludge and soil occurs) by placing the wastes within an approved
RCRA landfill. Contaminant toxicity or volume is not reduced in
the offsite disposal alternatives. .
~
~
Alternatives 7 through 8 (solidification) reduce mobility, and
perhaps toxicity, by immobilizing the contaminated sludge and
soil. However, the waste volume may increase substantially,
depending on the process used. -
Alternatives 9 through 12 (incineration) reduce contaminant
volume, and may also reduce mobility and toxicity. Incineration
is expected to reduce the volume of the wastes by approximately
50 percent, however, the toxicity and mobility of the heavy. .
metals in the ash may require treatment as a hazardous waste,
raising uncertainties associated with land disposal.
The groundwater treatment processes will reduce contaminant
mobility. The oil/water separator and DAF unit will reduce oil
concentrations to approximately 10 parts per million. The
groundwater treatment methods also allow for capture and
recycling of oils. In-situ soil washing provide~ treatment of
contaminated soils in Alternatives 3 through 12 by flushing soil
contaminants to the groundwater where they-will be treated via
the oil/water separator and the DAF unit.
5. Short-term Effectiveness. This criteria refers to the period
of time needed to achieve protection, and any adverse impacts on
human health and the environment, specifically site workers and
community residents, that may be posed during the construction
and implementation period until cleanup goals are achieved.
Alternatives 3 through 12 pose some short-term risk to the
community and site workers associated with the disturbance of
contaminated soils generated during remedial activities.
However, dust control measures and air monitoring are expected to
minimize these effects. Additionally, short-term compliance with
air quality standards could be more difficult for the
solidification and incineration alternatives (Alternatives 7 and
8, and 9 through 12, respectively) than other alternatives due to
air process emissions associated with those treatment options.
~
Excavation, backfilling of excavated areas, and transport and
disposal of contaminated sludge and soil is estimated to take ten
(10) months. If excavation in Alternatives 3 and 4 continues
.
-------
~
beyond the estimated maximum of 4,200 cubic yards, then
Alternatives 5 and 6 may be faster to implement than Alternatives
. 3 and 4, and the other alternatives, thus providing protection in
a shorter timeframe. However, the remaining contaminated soil.
would be treated by in-situ soil washing requiring more time to
reduce contaminant concentrations.
~
While the groundwater remediation is expected to last at least
five (5) years, cleanup will begin immediately and the greatest
improvements in groundwater quality should be made within the
. first two years. .
6. Imclementabilitv. This criteria refers to the technical and
administrative feasibility of a remedial alternative, including
the availability of goods and services needed to implement the
selected remedy. .
All of the alternatives can be implemented with varying degrees
of difficulty.
Alternatives 5 and 6 are easily implemented technically, since
excavation of 4,200 cubic yards of contaminated sludge and soil,
its transportation and disposal at the RCRA approved landfill,
and capping of the excavated pit are routine operations.
Alternatives 3 and 4, and 9 through 12 assume contaminated sludge
and soil will be excavated to. cleanup goals. However, excavation
of soils beneath the "visible" sludge may be technically
impracticable, if not impossible, due to its extremely coarse
nature (i.e. a dense mixture of gravel, cobbles, and boulders
ranging up to 9 feet in diameter). Therefore, excavation will
likely be limited to practicable depths, resulting in the removal
of approximately 4,200 cubic yards of contaminated sludge and
soil.
The solidification alternatives (7 and 8) currently present
significant implementation uncertainties due to the unknown
reliability and effectiveness of solidification at the UPRR site
and the potential for an increase in volume associated with the
solidification process. None of these uncertainties can be fully
addressed until a small scale test simulating site conditions is
conducted. .
-
Air pollution problems could affect the technical
implementability of Alternatives 9 through 12. Elevated
contaminant levels of metals found in the sludge present
significant uncertainty in the technology's ability to
effectively control process emissions.
.
Alternatives 3, 5, 7, 9 and 11 will require an increase in volume
to UPRR's current wastewater discharge limit with the City of
Pocatello. All of these alternatives use offsite discharge of
-------
treated wastewater to the Pocatello POTW. Preliminary
discussions with J. Ulrich, current Manager of the Pocatello
POTW, indicate that revisions to existing discharge permits
should be negotiable~ .
,
United states Pollution Control Inc. (USPCI), a RCRA-approved
waste disposal facility in Wendover, Utah, can accept the
contaminated soil and sludge excavated from the sludge pit, as
well as the sludge produced by treating contaminated groundwater
using the oil/water separator and dissolved air flotation unit.
~
7. Cost. This criteria refers to the cost of implementing a
remedial alternative, including operation and maintenance costs.
Total cleanup costs for Alternative 5 (the preferred alternative)
are estimated at $3,797,550. This alternative ranks in the
middle among the 12 alternatives considered. The range of
estimated costs is $635,300 (Alternative 1) to $43,338,750
(Alternative 12). Alternative 5 is cost-effective because it has
been determined to provide overall effectiveness proportional to
its costs and duration for remediation of the contaminated
sludge, soil and groundwater.
c.
Modifying criteria
Modifying criteria are used in the final evaluation of the
remedial alternatives after the formal comment period, and may be
used to modify .the preferred alternative that was discussed in
the proposed plan. .
8. state AcceDtance. This criteria refers to whether the state
agrees with the preferred remedial alternative.
IDEQ concurs with the selection of the preferred remedial
alternative. IDEQ has been involved with the development and
review of the Remedial Investigation/Feasibility study, the
Proposed Plan, and the Record of Decision.
9. Community AcceDtance. Tnis criteria refers to the public
support ofa given remedial alternative.
No written comments were received during the public comment
period. Pocatello residents present at the public meeting on
June 18, 1991, did not express a preference for a particular
alternative, nor was there any opposition to the EPA preferred
alternative. Community response is presented in the.
Responsiveness Summary, which addresses comments received during
the public meeting. . .
.
IX.
THE SELECTED REMEDY
.
The selected remedy is Alternative 5- excavation and offsite
disposal/low permeability cap/groundwater treatment (with
-------
l
$
oil/water .separation and dissolved air flotation)/soil
flushing/offsite discharge/alternate drinking water SUpply, if
necessary/institutional controls/air monitoring and dust
control/groundwater monitoring.
...
Alternative 5 is protective of human health and the environment,
complies with state and federal laws, and is cost .effective. It
utilizes a readily available technology to address sludge and
soil contamination and a proven treatment system to provide a
permanent solution to the groundwater contamination. Promulgated
state rules and regulations which are more stringent than federal
requirements are included as ARARs.
Maior Components of the Selected Remedy
The major components of the selected alternative are:
excavation of "visible" sludge (i. e. material that is
discolored or noted to have the consistency of sludge) and
underlying silt and soil to the maximum extent practicable;
treatment of remaining sQils via in-situ soil flushing to
remediation levels.
testing of contaminated sludge and soil prior to disposal at
a frequency specified in the receiving facility's waste
analysis plan including TCLP Extraction to demonstrate
compliance with land disposal restriction (LDR) treatment
standards; treatment, if necessary prior to disposal. Test
results indicate that the sludge and soil are not RCRA
characteristic waste, and therefore, no problems are
anticipated with disposal at the facility. However, if
unforseen circumstances arise, a treatability variance for
the wastes is requested should the wastes fail TCLP and the
Paint Filter Test at the disposal facility.
disposal at an approved RCRA offsite landfill; excavated
areas are backfilled with clean fill and graded.
..
placement and maintenance of a. low permeability cap over the
ent"ire pit boundary following excavation, ba.ckfilling and
grading. Areas outside the pit that are excavated will. be
backfilled with clean fill and graded.
extraction and treatment of nonaqueous phase liquid (NAPL)
contaminated groundwater via the onsite oil/water separator
and a dissolved air flotation unit to remediation goals;.
wastewater discharged to the pocatello publicly owned
treatment works; residual sludge resulting from groundwater
treatment tested and disposed in an approved, offsite
landfill; clean water obtained from Batiste Springs for use
in washing contaminated soils.
..
-------
providing advance funding for design and installation of an
alternate drinking water supply system to serve potential
future onsite businesses and/or residences, in the event
that the system is determined to be needed. Since
businesses and residences do not exist onsite, installation
of a new water supply is not immediately required.
,.
construction of a six-foot-high chain link fence around the
entire sludge pit to ensure site security and to restrict
public access to the site.
~
implementing administrative and institutional controls in
the property deed such as air monitoring, groundwater
monitoring, and land and water use restrictions that
supplement engineering controls and minimize exposUre to
releases of hazardous substances during and following
remedial activities.
conducting quarterly sampling and analysis of groundwater
from all onsite wells, at a minimum, for the first three
years following completion of remedial activities. If
deemed appropriate, the sampling rate will be reduced to a
lesser frequency for the remaining 27 years. Monitoring of
the groundwater and the pump/treat system during groundwater
remediation activities will be conducted to ensure that
groundwater remediation goals are achieved. . If cleanup
goals are not met, modifications to the groundwater
treatment system will be necessary.
implementing a comprehensive, onsite and offsite, soil and
groundwater sampling effort, prior to initiation of remedial
activities, to determine background levels in these media
and the extent to which onsite concentrations exceed
background levels. Preliminary target
concentrations/remediation goals for contaminants of concern
have been established for the site and are provided in the
Record of Decision. Final remediation goals, target.
concentrations and performance standards for contaminants of
~oncern will be established following the determination of
soil and groundwater background concentrations.
To the extent required by law, EPA wil-l review the site at least
once every five years after the initiation of the remedial
action. The five year review assures that the remedial action
continues to protect human health and the environment and
assesses the need for additional remediation of any hazardous
substance~, pollutants or contaminants remaining at the site.
-
Remediation Goals
Guidance for Conducting Remedial Investigations and Feasibility
Studies Under CERCLA (Interim Final, EPA/540/G-89/004) regarding
.
-------
I
development of remedial alternatives was used. to assist EPA in
the development of remedial actions. By utilizing the results of
the assessment, reviewing site ARARs, considering :actors related
to technical limitations such as detection/quantitation limits,
unc.ertainties and other pertinent information, chemical-specific
remediation goals are being developed to mitigate existing and
future threats to human health and the environment.
,;>
"
Chemical-specific remediation goals have not been finalized for
the Union Pacific Railroad Sludge Pit, primarily due to the
current lack of data regarding background concentrations of
contaminants in groundwater and soil. With the exception of lead
(noted below), chemical-specific remediation goals for
sludge/soil and for groundwater will be established according to
the following procedures prior to implementation of the remedy:
(3)
-
.
(1)
Identification of reqional backqround concentrations.
and 'lowest practical cruantitation limits (LOLs) for
contaminants. Prior to establishing final remediation
goals, regional background concentrations of chemicals
of concer~ in soil/sludge and groundwater must be
determined, and lowest quantitation limits (LQL) must
be defined. If contaminants of concern are below
background levels, these contaminants will be
eliminated from further consideration and from
calculation of site-related risk levels based on a risk
management decision. ~
(2)
Compliance with qroundwater ARARs identified in the FS.
ARARs will be used as the remediation goals with two
exceptions: .
(a) when the contaminant concentration is greater than
the background concentration or LQL, and the background
concentration or LQL is greater than the groundwater
ARAR, then the background concentration or LQL will be
used as the remedia~ion goal, or
(b) when the contaminant concentration is greater than
the background concentration or LQL, but less than the
groundwater ARAR, then the groundwater ARAR will be
used as the remediation goal unless the cumulative
risk-based level exceeds the upper end of the
acceptable risk r~nge.
Identification of risk-based tarqet concentrations.
For soil contaminants, and groundwater contaminants
without ARARs, risk-based concentrations will be used
as cleanup goals. If the lowest quanti tat ion limit or
background is above the risk-based level, the LQL or
background will be the cleanup level.
-------
Once the background concentrations have been obtained, each
contaminant will be compared to its LQL and its calculated target
cancer, noncancer (chronic and subchronic) concentration (risk
level = 1 x 10-6, Hazard Index < 1). The highest of the three
values (background, LQL or target concentration) will then become
the final cleanup level. Finally, risks which will be cleaned up
to either the target concentration or the LQL, will be summed to
verify that they are within the acceptable risk range (for
carcinogens) and below a Hazard Index of 1 (for non-carcinogens).
Risk-based concentrations will be derived from risk estimates of
potential future uses (residential and industrial) which are.
higher than current risks, and which are cumulative across all
chemicals and exposure media and pathways. .
~.
~
In the Human Health Risk Assessment, site risks were calculated
separately for the residential and industrial scenarios. In
order to calculate risk-based cleanup goals, itwas~assumed in
the Feasibility study that a person would both live and work on
the site. The procedure involved adding the risk for a given
chemical in the residential scenario to that in the industrial
scenario. The resulting risk was used as the starting point to
back calculate a risk-based concentration. While such a combined
exposure scenario could theoretically occur, adding risks from
the residential and industrial scenarios introduces potentially
significant double counting of exposure and .risk in, for example,
the soil ingestion and inhalation pathways. However, the
uncertainties associated with future land use in the area is
accounted for by selecting the combined risk scenario.
Tables ~-11 through 2-15 in the Feasibility Study (FS) present
the risks for each respective chemical of concern in the
sludge/soil through each exposure pathway assuming a combined
industrial/residential scenario. Similarly, Tables 2-16 through
2-19 of the FS present risks from ingestion and inhalation
exposures for each chemical of concern in groundwater. Target
concentrations for each contaminant are also presented which.
represent either a 10'6 cancer risk or cumulatlve.hazard index of
1 apportioned over all chemicals.
These risks have been revised, incorporating the results
air pathway reassessment, to provide cumulative residual
preliminary remediation goals for the reasonable maximum
(RME) individual (combined onsite worker/onsite resident
scenario) for all contaminants and all pathways. The results are
presented in Table 17 (soil/sludge), Table 18 (Upper Aquifer non-
NAPL wells), Table 19 (Upper Aquifer NAPL wells), and Table 20
(Lower Aquifer) along with revised target risk concentrations.
In addition, ARARs presented in Table 5-21 of the Feasibility
study are summarized and presented in these tables for
comparison.
of the
risk at
exposed
~
.
-------
i8
.
.
,
Table 17: Preliminary Risk-Based Concentrations for Sludge/Soil
Future risk (a) Risk at. target concentration
Cancer Chronic Subchronic Lowest
Present Cancer Chronic Subchronic Target Target Target Target
Concen. Cumulative Cumulative Cumulative Conc. Conc. Conc. Conc. Cancer Chronic Subchronic
Chemical (mg/kg) Risk HI HI (mg/kg) (mg/kg) (mg/kg) (mg/kg) Risk HI HI.
(b) (c) (d) (e)
1.1.2.2-Tetrachloroethane 0.99 8.8E-06 1.1E-Ol 1.12E-Ol 1.00E-06 O.OOE+OO O.OOE+OO
1.1-0Ichloroethane 8.3 3.4E-05 1.1E-03 1. OE -03 2.4E-Ol 1.05E+00 4.92E+00 2.45E-Ol 1.00E-06 3.12E-05 3.04E-05
1.2 dichlorobenzene 38 2.2E-02 2.0E-07 4.81E+00 2.27E+Ol 4.81E+00 O.OOE+OO 2.78E-03 2.49E-08
1.4-0Ichlorobenzene 10 1.IE-05 6.1E-09 1.4E-07 9.3E-Ol 1.26E+00 5.97E+00 9.31E-Ol 1.00E-06 5.70E-IO 1. 28E -08
2.6-0initrotoluene 51 1. 5E -03 3.3E-02 3.32E-02 1.00E-06 O.OOE+OO O.OOE+OO
Antimony 3.3 4.3E-Ol 1. 5E -01 4.17E-Ol 1.97E+00 4.17E-Ol O.OOE+OO 5.44E-02 1.92E-02
Arsenic 27.4 1. 2E -03 1.4E+00 5.3E-Ol 2.3E-02 3.47E+00 1.64E+Ol 2.34E-02 1.00E-06 1.23E-03 4.53E-04
Benzo(a)Anthracene 23 1. 2E -02 2.lh 03 1. 96E -03 1.00E-06 O.OOE+OO O.OOE+OO
Benzo(a)Pyrene 17 8.6E-03 2.0E-03 1. 98E -03 1.00E-06 O.OOE+OO O.OOE+OO
Benzo(k)Fluoranthene 33 1. 6E -02 2.0E-1)3 2.00E-03 1.00E-060.00E+00 O.OOE+OO
Benzyl Alcohol 67 1. 2E -02 8.47E+00 8.47E+00 O.OOE+OO 1.45E-03 O.OOE+OO
Bery 111 um 1.2 1. 5E -04 1. 2E -02 8.1E-03 1. 52E -01 8.06E-03 1.00E-068.06E-05 O.OOE+OO
Cadmium 40.2 2.7E-08 2.2E+00 1. 5E+03 5.08E+00 5.08E+00 3.44E-09 2.73E-Ol O.OOE+OO
Carbon Tetrachloride 0.013 1. OE -07 1. 3E -01 1.25E-Ol 1.00E-060.00E+00 O.OOE+OO
Chlorobenzene 0.66 1. 6E -04 1. 5E -04 8.35E-02 3.91E-Ol 8.35E-02 O.OOE+OO 1.97E-05 1. 92E -05
Ch 1 oroform 0.38 9.9E-08 3.8E+00 3.84E+00 1.00E-06 O.OOE+OO O.OOE+OO
Chloromethane 2.5 2.4E-06 1.1E+00 1. 05E +00 1.00E-06 O.OOE+OO O.OOE+OO
'Chroml um 136 6.7E-07 1. 5E+00 1. 9E -01 2.0E+02 1.72E+Ol 8.12E+Ol 1. 72E+Ol 8.52E-08 1.87E-Ol 2.44E-02
Chrysene 23 1. 2E -02 2.0E-03 1.96E-03 1.00E-06 O.OOE+OO O.OOE+OO
Ethyl benzene 100 B.OE-07 7.2E-02 1. 26E+Ol 1. 26E+Ol 1.02E-079.13E-03 O.OOE+OO
Indeno(I.2.3-cd)Pyrene 12 6.1E-03 2.0E-03 1. 97E -03 1.00E-060.00E+00 O.OOE+OO
Manganese 261 6.7E-02 9.7E-03 3.30E+Ol 1.55E+02 3.30E+Ol O.OOE+OO 8.53E-03 1. 23E -03
Mercury 0.96 1. 6E -01 2.0E-05 1.21E-Ol 5.69E-Ol 1.21E-Ol O.OOE+OO 2.02E-02 2.47E-06
Methylene Chloride 86 3.3E-05 1.1E-Ol 1. 6E -01 2.6E+00 1.09E+Ol 5.14E+Ol 2.58E+00 1.00E-063.36E-03 4.78E-03
Naphthalene 14 2.5E-Ol 2.9E-Ol 1.77E+00 8.36E+00 1.77E+OO O.OOE+OO 3.22E-02 3.66E-02
Nickel 35.8 7.9E-09 9.2E-02 3.0E-02 4.5E+03 4.53E+00 2.14E+Ol 4.53E+00 9.99E-I0 1.16E-02 3.78E-03
n-Nitrosodiphenylamine 54 1. 2E -05 - 4.6E+00 4.61E+00 1.00E-06 O.OOE+OO O.OOE+OO
-------
Tetrachloroethene 56 1. 3E -04 4.2E-Ol 3. 7E -02 4.4E-Ol 7.08E+00 3.35E+Ol 4.42E-Ol 1.00E-063.32E-03 2.92E-04
Toluene 7.4 7.3E-06 7.1E-05 9.36E-Ol 4.39E+00 9.36E-Ol O.OOE+OO 9.27E-07 9.04E-06
Total Xylenes 370 2. 7E-04 2.6E-03 4.68E+Ol 2.19E+02 4.68E+Ol O.OOE+OO 3.38E-05 3.27E-04
Trlchloroethene 51. 0 3.1E-05 1. 6E+00 1. 64E+00 1.00E-06 O.OOE+OO O.OOE+OO
t-l,2 dlchloroethene 107 3.9E-Ol 3.5E-02 1.35E+Ol 6.39E+Ol 1. 35E+Ol O.OOE+OO 4.93E-02 4.43E-03
Vanadium 45.8 3.4E-Ol 1.1E-Ol 5.79E+00 2.74E+Ol 5. 79E+00 O.OOE+OO 4.30E-02 1.38E-02
line 1530 4.0E-Ol 1. 4E -01 1.93E+02 9.14E+02 1.93E+02 O.OOE+OO 5.07E-02 1. 75E-02
TOTALS: 5. 77E-02 7.91E+00 1. 69E+00 1.82E-05 7.57E-Ol 1.27E-Ol
Notes:
HI - Hazard Index
(a) - based on combined residential and Industrial risks and reanalysis of air pathway risks
for the reasonable maximum exposure case.
(b) - concentration at which the cancer risk Is 1 x 10E-06
(c) - concentration derived by apportioning a hazard Index of lover all chemicals
(d) - concentration derived apportioning a hazard Index of lover all chemicals
(e) - lowest risk based target concentration as calculated In (b), (c) and (d).
(f) - residual risk if site were cleaned up to the lowest target concentration.
.
.
...
-------
:..
..
.'.
. ,-.
Table 18: Preliminary Risk-Based Concentrations for Upper Aquifer NAPL Wells Risk at lowest target concentration
ARARs Future Risk (a)
Cancer Chronic Subchronic Lowest
RHE Drinking AWQC Cumulative Cumulative Cumulative Target Target Target Target Cumulative Cumulative Cumulative
Cone. water Chronic Cancer Chronic Subchronic Cone. Cone. Cone. Cone. Cancer Chronic Subchronlc
Compound (mg/l'). (mg/l) (mg/l) Risk HI HI (b) (c) (d) (e) Risk HI HI
1.I-Dlchloroethane
1.I-Dlchloroethene 0.007 MCL
1.3-Dlchlorobenzene 0.11 0.763 1. 23E -04 8.92E-04 8.92E-04 1. OOE -06
Antimony 0.0085 0.003 PMCLG 1.6 1.27E+00 2.38E+00 2.14E-03 4.61E-03 2.14E-03 3.22E-Ol 6.00E-Ol
Arsenic 0.0059 0.050 MCL 0.048 4.15E-04 3.54E-Ol 6.60E-01 1.42E-05 4.13E-04 8.88E-04 1.42E-05 1. OOE -06 8.53E-04 1.59E-03
8enzene 0.005 HCL
Benzo(a)Anthracene 0.018 0.0001 PHCL 9.65E-03 1.86E-06 1.86E-06 1. ODE -06
Benzo(b)Fluoranthene 0.01 0.0002 PHCL 5.35[-03 1.87E-06 1. 87£ -06 1. OOE -06
.Bery11 ium 0.0025 0.001 PHCL 0.0053 5.04E-04 3.00E-02 5.60E-02 4.96E-06 1.48£-05 3.19£-05 4.96E-06 1. OOE -06 5.95E-05 1. llE-04
bls(2-ethylhexyl)Phthalate 0.014 0.004 PHCL 9.19£-06 4.20E-02 7.83£-02 1.52£-03 1. 16E-04 2.50£-04 1. 16E-04 7.63E-08 3.49£-04 6.51£-04
Cadmium 0.005 MCL 0.0011
Chlorobenzene O. 1 MCL
Ch I oroform 0.0025 0.1 MCL 1.24 3.81E-05 2.08E-02 6.55E-05 1.19E-05 1. 19E-05 1.81£-07 9.90£-05
Chromium 0.0256 0.1 MCL 0.011 3.07E-Ol 1. 43E-Ol 1. 56£ -03 8.36£-04 8.36E-04 1. 00E-02 4.68£-03
Chrysene 0.01 O. 0002 PM.Cl 5.35£-03 1.87E-06 1.87£-06 1. 00£ -06
Lead 0.0079 0.015 AL 0.0032
Manganese 0.2 0.050 S 6.00E-02 4.48E-02 2.37£-03 2.04E-03 2.04E-03 6.12£-04 4.57E-04
Mercury 0.0001 0.002 MCL 0.000012 1. 05E -02 2.07£-07 2.07E-07 2.17E-05
Methylene Chloride 0.005 0.005 PMCL 1. 21E-03 4.12E-06 4.12E-06 1. 00E-06
Nickel 0.03 O.IPMCL 0.16 9.00£-02 1. 68E -01 5.34E-04 1.15E-03 5.34E-04 1. 60E-03 2.99£-03
Selenium 0.0014 0.05 MCL 0.035 2.80E-02 5.22£-02 7.75£-06 1. 67E -05 7.75£-06 1. 55£-04 2.89£-04
SII ver 0.01 0.05 MCL 0.00012 2.00£-01 3.96£-04 3.96E-04 7.91E-03
'Tetrachloroethene 0.0025 0.005 HCL 0.84 7.48E-06 3.34£-04 3.34E-04 1. 00£ -06
Tha 111 um 0.0028 0.0005 PMCLG 0.04 2.40E+00 4.48E-Ol 1. 33E -03 2.86E-04 2.86E-04 2.45£-01 4.57£-02
Toluene 1. 0 HCL
Total Xylenes 10.0 MCL
Trichloroethene 0.0025 0.005 MCL 21.9 ' 9.24E-06 2.71E-04 2.71E-04 1. OOE -06
t-l;2-Dichloroethene 0.003 0.1 HCL 5.50E-02 3.50E-02 3.26£-05 2.39£-05 2.39E-05 4.39E-04 2.79£-04
Vanadium 0.0132 1.13E -01 2.llE-Ol 2.95E-04 6.35E-04 2.95E-04 2.53E-03 4.72£-03
Zinc 0.12 5.0 S 0.11 3.61E-02 6.71E-02 8.58E-04 1. 84E -03 8.58E-04 2.58E-04 4.80E-04
-------
Total Risk
2.27E-02
4.4
5.1
(a) - based on combined risks for residential and industrial exposures. Al - USEPA action level
(b) - concentration representing a 1 x 10E-06 cancer risk. AWQC - USEPA ambient water qual.ity criteria
(c) - concentration derived by apportioning a hazard index of lover all chemicals.HCl - USEPA primary maximum contaminant level
(d) - concentration derived by apportioning a hazard index of lover all chemicals.PHCl - USEPA proposed maximum contaminant level
(e) - lowest risk based target concentration calculated in (b).. (c) and (d) above. PHClG - USEPA proposed maximum contaminant level goal
* . - sum of hazard Indices < 1.0E-02 or sum of cancer risks < 1.0E-08. S - USEPA secondary maximum contaminant level
(Reference: Appendix G In FS)
~
.II
9.26E-06
it-
0.6
0.7
-------
.'
.
~-
..~
-,
Table 19: Preliminary Risk-Based Concentrations for Upper Aq~ifer Non-NAPl Wells Risk at lowest target concentration
ARARs Future Risk (a)
Cancer Chronic Subchronic lowest
RHE Drinking AWQC Cumulative Cumulative Cumulative Target Target Target Target Cumulative Cumulative Cumulative
Cone. water Chronic Cancer Chronic Subchronic Cone. Cone. Cone. Cone. Cancer Chronic Subchronic
Compound' (mg/1 ) (mg/1) (mg/1) Risk HI HI (b) (c) (d) (e) Risk HI HI
1.I-Dlchloroethane D.0025 1. 07E -05 2.34E-04 2.34E-04 1. OOE -06
1.I-Dlchloroethene 0.D025 0.007 HCl 6.99E-05 2.3IE-02 3.58E-05 5.24E-06 5.24E-06 1. 46E -07 4.85E-05
1.3-Dlchlorobenzene 0.763
Antimony 0.0213 0.003 PHCl 1.6 3. \9E+00 5.96E+00 6.67E-03 3.57E-03 3.57E-03 5.36E-Ol 1. OOE +00
Arsenic 0.0283 0.050 HCl 0048 1.98[-03 1.70[+00 3 . 17E +00 1. 43E -05 5.39E-03 ,8 .l3E -03 1.43E-05 1. OOE -06 8.58E-04 1. 60E-03
Benzene 0 005 HCl
Benzo(a)Anthracene 0 0001 PHCl
Benzo(b)Fluoranthene 0.0002 PHCl
Beryllium 0.0025 0.001 PHCl 0.0053 5.04[-04 3.00[-02 5.60E-02 4.96E-06 8.40E-06 1. 27E-05 4.96E-06 1.00E-06 5.95E-05 1.11E-04
bls(2-ethylhexyl)Phthalate 0.01 0.004 PHCl 6.53E-06 3.00[-02 5.60E-02 1.53E-03 3.36E-05 5.07E-05 3.36E-05 2.20E-08 1.01E-04 1. 88E -04
Cadnlum 0.0008 0.005 HCl 0.0011 9.60E-02 8.60E-06 8.60E-06 1. 03E -03
Chlorobenzene O. 1 HCl
Chloroform O. 1 HCl 1.24
Chromium 0.02 O. 1 HCl 0.011 2.40E-Ol 1.12E-Ol 5.38E-04 2.03E-04 2.03E-04 2.43E-03 1.13E-03
Chrysene 0.01 0.0002 PHCl 5.35E-03 1.87E-06 1. 87E -06 1.00E-06
Lead 0.01 0.015 AL 0.0032
Manganese 1.82 0.050 S 5.46E-Ol 4.07E-Ol 1.11E-Ol 6.72E-02 6.72E-02 2.01E-02 1.50E-02
Mercury 0.0004 0.002 MCL 0.000012 8.40E-02 3.95E-06 3.95E-06 7 .90E-04
Methylene Chloride 0.005 PMCL
Nickel 0.05 0.1 PHCL 0.16 1.50E -01 2.80E-Ol 8.40E-04 1. 27E -03 8.40E-04 2.52E-03 4.70E-03
Selenium 0.0014 0.05 HCL 0.035 2.80E-02 5.22E-02 4.39E-06 6.62E-06 4.39E-06 8.78E-05 1. 64E-04
Silver 0.005 0.05 HCL 0.00012 1. OOE -01 5.60E-05 5.60E-05 1.12E-03
Tetrachloroethene 0.0025 0.005 HCL 0.84 7.44E-06 3.36E-04 3.36E-04 1.00E-06
Tha lllum 0.0028 0.0005 PHCL 0.04 2.40E+00 4.48E-Ol 7.53E-04 1.14E-04 1.14E -04 9. 73E-02 1. 82E-02
Toluene 1. 0 HCl
Total Xylenes 10.0 HCL
Trlchloroethene 0.0025 0.005 HCL 21.9 9.28E-06 2.69E-04 ' 2.69E-04 1. OO[ -06
t-l.2-Dlchloroethene 0.0025 0.1 HCl 5.50[-02 3.50[-02 1. 54E -05 7.93E-06 7.93[-06 1. 74[-04 1. 11E-04
Vanadium 0.0225 1.93[-01 3.60E-Ol 7.33E-04 7.33E-04 6.28E-03 . 1.1?E -02
Zinc 0.12 5.0 S 0.11 3.61[-02 6.71[-02 4.86[-04 7.30[-04 4.86[-04 1.46[-04 2.72[-04
-------
Total Risk
7.94E-03
(a) - based on combined risks for residential and industrial exposures.
(b) - concentration representing a 1 x 10E-06 cancer risk. .
(c) - concentration derived by apportioning a hazard index of lover all chemicals.
.(d) - concentration derived by apportioning a hazard index of lover all chemicals.
(e) - lowest risk ,. ~ed target concentration calculated in (b). (c) and (d) above.
* - sum of hazard indices less than 1.0E-02 or sum of cancer risks less than 1.0E-08,
..
..
8.9
11. 0
AL - USEPA action level
AWQC - USEPA ambient water quality criteria
MCl - USEPA primary maximum contaminant level
PMCL - USEPA proposed maximum contaminant level
PMClG - USEPA proposed maximum contaminant level goal
S - USEPA secondary maximum contaminant level
"
6.17[-06
.~-
0.7
1.1
-------
.
.
'-
,.~
-,
Table 20: Preliminary Risk-Based Concentrations for Lower Aquifer Wells Risk at lowest target concentration
ARARs Future Risk (a)
Cancer Chronic Subchronic Lowest
RHE Drinking . AWQC Cumu I at! ve Cumulative Cumulative Target Target Target Target Cumulative Cumulative CumU'l at I ve
Cone. water Chronic Cancer Chronic Subchronic Conc. Conc. Conc. Conc. Cancer Chronic Subchronlc
Compound (mg/l ) (mg/l) (mg/l) Risk HI HI (b) (c) (d) (e) Risk HI HI
1. 1-01 chI oroethane
1.1-0Ichloroethene 0.007 HCl
'1.3-0Ichlorobenzene 0.763
Antimony 0.003 PMClG 1.6
Arsenic 0.002 0.050 HCl 0.04B 1. 42E -04 1. 20E -01 2.24E-Ol 1.41E-05 6.73E-05 2.BBE-04 1.41E-05 1. OOE -06 B.44E-04 1. 5BE -03
Benzene 0.0042 0.005 HCl 2.BIE-05 4.37E-Ol 1. 49E -04 5.15E-04 1.49E-04 1.00E-06 1. 55E -02
Benzo(a)Anthracene 0.0001 PHCl
Benzo(b)Fluoranthene 0.0002 PHCl
Berylll um 0.0025 0.001 PHCl 0.0053 5.00E-04 2.97E-02 5.57E-02 5.00E-06 2.09E-05 8.95E-05 5.00E-06 1.00E-06 5.94E-05 1. 11E-04
bls(2-ethylhexyl)Phthalate 0.012 0.004 PMCL 7.88E-06 1.89E-02 6.70E-02 1. 52E -03 6.36E-05 5. 17E-04 6.36E-05 4.17E-08 9.99E-05 3.55E-04
Cadnlum 0.0006 0.005 HCl 0.0011 8.10[-02 1. 37E -05 1.37E-05 1. 84E-03
Chlorobenzene 0.0025 0.1 HCl 1. 20E -01 1.67E-02 8.42E-05 2.68E-05 2.68E-05 1. 29E-03 1. 79E-04
Chloroform o. 1 MCl 1. 24
Chromium 0.0145 0.1 MCl 0.011 1.80E-Ol 8.14E-02 7.34E-04 7.60E-04 7.34E-04 9.I1E-03 4.12E-03
Chrysene 0.0002 PHCl
Lead 0.028 0.015 Al 0.0032
Manganese 0.550 0.050 S 1. 65E -01 1. 24E-Ol 2.56E-02 4 ..38E -02 2.56E-02 7.69E-03 5.75E-03
Mercury 0.0007 0.002 HCl 0.000012 1.40E-Ol 2.76E-05 2. 76E-05 5.53E-03
Hethylene Chloride 0.005 PHCl
Nickel 0.010 0.1 PMCl 0.16 2.97E-02 5.57E-02 8.35E-05 3.58E-04 8.35E-05 2.48E-04 4.65E-04
Selenium 0.0012 0.050 HCL 0.035 2.36E-02 4.43E-02 7.94E-06 3.42E-05 7.94E-06 1. 56E -04 2.94E-04
SI1 ver 0.050 MCl 0.00012
Tetrachloroethene 0.0025 0.005 MCL 0.84 7.44E-06 3.36E-04 3.36E-04 1.00E-06
Thallium 0.0023 0.0005 PMCLG 0.04 1. 97E+00 3.68E-01 1. 27E-03 5.44E-04 5.44E-04 4.67E-01 8.70E-02
Toluene 0.0025 1. 0 HCL 5.00E-02 3.51E-05 3.51E-05 7.02E-04
Total Xylenes 0.0076 10.0 MCl 2.11E-02 3.95E-02 4.51E-05 1. 93E -04 4.51E-05 1.25E-04 2.34E-04
Trlchloroethene 0.0025 0.005 MCL 21.9 9.28E-06 2.69E-04 2.69E-04 1.00E-06
t-l,2-0ichloroethene 0.1 HCL
Vanadium 0.01.2 1. 03E -01 1. 93E -01 3.51E-04 1.50E-03 3.51E-04 3.00E-03 5.60E-03
Zinc 0.15 5.0 S 0.11 4.4Sf.-02 2.73E-Ol 1. B8E -03 2.63E-02 1. 88E -03 5.58E-04 3.42E-03
-------
Total Risk
6.95E-04
(a) - based on combined risks for residential and industrial exposures.
(b) - concentration representing a 1 x 10E-06 cancer risk.
(c) - concentration derived by apportioning a hazard index of lover all chemicals.
(d) - concentration derived by apportioning a hazard index of lover all chemicals.
(e) - lowest risk based target concentration calculated in (b), (c) and (d) above.
* - sum of hazard indices < 1.0E-02 or sum of cancer risks < 1.0E-08.
~
~
';;.6
Totals
1.6
AL - USEPA action level
AWQC - USEPA ambient water quality criteria
HCL - USEPA primary maximum contaminant level
PHCL - USEPA proposed maximum contaminant level
PHCLG - USEPA proposed maximum contaminant level goal
S - USEPA secondary maximum contaminant level
5.04E-06
or
5.14E-Ol
1.09E-Ol
-------
r
,
...
To derive media-specific, risk-based concentrations for
carcinogens, a 10-6 cancer risk level will be the target for each
media. As discussed earlier, risk-based concentrations will be
based on cumulative risks from all exposure pathways except the
dermal route. Dermal exposure 'and risk estimation is not well
understood at this time, and guidance is just now being developed
to more formally evaluate the pathway. In particular, factors to
estimate how much of a chemical is absorbed by the skin from a
soil media are only available for PAHs, PCBs, DDT, and dioxin
(2,3,7,8 TCDD). Of these, only PAHs are found at the UPRR
facility.
.~
A more refined dermal exposure estimate could be prepared for
PAHs based on a recently developed estimate of PAH permeability
from soil, i.e. 30%. A default value of 80% was' used in the risk
assessment. However, estimating cancer and noncancer risk will.
remain problematic. A dermal cancer potency factor has not been
developed for PAHs (or other compounds) so the oral slope factor
for benzo(a)pyrene (SaP) is commonly used to estimate oral and
dermal cancer risk. SaP is known to cause tumors at the site of
application (e.g. skin tumors in skin painting studies, etc.).
The oral potency for SaP is based on an ingestion route of
exposure. The rate of tumor formation and relative potency may
be substantially different for dermal exposures, since there
could be significant metabolic and other differences in exposed
tissue types. For this reason, it has been determined to be
inappropriate to estimate dermal cancer risks from PAHs based on
the existing oral slope factor. If SaP acted solely in a
systemic fashion (i.e. tumors occurred only at sites remote from
the point of application, estimating dermal risks from an oral
slope factor would be more appropriate).
Estimating systemic noncancer risks from dermal exposure to PAHs
would be appropriate if reference doses (dermal, or oral) were
available, Several reference doses have'been established for
PAHs, but of the PAHs found at UPRR, a reference dose is only
available for naphthalene. The naphthalene combined chronic and
subchronic risk for all sludge/soil exposure pathways is 0.3,
which includes a conservative estimate of dermal risks (80%
absorption). Based on this low hazard index, it does not appear
that a remediation'goal will need to be established for
naphthalene. This may change during remedial design, when
chemicals are grouped by similar toxic endpoint. If cumulative
risks are significant, remediation goals will be established.
.
In summary, risk-based concentrations will not be based on dermal
pathway risks for the reasons outlined above, with the possible
exception of naphthalene.
.
-------
To derive media-specific concentrations of noncarcinogens,
chemicals will first be grouped by similar toxic effects.
Generally, the target risk level for each group will be a hazard.
index of 1, which will include exposures from all media. Media-
specific concentrations for each chemical will be determined by
apportioning the target hazard index over all media, such that
the combination of groundwater and sludge/soil exposures will
equal the target hazard index.
~
~
Deviation from a hazard index of 1 may'be appropriate in some
circumstances. For example, when large uncertainty and modifying
factors are used to establish a reference dose (e.g. 1,000-
10,000), a hazard index calculated based on it will be far less
precise than one calculated using an uncertainty/modifying factor
of 10. In the former case, there would be no distinguishable
difference between a hazard index of 1 versus 3 from a
toxicologicaL standpoint, since such a large
uncertainty/modifying factor was applied to the data. In such a
circumstance, if factors of technical feasibility make it
difficult to achieve a hazard index of 1, setting a target
cleanup goal at a hazard index less than 1 may be appropriate
based on a review of data and procedures used to establish the
respective reference dose. '
Lead. ARARs and potential cleanup goals for lead are discussed
below. At the present time, neither a reference dose nor a
cancer slope factor exist from which to estimate the risk from
lead exposure. In their absence, an Uptake/Biokinetic Model has
been developed by EPA to estimate blood lead concentrations in
childr~n (the sensitive population) from exposure to lead in
food, water, soil, dust and air. However, EPA has not identified
a blood lead level which is without adverse effects, nor has a
policy been established for using blood lead data to derive soil
or water cleanup levels.
Lead in Soil. Currently, EPA (OSWER Directive #9355.4-02)
recommends an interim soil cleanup level of 500-1000 ppm for
lead at CERCLA sites characterized as residential or
potential residential. This directive is undergoing
revisiqns to reflect use of the EPA Lead Uptake Biokinetic
(UBK) Model as the best approach available for establishing
soil cleanup levels. The model accounts for the
contribution of various media to total exposure at a site
and provides a strong scientific basis for choosing lead
cleanup levels. An acceptable soil lead level of,
approximately 500 ppm is predicted for lead when theUBK
model is run using: (1) the model's default parameters and
(2) a benchmark of either a 95% probability of an individual
having a blood lead level below 10 ug/dl or 95% of. the
sensitive population having blood lead levels below 10
ug/dl.
.
.
-------
,
"
. .
The UPRR property is currently industrial, but there are
residences within 0.3 miles of the sludge pit. Given the
potential for future residential use and close proximity to
existing residential areas, 500 ppm will be. used as a target
cleanup level for all UPRR soils to ensure protection of
publi~ health. .
-4
Lead in Groundwater. During the course of the Remedial
Investigation/Feasibility Study, the maximum contaminant
level (MCL) for lead was 0.050 mg/l. In 1988, EPA proposed
a new source water MCL of 0.005 mg/l. On June 7, 1991, EPA
published a revised lead "Action Level" of 0.015 mg/l which
replaces the 0.050 mg/l MCL. This value is consistent with
a June 21, 1990, Office of .Emergency and Remedial Response
memorandum to EPA Region 4 establishing a cleanup level of
15 ug/lfor lead in groundwater usable as a drinking water
source at Superfund sites. This level is intended to be
protective of sensitive populations, e.g. children. The
0.015 mg/l "Action Level" is considered an ARAR, therefore
it will be used as the groundwater remediation goal at the
UPRR Sludge Pit in Pocatello, Idaho.
x.
statutory Determinations
The procedures and standards for responding to releases of
hazardous substances, pollutants and contaminants at the site
shall be in accordance with CERCLA, as amended by SARA, and to
the maximum extent practicable, the National Oil and Hazardous
Substances Pollution Contingency Plan (NCP), 40 CFR Part 300
(1990), promulgated in the Federal Register on March 8, 1990.
,
EPA's primary responsibility at Superfund sites is to undertake
remedial actions that are protective of human health and the
environment. In addition, Section 121 of CERCLA establishes
several other statutory requirements and preferences; including:
a requirement that EPA's remedial action, when complete, must
comply with applicable or relevant and appropriate environmental
standards established under federal and state laws unless a
statutory waiver is invoked;.a requirement that EPA select a
remedial .action that is cost-effective and that utilizes
permanent solutions and alternative treatment technologies or
resource recovery technologies to the maximum extent practicable;
and a statutory preference for remedies that permanently and
significantly reduce the volume, toxicity or mobility of
hazardous substances over remedies that do not achieve such
results through treatment. Remedial alternatives at the site.
were developed to .be consistent with these Congressional.
mandates.
..
The selected remedy meets statutory requirements of section 121
of CERCLA, as amended by SARA, and to the extent practicable, the
-------
National contingency Plan.
below.
The evaluation criteria are discussed
~
A.
Protection of Human Health and the Environment
The selected remedy protects human health and the environment
through excavation, removal, capping and offsite disposal of
contaminated sludge and soil, and through extraction, soil
flushing and treatment of contaminated groundwater. NAPL
contaminants will be permanently removed from the groundwater by
oil/water separation and dissolved air flotation.
.~
Excavation, removal and offsite disposal of the contaminated
sludge and soil will significantly reduce -the threat of exposure
from ingestion, dermal contact and inhalation. A baseline risk
for the combined industrial/residential scenario associated with
these exposure pathways is estimated at 6 x 10-2 for carcinogenic
risk with a HI=8 for chronic, noncarcinogenic risks. By
excavating and removing the contaminated sludge and soil to
preliminary target concentrations, the cancer risk will be
reduced to 2 x 10-5 and the chronic HI will decrease to 0.8. -
soil flushing, extraction and treatment of the contaminated
groundwater will eliminate the threat of exposure from ingestion
or inhalation of contaminated groundwater. The highest baseline
risk for the combined industrial/residential scenario associated
with these exposure pathways is estimated at 2 x 10.2 (Upper
Aquifer NAPL wells) for carcinogenic risk with a HI=9 (Upper
Aquifer non-NAP~; wells) for chronic, noncarcinogenic risks." By
excavating and removing the contaminated sludge and soil and
_owering groundwater concentrations to preliminary target levels,
the cancer risk from groundwater exposure will be reduced to 9 x
10:6 (Upper Aquifer NAPL wells) and the chronic HI will decrease
to 0.7 (Upper Aquifer non-NAPL wells).
The residual risk after cleanup may differ from estimates
presented above if:
--ARARs (e.g. MCLs) are used rather than risk-based targets,
--another target cancer risk is used (e.g. 10.5 or 10.4)
--another method of calculating target concentrations for-
noncarcinogens is used (e.g. group by critical endpoint; use
hazard index greater than 1.0)
c
--chemicals were eliminated based upon results of the
background analysis because measured contaminant
concentrations were below background concentrations.
.
-------
I
..
Regardless of the methodes) used to establish remediation levels,
the residual risk following cleanup will be within the acceptable
risk range established in the NCP.
~
Potential short-term risks could arise during cleanup from
vehicle traffic dust emissions, volatilization of sludge/soil
contaminants during excavation, worker contact via ingestion of
contaminated material, and volatilization of contaminants from
dissolved air flotation. Short-term risks are currently low and
are not expected to increase significantly during remedial
activities. Control strategies such as dust suppression, ongoing
air monitoring, and worker protection (clothing, equipment, etc.)
will be implemented to minimize short-term risks. As specific
information regarding contaminant concentration and emissions are
obtained during remedial design, short-term risks will be re-
evaluated. Modifications to the remedy will be made~ if
nece~sary, to protect nearby workers and residents.
B.
Attainment of Applicable or Relevant and Appropriate
Requirements of Environmental Laws
The selected remedy of excavation, removal, capping and offsite
disposal of contaminated sludge and soil, and soil flushing,
extraction, and treatment and offsite discharge of treated
groundwater will comply with all applicable or relevant and
appropriate requirements (ARARs) of Federal, as well as more
stringent, promulgated State environmental and public health
laws.
1.
Acclicable or Relevant and Accrocriate Reauirements (ARARs)
The ARARs for the sludge/soil component of the alternatives are
listed below:
Act ion-Scecific'
Occupational Safeti' and Health Act (OSHA) (29 U.S.C~) (CFR
1910.12)- OSHA requirements pertain to workers engaged in
response or other h3zardous waste operations. (Applicable)
,
Idaho Solid Waste ~~~~agement Regulations and Standards
Manual (Section 1 G, '.,: . 6004,01, 16'.01. 6005,01 and
16.01.6008,16)- requlres that all solid wastes be managed
during storage, coi:ection, transfer, transport, processing,
separation, inciner3tion, composting, treatment, reuse,
recycling, or dispcs~l to prevent health hazards, public
nuisances, or poll~:~cn of the environment. (Relevant and
Appropriate) .
.
~~e~ical-Scecific
-------
Clean Air Act (42 U.S.C. 7401, 7410 and 7411)- CAA
requirements pertain to national ambient air quality
standards (NAAQS) and state implementation plans for
compliance with NAAQS. (APplicable)
Rules and Reguiations for the Control of Air Pollution in
Idaho (Citations: 16.01.1011, 16.01.1201, 16.01.1501-
16.01.1550, 16.01.1957)- The State of Idaho air pollution
regulations pertain to state air quality standards, process
emissions, visible emission standards and fugitive dust
standards. (Applicable) .
~
~
The ~s for the groundwater component of the remedial
alternatives are as follows:
Action-SDecific
Idaho Solid Waste Management Regulations and Standards
Manual (Section 16.01.6005,01, 16.01.6008,07)- see above
under sludge/soil principal regulations. (Relevant and
Appropriate)
Idaho State Well Construction Standards (Idaho Code Title
42-238(4»- provide rules that apply to all water wells,
monitoring wells, etc., which are more than 18 feet bgs.
(Applicable)
Idaho Construction and Use of Injection Wells. (Idaho Code
Title 42, Chapter 39- Rule 8,1,1, Rule 8,2,1,a., Rule
8,3,1)- rules and regulations are designed to protect state
groundwater a~ainst unreasonable contamination or
deterioration in order to preserve the resource for
beneficial uses. (Applicable)
Idaho Regulations for Public Drinking Water Systems have
been established to control and regulate the design,
construction, operation, maintenance, and quality control of
the public drinking water system to protect the hea: -j of
consumers. (Applicable)
Chemical-SDecific
Clean Water Act (CWA) (33 U.S.C. 1251) (Sections 101,
301(b) (1), 301(e), 302)- establishes objectives to restore
and maintain the chemical, physical, and biological
integrity of the waters of the United States. (Applicable)
.
Safe Drinking Water. Act (SDWA) (42 U.S.C. 300[f]) (40 CFR
Sections 141.11-141.16, 141.50-141.51, 141.61, 143.3, 144)-
establishes the development of national primary drinking
water regulations. The regulations provide maximum
.
-------
~~
contaminant level standards which drinking water quality
cannot exceed. (Relevant and Appropriate)
Underground Injection Control, 40 CFR 144- Rules and
regulations promulgated under RCRA and Part C of the Safe
Drinking Water Act. (Applicable)
'4
Idaho Water Quality Standards and Wastewater Treatment
Requirements (Section 16.01.2200, 16.01.2250,06, 16.01.2302,
16.01.2460, 16.01.2600)- Both surface and groundwaters of
the State of Idaho must not contain hazardous materials in
concentrations found to be of public health significance.
Deleterious materials must not impair designated or
protected beneficial uses. (Applicable)
Location-Specific (Offsite only)
City of Pocatello Municipal Code- Non-Residential Wast~water
Discharges (Sections 13.20.030 N.3, 13.20.040 D.1)- ~his
code provides uniform regulations and requirements for
dischargers into the city wastewater collection and
treatment system. (Applicable) "
2.
Information To-Be-Considered
The following TBCs will be used as guidelines when implementing
the selected remedy:
--Proposed maximum contaminant levels (PMCLs) and proposed
maximum contaminant level goals (PMCLGs) for contaminated
groundwater.
--OSWER Directive
Establishing Soil
September 7, 1989
total lead at 500
#9355.4-02 entitled "Interim Guidance on
Lead Cleanup Levels at Superfund sites",
sets forth an interim soil cleanup~level
to 1000 mgjkg.
dated
for
--Memorandum re: "Cleanup Level for Lead in Groundwater: from H.
Longest, OERR and B. Diamond, OWPE to P. Tobin, Region IV Waste
Management Division recommends a final cleanup level for" lead in
groundwater usable for drinking water, which will meet the CERCLA
requirement of protectiveness of human health and the
environment.
~
--American Conference of Governmental Industrial Hygienists
Threshold Limit Value- Provides recommended short- and long-
term worker exposure values for contaminants.
.
--Drinking Water Health Advisories-
for contaminants in drinking water.
Health-based guidance levels
C.
Cost Effectiveness
-------
The selected remedy is cost-effective because it has been
determined to provide overall effectiveness proportional to its
costs and duration for remediation of th~ contaminated sludge,
soil and groundwater. Since the technical feasibility of
excavating. through soils is uncertain, it is assumed that 4,200
cubic yards will be the limit of removal and contaminants will
remain in unexcavated soils. Therefore, additional protection is
necessary. Although the 30-year present worth of $3,797,550 for
the selected remedy is higher than Alternatives 3 and 4 (all
excavated amounts of contaminated sludge and soil being equal,
i.e. 4,200 cubic yards, in the three alternatives), the benefits
of a low permeability cap over the sludge pit include: (1) added
protection against contaminant leaching from infiltration of rain
or snowmelt, potentially decreasing the exposure duration: and
(2) reducing the lateral and vertical migration of contaminants
possibly remaining after excavation of the contaminant plume both
downgradient of the sludge pit and near areas of highest
groundwater contamination.
~
\-
D. Use of Permanent Solutions and Alternative Treatment
Technologies or Resource Recovery Technologies to the Maximum
Extent Practicable
The State of Idaho and EPA have determined that the selected
groundwater remedy for the treatment of contamination at the site
represents the maximum extent to which permanent solutions and
treatment technologies can be used in a cost-effective manner for
theUPRR Sludge Pit site. Th~ risk from the groundwater.
contamination is permanently reduced through soil flushing and
treatment to acceptable exposure levels without transferring the
risk to another media (e.g. air). The selected groundwater
remedy provides the best balance of tradeoffs in terms of long-
term effectiveness and permanence: reduction in toxicity,
mobility or volume achieved through treatment: short-term
effectiveness: implernentability: and, cost. .In addition, state
and community acceptance were considered in making this
determination. .
Alternative sludge/soil treatment technologies including
incineration and solidification were considered, to the maximum
extent practicable, but were determined to be technically
unsuitable for implem~ntation at this site. Because of the oily
consistency of the sludge, the ability to ensure successful
implementation and maintenance of the solidification alternative
is highly uncertain. Elevated contaminant levels of metals found
in the sludge present significant uncertainty in the incineration
technology's ability to achieve target cleanup concentrations.
;J
Therefore, the selected remedy employs excavation of contaminated
sludge and soil to technically practicable depths. The excavated
sludge and soil will be removed from the site and disposed in an
.
-------
I
y
approved, offsite landfill. The excavated pit area will be
. backfilled, graded and covered with an impermeable cap. An .
innovative treatment technology, in-situ soil flushing system,
will be installed and used to remove contaminants in remaining
'soils. Existing analysis of railyard and wastewater treatment
plant operations, applicable governmental regulations, and the
results of sludge chemical analyses indicate the sludge is not a
hazardous waste as defined by RCRA, pursuant to 40 CFR
261.4(b) (7); therefore, the RCRA LDRs do not apply.
~
E.
Preference for Treatment as Principal Element
By treating the contaminated groundwater and soil via flushing in
an onsite treatment facility, the selected groundwater remedy
addresses future ingestion/inhalation of contaminated groundwater
posed by the UPRR.Sludge Pit site through the use of treatment
technologies. Therefore, the statutory preference for remedies
that employ treatment as a principal element is achieved when
addressing groundwater contamination at this site. .
XI.
DOCUMENTATION OF SIGNIFICANT CHANGES
The Proposed Plan for the Union Pacific Railroad Sludge Pit site
was released for public comment on June 3, 1991. The Proposed
Plan identified Alternative 5, contaminated sludge and soil
. excavation/offsite disposal/capping/soil flushing/groundwater
pump and treat via oil-water separation and dissolved air
flotation/institutional, eng~neering and administrative controls,
as the preferred alternative. No verbal or written comments were..
received during the public comment period. Therefore, EPA has
determined that no significant changes to the remedy, as it was
originally identified in the Proposed Plan, were necessary.
,
~
-------
UNION PACIFIC RAILROAD RESPONSIVENESS SUMMARy
I. Overview
~
The purpose of this responsiveness Summary is to summarize
and respond to substantive comments received during the public
comment period held by EPA from June 7, 1991, through July 8,
1991, regarding the Environmental Protection Agency's (EPA)
proposed cleanup plan for the Union Pacific Railroad (UPRR)
sludge pit located near Pocatello, Idaho. The proposed plan was
based on information in the Remedial Investigation and
Feasibility Study (RI/FS) report prepared for this site. The
RI/FS and proposed plan are/were available for review at the
Pocatello Public Library and at EPA's office in Seattle,
Washington. As well, copies of the proposed plan were mailed to
local citizens that were on a mailing list developed as part of
the Community Relations Plan for the UPRR site.
~
On June 18, 1991, EPA held a public meeting at the Pocatello
Quality Inn Convention Center to present the results of the RI/FS
and to discuss EPA's proposed plan. EPA encouraged participants
to submit verbal comments during the meeting .and/or submit
written comments.
II. Background on Community Involvement
In June of 1988, EPA released a community relations plan
outlining a program to address community concerns and keep the
public informed regarding the remedial site investigations at the
UPRR site. EPA intermittently ~eleased fact sheets during the
investigations to keep the community apprised.
The following is a list of activities conducted by EPA to
support community ~elations efforts for theUPRR Superfund site:
* September 1983 - Site proposed for National Priorities
List (NPL).
* September 1984 - Site listed on the NPL.
* June 1988 - Interview conducted with local officials and
citize~s to develop Community Relations Plan.
* June 1988 - CO~~LJnlty Relations Plan was published.
* June 1988 - Infor~ation repositories established at the
Southeastern Idaho Health District Office and
at the Pocatello Public Library.
(
* August 1988 - EPA distributed a fact sheet providing
information on the start of the field work
for the Remedial Investigation.
-------
<~
* July 1989 - EPA distributed a fact sheet on findings of
the RI and announced upcoming activities
related to the cleanup of the site.
* January 1990 - EPA distributed a fact sheet to update the
public on site work.
~
* June 1991 - Proposed Plan was published.
* June'7, 1991 to July 8, 1991 - Public comment period for
Proposed Plan.
* June 18, 1991 - Public meeting on Proposed Plan. Meeting
was announced in proposed plan and local
newspaper. .
III. Summary of Public Comments and Lead Aqency Response
There were no comments submitted during the public comment
period (June 7, 1991 - July 8, 1991). Additionally, no oral
comments were given during the public meeting (June 18, 1991).
,
-------
~
-...
. .
Please Sign
.,. . w. 1""\&.'."
.
tn......
Address
15' 71. .,(f7.JR e/(jt.f)'l
---/1"1< Cy~ ~,
t.4 4..\ 'E.
..
.-
Public Mee t ing
Proposed Plan
Union Pacific Railroad Sludge Pit (UPRR)
June 18, 1991
Pocatello, Idaho
City/State
Q
D,
/ cj tL
Zip
Mailing List?
9//Jjt!Il~. (f.(£~ DC- Let
~
It ):~k~~,
Y.J~
qc;) ~
!J
NU
~'.s
.6.JA-J..~
"
.\.,~ 1-11-
-j
S 3:/ (> /
.-" .
( -£-.. t: r~'
'-~ .,j. C,''''' j
4
~.
Q.--~
D ':;»tJ I
-------
&EPA
Superfund Glossary
.1Ir'
..
AquIf8r: NI underground rack .
formation COI'f1)OMd of mar8lia!s SUCh
as sand. soil. or gravellhar can stOnt
and supply ground wid. to wells and
spnngL Most aquifers used In the
United Statea are within a thouaand
feet of the eatth's surface.
cs.....p: ActIons taken to deal with a
release or threatened release of
hazardous substances that could affect
public heaJth anellor the environment.
The tenn 8c1eanup. Is otten used
broadly to describ8 vanous response
actions or phases of rwn8d1al
r8Sp0nsa such as the rwnedlaJ
Invutlgatlon/f88Slblllty study.
Enforcement: EPA's effortS through
lev" action it nec:esaaty to force
pol8ntJaJly r88ponalba. partl.. to
perform or pay tor a SUperfund silt)
ca.....p.
FeasJblllty Study (FS): See
RemedlaJ Investigation/Feasibility
Study.
.,
Ground W8t8r: W- tGund b8n8aU1
the earltt's surface that ftIs pores
between materiaJ8 such as sand. soil,
or graveL In 8qU1f8r'8. ground water
occurs in sufficient quantities that it can
be used for drinking water, irrigation.
and other purposes.
Hazard Ranking System (HRS): A
scoring system used to evaluate
potential relative risks to public health
and the environment from releases or
threatened releases of hazardous
substanc88. EPA and states use the
HAS to calculate a site score, from 0 to
100. based on the ac:tua.I or potentiaJ
release of hazaraou. subatancee
from 8 site throu~h air, surface
water, or ground WIlt.,. to affect
people. This score is the primary
factor used to decide it a hazardous
waste site should be placed on the
National Prtoritles List.
..
Hazardou. SUb8tanC88: Any materiaJ
that poses a threat to public health
and/or the environment. TypicaJ
hazardous substances are materials
that are toxic. corrosive. ignitable.
explosive. or chemically reacUve.
National Priorities Ust (NPL):
EPA's list of the most serious
controlled or abandoned hazardous
waS1e sites identified tor possible long-
tenn rwn8dJat r88p0nse using money
from the Trust Fund. The Ust is based
prtmanly on the score a site receives
on the H8zard Ranking System
(HAS). EPA is required to update the
NPL at least once a year.
O""lon and MaJntenance (OUl):
ActIvitIes conducted at a site after a
response action occurs. to ensure
that the cJeanup or comalnment
system is functioning property.
Preliminary t\nesament (PA): The
process of collecting and reviewing
availaDle information about a known or
suspected hazardous waste site or
release. EPA or states use this
informal Ion to determine if the site
requires funher Study. If further study
is needed, a atte Inspection Is
undenaken.
Quality Assuranc8iOUaIIty Control
(QAlQC): A system of procedures.
checks. audits. and corrective actions
used to ensure that field wone and
laboratory analysis during the
investigation and cl..... 01-. . ~
Superfund sites meet established
standards.
Record of Decision: A public
cocument that explains which cleanup
allemative(s) will be used at National
Prioritl.. Ust sites where the Trust
Fund pays tor the cleanup. The
Record ot Decision is based on
inlormation and technical analysis
generated during the remedial
inv8stlgatlon/feasi~1I1ty study and
consideration of public comments
and community conC8m8.
Remedial Actions (RA): The actual
cc:':~rnJctlon or imp:ementation phase
::1al ~ollows Ihe remedial design of the
selec:ed c!eanup altemative at a site
on !l'1e National Prlorltl.. Ust.
Remedial Design (RD): An
eng1neenng phase that tollows the
Recore 01 Decision when technical
drawings and specifications are
develooed lor the subsequent remedial
ac.lon sat a site on the National
Priontl.. Ust.
RemedlallnvestigatloniFeasibillty
Study:
Two Ollterent bul relaled studies. They
are uSually oertormed at the same time
ana togetr.er referred 10 as the -RUFS.-
~
They. are Intended to:
. Gather the data necessary to
determine the type and extem of
contamination at a SUperfUnd site:
. establish criteria tor cleaning up the
site. .
. Identity and screen cleanup
alternatives for l'8m8dlai action; and
. Analyze in detail the technology and
costs of the altematlves.
ResPOnaNen8SS Summary: A
summary of oral andfor Written public
commentS received by EP A during a
comment period on key EP A
documents. and EPA's responseS to
those comments.
Risk A"...nMnt: Nlevaluatlon
performed as part of the rwmedlal
Inv88tlg8tlon to assess conditions at a
SUperfund site and detennine the risk
posed to public health and/or the
environment.
Sit. Inspection (SI): A technical
phase thai follows a preliminary
'" 1T. ...*It d8si;n8dto collec:l mor:e
ext8n81v8 informadon on a hazaraoua
waste lb. The intonnallon is used to
score the sit. with the Hazard Ranking
System to determine whether
response aalon is needed.
SUperfund: The common name USed
tor the Comprehensive
Environmental Response
Compensation. and Uaaility Act. A
tederal law passed in 1980 and
modified in 1 986 by the Superfund
Amendment and ReauthoriZation Ad.
The AdS created a special tax that
g085 into a Trust Fund. commonly
known as SUperfund. to investigate
and ctean up abandoned or controlled
hazardous waste sites. Under the
program. EPA cari either.
. Pay for site cleanup when parties
responsible tor the contamination
cannot be located or are unwilling to
unable to perfonn the won<.
8 Take legal adion to force parties
responsible tor site comamination to
clean up the site or pay bad( the
tederal govemment tor the cost of the
-------
AGENDA
MENTAL PROTECTI AGE CV PUBLIC MEETING
JUNE 18. 1991
~
I.
UNION PACIFIC RAILROAD SLUDGE PIT
SUPERFUND SITE POCATELLO, IDAHO
T
.a..
INTRODUCTXON
II. TECHNICAL PRESENTATION
III. QUESTIONS AND ANSWERS
IV. ORAL CO~ENTS FOR THE RECORD
BUB LOISELLE
ANN WILLIAMSON
BUB LOISELLE
ANN WILLIAMSON
GENERAL PUBLIC
.
..
-------
&EPA
Region 10
1200 SlX1h Avenue
Sea1IIe WA 98101
AlasKa
Idaho
Oregon
Washing1Dn
,,,
Superfund Fact Sheet
June 3, 1991
The Proposed Plan
Union Pacific Railroad Sludge Pit
Pocatello, Idaho
..;
Public Comment Period on.Cleanup Alternatives
June 7, 1991 to July 8, 1991
Public Meeting to Discuss Cleanup Alternatives
. June 18, 1991 at 7:00 p.m. .
Quality Inn Convention Center
. 1 555 Pocatello Creek Road
Pocatello, Idaho
Introduction
This fact sheet describes the alternatives for addressing
contamination at the Union Pacific Railroad (UPRR)
Sludge Pit site in Pocatello, Idaho. In addition, it high-
'lights the U.S. Environmental Protection Agency's pre-
ferred alternative or "Proposed plan" lor cleanup..
,
The proposed plan is the document which describes the
preferred alternative for remediation at the UPRR Sludge
Pit. This proposed plan was developed atter completion
ofthe remedial investigation and feas!bilrty study (RifFS)
required by the Con1Jrehensive Environmental Response,
Compensation, and liability Act of 1980 (CERCLA or
Superfund) as amended by the Superlu nd Amendments
and Reauthorization Act of 1986 (SARA) The Super-
fund process includes the following phases. which were
completed prior to the proposed plan: (1) an investiga-
tion of the nature and extent of contamination in sludge,
'oil, surface water, air, groundwater. and to biota (RI);
(2) a risk assessment to estimate potential effects of
contamination on human health and the environment
(Human Health and Ecological Risk Assessments); and
(3) an FS to evaluate the alternatives for cleanup of the
contamination. The Environmental Protection Agency
(EPA), in collaboration with the Idaho Department of
Health and Welfare (IDHW), coordinated efforts during
this process.
11
This proposed plan requires public comment-your views
and suggestions-before EPA can proceed further. You
are invited to comment in writing, attend the public
meeting noted above where a presentation of the cleanup
alternatives will be given, or both. Writtencomments
should be sent to: .
Ann Williamson
Environmental Protection Agency
1200 Sixth Avenue, HW-113
Seattle, Washington 98101
To assist your analysis of the proposed plan, other
reports and studies on the UPRR Sludge Pit can be
reviewed at the infonnation repositories listed on page
14 of this fact sheet. Afterthe public comment period has
ended, your comments will be considered when devel-
oping the final cleanup plan. The preferred alternative
may be modified as a result of public comment. In
accordance with CERCLA Section 120, EPA in collabo-
ration with IDHW, will select the final cleanup plan. If
EP A and IDHW are unable to reach an agreement on the
cleanup plan, the selection is made by EPA.
EPA's preferred remedy is Alternative 5, described in
detail on page 14 of this proposed plan. A summary at
-------
tion and transportation of contaminated sludge, silt and
soils oHsite for disposal at a Resource Conservation and
Recovery Act (RCRA) approved landfill: (2) backfilling of
the pit with clean material and construction of a low
permeability cap; (3) groundwater extraction and treat-
ment using oiVwater separation and dissolved air flota-
tion; (4) partialtreatment of any remaining contaminated
soils by soil flushing using clean water circulated through
an infiltration gallery system followed by groundwater
treatment; (5) provision of an altemate drinking water
supply; land and water use restrictions; long-term ground-
water monitoring, and; air monitoring and dust control.
The estimated cost of cleanup is $3,797,550.
Overview of Investigation
The one-acre site is located north of UPRR's West
Pocatello Railroad Yard, which covers a few hundred
acres and is northwest of the city of Pocatello, Idaho.
The site is bounded by U.S. Highway 30 to the north and
the Portneuf River to the south, in a light industriaV
commercial setting (see maps on pages 2 & 3). Residen-
tial areas are located northeast of the site across U.S.
Highway 30.
Union Pacific Railroad (UPRR) has owned and operated"
a rail yard on the prope:,y since the turn of the century.
Typical activities there include train maintenance. repair,
assembly, refueling, diesel engine repair and track
maintenance.
Study Area
Sludge Pit
Sc.18in FMI
Pocstello.
6000
12000
o
2
-
UPRR operates an onsite wastewater treatment plant
(oil/water separator and dissolved air flotation unit). The
treatment plant receives water from all rail yard storm
drains and from many building floor drains. This plant
treats onsite, industrial railroad wastes exclusively.
Between 1961-1983, approximately 3,000 gallons per
week of sludge from the treatment plant were. disposed
in an unlined pit. Sludge thickness ranges from 1.5 to 4.4
feet, with an estimated total volume of 2,500 cubic yards.
In 1983, an EPA site investigation found that seepage
from the sludge pit and an old tie treating f~cility contrib-
uted to groundwater contamination. Samples from
nearby, domestic wells co!)tained low levels of organic
compounds consistent with the wastes discharged to the
pit. As a result of the investigation, the site, which has
become known as the UPRR Sludge Pit, was placed on
the EPA's National Priority list in 1984.
During 1990, UPRR finalized the Remedial Investigation
(RI), as well as the Human Health and Ecological Risk
Assessments. The Feasibility Study (FS) was com-
pleted earfy in 1991. The RIIFS contains the results of
the entire investigation and describes the alternatives for
cleanup. All of the RIIFS reports are available for review
at the information repositori8i 1is&8d on page 14.
. "i' . .
. -
~-
Significant findings of the RI aresummarized below:
Nature and Extent of Contamination
. Sludge (solids and liquids) material found in the pit
were sampled for volatile and semivolatile organics,
metals, pesticides, and polychlorinated biphenyls
(PCBs). Test results indicate that the sludge con-
tains heavy metal contaminants, volatile organic
compounds (VQCs) and semivolatile compounds at
relatively low concentrations. Present concentra-
tions range from a high of 1460 parts per million
(ppm) (lead) to a low of 0.013 ppm (carbon tetrachlo-
ride). Cleanup goals for these contaminants are 500
ppm and 0.21 ppm, respectively.
Leach test results suggest that rain or snow melt
percolating through the sludge may leach various
organic contaminants from the sludge into the un-
derfying soil and groundwater.
. Soils directly adjacent to and beneath the sludge pit
were found to be contaminated with petroleum hydro-
carbons, other volatile and semivolatile compounds,
and various heavy metals. Present concentrations
range from a high of 717 ppm (manganese) to a low
of 0.006 ppm (carbon tetrachloride). Cleanup goals
for these contaminants are 0.28 ppmand 0.21 ppm,
respectively.
,
-------
. ,
,
" '
"
Map 2: it and Study Area
3
~
~
o
o
o
I:DTUCf .Uf.
o
..
Legend
o
domestic 01 industrial""
-------
~
Soil contamination extends as deep as 42 feet below
the sludge pit and into the Upper Aquifer. Figure 1
below indicates the estimated extent of soil contami-
nation based on a summary of all data from 1985-
1989.
. Groundwater beneath the sludge pit occurs in two
distinct water bearing zones (Upper and Lower
Aquifer). They are separated by a clay layer. The
regional groundwater flow direction is generally to
the northwest. The Lower Aquifer is a very produc-
tive drinking water source used by local private
residents. businesses. and the City of Pocatello
(Supply Well No. 32). No water supply wells in the
area have been identified as originating from the
Upper Aquifer.
The Upper Aquifer is contaminated with organic
compounds in the form of nonaqueous phase liquids
(NAPL). The NAPL layer, which floats on the
(TT) Int...ed extent alleil allfttaminelion
"';.0.;- summaty aI all_allons 1i115 . '"'
. Soil borin; Of mon.Of wetl ""'... .ilually
COftlaminaleel 1011 has - -_eel
o
Soil bonn; Of monSOf well ""'... .iluaJly
contamonateel 1011 has not - obs8I¥eeI
4
..
surface of the groundwater below the pit. is similar in
composition to a medium weight fuel or lubricating oil
and is approximately 2 inches thick. Sampling of
wells in the Upper Aquifer indicates the presence of
a small. seasonal contaminant plume associated
with the NAPL. Figure 2 on page 5 indicates the
estimated extent of NAPL floating on the surface of
the groundwater based on observations made from
1985-1989.
I,
Low levels of several chlorinated VOCs were de-
tected in most Upper and Lower Aquifer wells near
the sludge pit and in several. offsite drinking water
supply wells. both upgradient and downgradient of
UPRR wells. Metals. such as lead. were also found
in the private. offsite wells and UPRR wells. All
contaminant concentrations of metals and vecs
were below their respective federal. primary drinking
water maximum contaminant levels (MCLs) and
aJrrent maximum contaminant level goals (MCLGs).
SCALI III 'liT
o
ISO
JOO
...l
{U\
-\R/
j.'
1
-------
a
!If
-'"
. Surface water bodies investigated included the Port-
neuf River. an irrigation canal. intermittent ponds in
the gravel pit southwest of the sludge pit. and water
observed in the sludge pit. Studies indicate that
neither surface water nor groundwater from the site
impact the quality of water in the Portneuf River,
Swanson Road Spring and Batiste- Papoose Spring.
. Air quality was not monitored at the site. conse-
quently, current impacts are unknown. However, air
quality data (such as wind speed. wind direction,
etc.) was collected for use in estimating.volatile and
dust emissions as part of the risk assessment.
. Biota impacts were qualitatively evaluated in and
arou nd the study area. No negative impacts were
observed and future impacts are not expected.
"\
-
(.7') Inferred mUn..m...18nI 01 NAPL
';.;;:;;.;;. ~ 01 all obserVations I98S . 89
. Soi bor;,,; or monitor _I wNlt. NAPL or
oily .- has "-" --.cI
o Soil boring or monitor _I w+-. NAPL or
oily .h.... has no! "-" -.."",,
5
Summary of Heahh and Environmental Risk
As part of the investigation, Union Pacific Railroad
evaluated the potential human health and environmemal
risks due to contamination from the UPRR Sludge Pit
site. This assessment uses conservative assumptions
to determine risk, such as daily exposure to the contami-
nants for 75 years. The risk assessment also considered
any changes in land or groundwater use that may occur
in the future. According to federal and state hazardous
waste laws. an acceptable risk is generally defined as a
risk within in a range that does not exceed one additional
chance of cancer in 10,000 to one additional chance of
cancer in 1.000,000 for a person exposed to site.condi-
tions. This risk from exposure to a site is in addition to
the normal cancer rate of 1 in 4 people. . For noncancer-
causing contaminants, acceptable levels are generally
those to which the human population may be exposed
during a lifetime of 75 years without adverse effects..
8C&I III ruT
o 1M
soo
N~
;;N° ;.
:. i
,
.......
...
...
~
....
-------
. I
Current and Future Human Health Risks: Arsenic
chromium, cadmium, beryllium and polycyclic aromatiC
hydrocarbons (PAHs) are the contaminants which could
pose the greatest risk of cancer or other adverse human
health effects at the site. The risk assessment indicates
that exposure to these contaminants in air, sludge/silt!
soil, and grou ndwater could pose an unacceptable risk to
residents and workers. However, no one currently
resides onsite and the nearest residences are approxi-
mately 0.3 mile northeast of the site; the pit area is no .
longer used by UPAA workers; and, the Upper Aquifer is
not used as a drinking water source in Pocatello.
Currwlative ris~.,' which is the sum of risks across path-
ways (i.e. air, soil ingestion and dermal contact) was
estimated for both the current and future industrial and
residential larid-use scenarios. Current site risks are
estimated to be 3 add.ionaI chances of cancer in 1,000,000
for an offsite resident and 4 additional chances of cancer
in 100 for an onsite industrial worker, given existing site
conditions. Future site risks are estimated to be 6
additional chances of cancer in 100 for a person residing
onsite and 5 additional chances of cancer in 100 for an
onsite industrial worker, based on no cleanup.
Ecological Risk: No threatened or endangered species
of animals or plants are known to inhabit th~ UPAA
Sludge Pit. Impacts to the Portneuf Aiver. the Swanson
Aoad Spring and Batiste-Papoose Spring from surface
water runoff were found to be nonexistent.
Principal Threats
CEACLA remedial actions are expected to include treat-
. ment 01 wastes that pose principal threats at a site,
wherever practical. Generally. pnnclpal threats. are
attributable to wastes which cannot be reliably controlled
in place such as liquids, highly mobile materials (e.g.
cleaning solvents), or compounds at h~g toll)' toxic concen-
trations.
For this site, the following principal threats may include
some metals, sernivolatile organic compounds and ten-
tatively identified organic compounds In t he nonaqueous
phase liquids (NAPL); volatile and semll/olatlle organic
compounds in groundwater; and, some metals (such as
arsenic) and polycyclic aromatic hydrocartx>ns (PAHs)
in the sludge and underfying soils at the site.
Cleanup Goals'
The results of the AI and the risk assessment were used
to establish the goals that define the extent of cleanup
r~uired by state, local and feoerallaw. In establishing
these cleanup goals, a variety of federal, state and local
laws and regulations as well as the results from the risk
assessment were used. These laws and regulations
comprise the applicable or relevant and ~ropriate re-
6
'f.
quirements (AAARs); a list of ARAAs for this site can be
found in Appendix D of the Feasibility Study. If the
cleanup goals differ between the federal and state law,
the cleanup goal is set at the more stringent level.
In accordance with federal and state law, the cleanup
goals at UPAA have been set at a level that does not
exceed one additional chance of cancer in 1,000,000 for
a person exposed to site conditions. For non-carcincr
genic effects, the levels are set such that no adverse
effects are anticipated based on a 75-year lifetime
exposure. This includes exposure via aU potential routes-
sludge/soil, groundwater, surface water, and air.
Cleanup levels for contaminants found in the sludge/soil
and groundwater were calculated based on protection of
human health and the environment. These levels are
called target concentrations anQ.will generally be used to
determine when cleanup goals have been achieved. If
additional sampling indicates that either laboratory de-
tection limits or naturally occurring levels of chemicals in
soil or groundwater exceed risk-based cleanup goals,
the detection limits or background concentrations will be
used instead of the risk-based values to establish reme-
diation targets.
~
SpecnlC cleanup goals for contaminants identified in the
groundwater and sludge/soil can be found in the Feasi-
bility Study, Tables 2-11 through 2-22.
Cleanup Alternatives
A wide range of sludge/soil and groundwater remedial
alternatives were evaluated as part of the FS. Several
alternatives were eliminated early in the screening proc-
ess because it was readily apparent that they would not
effectively address contamination, could not be imple-
mented, or would have had excessive cost compared to
an altemative that would achieve the same degree of
protection or level of effectiveness. After this screening
process was complete, twelve remedial alternatives
remained for detailed analysis. Table 1 on page 7 lists
each of the proposed alternatives and identifies the
elements of each.
These alternatives consider four treatment options for
sludge/soil:
--excavation and offsite disposal
--excavation, offsite disposal and capping
--onsite solidification
--incineration
I
f
In addition, contaminated groundwater will be treated
either by:
--oiVwaterseparation and dissolved air flotation (DAF)
-------
.
Table 1
Elements of Proposed Alternatives
,
111 Proposed Alternatives 12 \
Remedy Elements 2 3 4 58 6 7 8 9 10 11
Groundwater (GW) Monitoring i ~ I ~ ~ ~ ,/ ,/ ,/ ~ ~ ,/ ,/ ~
Instltutlonsl Controls ! ,/ ~ ,/ ,/, ~ ,/ ,/ ~ ,/ ,/ ,/
Dust Control and Air MonItorIng ~ ~ ",/;"' ~ ,/ ,/ ~ ,/ ,/ ~
Backfilling of PIt with Clean MaterIal I ~ ,/ ",/ ,/ ~ ~ ,/ ,/ ,/ ,/
I
Altematlve Drinking Water Supply ,/ ~ ,/ ,/ ~ ~ ,/ ~ ,/ ,/ ,/
GW extraction a. Soli Flushing i , ~ 1 ,/ ~ ~ ~ "~ ~ ~ ,/ ~
" I ! I \
GW Treatment by OlllWater Separation i !
80 Dissolved AIr Rotation (DAF) I ~ ,/ ~ ~ ~
GW Treatment by OlllWater Separation i I
!
I
a. Carbon Adsorption I ,/ ~ ~ ,/ ~
; I
Off-Site GW Discharge ; ~ ,/ ~ ~ ,/
I
,
On-8lte GW Dlschsrge i ,/ ~ ~ ~ ~
Low Permeability Cap I i ~ ~ I ~ ~
I I ! I I
Soli excavation Off-Site DIsposal I I I ~ ~ ~ ~
I ! I I I I
Soil excavation Solldmcallon ! ~ ~ !
On-8lte Soli Incineration I I ~ ~ I
Off-Site Soli Incineration I I ~ ~
I
. EPAlIDHW Preferred Atremarive
,.
"iii
All alter~atives, e"xc~pt Alternative 1 (No Action) and
AlternatIVe 2 (Institutional Controls), have the following
features in common:
--soil flushing
--air monitoring and dust control measures during
construction
--alternate onsite drinking water supply, if necessary
--post-oonstruction institutional controls maintained"
by UPRR and operation and maintenance (0 & M)
In addition to the cleanup actions identified in the alter-
natives. EPA and IDHW are requiring supplemental
groundwater sampling. Contaminants found in ground-
water are below both MCLs and MCLGs. However,
treatment of the upper groundwater aquifer is necessary
to prevent migration of NAPL and other contaminants to
the lower aquifer and to remove NAPL and other con-
taminants which exceed proposed MCLs and MCLGs. I
"'
.
7
Based on the results of the sampling, the need for
additional groundwater treatment will be considered.
The following twelve remedial groundwater and sludge!
soil remedial altematives were evaluatee Costs for all
altematives are estimates only and fell w.min the -30 to
+50 percent range.
Alternative 1 : No Action.
Capital Cost ...~........................................ ~
o & M .......................................... $635.300
Total (Present Worth) .................. $635,300
The No-Action Altemative is required by law to be devel-
oped and acts as a baseline for comparison with the
cleanup alternatives. Under this alternative. no action"" ..
would be taken to clean up contaminated sludge. silt,..
soils or groundwater. However, a long-term groundwa- :""
ter monitoring program would be implemented to monitor :.
movement of the contamination plume.
.,
~~
,:-."'"
-------
. I
Alternative 2: Institutional Controls.
Capital Cost .................................. $33,150
o & M .......................................... $636,700
Total (Present Worth) .................. $669,850.
This altemative involves surrounding the sludge pit with
a six-foot chain link fence. land and water use restric-
tions would be added to the property deed to prohibit
current and future landowners from disturbing the site
and from using the site groundwater resources.
Alternative 3: Excavation & Offsite DisposaVGround-
water Treatment via OiVWater Separation and Dis-
solved Air Flotation (DAF)/Soi/ Flushing/Offsite Dis-
charge/Institutional Controls/Air Monitoring & Dust
Control.
Capital Cost ........................ (up to) $4,894,208
o & M .............................................. $1,624,300
Total Cost (Present Worth).. (up to) $6,518,508
r
This altemative is designed to reduce potential human
and environmental exposure to contaminants contained
in the sludge. By removing the sludge. the source of
contamination to groundwater beneath the pit will be sig-
nificantly reduced.
In addition, this altemative is designed to prevent offsite
migration of contaminated groundwater.
The altemative consists of excavating sludge and soil,
transporting it to an approved landfill, and backfilling the
. pit and other excavated areas with clean fill. Because the
vertical and horizontal extent of this contamination is
presently unknown, sampling of the under1ying and sur-
rounding soil would be performed periodically during
excavation, with the results determining whether to
excavate further in order to meet cleanup goals.
Although it is intended that all contaminated sludge and
soil which exceed cleanup goals will be excavated. this
may not be feasible due to subsurface conditions. Cur-
rent estimates indicate that approximately 4,200 cubic.
yards of sludge and soil could be removed from the pit
and surrounding areas. Therefore. contaminants may
remain in soils beneath the excavated area. Soil flush-
ing. using uncontaminated water from Batiste Springs,
would be used to flush contaminants beneath the exca-
vated area to the groundwater surface via infiltration
galleries. By using a system of perforated drains. the
water would infiltrate into and through the unsaturated
soil down to the Upper Aquifer where it would be cap-
tured with groundwater extract10n wells and pumped to
the surface for treatment.
8
'~
Treatment of groundwater and nonaqueous phase liq-
uids (NAPL) would involve using an oil/water separator
to skim off floating oil. The wastewater would then be run
through the onsite dissolved air flotation unit (OAF) for
removal of primarily emulsified oil, semivolatile organic
compounds and, metals in the NAPL before discharge to
the Pocatello publicly owned treatment works (POTW).
Organic contaminants remaining in the wastewater will
receive biological treatment at the POTW. Skimmed oil
will be kept in an onsite holding tank for sale to a recycler.
An altemate drinking water supply system would be
provided to serve potential future businesses and/or
residents moving onto the site property. Air monitoring
and dust control measures will be implemented during
site cleanup activities to reduce emissions and to ensure
the protection of site workers, nearby workers and resi-
dents. . The dust control measures may include spraying
the ground surface with clean water or an approved
chemical suppressant. Long-term groundwater moni-
toring and deed restrictions would be required.
\{
Alternative 4: Excavation & Offsite DisposaVGround-
water Treatment via OiVWater Separation and Car-
oon Adsorption/Soil Flushing/Onsite Discharge/Alter-
nate Drinking Water Supply/Institutional Controls/Air
Monitoring & Dust Control. .
Capital Costs ................ (up to) $5,689,163
o & M ........................................ $4,130,400
Total (Present Worth).... (up to) $9,819,563
Treatment of the sludge and soil contamination in Alter-
native 4 is identical to the treatment discussed in Alter-
native 3. The groundwater treatment and disposal
method in Alternative 4, however, would involve carbon
adsorption and onsite discharge ratherthan dissolved air
flotation and.offsite discharge. The carbon adsorption
system would enhance groundwater cleanup by specifi-
cally removing organic contaminants.
The extracted groundwater would be pumped from the
oiVwater separator to the carbon adsorption unit for
further treatment. The carbon adsorption system brings
the contaminated groundwater into direct contact with
activated carbon by passing the water through carbon
containing vessels. The activated carbon selectively
adsorbs hazardous organic particles. The treated water
would then be routed to the infiltration galleries for use in
the soil washing process. Used carbon would be re-
cycled offsite through combustion at an approved regen-
eration facility.
f
f
The altemate drinking water supply system, institutional
controls, dust control and air monitoring are also in-
-------
, I
Ii
:;
Altemative 5:. Excavation & Offsfte DisposaVLow Per-
meability Cap/Groundwater Treatment via OiVWater
Separation and OAF/Soil Rushing/Offsfte Discharge/
Altemate Drinking Water Supply/lnstftutional Con-
trols/Air Monitoring & Dust Control.
Capital Costs ................ (up to) $2,139.650
o & M ........................................ $1,657,900
Total (Present Worth) .... (up to) $3,797,550
This alternative is designed to reduce the primary source
of contamination at the site by excavating contaminated
sludge and soil to a depth that is technically practical,
backfilling the excavated area with clean fill and covering
it with a low permeability cap. It is assumed that only
visible sludge (i.e. material that is discolored or noted to
have the consistency of sludge) and underlying silt; up to
a maximum of 4,200 cubic yards, would be removed.
Soil flushing and groundwater eXtraction and treatment .
using the existing onsite oiVwater separator and DAF
unit, infiltration galleries, altemate drinking water supply
system, institutional controls, dust control and air moni-
toring are also included in this alternative as described in
Alternative 3.
Alternative 6: Excavation & Off site Disposal/Low Per-
meability Cap/Groundwater Treatment via OiVWater
Separation and Carbon AdsorptioNSoil Flushing/On-
site Discharge/Alternate Drinking Water Supply/Insti-
tutional Controls/Air Monitoring & Dust Control.
Capital Costs ................ (up to) $2,820,750
o & M ........................................ $4,164,000
Total (Present Worth).... (up to) $6,984,750
Alternative 6 combines the contaminated sludge/soil
excavation, offsite disposal and capping remedial activi-
ties described in Alternative 5 with the carbon adsorption
groundwater treatment system described in Alternative
4. The alternate drinking water Supply system, institu- I
tional controls, dust control and air monitoring are also
included in this alternative as described In .r. ~ernative 3.
,
Altemative 7: Sludge SolidificatioNLow Permeability
Cap/Groundwater Treatment via Oil/Water Separa-
tion and OAF/Soil Flushing/Offsite Discharge/Alter-
nate Drinking Water Supply/Institutional ControlS/Air
Monitoring & Dust Control.
Capital Costs ................ (up to) $6,410,850
o & M ........................................ $1,643,500
Total (Present Worth) .... (up to) $8,054,350
.
This altemative is designed to treat the contaminated
sludge and soil in, around and below the pit. Under this
option, sludge and contaminated soils would be exca-
9
vated to a depth that is technically practical and mixed
with stabilizing agents such as fly ash, lime, cement or
proprietary chemicals to immobilize contaminants. An
onsite landfill will be constructed for disposal of the
solidified sludge and soil. To' prevent possible future
leaching of contaminants from the solidified mass to the
groundwater, the landfill cell will be double lined and
contain a leachate collection system. The entire landfill
will be covered with a low permeability cap.
Soil flushing and groundwater extraction and treatment
using the existing onsite oiVwater separator and DAF
unit, infiltration galleries, altemate drinking water supply
system, institutionaf controls, dust control and air moni-
toring are also included in this altemative as described in
Alternative 3. '.
Alternative 8: Sludge SolidifICation/Low Permeability.
Cap/Groundwater Treatment via OiVWater Separa-
tion and Carbon Adsorption/Soil Flushing/Onsite Dis-
charge/Alternate Drinking Water Supply/Institutional
Controls/Air Monitoring & Dust Control.
Capital Costs ................ (up to) $7,195,950
o & M ........................................ $4,149,600
Total (Present Worth) .. (up to) $11,345,550
This alternative combines the sludge solidification and
its onsite disposal in a specially constructed landfill as
described in Alternative 7 with the carbon adsorption
groundwater treatment system described in Alternative
5.
The altemate drinking water supply system; institutional
controls, dust control and air monitoring are also in-
cluded in this alternative as described in Altemative 3.
Ahernatlve 9: Onsite Incineration/Groundwater Treat.
ment via OiVWater Separation and OAF/Soil Rush-
ing/Offsite Discharge/Alternate Drinking Water Su~
ply/Institutional Controls/Air Monitoring & Dust Con-
trol. .
Capital Costs .............. (up to) $23,240,950
o & M ........................................ $1,624,300
Total (Present Worth).. (up to) $24,865,250
This alternative is designed to treat contaminated sludge
and soil in the pit which is the major source of groundwa-
iter contamination. Soil exceeding cleanup goals and
. sludge within the pit would be excavated and incinerated
in an onsite incinerator. Ash would be transported and
disposed in an approved landfill. Procedures for deter-
mining the extent of contaminatian of the underlying and
surrounding soil and commensurate excavation, back-
filling and grading are identical to those described in
-------
.
Soil flushing and groundwater extradion cind treatment
using the existing onsite oiVwater separator and DAF
unit, infiltration galleries, altemate drinking water supply
system, institutional controls, dust control and air moni-
toring are also included in this altemative as described in
Alternative 3.
Alternative 10: Onsite Incineration/Groundwater Treat-
ment via OiVWater Separation and .Carbon Adsorp-
tion/Soil Flushing/Onsite Discharge/Alternate Drink-
ing Water Supply/Institutional Controls/Air Monitoring
& Dust Control.
Capital Costs ............ (up to) $23,786,250
o & M ...............;...................... $4,130,600
Total (Present Worth) (up to) $27,916,850
This altemative combines the carbon adsorption ground-
water treatment system remedial adion described in
Alternative 4 and the onsite incineration of contaminated
sludge and soil described in Alternative 9. The remaining
remedial features of this alternative are also described in I
Alternative 3.
10
..
Alternative 11 : Offsite Incineration/Groundwater Treat-
ment via OiVWater Separation and DAF/Soil Rush-
ing/Offsite Discharge/Alternate Drinking Water Sup-
ply/Institutional Controls/Air Monitoring & Dust Con-
trol.
-..:
Capital Costs .............. (up to) $38,662,850
o & M ........................................ $1,624,300
Total (.present Worth).. (up to) $40,287,150
This alternative is designed to treat contaminated sludge
and soil in the pit which is the major source of groundwa-
ter contamination. Soil exceeding cleanup goals ana
sludge within the pit would be excavated and incinerated
in an offsite incinerator. Ash would be disposed in an
approved landfill. Procedures for determining the extent
of contamination of the underlying and surrounding soil
and commensurate excavation, baCkfilling and grading
are identical to those described in Alternative 3.
Soil flushing and groundwater extradion and treatment
using the existing onsite oiVwater separator and DAF
unit, infiltration galleries, altemate drinking water supply
system, institutional controls, dust control and air moni-
toring are also included in this altemative as described in
Alternativ~"3." .
Table 2:
Evaluation of Remedial Alternatives
In the Feasibility Study, nine criteria are used to evaluate and compare altematlves. These nine criteria are:
1. OVerall Protection of Human Health and the Environment - How well does the altematlve proted human health and
the environment?
2.. Compliance with Regulations. Does the altemative meet all applicable or relevant and appropriate state and federal
laws (ARARs), or if not. Is a waiver justified?
3. Short-term Effectlvene.. - Are there potential adverse effects to either the community. site workers or the environ-
ment during construction or implementation of the alternative? How fast does the alternative reach the cleanup goal?
4. LOr'!g-term Effectiveness and Permanence. How well does the alternative protect human health and the environmont
after cleanup goals have been reached? What. if any, risks will remain atthe site? What is the adequacy and reliability
of controls?
5. Reduction of Toxicity, Mobility, or Volume. Is the toxicity. mobility, or volume of the hazardous substance
significantly reduced through treatment? What are the type and quantity of residuals remaining? What is the degree
of eXpeded reductions, and to which treatment is irreversible?
,"
6. Implementability - Is the altemative both technically and administratively feasible? Has the technology been used
successfully on other similar sites?
7. Cost. What are the estimated present worth costs of the alternative?
.
8. State Acceptance. What are the state's comments or concerns about the alternatives considered and about the
preferred alternatiye? Does the state support or oppose the preferred alternative?
9. Community Acceptance - What are the community's comments or concerns about the alternatives considered and
about the preferred alternative? Does the community generally support or oppose the preferred alternative?
I'
-------
. i
'.'
J
Alternative 12: Off site IncineratioNGroundwater Treat-
ment via OiVWater Separation and Carbon Adsorp-
tioNSoil RushingJOnsite Discharge/Alternate Drink-
ing Water Supply/Institutional ControlS/Air Monitoring
& Dust Control.
Capital Costs .............. (up to) $39,208,150
o & M ........................................ $4,130,600
Total (Present Worth).. (up to) $43,338,750
This altemative combines the carbon adsorption ground-
water treatment system remedial action described in
Altemative 4 and the offsite incineration of contaminated
sludge and soli described in Altemative 11. The remain-
ing remedial features of this alternative are also de-
scribed in Alternative 3.
Comparative Analysis of Alternatives
These criteria. as defined in Table 2. are used to com-
pare the alternatives to determine their relative perform-
ance and to identify their respective advantages and dis-
advantages. .
1. Overall Protection 0' Human Health and the
Environment:
All ofthe altematives except Alternative 1 (no action) and
Alternative 2 (institutional controls) appear to be protec-
tive of human health and the environment. However,
although excavation is involved, Altematives 3-6 (sludge!
soil removal and offsite disposal) pnmarily treat the
. contaminated groundwater, with only limited treatment
of the contaminated sludge and sOIL
Of the two groundwater treatment systems proposed in
the alternatives, carbon adsorption WOJId enhance ground-
water cleanup by specifically removing organic contami-
nants. Underthedissolved air flotatIOn (DAF) treatment
scenario, biological treatment at the Pocatel!o POTW is
further expected to remove additional organic-contami-
nants.
,
2. ComplianCe with Applicable or Relevant and
Appropriate Requirements (ARARs):
Alternative 1 (no action) and AlternatIve 2 (institutional
controls) will not meet ARARs. Alternatives 3-' 2 comply
with the applicable or relevant. and appropriate require-
ments (ARARs) in varying degrees. ARARs identified
for this site. which are currently under consideration,
appear in the discussions which follow.
.
Tests performed on the sludge and soil indicate it is not
a Resource Conservation and Recovery Act (RCRA)
11
waste. Therefore. land disposal restrictions do not apply
nor do RCRA landfill closure requirements.
All of the alternatives should meet state and federal air
quality standards for visible emissions and fugitive dust,
as each alternative includes dust control measures.
With the exception of Alternatives 1 and 2, all of the
alternatives include groundwater extraction, treatment,
and discharge process options that will meet both federal
and state water quality ARARs 'orgrouncJwater, drinking
water, and leaching. Altematives 3, 5, 7, 9 and 11 will
require an increase to UPRR's current wastewater dis-
charge limit with the City of Pocatello. All 0' these
alternatives use offsite discharge of treated wastewater
to the Pocatello publicly owned treatment works (POTW). :
3. Short-Term Effectiveness:
Alternatives 3-12 pose some short-term risk to the
community and site wor1
-------
. i
capping included in Alternatives 5-8 reduces the amount
. of water available for leaching contaminants into the
subsurface after soil flushing has been completed. 0 &
M costs associated with cap maintenance have been
calculated for a period of 30 years.
Because contaminants in sludge and soil will be con-
tained but not destroyed, remedial activities associated
with Alternatives 3-6 do not entirely meet the stated.
preference of the Superfund law which calls for utilization
of permanent solutions and treatment to the maximum
extent practicable:
The groundwater extraction and treatment systems and
the alternate water supply included in Alternatives 3-12
address groundwater threats by remediating the Upper
Aquifer and by providing a clean drinking water source,
if necessary, for potential future onsite users. The
groundwater treatment system will further reduce the
potential for any contaminants to reach the Portneuf
River.
5. Reduction of Toxicity, Mobility, or Volume Through
Treatment:
The "No Action" Alternative and Alternative 2 (institu-
tional controls) do not reduce any of the properties (i.e.
toxicity, mobility, or volume) ofthe contamination. For all
other alternatives, reductions in toxicity. mobility or vol-
ume will be accomplished through treatment to the
extent practicable. .
Alternatives 3-6 provide some treatment of contami-
nated soils through insitu soil washing below soils that
have been excavated and disposed offsite. Alternatives
7-8 (solidification) reduce mobility and Alternatives 9-12
(incineration) reduce mobility and volume. Alternatives
9-12 may also reduce toxicity, however. metals remain-
ing in the resulting ash are likely to increase in concen-
tration. .
6. Implementability:
All of the alternatives can be implemented with varying
degrees of difficulty. Although Alternatives 3-4 and 9-12
assume contaminated sludge and soil will be excavated
to cleanup goals, excavation of soils beneath the "vis-
ible" sludge may be very difficult, if nOI impractical, due
to its extremely coarse nature (i.e. a dense mixture of ,
gravel, cobbles, and boulders ranging up to 9 feet in
diameter). Therefore, excavation will likely be limited to
practicable depths. A limited excavation may be capable
of meeting cleanup goals in some areas where silt is
present. This is due to the fact that silt has a demon-
strated low permeability and is capable of absorbing
some contaminants. .
12
.
The solidification alternatives (7 and 8) currently present
significant implementation uncertainties due to the un-
known reliability and effectiveness of solidification at the
UPRR site and the potential for an increase in volume
associated with the solidificatiOn process. None of these
uncertainties can be fully addressed until a small scale
test simulating site conditions is conducted.
Alternatives 3, 5, 7,9 and 11 will require an increase to
UPRR's current wastewater discharge limit with the City
of Pocatello. All of these alternatives use offsite dis-
charge of treated wastewater to the Pocatello POTW.
Coordination between UPRR and the Pocatello POTW
to obtain the necessary revisions to existing discharge
permits has been initiated and it is expected to be
administratively feasible.
'~'.
Services and materials for implementing excavation,
removal and disposal of, or solidification of, Contami-
nated sludge and soil, and for installing a soil flushing
system and a low permeability cap are expected to be
available within the state of Idaho. An out-of-state
landfill, with the capacity for handling excavated sludge
and soil from the pit, has been identified. The waiting
period to secure the use of an offsite or onsite incinerator
is expected to be long, pot~ntially causing unacceptable
delays in implementation.
7. Cost:
Total cleanup costs for Alternative 5 (the preferred
alternative) are estimated at $3,797,550. Thisaltema-
tive ranks in the middle among the 12 alternatives
considered. The range of estimated costs is $635,300
(Alternative 1) to $43,338.750 (Alternative 12).
8. State Acceptance:
IDHW has reviewed all documents that are part of this
proposed plan and support its presentation to the public.
While reserving the right to amend or change its recom-
mendation after review of public comment, IDHW sup-
ports the proposed plan as protective of Idaho's environ-
mental laws and regulations.
f
9. Community Acceptance:
Community acceptance will be evaluated based upon
comments received during the public comment period.
-------
I l
.'
13
:.
The Preferred Alternative
The preferred alternative is Alternative 5 as it appears to
best satisfy EPA's nine criteria. Alternative 5 is protec-
tive of human health and the environment. complies with
state and federal laws. and is cost effective. It utilizes a
readily available technology to address sludge and soil
contamination and a proven treatment system to provide
a permanent solution to the groundwater contamination.
The major components of the preferred alternative are:
. excavation of "visible" sludge (i.e. material that is
discolored or noted to have the consistency of sludge)
and underlying silt up to a maximum of 4,200 cubic
yards.
. testing of contaminated sludge and soil will be con-
ducted prior to disposal to demonstrate compliance
with land disposal restrictions (LOR) treatment stan-
dards.
. disposal at an approved offsite landlilliocated in Utan; I
excavated areas are backfilled with clean liII and
graded.
. placement and maintenance of a low permeability,
cap overthe entire pit following excavation, backfilling
and grading. Areas outside the pit that are excavated
will be backfilled with clean fill and graded.
. extraction and treatment of groundwater and nonaque-
ous phase liquids via the onsite oiVwater separator
and a dissolved air flotation unit: wastewater dis-
charged to the Pocatello publicly owned treatment
works: clean water obtained from Batiste Spr'ngs for
use in washing contaminated soils.
. alternate drinking water supply system provided, if
necessary, to serve potential Mure onsite businesses
and/or residences. Since businesses and residences
do not exist onsite, installation 01 a new water supply
is not immediately required.
,
. construction and maintenance lor thIrty years 01 a six~
foot-high chain link fence around the pit to restrict
public access to the site.
. placement of deed restrictions on land and groundwa-
ter use to protect the property and potential future
businesses and/or residents following completion of
the cleanup. UPRR will be responsible lor maintain-
ing these controls for as long as they own the property.
U PRR is also responsible for ensuring that these deed
restrictions remain in the deed upon sale of the
property .
"
. long-term. on-site groundwater monitoring for a mini-
mum 01 30 years after cleanup levels are achieved.
How You Can Participate
EPA welcomes your comments on the proposed plan.
You are encouraged to comment on all the alternatives
considered, not just the preferred alternative. The
selection of the preferred alternative is preliminary and
could change in response to public comments or other
new information.
All of the reports in this study are available at the
information repositories listed on the back page. The
Administrative Record for the study, which includes a
complete record of all actions and decisions upon which
the preferred alternative is based, is located at the
Pocatello Public Library. .
The public comment period begins on June 7, 1991 and
will run for 31 days, until July 8, 1991. A public meeting
is scheduled for ltJesday, June 18, 1991 at the Quality
Inn Convention Center. At that time, EPA will provide an
explanation of the cleanup alternatives and will be avail-
able to answer your questions. The meeting will also
provide an opportunity for you to submit written or verbal
comments on the proposed plan.
At the end of the comment period and after considering
all public comment receivad, EPA, in collaboration with
IDHW, will select a final cleanup plan. The selected
cleanup plan is documented in the Record of Decision
(ROD) which includes. the Responsiveness Summary
providing responses to all public comment received.
After the ROD is cOmplete, a fact sheet presenting the
Responsiveness Summary and the selected remedy will
be mailed to all interested parties. The ROD, including
the Responsiveness Summary, will also be placed in the
local repositories.
For More Information Contact:
To Contact EPA Staff in Seanle:
Call Toll-Free: 1-800-424-4372
Ann Williamson, EPA Project Manager
(206) 553-2739
In Pocatello:
Boyd Roberts. State of Idaho
-------
II I
14
..
Information Repositories
Southeast Idaho Health District Office
465 Memorial Drive
Pocatello. Idaho
Pocatello Public Library
812 East ClarK Street
Pocatello. Idaho
',",',
U.S. Environmental Protection Agency Library
ParK Place Building, 10th Floor
1200 6th Avenue '
Seattle,Washington 98101
.',
.'...,.
&E
United Slates
Environmental Protection
Agency
Region 10 (HW.117-CR)
1200 Sixth Avenue
Seanle WA 98101
I
-------
..
ERRATA SHEET FOR UPRR
PUBLIC HEARING TRANSCRIPT
JUNE 18, 1991
.'Jl
Page 2,
line 6;
"my" should be "My".
Page 4,
line 15; "Superfunds" should be "Superfund".
Page 4,
line 20; "you" should be "of".
Page 5,
line 4;
"have" should be insert~d between "will Ann".
Page 6,
line 24; "is" should be inserted between "site in".
Page 7,
line 12;
"it's"
should be "This is".
Page 8,
line 1;
Insert. a period after "parties" and capitalize
"once".
Page 8,
line 5;
Delete "the".
Page 8,
line 15: "sunlight" should be "unlined".
Page 12, line 7;
"determine" should be "determination".
Page 14, line 4;
"swales" should be "soils".
Page 15, line 14; "And" should be "In".
Page 17, line 21;
"arell
should be "is the".
Page 17, line 22; "alternatives" should be "alternative".
Page 19, line 2;
"thell should be deleted.
Page 20, line 22; Insert a period "pit" and capitalize IIwithll.
Page 20, line 23; Delete the pe~iod after "treatment" and insert
a comma. Capitalize "we".
Page 21, line 14; "511 should be "6".
Page 23, line 21; "metal" should be "metals".
~
-Page 24, line 22; Insert "a" after "by".
Page 28, line 22; "down" should be
"on".
-------
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16 BEFORE:
17
18
19
20
21
22
23
24
25
BEFORE THE ENVIRONMENTAL PROTECTION AGENCY
-.
~-
In the Matter of:
The Proposed Plan
Union Pacific Railroad
Sludge Pit
------------~---)
The Public Meeting came on for hearing at 7:00 .
p.m. ,
June 18, 1991, at the Quality Inn Convention
Center,
1555 Pocatello Creek Road, pocatello, Bannock
County,
Idaho.
BUB LOISELLE
ANN WILLIA~SON
{JRI GI NA L
J
'.
1
-------
~
~
,
-~
.
1
JUNE 18, 1991
2
7:08 A.M.
3
MR. LOISELLE":
Good evening.
I am going to try
4
to speak without the use of the microphone because I
5
think everybody can hear me.
6
my name is Bub Loiselle.
I am with the
7
Environmental Protection Agency in Seattle, Washington.
8
9
I'll be the moderator "for tonight's public meeting.
With
me tonight is Ann Williamson with EPA.
Ann is a
10
Superfund site manager or she is the person who manages
11
the clean up of Superfund sites.
12
With us also is Boyd Roberts.
Boyd is with the
13
State of Idaho and Boyd will be available after the
14
formal public meeting is over to answer any questions you
15
may have regarding the state's involvement with the
16
Superfund process at the Union Pacific Railroad site.
17
First I would like to welcome you to tonight's
18
19
meeting.
This public meeting is part of the Superfund
process regarding the proposed plan for the Union Pacific
20
Railroad Superfund site located here in Pocatello, Idaho.
21
The proposed plan is the document that describes the
22
EPA's preferred alternative for cleaning up the sludge
23
pit at the Union Pacific Railroad site.
24
The purpose of the public meeting is so the
25
agency can recei""~ comments from the public regarding our!
2
-------
20
21
22
23
24
25
1
preferred alternative for cleaning up the sl~dge pit
2
located at that site.
.
As well we also are interested in
3
receiving comments on the eleven other alternatives that
4
are part of the proposed plan.
~
5
The public comment for this particular proposed
6
plan runs from June 7, 1991, to July 8, 1991, so for
7
those of you who do not wish to submit oral comments this
8
this evening, you will have an opportunity to submit
9
written comments.
And those comments should be submitted
10
to Ann Willjamson.
11
After the c~ose of the public comment period
EPA will consider all substantive comments that are
12
13
received and we will put those in a responsiveness
14
summary.
The comments as well as the responsiveness
15
summary will all be part of the final decision document
16
that details the final cleanup remedy at the Union
17
Pacific Railroad site.
18
19
We scheduled this public meeting for about two
hours and I really don't think we will need that much
time, but for these of you who do wish to speak,
I would
like to suggest that we keep the comments limited to.
somewhere between five and say, ten minutes so everyone
who wishes to speak will. have the opportunity to do so.
~
Also for your convenience we have provided
~
copies of the proposed plan.
They are located at the
~
3
-------
~
~
,
24
25
~
1
back table there.
And if you would like to see
2
additional information regarding the Superfund process at
3
the UPRR site, information detailing the research and the
lnvestigationis available at the Pocatello Library, the
4
5
public library on 812 East Clark Street, as well as if
6
any of you wish to venture over into the great country .of
7
Seattle, we have a duplicate record there also.
8
There is also a sign-up sheet at the back of
9
the room and for those of you who wish to receive
10
information regarding the Union Pacific Railroad site, I
11
encourage you to go ahead and sign up and get on our
12
mailing list.
13
And also since the Sup.rfund process can be so
14
doggoned confusing, we provided a one-page handout back
15
there and it's entitled Superfunds Glossary on one side.
16
It kind of tells you what all the cute little buzz words
17
are that we bureaucrats use when we get into these
18
processes.
19
The other side is entitled Superfund Remedial
20
Response Process.
I think this document will kind you
21
help you understand the ove~all Superfund process a
22
23
little better and how it relates to the Union Pacific
Railroad site.
That's my ten cent speech, so before we get
into Ann Williamson's technical presentation on the Union
4
-------
)
)
15
16
17
18
19
20
21
22
23
24
25
1
Pacific Railroad site, I would like to see if there are
2
any questions or any clarifications that may be needed.
.
3
MR. JACKSON:
Who will pay for the cleanup?
4
~
MR.
LOISELLE:
I will Ann address that.
She
5
is the technical person, and if she wishes to do that
6
now, fine, or if you want to hold that until after her
7
presentation,
I will do whatever.
Why don't you just
8
9
hold that, then, until after that.
If there are no questions on my part, let me
10
just go ahead and get started with the technical
11
presentation and the comment portion of this meeting.
12
So let me officially state for the record that
this'is a public meeting regarding the proposed plan
13
14
detailing the cleanup alternatives for the Union Pacific
Railroad sludge pit.
Today's date is June 18, 1991.
Now I would like to introduce Ann Williamson.
She will give you a technical overview of the site in
question.
Thank you.
MS. WILLIAMSON:
Thanks, Bub.
I am glad to see
that I have at least a- few interested folks from the City
of Pocatello or wherever you are from.
1
I am. not going to use the mike either.
I have
been known to have a voice that carries, so if you can't
.
5
-------
.'
;;
,
~'
1
hear me,
let me know, but I am sure you will be able to.
2
What I would like to do is kind of break down
3
my presentation into three components.
The first
4
component will be just an overview of what's happened up
5
to this point, both in terms of the investigation, what
6
we found out.
And then what we are proposing, what the
7
agency is proposing to do at the site in terms of
8
remediation, how the Union Pacific Railroad will be
9
involved in that process, and then fi~ally what I would
like to do is offer you the opportunity to ask questions
10
11
that we can address where it's not something that you
12
necessarily want to have on the record, if you don't want
13
to make a presentation, feel free to ask questions.
So,
14
you know,
if there is anything that you want to ask or
15
that you want to know abou~ the process or about this
16
site in particular,
feel free to ask me.
17
What I am going to try to do in my technical
18
presentation is to follow what you have in the proposed
19
plan.
As Sub mentioned, it's in the back of .the room.
I
20
will just ki~d 0f go through that.
Most of my
21
posterboard and the overheads that I have you can find in
22
that document,
If you want to follow along if you can't
23
In the document.
see,
they are
24
Sasi::ally YOll know the site in Pocatello,
25
that's why we a~e here.
Specifically it's located off of
6
-------
1
u.s. Highway 30 and you probably haven't seen it, or if
2
you have tried to see it, you can't see it, because it's
~
3
not something that's obvious from the highway.
In fact
4
the Pacific Hide & Fur property is directly north and a
~
5
bit -- well,
just say it's directly north of the
let's
6
And Great Western Maltirtg is to the south.
sludge pit.
7
So it's sandwiched in between those two pieces of
8
property.
9
Both that posterboard, which we will come and
10
look at later, and this map give you kind of a better
11
feel for exactly where that is, where the site is at.
12
Here is the sludge pit, this black line.
It's a
, ~
.w
residential area [indicat1ng), and ,State Route 30
14
(indicating) .
So my discussion is going to be limited to
15
16
that ar~a which was investigated.
This is a Superfund site.
It's listed on the
17
national priorities list.
That occurred back in 1984
18
19
The reason for that is that groundwater
officially.
contamination was suspected on the property and in fact
20
was confirmed and the primary suspect for that
21
contamination was the sludge pit.
As a result of the
22
23
listing of the site, the Union Pacific Railroad was
contacted ,as a potentially Yesponsible party and agreed
,
24
to investigate the site.
That process is part of the
25
Superfund process and we go about that by looking for
.
7
-------
~
~
,
.
1
responsible parties, once they have been identified, we
enter into legal agreements with them to perform remedial
2
3
investigations and' feasibility studies, and then they
4
begin the process.
And that's exactly what took place
5
with the Union Pacific.
6
They evaluated not only the groundwater
7
contamination but they looked ~t what was in the sludge
8
pit, and the sludge pit was an active part of their
9
facility, if you will, for approximately 22 years.
It
10
was used as a disposal sLte for treated wastewaters that
11
they collected from their treatment -- or from their
12
properties which they ran through a treatment, wastewater
13
treatment facility that's also located on the site.
The
14
residual material or the sludge was disposed in a
15
sunlight pit for a period of years.
16
They hired a contractor, who has spent since
17
1985 -- is that right, Vince?
-- since 1985 evaluating
18
contaminants in the sludge and contaminants in the
19,
groundwater and based on the results of that
20
investigatio~, it's been determined that the sludge
21
contains certain metals, certain petroleum hydrocarbons,
22
23
other volatile organic compounds, semivolatile organic
compounds, and all of those contaminants will be dealt
24
with in this remedial operation; in other words, the
25
contaminant will be dealt -- treated in some way, shape,
8
-------
1
2
or form and the risk posed by the contamination from the
sludge pit and from the groundwater will be reduced to
~
3
levels that will not be harmful to public health or the
4
environment.
~
5
I mentioned the groundwater.
It's contaminated
6
as well and the source of that contamination has been
7
identified primarily as the sludge pit.
There are two
8
aquifers in the area below the sludge p1t, and I have put
actually this overhead up to distinguish what we know to
9
10
be or what we presume to be the extent of the soil
11
contamination around the sludge pit, and we have also or
12
the Union Pacific Railroad contractors also did that for
13
the groundwater contamination.
Again, this is the sludge
14
pit here (indicating) and the dashed line, dotted area
IS- (indicating) i~ the extent of the groundwater
16
contamination.
17
18
And what we are finding and what's been found
is that the surface of the upper aquifer has around a
19
two-inch bit of oily film of petroleum hydrocarbon that
20
migrated down through the soils to the surface of the
21
water table from the sludge pit, and there are other.
22
contaminants in that liquid film as well as in the
23
.groundwater, and because we are not sure, nor has there
been sufficient information obtained to date to
,
24
25
contribute that contamination entirely to Union Pacific
~
9
-------
t-
,
!\
-./
~
1
Railroad's operations at this site, they will be doing
some additional groundwater sampling and analyses, and
2
3
they will also be doing some soil sampling and analyses
4
to determine what background concentrations are at this
5
-- well,
in this area.
6
Just really quickly,
too,
because it's hard to
7
visualize a flat surface, these are cross sections of the
8
9-
sludge pit just -- what I want you to take away from this
overhead is this material and this material is the'
10
sludge.
This material here is a sandy gravel,
and it's
11
been difficult to penetrate both because of its geologic
12
nature and also. because the contaminant has migrated down
13
through this material (indicating), has solidified or
cemented the underlying gravels.
14
15
And so part of the problem that we ar > hav ing '::';.".. :<.
in identifying the extent of contamination on the
16
17
property is that we can't necessarily drill down to the
18
19
surface of the water table and get an accurate sens. for
what the levels of contamination might be.
That's why
20
one of the components, and I'll be getting into that when
21
I talk about the preferred alternatives~ will be to
22
address potential contamination in this gravel by soil
23
flushing, which is kind of a novel approach to dealing
24
with the unexcavated but potentially contaminated soil.
25
I mentioned that we know there is contamination
10
-------
1
at the site both from the sludge in the soil and that the
2
groundwater is contaminated but what I haven't discussed
.
3
or what I haven't told you is that there are federal and
4
( ,
~
state requirements for cleaning up contaminated materials
5
and they range from regulations and rules that have been
6
put into place to no rules that are in place, nothing to
7
guide you.
8
9
With respect to the sludge in the soil, we
don't have the kind of rules and regulations in place
10
that we do for groundwater, so part of the exercise that
11
the contractor performed for evaluation of the site was
12
to determine what the risks were at the site to human
13
health and to the environment and to try to establish
14
remedial goals such that if material was going to be
15
cleaned up, that it would eliminate or essentially
16
eliminate or get within a range that was acceptable to
17
the agency and to you, the general public, where the risk
18
19
to you would be significantly reduced.
Those goals exist today for treatment of the
20
sludge and the soil.
However, in many cases we don't
21
have the technology to reduce contaminant levels to the
22
point where the residual would not cause significant
23
impact to human health and the environment.
1
24
Additionally, we don't know what the background
25
concentrations are of these contaminants in the area,and
,
11
-------
~
~
,
t
1
perhaps they may be significantly above these risk
2
levels.
So that's why the Union Pacific Railroad is
3
going to be going back out to determine what the
4
background concentrations are.
5
The agency is not in a position to say
6
absolutely right now what the remedial goals will be for
7
the sludge and the soil.
That determine will be made
8
9
once we get the information on background concentrations
and we'll be better able to evaluate~to what level the
10
Union Pacific Railroad needs to clean up the site,
11
specifically for the sludge and the soil.
With respect to the groundwater, there are
12
13
promulgated federal and state standards and there are
14
safe drinking water standards, so you as the general
15
public, if you were going to go out and drink the water,
16
would want to be assured that you weren't getting
17
contaminants that were above those levels.
18
19
Right now at thii particular site none of the
contaminants in the groundwater exceed those levels, they
20
are all below those levels.
However, they do exceed
21
proposed, several proposed levels and, also, because we
22
are talking about two aquifers, the upper aquifer being
23
the more contaminated of the two, migration down to the
24
lower aquifer could occur and that's where your source of
25
groundwater is in Pocatello.
We want to prevent that
12
-------
11'
12
1
from happening, and so, consequently, we'll be treating
or the Union Pacific Railroad will be treating the
4
2
3
groundwater to achieve levels that will stay protective
~
4
and will not unduly harm you at some future point.
5
So I guess what I'll do now is get into the
6
proposed alternatives, and as Bub mentioned, there are
7
twelve that were evaluated at the site.
Rather than try
8
to go through each one individually I am going to talk
9
10
about the one that the agency prefers, and it's
highlighted here as No.5.
It's also in your proposed
plan.
And then what I'll do is I'll just sort of
generally describe the differences between it and the
13
remaining eleven alternatives.
14
Alternative 5 essentially would have the Union
15
16
Pacific Railroad excavate sludge, contaminated sludge in
soil at approximately 4,200 cubic yards of that material.
17
It's estimated that's what could be practicably
18
excavated.
That material would then be hauled off the
19,
20
property and taken to a RCRA, Resource Conservation
Recovery Act, facility in Utah where it will be placed.
21
The pit will be back filled with clean material and
22
capped with a low permeability cap.
23
Prior to doing that, however, we know that
#
24
there is probable contamination of soil beneath the
25
excavated material that we don't want to just leave in
,
13
-------
'~
~
\
~
1
place and not treat, so we are proposing to put in a soil
flushing unit which would essentially look like a grid of
2
3
perforated pipes with holes in it, water percolated
4
through that system and allowed to get into those swales,
5
which would then allow it to percolate down to the
6
surface of the groundwater, where it would be pumped and
7
treated along with the oth~r contaminated groundwater.
8
There are two groundwater treatment components
9
that were considered for all the alternatives and the one
10
that was selected or the one that we are proposing to
11
have the Union Pacific implement, they have an existing
12
oil-water separator unit onsite as well as a dissolved
13
air" flotation unit, and essentially what those two
14
treatment processes do is remove the oily material off
15
the surface -- from the groundwater that's extracted and
16
then the dissolved air flotation unit allows anything
17
else that's remaining in that groundwater to volatilize,
18
19
like if there were any volatile organic compounds in it,
volatilize and then the water would be sentoffsite to
20
the Pocatello publicly-owned treatment works for further
21
treatment or whatever, and that would be an ultimate end
22
point.
And that's the alternative, the groundwater
23
alternative that's a component of the preferred
24
alternative.
25
The other one,
just so I don't have to go back
14
-------
1
and describe it to you again but so you get a sense of
2
what it was or what it is, the difference is that there
(
3
would be a carbon absorption unit instead of the
4
dissolved air flotation unit put onsite.
~
There isn't one
5
there yet, they have the dissolved air flotation unit.
6
And essentially what it would do, its ability to remove
7
to considerably lower levels volatiles and other -- well,
8
biological contaminants int.he groundwate~ is much better
9
than the dissolved air flotation unit; however, we don't
10 feel that the type of contaminant in the groundwater
11
necessarily warrants anything in addition to the
12
dissolved air flotation unit.
So that's why we opted for
13
preferring that groundwater treat~ent.
14
And Alternative 5, as I mentioned, the treated
15
groundwater would be sent to the POTW, and the other, it
16
would be recirculated back through the site or through
17
the system, through the perforated pipes that I was
mentioning and used in the soil flushing component of the
18
19
treatment process.
And, as I mentioned before, a low
20
permeability cap would be placed on the site and, again,
21
the material would be hauled off the property, using the
22
trains. to haul the material down to the Utah facility.
23
Okay, that's the preferred alternative.
24
The differences between the preferred
I
25
alternative just very briefly are Alternatives 9 through
.
15
-------
l-
"
,
~
1
12 involve incineration of sludge and soil, whether
2
onsite or offsite.
The evaluation that the Union Pacific
3
Railroad's contractor performed on the viability of this
particular alternative didn't demonstrate to our
4
5
satisfaction that what we wouldn't end up with was
6
actually hazardous waste, when we didn't have hazardous
7
waste necessarily to begin with.
The concentration of
8
9-
metals and other contaminants in the residual ash would
most likely be much higher than what's in existence today
10
in the sludge itself.
Also, the type of contaminants in
11
the sludge, primarily cadmium and chromium, which are
12
metals, may be difficult to handle.
Some incinerators
13
are not capable of handling emissions of those materials.
14
Alternatives 7 and 8 involve solidification of
15
the sludge and soil, and, again, the evaluation that" the
16
contractor performed on those alternatives indicated that
because of the oily nature of the sludge it would be very
difficult to ensure that once solidified it would stay
17
18
19
solidified for the duration of the fix at the site.
So
20
21
w~thout being absolutely sure that we would have a
successful treatment of the sludge and soil, we didn't
22
feel that that was a preferable approach.
23
Alternative 6 is identical to Alternative 5;
24
however,
it would have used the carbon absorption
25
groundwater treatment component as opposed to the OAF as
16.
-------
1
I mentioned.
2
Alternatives 3 and 4 are very similar to
~
3
Alternatives 5 and 6 in that the sludge and soil would be
excavated and hauled offsite but there would be no cap
~
4
5
placed over the sludge pit and theoretically the
6
excavation of the materials would proceed down to even
7
the groundwater table if it was technically practicable,
8
which we don't believe that it is.
So we opted for
9
Alternative 5 because it had the low permeability cap as
10
a component, which would prevent leaching of any
11
contaminants from the surface of the sludge pit or from
12
13
the remaining soil beneath the excavated area down to
recontaminate the water table.
14
And Alternatives 1 and 2, Alternative 1 is a no
15
action alternative which is required under the Superfund
16
We have to use it as a baseline for evaluating all
Act.
17
the other alternatives.
It doesn't actually involve any
18
remedial activities.
The only thing that would take
19
20
place is groundwater monitoring over a period of 30
years.
21
And Alternative 2 are institutional controls
22
alternatives which would merely provide deed restrictions
23
that would limit the type of land use and future
-;
24
groundwater use on the property and would include
25
installation of a six-foot-high barbed wire fence or
.
17
-------
~
~
,
~
1
2
fence around the sludge pit, and if residents or
businesses were to locate to the property, the alternate
3
drinking water supply would be made available to those
4
people.
5
I should mention that in Alternative 5 and in
6
all the other alternatives institutional controls are a
7
part of that alternative, as is dust control and air
8
9
monitoring, which is, we believe, necessary during any
remediation at the site.
We wouldn't want to be
10
impacting air quality unn~cessarily and, therefore, there
11
would be dust control measures put into place.
12
And finally, as I mentioned before, the
13
alternate
drinking water supply would be provided in all
14
of these alternatives should residents or businesses
15
choose to locate to the property.
16
Finally, I just want to let you know that the
17
proposed plan is kind of the first official step that we
18
take to inform you as the general public about what it is
19
we are proposing to do at a Superfund site and to give
you the opportunity to ask some questions or give us
20
21
input, but that it goes much farther than just this.
22
I have "iecently completed. a document that is
23
just in draft and will go out for review, and it's the
24
record of decisiQn, and what it does is it takes all of
25
the information that was produced by the Union Pacific
18
-------
.22
23
24
25
1
Railroad and their contractors and condenses it into a
2
form that we can use and the Union Pacific can use at a
~.
3
later date to make determinations about how to remediate
4
~
the property.
But we go through a fairly sophisticated
5
process i~ order to reach decisions about why we prefer
6
one alternative over another, and these are the nine
7
criteria that we used (indicating).
8
9
.With respect to the alternative that we prefer,
we-have done an evaluation of these criteria and we have
10
compared the alternative to all twelve of the others --
11
it's not going to fit on here -- and as you can see with
12
13
respect to what we consider to be a gauge of the
performance of the alternative compared to the criteria
14
and compared to the othe~ alternatives, Alternative 5
15
along with Alt€~native 6 rank or performs the best when
16
we do the comparison.
This information is not in the
17
proposed plan, it's something that we have just recently
18
19
completed with respect to preparing this final record of"
decision document.
20
That's really all I had.
I guess what I would
21
like to do is emphasize that if you do have any
questions,
if you have any concerns, this is your forum
to ask us questions.
It's an opportunity for you to get
t
up and give us formal comments on what we are proposing
to do at the site and it's your opportunity to review
.
19
-------
~
~
.
~
1
what we're suggesting is the best way to deal with
2
contamination on the property.
if you feel
However,
3
otherwise, we are looking to have your input.
4
I guess I should answer your question first
5
just because I didn't mention cost at all in my
6
presentation.
This particular alternative would cost 3..8
7
million dollars to implement.
That includes both the
8
9
sludge and soil excavation, back filling,. disposal,
10
capping, and also the groundwat~r treatment component.
The range, and there is -- it's discussed more in detail
11
in the proposed plan, the range goes from, oh, $670,000
12
for the groundwater monitoring in the no action remedy up
13
to, I don't know, 43 million or something like that for
14
the final incineration alternative.
15
This one ranks pretty cheaply, I would say,
16
among those considered, but we feel very confident that
17
if properly implemented, the site will be cleaned up and
made safe for the public in a fairly short period of
18
19
I think we are estimating, what,. four to six
time.
20
months total for excavation of the s~udge and soil, .
21
installation of the soil flushing component and back
22
23
filling and capping of the pit with groundwater
treatment.
We are estimating around five years and we
24
won't know for sure if that's true until we start
25
implementation of the treatment.
20
-------
25
1
So that's it for me.
Bub, did you want to --
2
~
MR. LOISELLE:
Are there any questions that you
3
may have on the technical side right now?
4
~
MR. JACKSON:
I am Tim Jackson with the Idaho
5
State Journal.
I wanted to ask,. it looked like
6
Alternatives 5 and 6, one of the main differences was
7
offsite groundwater discharge versus onsite groundwater
8
9
discharge.
MS. WILLIAMSON:
Right.
10
Could you describe the difference
MR. JACKSON:
11
between those t~ and how much of a difference in cost
12
that entails and why you chose the 6ffsite groundwater
13
discharge instead of the onsite?
14
On Alternative 5 you were
MS. WILLIAMSON:
15
right, the onsite groundwater discharge would be the
16
water that had been treated in the carbon absorption unit
17
and going through oil-water separation would be clean
18
enough to be used to treat or to use in the soil flushing
19
component, so rather than using water that comes onto the
p~operty already from Batiste Springs which. would be used
I .
20
21
in the other alternative, in the- DAF (indicating)
22
alternative,
the circulation, recirculation of the
23
treated groundwater under Alternative 6 would be achieved
~
24
without bringing new water onto the property.
With respect to the difference in cost
4
21
-------
t'
',",
.
~
1
associated with that, I am not so sure that that's where
2
the increase or the considerable increase in cost arises.
3
I think it's with the actual carbon absorption unit
4
itself.
I would have to -- let's see if we can look here
5
on Alternative 6 -- we don't break down in this document
6
what the costs are for each of the components, but you
7
can see that capital costs for Alternative 5 and
8
Alternative 6 are -- is about a $700,000 difference and 0
9
and M with respect to dealing with the carbon filters,
10
because they have to be cleaned periodically,
kind of
is
11
I can't tell you exactly ~nat the cost
a gauge.
- .'. .
12
difference is.
13
14
MR. JACKSON:
Can you tell us again, please,
why the carbon absorption is not needed?
15
MS. WILLIAMSON:
The type of contaminant that's .- l'
16
being treated at the site is a nonaqueous phase liquid
_. .
17
petroleum hydrocarbon that's on the surface of the upper
18
aquifer, which is of the water table, and the existing
19
oil-water separator and dissolved air flotation units are
20 . doing a sufficient job in removing contaminants like that
21
from the wastewater onsite and theoretically they would
22
do equally as adequate a job in treating the upper
23
aquifer groundwater without having to go to a carbon
24
absorpt10n unit.
25
What you get with the carbon absorption unit is
22
-------
1
additional treatment of biological materials that
are in
2
the groundwater that we aren't seeing and needing
..
3
4
treatment or this additional treatment or warranting the
And, in
'#.
cost associated with this additional treatment.
5
fact, the POTW can treat any residual contamination like
6
volatile organic compounds in their facility.
7
MR. JACKSON:
Is any of this remediation going
8
on right now? . What has happened so far?
9
MS. WILLIAMSON:
NO, there has been no
10
11
remediation at the proper~y.
There is a fence around the
site so access is limited to birds and other creatures
12
that might get onto it, but I don't think any individuals
13
are capable of getting onto that, onto the pit itself.
14
Virginia Larson.
MS. LARSON:
15
I was just wondering, has air stripping been
16
I understood that you hadn't gotten the
looked into?
17
level of contaminants yet of the groundwater, that you
18
didn't know quite what the level was.
19
Well, the type of contaminants
MS. WILLIAMSON:
20
that we are primarily interested in ~valuating in greater
21
detail in the groundwater are metal, so I am not sure
22
that the air stripping necessarily would get at those
23
24
But air stripping was one of
'j
particular contaminants.
the treatment .options considered by Union Pacific
25
Railroad's contractors.
.
23
-------
),
,~
1
~
1
MS. LARSON:
Well, air stripping does quite
2
similar to what carbon absorption does but not the cost
3
for replacement on your carbon and for your carbon tet
4
and that type of thing, I didn't understand that it was
5
the metal was the only thing you hadn't gotten the level
6
of contamination from yet.
7
MS. WILLIAMSON:
Right, I think in this
8
document,
I think what you probably need to see is
some
9
more detailed remedial investigation document and that at
10
some point when the record of decision is finalized, that
11
would give you additional informa~ion with respect to all
12
of the options that were considered and the reasons why
13
they were rejected.
And those documents are available
14
right now at the Pocatello Public Library.
15
MR. BROWN:
My name is Gordon Brown.
16
On Page 4 of the publication that you gave us
17
today it comments on the groundwaters and the two
18
different aquifers that exist, and if I may read that, it
19
says, "Groundwater beneath the sludge pit occurs in
20
distinct water bearing
zones,"
and you talked about the
21
first aquifer and then the second aquifer~ the upper and
22
the lower, and it.-indicates that they are separated by
23
clay layer, and then you talk about the groundwater flow
24
direction is generally to the north~est, and the lower
25
aquifer is very productive drinking water and goes toward
24
-------
22
23
25
1
the Supply Well no. 32.
And then it indicates that no
2
water supply wells in the ar~a have been indicated as
~
3
originating from the upper aquifer.
Do we have a handle
4
.
on what is happening with the upper aquifer, what it
5
dumps into or what the water flow of that is in
6
comparison to the lower aquifer?
7
MS. WILLIAMSON:
Yes, basically -- I don't know
8
if I have something here that -- no, that doesn't really
9
do-it.
10
MR. BROWN:
While you are looking for that --
11
MS. WILLIAMSON:
This doesn't actually show the
12
Portneuf River.
Basically the concern with the upper
13
aquifer is not that it's been used, and like this states,
14
there have been no wells identified in the upper aquifer.
15
16
The primary reason for that is there is not a sufficient
amount of water available for use and because the lower
17
aquifer is so much more productive, it's the preferable
18
19
aquifer.
That's not to say that you couldn't put a well
in the upper aquifer and use it for your drinking water.
20
But right now it's just not being used that way.
21
MR. BROWN:
What about contamination of surface
water,
though?
I mean you have got the Portneuf there
and on Page 5 you indicate the Swanson Road Spring and
,
24
Batiste-Papoose Spring.
Those springs are probably fed
by the --
.
25
-------
'}-
-------
1
implement the remedy, would probably only be able to
2
excavate roughly 4,200 cubic yards of sludge and soil.
t
3
And that once you got to this gravel layer (indicating),
which wa~ difficult to excavate, technically difficult to
~
4
5
excavate, you would then locate the soil flushing system,
6
which is the perforated pipe, and then put water through.
7
that system, which is sort of a passive system, and allow
8
9
that to percolate down through this gravel to the surface
of the water table, which is the upper aquifer.
10
11
And then treat it and then pump it
MR. BROWN:
out and transport it to --
12
To the.POTW in our preferred
MS. WILLIAMSON:
13
alternative but in the carbon absorption alternative it
14
would. be recirculated through the system and used in the
15. soil flushing.
16
How thick is the clay layer between
MR. BROWN:
17
the upper and the lower aquifer?
18
I don't know.
It's not
MS. WILLIAMSON:
19
consistent, it's not a consistent unit across.
20
MR. LASCKO:
Directly under the sludge pit at
21
least lO.feet, and sometimes 15 or 20 feet thick.
22
MR. BROWN:
.The last question, I fail to
23
24
understand on the alternatives why when you look at the
r
proposed sheet that you had that shows all of the
25
alternatives, on No.3 the only difference that I
.
can see
27
-------
,.
{J!
,
.
1
between No.3 and No.5 is the permeability cap; is that
2
correct?
3
Right, no, it's not, and I
MS. WILLIAMSON:
4
mentioned in my discussion and it's discussed in a little
5
bit more detail on Page 8 u'nder that particular
6
alternative that what the Union Pacific proposed to do in
7
that alternative was to excavate literally to the surface
8
9
of the groundwater -- or to the surface of the water
table if that was at all possible.
So rather than
10
setting a limit at 4,200 cubic yards, they would go down
11
until they couldn't go down anymore.
like I think I
But,
12
mentione~, we feel that it's probably not going to be
13
technically practicable to excavate a lot of the gravely
14
material beneath the sludge and soil.
15
16
MR. L0ISELLE:
Any other questions of Ann?
(No response.)
17
What I would like to suggest is
MR. LOISELLE:
18
19
we take a five or ten minute break and then we will come
back and any of you folks that wish to give a
20
presentation or provi~e public comments regarding Ann's
21
proposal or in general the proposed plan for the UPRR
22
23
site, we will get down with that.
Thank you.
(Short recess.)
24
MR. . LOISELLE:
I guess I would like to go back
25
on the record now and open the remainder of this public
28
-------
24
25
1
meeting up to any public comment, so any of you who wish
2
to give testimony or whatever, please feel free to do so.
i
3
My only request is that you come up to the lectern and
speak clearly so that we can get it recorded and have a
~
4.
5
clean transcript.
6
So anybody that wishes to give public
7
testimony, please do so at this time.
The audience is
8
9
limited enough that I don't have to have a sign-up sheet
and then call on everybody, so don't be embarrassed, feel
10
free, let's rock and roll here.
And I'll even shut up
11
for at. least five minutes in case there is some nervous
12
butterflies or whatnot and people are trying to work up
13
their courage, but after about five minutes or so, if
14
nobody shows up, I will feel free to kind of call an end
15
to the official public meeting and then we can discuss
16
whatever other issues that you folks want to kick around.
17
Is that acceptable to everybody?
18
(No response.)
19
(Paus~ in the proceedings.)
20
MR. LOISELLE:
If there are no individuals that
21
wish to give comment at this time or give testimony, then
2.2
I would like to terminate the official public meeting at
23
about I guess it's 8:15 on today's date; June 18, 1991,
,
and we'll stick around a while after this meeting to
answer and address any questions or anything like. that.
.
29
-------
i)-
~
9
10'
11
12
13
14
15
16
17
18
19
20
21
22
23
\1
24
25
.
1
So I want to thank all of you for coming out and
2
participating, and those of you who are on the mailing
3
list will be receiving. information in the future
4
regarding this Union Pacific Railroad site.
5
Again thank you very much.
6
(Hearing adjourned at 8:17 p.m.)
7
8
*
*
*
*
*
30
BUCHANAN REPORTING SERVICE
-------
1
2
3
4
5
6
i 7
I
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
REPORTER'S CERTIFICATE
.
STATE OF IDAHO
10
County of Bannock
ss
I, PAUL D. BUCHANAN, CSR, DO HEREBY CERTIFY
that I reported in stenotype the evidence and proceedings
adduced in the above and foregoing cause, and that I
thereafter transcribed said stenotype notes into longhand
typewriting, and that the within and foregoing
constitutes and is a full, true, and correct copy of the
transcript consisting of Pages One through Thirty,
inclusive.
IN WITNESS WHEREOF, I have hereunto set my hand
this, the 25th day of June, 1991.
-l?;;~ /)~/ ~1 ~
'. .!'", '"
..G~_! -<,-C.L c'''--,' ".r ~A-......-
AULD. BUCHANAN, CSR and
Notary Public, in and for
the State of Idaho
('
.
31
-------
I)'
u.s. ENVIRONMENTAL PROTECTION AGENCY
REGION 10
1200 sixth Avenue
Seattle, Washington 98101
~
ADMINISTRATIVE RECORD INDEX
for
UNION PACIFIC RAILROADSLVDGE PIT SUPERFUND SITE
Pocatello, Idaho
~
June 28, 1991
-------
UNION PACIFIC ADMINISTRATIVE RECORD INDEX
HEADING:
1. o.
SITE IDENTIFICATION
.'
SUB-HEAD:
1.1.
Background
- 0001 Microfilm Reel
DATE: 12/01/80 PAGES:
AUTHOR: R. C. FUENTES/EPA
ADDRESSEE: FILE/EPA
DESCRIPTION: POTENTIAL HAZARDOUS WASTE SITE LOG FOR SITE #810.
SHOWING LOCATION OF SITE
1. 1.
Frame Begins
Ends
(j)
2
INCLUDES MAP
1. 1.
Microfilm Reel
PAGES:
Frame Begins
Ends
- 0002
DATE: 01/01/01
AUTHOR: /
ADDRESSEE: /
DESCRIPTION: BRIEF SUMMARY OF HAZARDOUS
RAILROAD, POCATELLO SITE
1
WASTE HISTORY OF UNION PACIFIC
SUB-HEAD:
1. 2.
Notification/Site Inspection Reportrs
- 0001 Microfilm Reel
DATE: 02/09/83 PAGES:
AUTHOR: RICH FULLNER/EPA
ADDRESSEE: FILE/EPA
DESCRIPTION: FILE REVIEW CHECKLIST AND WASTE INFORMATION ABOUT UNION PACIFIC
RAIT~OAD, POCATELLO
1. 2.
Frame Begins
Ends
3
SUB-HEAD:
1. 3.
Preliminary Assessment (PA) Report
1. 3. - - 0001 Microfilm Reel
DATE: 12/27/79 PAGES:
AUTHOR: HOWARD BURKHARDTjEPA
ADDRESSEE: FILE/EPA
DESCRIPTION: POTENTIAL HAZARDOUS WASTE S~TE IDENTIFICATION AND PRELIMINARY
ASSESSMENT FORM ON UNION P,.CIFIC RAILROAD, POCATELLO
Frame Begins
Ends
4
f
-------
UNION PACIFIC ADMINISTRATIVE RECORD INDEX
1. 3.
Microfilm Reel
PAGES:
Frame Begins
Ends
.t'
- 0002
DATE: 12/01/82
AUTHOR: /EPA
ADDRESSEE: FILE/EPA
DESCRIPTION: POTENTIAL HAZARDOUS WASTE SITE IDENTIFICATION & PRELIMINARY
ASSESSMENT FORM ON UNION PACIFIC RAILROAD, POCATELLO. WITH
TENATIVE DISPOSITION FORM DATED 04/30/80 ATTACHED
3
~
SUB-HEAD:
1. 4.
Site Investigation (SI) Report
- 0001 Microfilm Reel
DATE: 12/27/79 PAGES: 11
AUTHOR: HOWARD BURKHARDT/EPA
ADDRESSEE: FILE/EPA
DESCRIPTION: POTENTIAL HAZARDOUS WASTE SITE, SITE INSPECTION REPORT ON UNION
PACIFIC RAILROAD, POCATELLO, INCLUDES SURFACE IMPOUNDMENTS SITE
INSPECTION REPORT
1. 4.
Frame Begins
Ends
- 0002 "Microfilm Reel
DATE: 07/25/83 PAGES:
AUTHOR: RON MOCZYGEMBA/EPA
ADDRESSEE: GEORGE HOFER/EPA "
DESCRIPTION: MEMORANDUM: REFERENCE RCRA COMPLIANCE INSPECTION OF UNION
PACIFIC RAILROAD, POCATELLO. INCLUDES FACT SHEET ON UNION
PACIFIC RAILROAD FACILITY AND LETTER FROM IDAHO STATE DEPARTMENT
OF HEALTH & WELFARE
1. 4.
Frame "Begins
Ends
7
\J
-------
. .
UNION PACIFIC ADMINISTRATIVE RECORD INDEX
HEADING:
2. O.
REMOVAL RESPONSE
(
SUB-HEAD:
2. 1.
Correspondence
- 0001 Microfilm Reel
DATE: 11/22/88 PAGES: 2
AUTHOR: J. R. BERAN/UNION PACIFIC RAILROAD
ADDRESSEE: STEVE R. HILL/IDAHO DEPARTMENT OF HEALTH & WELFARE
DESCRIPTION: DISPOSAL OF BARRELS, ORIG~NALLY SOLD TO WILLIAM SCRAP
04/25/86
2. 1.
Frame Begins
Ends
'.tl
METAL ON
2. 1.
- 0002 Microfilm Reel
DATE: 11/28/89 PAGES: 2 .
AUTHOR: J. R. BERAN/UNION PACIFIC RAILROAD
ADDRESSEE: STEVE R. HILL/IDAHO DEPARTMENT OF HEALTH & WELFARE
DESCRIPTION: DISPOSAL OF BARRELS FROM UNION PACIFIC RAILROAD, POCATELLO
COVER LETTER FOR HEALTH AND SAFETY PLAN
Frame Begins
Ends
SITE.
- 0003 Microfilm Reel
DATE: 01/12/89 PAGES: 15
AUTHOR: J. R. BERAN/UNION PACIFIC RAILROAD
-.. ADDRESSEE: STEVE R. HILL/IDAHO DEPARTMENT 9F HEALTH. & WELFARE
DESCRIPTION: STATUS REPORT ON DRUMS FROM UNION PACIFIC RAILROAD, POCATELLO
SITE. INCLUDES LETTER FROM USPCI, INC. AND WASTE MANIFESTS
2. 1.
Frame Begins
Ends
SUB-HEAD:
2. 2.
Reports/Data
2. 2.
- 0001 Microfilm Reel
DATE: 10/18/88 PAGES: 15
AUTHOR: BOB KENNEDY & P. H. GOVER/HYDROCARBON
ADDRESSEE: / .
DESCRIPTION: WASTE SAMPLE ANALYSIS
Frame Begins
Ends
RECYCLERS, INC.
c
-------
"
'.
UNION PACIFIC ADMINISTRATIVE RECORD INDEX
~,
HEADING:
3. O.
PHASE I INVESTIGATION (NON-CERCLA)
SUB-HEAD:
3. 1.
Correspondence
!J
- 0001 Microfilm Reel
DATE: 09/04/84 PAGES: 2
AUTHOR: BRADLEY D. HARR/IDAHO DEPARTMENT OF HEALTH & WELFARE
ADDRESSEE: A. D. WILLIAMS/UNION PACIFIC RAILROAD
DESCRIPTION: REPLY TO UNION PACIFIC RAILROAD'S REQUEST TO CAP THE
SITE, PROVIDING DATA, WHY CAPPING IS NOT RECOMMENDED
POCATELLO
3. 1.
Frame Begins
Ends
3. 1.. - 0002 Microfilm Reel
DATE: 10/03/85 PAGES:
AUTHOR: S. J. MC LAUGHLIN/UNION
ADDRESSEE: NEIL E. THOMPSON/EPA
DESCRIPTION: LETTER: TRANSMITTAL OF
Frame Begins
Ends
1
PACIFIC RAILROAD
WORK PLAN FOR PHASE I
3. 1.
Frame Begins
Ends
- 0003 Microfilm Reel
DATE: 12/01/86 PAGES:
AUTHOR: S. J. MC LAUGHLIN/UNION
ADDRESSEE: NEIL E. THOMPSON/EPA
DESCRIPTION: LETTER: TRANS1HTTAL OF
2
PACIFIC RAILROAD
PHASE I
II~"ESTIGATIOrJ
3. 1.
Microfilm Reel
PAGES:
Frame Begins,
Ends
- 0004
DATE: 01/22/88
AUTHOR: TED WALL/EPA
ADDRESSEE: BILL SCHMIDT/EPA
DESCRIPTION: REQUESTING QUALITY ASSURANCE REVIEW ON DATA DEVELOPED
PACIFIC RAILROAD FOR THE PHASE I INVESTIGATION REPORT
1
BY UNION
3. 1.
Frame Begins
Ends
- 0005 Microfilm Reel
DATE: 03/01/88 PAGES: 3
AUTHOR: J. R. BERAN/UNION PACIFIC RAILROAD
. ADDRESSEE: TED WALLjEPA
DESCRIPTION: LETTER: POCATELLO SLUDGE PIT - MATERIALS DUMPED, LOCATION, AND
POSSIBLE OTHtR USERS
,
-------
"
UNION PACIFIC ADMINISTRATIVE RECORD INDEX
- 0006 Microfilm Reel
DATE: 03/24/88 PAGES:
AUTHOR: RALEIGH FARLOW/EPA
ADDRESSEE: DAVID FRANK/EPA
DESCRIPTION: MEMORANDUM: REVIEW OF POCATELLO SLUDGE PIT INVESTIGATION REPORT
3. 1.
Frame Begins
1
Ends
1
{I
2
~
3. 1.
- 0007 Microfilm Reel
DATE: 03/28/88 . PAGES: 5
AUTHOR: ENVIRONMENTAL SERVICES DIVISION
ADDRESSEE: TED WALL/EPA
DESCRIPTION: MEMORANDUM: REVIEW OF PHASE I
MAPS OF UPPER & LOWER AQUIFERS
Frame Begins
Ends
TEAM/EPA
INVESTIGATION REPORT.
INCLUDES 2
3. 1.
- 0008 Microfilm Reel
DATE: 04/14/88 PAGES: 8
AUTHOR: RICH REED/IDAHO DEPARTMENT OF HEALTH & WELFARE
ADDRESSEE: DEAN NYGARD/IDAHO DEPARTMENT OF HEALTH & WELFARE
DESCRIPTION: MEMORANDUM: REVIEW OF PHASE I INVESTIGATION REPORT.
ASSORETED ACQUIFER MAPS
Frame Begins
Ends.
INCLUDES
3. 1.
- 0009 Microfilm Reel
DATE: 06/27/88 PAGES:
AUTHOR: DAVID FRANK/EPA
ADDRESSEE: TED WALL/EPA
DESCRIPTION: MEMORANDUM: EVALUATION OF UNION
INVESTIGATION ANALYTICAL METHODS
Frame Begins
Ends
2
PACIFIC RAILROAD'S REMEDIAL
3. 1.
- 0010 Microfilm Reel
DATE: 12/18/88 PAGES:
AUTHOR: LEIGH WOODRUFF/HEAS
ADDRESSEE: JERRY MUTH/EPA
DESCRIPTION: RECORD OF TELEPHONE CONVERSATION CONCERNING TESTING NON-TARGET
LIST COMPOUNDS
Frame Begins
Ends
1
3. 1.
- 0011 Microfilm Reel
DATE: 01/04/89 PAGES: 2
AUTHOR: ROBERT WILKOSZ/IDAHO DEPARTMENT OF HEALTH & WELFARE
ADDRESSEE: ELIZABETH WADDELL/EPA
DESCRIPTION: LETTER: REVIEW OF THE PHASE I INVESTIGATION REPORT AND THE
PROJECT'S RELATION TO IDAHO'S AIR QUALITY REGULATIONS
Frame Begins
Ends
f/
-------
'.
UNION PACIFIC ADMINISTRATIVE RECORD INDEX
,
- 0012 Microfilm Reel
DATE: 01/06/89 . PAGES:
AUTHOR: TED WALL/EPA
ADDRESSEE: ELIZABETH WADDELL/EPA
DESCRIPTION: MEMORANDUM: REVIEW OF THE
UNLIKELY OCCURRENCE OF AIR
& SLUDGE DISTURBANCE
1
3. 1.
Frame Begins
1
Ends
1
(!.I
PHASE I INVESTIGATION REPORT AND THE
QUALITY BEING EFFECTED BY SIMPLE SOIL
SUB-HEAD:
3. 2.
Sampling and Analysis Plan
3. 2.
Microfilm Reel
PAGES: 4
GEOTECHNOLOGY, INC.
F.rame Begins
Ends
- 0001
DATE: 01/01/01
AUTHOR: /APPLIED
ADDRESSEE: I
DESCRIPTION: SCOPE OF
SERVICES, PHASE I INVESTIGATION
SUB-HEAD:
3. 3.
Proposed Plan
- 0001 Microfilm Reel
DATE: 11/01/86 PAGES: 32
AUTHOR: /APPLIED GEOTECHNOLOGY, INC.
ADDRESSEE: /UNION PACIFIC RAILROAD
DESCRIPTION: REPORT: PROPOSAL FOR RI/FS FOR
POCATELLO, SITE
3. 3.
Frame Begins
Ends
THE UNION PACIFIC RAILROAD,
SUB-HEAD:
3. 4.
Phase I Investigation Report
3.4.
Microfilm Reel
PAGES: 311.
& MACKEY SMITH/APPLIED GEOTECHNOLOGY, INC.
RAILROAD .
I INVESTIGATION, POCATELLO SLUDGE PIT
Frame Begins
1
Ends
1
- 0001
DATE: 11/01/86
AUTHOR: VINCENT LASCKO
ADDRESSEE: /UNION PACIFIC
DESCRIPTION: REPORT: PHASE
SUB-HEAD:
3. 5.
Soil Contamination Assessment
- 0001 Microfilm Reel
. DATE: 08/04/89 PAGES: 31
AUTHOR: ALAN D. CAREY, VINCENT LASCKO/APPLIED
ADDRESSEE: /UNION PACIFIC RAILROAD
DESCRIPTION: SOIL CONTAMINATION ASSESSMENT FORMER
PACIFIC RAILROAD. POCATELLO, IDAHO
3. 5.
Frame Begins
1
Ends
1
GEOTECHNOLOGY INC.
{J
BARREL STORAGE AREA
UNION
-------
"
UNION PACIFIC ADMINISTRATIVE RECORD INDEX
f3
~
f
-------
UNION PACIFIC ADMINISTRATIVE RECORD INDEX
\)
. HEADING:
4. O.
REMEDIAL INVESTIGATION/FEASIBILITY STUDY (RI/FS)
'PHASE II
SUB-HEAD:
4. 1.
Correspondence
11
- 0001 Microfilm Reel
DATE: 04/21/88 PAGES: 1
AUTHOR: J. R. BERAN/UNION PACIFIC RAILROAD
ADDRESSEE: CHARLES FINDLEY/EPA .
DESCRIPTION: LETTER: TRANSMITTAL OF DRAFT WORK PLAN FOR THE RI/FS, DRAFT
CONSENT AGREEMENT, AND A PROPOSED SCHEDULE OF WORK COMPLETION
4. 1.
Frame Begins
1
Ends
1
4. 1.
Microfilm Reel
PAGES:
Frame Begins
i
Ends
1
- 0002
DATE: 05/04/88
AUTHOR: TED WALL/EPA
ADDRESSEE: ROBERT KUHN/UNION PACIFIC RAILROAD
DESCRIPTION: LETTER: COMMENTS ON DRAFT WORK PLAN
RAILROAD, POCATELLO SITE RI/FS
5
FOR THE UNION PACIFIC
- 0003 Microfilm Reel
DATE: OS/27/88 PAGES: 4
AUTHOR: VINCENT LASCKO/APPLIED GE01'ECHNOLOGY, INC.
ADDRESSEE: ROBERT MARKWORK/UNION PACIFIC RAILROAD
DESCRIPTION: MEMORANDUM: . RECORD OF TELEPHONE CONFERENCE CONVERSATION,
04/27/88, BETWEEN UNION PACIFIC RAILROAD, APPLIED GEOTECHNOLCGY,
INC., STATE OF IDAHO, AND EPA
4. 1.
Frame Begins
Ends
4. 1.
- 0004 Microfilm Reel
DATE: 07/11/88 PAGES:
AUTHOR: DAN DAVOLIL/EPA
ADDRESSEE: DAVE FRANK/EPA .
DESCRIPTION: MEMORANDUM: SUMMARY OF
WORK PLAN FOR PHASE II
Frame Begins
Ends
2
COMMENTS ON UNION PACIFIC RAILROAD'S
- 0005 Microfilm Reel
DATE: 07/12/88 PAGES:
AUTHOR: DE DE MONTGOMERY/EPA
ADDRESSEE: TED WALL/EPA
DESCRIPTION: MEMORA~~UM: REVIEW OF UNION PACIFIC
PLAN FOR PHASE II OF THE RI/FS
4. 1.
Frame Begins
Ends
1
RAILROAD'S HEALTH & SAFETY
~
b
i
-------
UNION PACIFIC ADMINISTRATIVE RECORD INDEX
- 0006 Microfilm Reel
DATE: 07/15/88 PAGES: 6
AUTHOR: ENVIRONMENTAL SERVICES DIVISIONTEAM/EPA
ADDRESSEE: TED WALL/EPA
DESCRIPTION: MEMORANDUM: REVIEW OF UNION PACIFIC RAILROAD'S WORK PLAN FOR
PHASE II OF THE RI/FS
4. 1.
Frame Begins
Ends'
(
.~
4. 1.
Microfilm Reel,
PAGES: 7
Frame Begins
Ends
- 0007
DATE: 07/18/88
AUTHOR: TED WALL/EPA
ADDRESSEE: ROBERT KUHN/UNION PACIFIC RAILROAD
DESCRIPTION: LETTER; TRANSMITTAL OF COMMENTS ADDRESSING
CONCERNS REGARDING UNION PACIFIC RAILROAD'S
EPA AND IDHW
POCATELLO REMEDIAL
4. 1.
- 0008 Microfilm Reel
DATE: 08/02/88 PAGES: 9
AUTHOR: VINCENT LASCKO/APPLIED GEOTECHNOLOGY, INC.
ADDRESSEE: R. C. KUHN/UNION PACIFIC RAILROAD. .
DESCRIPTION: LETTER: PROJECT WORK PLAN REVIEW FOR PHASE II OF
MODIFICATIONS TO RESOLVE ISSUES WITH EPA AND IDHW
Frame Begins
Ends
THE RI/FS.
4. 1.
- 0009 Microfilm Reel
DATE: 08/05/88 PAGES: 3
AUTHOR: DEAN J. NYGARD/IDAHO DEPARTMENT
ADDRESSEE. TED WALL/EPA .
DESCRIPTION: LETTER: TRANSMITTAL OF COMMENTS
RAILROAD'S RI/FS WORK PLAN
Frame Begins
Ends
OF HEALTH & WELFARE
BY IDAHO STATE ON UNION PACIFIC
4. 1.
- 0010 Microfilm Reel
DATE: 08/19/88 PAGES:. 6
AUTHOR: ENVIRONMENTAL SERVICES DIVISION TEAM/EPA
ADDRESSEE: TED WALL/EPA
DESCRIPTION: REVIEW OF UNION PACIFIC RAILROAD'S WORK PLAN, DRAFT TWO
Frame Begins
Ends
4. 1.
Microfilm Reel
PAGES:
Frame Begins
Ends
- 0011
DATE: 08/24/88
AUTHOR: TED WALL/EPA
ADDRESSEE: ROBERT KUHN/UNION PACIFIC RAILROAD
DESCRIPTION: LETTER: REVIEW OF UNION PACIFIC RAILROAD'S
6
WORK PLAN, DRAFT TWO
f
-------
UNION PACIFIC ADMINISTRATIVE RECORD INDEX
\)
- 0012. Microfilm Reel Frame Begins
DATE: 09/07/88 PAGES: 3 .
AUTHOR: VINCENT LASCKO/APPLIED GEOTECHNOLOGIES, INC.
ADDRESSEE: ROBERT C. KUHN/UNION PACIFIC RAILROAD
DESCRIPTION: LETTER: TRANSMITTAL OF FINAL PROJECT WORK PLAN
THE RI/FS
FOR PHASE II OF
4. 1.
Ends
(t\
4. 1.
- 0013
DATE: 11/02/88
AUTHOR: TED WALL/EPA
ADDRESSEE: ROBERT C. KUHN/UNION PACIFIC RAILROAD
DESCRIPTION: LETTER: OUTLINING TOPICS OF DISCUSSION FOR UPCOMING STATUS
REPORT MEETING. INCLUDES RI/FS WORK PLAN DEVELOPMENT SCHEDULE
Microfilm Reel
PAGES:
Frame Begins
Ends
3
4. 1.
Microfilm Reel
PAGES:
Frame Begins
Ends
- 0014
DATE: 12/16/88
AUTHOR: TED WALL/EPA
ADDRESSEE: ROBERT KUHN/UNION PACIFIC RAILROAD
DESCRIPTION: LETTER: DISCUSSION OF WHICH DATE EPA
THE WORK PLAN .
2
RECOGNIZES FOR APPROVAL OF
4. 1.
- 0015 Microfilm Reel
DATE: 12/27/88. PAGES: 18
AUTHOR: STEEVE D. HIGH & NANCY R. JACKSON/KENNEDY/JENKS/CHILTON
ADDRESSEE: VINCE LASCKO/APPLIED GEOTECHNOLOGY, INC.
DESCRIPTION: LETTER: EVALUATION OF ATMOSPHERIC FATE CONSIDERATIONS
POCATELLO SLUDGE PIT, UNION PACIFIC RAILROAD
Frame Begins
Ends
......,
AT THE
4. 1.
- 0016 Microfilm Reel
DATE: 01/03/89 PAGES: 1
AUTHOR: VINCENT LASCKO/APPLIED GEOTECHNOLOGY, INC.
ADDRESSEE: TED WALL/EPA
DESCRIPTION: LETTER: TRANSMITTAL - RISK ASSESSMENT DELIVERABLES FOR THE
UNION PACIFIC RAILROAD RI/FS
Frame Begins
Ends
~
-------
UNION PACIFIC ADMINISTRATIVE RECORD INDEX
4. 1.
Microfilm Reel
PAGES:
Frame Begins
Ends
(,
- 0017
DATE: 01/03/89
AUTHOR: STEVE ROY/EPA
ADDRESSEE: TED WALL/EPA
DESCRIPTION: MEMORANDUM: PRELIMINARY
POCATELLO SITE
1
ARAR'S FOR UNION PACIFIC RAILROAD'S
-1
4. 1.
M.icrofilm Reel
PAGES:
Frame Begins
Ends
- 0018
DATE: 01/05/89
AUTHOR: TED WALL/EPA
ADDRESSEE: ROBERT KUHN/UNION PACIFIC RAILROAD
DESCRIPTION: LETTER: EVALUATION OF ARAR'S FOR' UNION
POCATELLO SITE
4
PACIFIC RAILROAD'S
4. 1.
- 0019 Microfilm 'Reel
DATE: 01/17/89 PAGES: 1
AUTHOR: J. R. BERAN/UNION PACIFIC RAILROAD
ADDRESSEE: TED WALL/EPA
DESCRIPTION: LETTER: REQUESTING AN EXTENSION OF THE
RI REPORT FROM 01/23/89 TO 06/01/89
Frame Begins
Ends
DUE DATE OF THE PHASE II
4. 1.
- 0020 Microfilm Reel
DATE: 01/18/89 PAGES: 1
AUTHOR: DEAN J. NYGARD/IDAHO DEPARTMENT OF HEALTH & WELFARE
ADDRESSEE: ~~D WALL/EPA
DESCRIPTION: LETTER: IDENTIFICATION OF ACTION SPECIFIC ARAR'S FOR
GROUNDWATER EXTRACTION, TREATMENT, AND INJECTION REMEDY
Frame Begins
Ends
4. 1.
- 0021 Microfilm Reel
DATE: 01/01/01 PAGES: 6.
AUTHOR: ENVIRONMENTAL SERVICES DIVISION TEAM/EPA
ADDRESSEE: TED WALL/EPA
DESCRIPTION: LETTER: REVIEW. OF DRAFT. 2 QF UNION PACIFIC RAILROAD'S WORK PLAN
Frame Begins
Ends
4. 1.
Microfilm Reel
PAGES:
Frame Begins
Ends
- 0022
DATE: 02/03/89
AUTHOR: TED WALL/EPA
ADDRESSEE: ROBERT SWANSON/MICHAUD RANCHES
DESCRIPTION: LETTER: NOTICE OF COMPOUNDS FOUND
2
IN WELL WATER SAMPLES
(
-------
- 0023 Microfilm Reel
DATE: 02/03/89 . PAGES:
AUTHOR: TED WALL/EPA '
ADDRESSEE: /MURDOCK & WALKER CONCRETE PUMPING
DESCRIPTION: LETTER: NOTICE OF COMPOUNDS FOUND
- 0024
DATE: 02/03/89
AUTHOR: TED WALL/EPA
ADDRESSEE: MAURICE MURDOCK/
DESCRIPTION: LETTER: NOTICE OF COMPOUNDS
4. 1. ,. - 0025
DATE: 02/03/89
AUTHOR: TED WALL/EPA
ADDRESSEE: FLOYD BARKER/
DESCRIPTION: LETTER: NOTICE OF COMPOUNDS
- 0026
DATE: 02/03/89
AUTHOR: TED WALL/EPA
ADDRESSEE: /E. J. BARTELL COMPANY
DESCRIPTION: LETTER: NOTICE OF COMPOUNDS
I.
4. 1.
(()
4. 1.
4. 1.
SUB-HEAD:
4. 2.
4. 2.
- 0001
DATE: 09/01/88
AUTHOR: /APPLIED
ADDRESSEE: /
DESCRIPTION: REPORT:
4. 2.
- 0002
DATE: 01/01/01
AUTHOR: /APPLIED
ADDRESSEE: /
DESCRIPTION: REPORT:
CJ
~
UNION PACIFIC ADMINISTRATIVE RECORD INDEX
Frame Begins
Ends
2
COMPANY
IN WELL WATER SAMPLES
Microfilm Reel
PAGES:
Frame Begins
Ends
1
,FOUND IN WELL WATER SAMPLES
Microfilm Reel
PAGES:
Frame Begins
Ends
2
FOUND IN WELL WATER SAMPLES
Microfilm Reel
PAGES:
Frame Begins
Ends
2
FOUND IN WELL WATER SAMPLES
Work Plan
Microfilm Reel
PAGES: 95
GEOTECHNOtoGY, INC.
Frame Begins
Ends
PHASE II, RI/FS, WORK PLAN
Microfilm Reel
PAGES: 10
GEOTECHNOLOGY, INC.
Frame Begins
Ends
-------
UNION PACIFIC ADMINISTRATIVE RECORD INDEX
SUB-HEAD:
4.' 2. 1.
Amendments
.)
4. 2. 1. - 0001 Microfilm Reel
DATE: 05/13/88 PAGES: 7
AUTHOR: VINCENT LASCKO & MACKEY SMITH/APPLIED GEOTECHNOLOGY, INC.
ADDRESSEE: ROBERT C. KUHN/UNION PACIFIC RAILROAD
DESCRIPTION: LETTER: TECHNICAL SCOPE OF SERVICES AND COST ESTIMATE -
REVISION I - PHASE II OF THE RI/FS
Frame Begins
Ends
1
4. 2. 1. - 0002 Microfilm Reel
DATE: 09/07/88 PAGES: 2 ,
AUTHOR: VINCENT LASCKO/APPLIED GEOTECHNOLOGY, INC.
, ADDRESSEE: ROBERT C. KUHN/UNION PACIFIC RAILROAD'
DESCRIPTION: LETTER: AMENDMENTS 1 AND 2 TO FINAL PROJECT
II OF THE RI/FS
Frame Begins
Ends
WORK PLAN FOR PHASE
4. 2. 1. - 0003 Microfilm Reel
DATE: 01/17/88 PAGES: 6
AUTHOR: VINCNET LASCKO & MACKEY SMITH/APPLIED GEOTECHNOLOGY, INC.
ADDRESSEE: R. C. KUHN/UNION PACIFIC RAILROAD .
DESCRIPTION: LETTER: WORK AMENDMENT NO.3 TO PHASE II OF THE RI/FS
Frame Begins
Ends
4. 2. 1. - 0004 Microfilm Reel
DATE: 11/14/88 PAGES: 5
AUTHOR: J. R. BERAN; 'UNION PACIFIC RAILROAD
ADDRESSEE: TED WALL/EPA
DESCRIPTION: LETTER: SUPPLEMENTAL INFORMATION. CHEMICAL
DETECTION LIMITS AND SAMPLING PROCEDURES FOR
FOR PHASE II OF THE RI/FS
Frame Begins
Ends
ANALYSES - TARGET
MONITORING WELL 4S
SUB-HEAD:
4. 3.
EPA Quality Assurance Plan (For RI Split Samples)
4. 3.
Microfilm Reel
PAGES: 10
Frame Begins
Ends
- 0001
DATE: 01/01/88
AUTHOR: /
ADDRESSEE: /UNION PACIFIC RAILROAD
DESCRIPTION: REPORT: QUALITY ASSURANCE
SLUDGE PIT, PHASE II RI/FS
PLAN FOR UNION PACIFIC RAILROAD,
f
-------
UNION PACIFIC ADMINISTRATIVE RECORD INDEX
~
SUB-HEAD:
4. 4.
Sampling and Analysis Data
4. 4.
Microfilm Reel
PAGES: 7
GEOTECHNOLOGY INC.
Frame Begins
1
Ends
1
,(2
- 0001
DATE: 04/01/89
AUTHOR: /APPLIED
ADDRESSEE: /
DESCRIPTION: CHEMICAL ANALYSES REPORTS EPA SPLIT SAMPLES UPRR
APRIL 1989 AGI PROJECT NO. 14,942.002 (MICROFICHE
SLUDGE PIT -
COPIES)
SUB-HEAD:
4. 5.
RI/FS Reports
4. 5..
- 0001 Microfilm Reel
DATE: 08/01/90 PAGES: 488
AUTHOR: /APPLIED GEOTECHNOLOGY, INC.
ADDRESSEE: /UNION PACIFIC RAILROAD
DESCRIPTION: VOLUME I FINAL REPORT POCATELLO
INVESTIGATION POCATELLO, IDAHO
Frame Begins
1
Ends
1
SLUDGE PIT NPL SITE REMEDIAL
4. 5.
- 0002 Microfilm Reel
DATE: 06/01/89 PAGES: 1102
AUTHOR: /APPLIED GEOTECHNOLOGY INC.
ADDRESSEE: /UNION PACIFIC RAILROAD -
DESCRIPTION: VOLUME II FINAL REPORT POCATELLO
INVESTIGATION POCATELLO, IDAHO
Frame Begins
1
Ends
1
SLUDGE PIT NPL SITE REMEDIAL
4. 5.
- 0003 Microfilm Reel
DATE: 04/01/91 PAGES: 484
AUTHOR: /APPLIED GEOTECHNOLOGY INC.
ADDRESSEE: /UNION PACIFIC RAILROAD
DESCRIPTION: FEASIBILITY STUDY POCATELLO
Frame Begins
1
Ends
1
SLUDGE PIT
POCATELLO, IDAHO
SUB-HEAD:
4. 5. 1.
4. 5. 1. - 0001 Microfilm Reel
DATE: 06/27/91 PAGES: 44
AUTHOR: Ann Williamson/EPA
ADDRESSEE: Bob Markworth/
DESCRIPTION: Letter documenting EPA'rs final comments on the April 5, 1991
final Feasibility Study for UPRR, containing EPA's revision of
the air pathways analysis, recalculated site risks and stating
EPA's acceptance of RIjFS with these revisions
Frame Begins
. 1
Ends
1
.
-------
UNION PACIFIC ADMINISTRATIVE RECORD INDEX
SUB-HEAD:
4. 6.
Proposed Plan
Microfilm Reel
PAGES: 14
4. 6.
- 0001
DATE: 06/03/91
AUTHOR: /EPA
ADDRESSEE: /
DESCRIPTION: Superfund Fact Sheet The Proposed
Sludge PitPocatello, Idaho
Frame Begins
I
Ends
Plan
union Pacific Railroad
(
1
J
I}
-------
UNION PACIFIC ADMINISTRATIVE RECORD INDEX
~
HEADING:
5. O.
STATE COORDINATION
SUB-HEAD:
5. 1.
Correspond,ence
1(:
- 0001 Microfilm Reel
DATE: 12/31/87 PAGES: 3
AUTHOR: DEAN NYGARD/IDAHO DEPARTMENT OF HEALTH & WELFARE
ADDRESSEE: TED WALL/EPA
DESCRIPTION: LETTER: STATE ARAR'S FOR MC CARTHY'S/PACIFIC HIDE & FUR AND
UNION PACIFIC RAILROAD
5. 1.
Frame Begins
1
Ends
1
- 0002 Microfilm Reel
DATE: 10/12/88 PAGES: 2
AUTHOR: DEAN NYGARD/IDAHO DEPARTMENT OF HEALTH & WELFARE
ADDRESSEE: TED WALL/EPA
DESCRIPTION: LETTER: RE-EMPHASIS OF CONCERNS REGARDING THE IMPLEMENTATION OF
THE RI/FS WORK PLAN AT POCATELLO
5. 1.
Frame Begins
Ends
5. 1.
Microfilm Reel
PAGES:
Frame Begins
1
Ends
1
- 0003
DATE: / /
AUTHOR: Ted Wall/EPA
ADDRESSEE: ~om Green/Idaho State Historical Society
DESCRIPTION: Request for information on what impact the UPRR cleanup
activities may have on the Oregon Trail cultural resource
3
5. 1.
Frame Begins
1
Ends
1
- 0004 Microfilm Reel
DATE: 06/29/89 PAGES: 1
AUTHOR: THOMAS J. GREEN/IDAHO STATE HISTORICAL SOCIETY
ADDRESSEE: TED WALL/EPA
DESCRIPTION: NOTICE THAT OREGON TRAIL DOES NOT PARALLEL THE UNION PACIFIC
RAIL LINE IN POCATELLO AS WAS INDICATED ON MAPS
SUB-HEAD:
5. 2.
State Certification of ARAR's
5. 2.
Microfilm Reel
PAGES: 243
IDAHO
Frame Begins
1
Ends
1
.(J
- 0001
DATE: 01/04/88
AUTHOR: /STATE OF
ADDRESSEE: /
DESCRIPTION: STATE APPLICABLE OR RELEVANT & APPROPRIATAE REQUIREMENTS
(ARAR'S). INCLUDES ATTACHMENTS A (RULES & REGULATIONS FOR THE
CONTROL OF AIR POLLUTION IN IDAHO), B (WASTEWATER TREATMENT
REQUIREMENTS), AND C (HAZARDOUS WASTE FACILITY SITING)
-------
UNION PACIFIC ADMINISTRATIVE RECORD INDEX
(
)
(
-------
UNION PACIFIC ADMINISTRATIVE RECORD INDEX
'.
HEADING:
6. O.
ENFORCEMENT
SUB-HEAD:
6. 1.
Correspondence
'e
6. 1. - 0001
, DATE: 05/19/88
AUTHOR: TED WALL/EPA
ADDRESSEE: ROBERT KUHN/UNION PACIFIC RAILROAD
DESCRIPTION: LETTER: REVISIONS TO DRAFT CONSENT AGREEMENT FOR THE RI/FS. ,
INCLUDES A COPY OF P. 12 OF THE ORDER OF CONSENT AND A COPY OF
THE RI/FS STUDY SCHEDULE
Microfilm Reel
PAGES:
Frame Begins
Ends
3
- 0002 Microfilm Reel
DATE: 05/31/88 PAGES:
AUTHOR: CHARLES FINDLEY/EPA .
ADDRESSEE: ROBERT KUHN/UNION PACIFIC RAILROAD
DESCRIPTION: LETTER: TRANSMITTAL OF FINAL ORDER
6. 1.
Frame Begins
Ends
1
ON CONSENT FOR SIGNATURE
- 0003 Microfilm Reel
DATE: 06/09/88 PAGES:
AUTHOR: COLLEEN A. LAMONT/UNION
ADDRESSEE: CHARLES FINDLEY/EPA
DESCRIPTION: LETTER: TRANSMITTAL OF
6. 1.
Frame Begins
Ends
1
PACIFIC RAILROAD
SIGNED ORDER ON CONSENT
- 0004 Microfilm Reel
DATE: 06/21/88 PAGES:
AUTHOR: CHARLES FINDLEY/EPA
ADDRESSEE: ROBERT KUHN/UNION PACIFIC RAILROAD
DESCRIPTION: LETTER: TRANSMITTAL Or FULLY CONFORMED
ORDER ON CONSENT
6. 1.
Frame Begins
Ends
1
COPY OF ADMINISTRATIVE
~ 0005 Microfilm Reel
DATE: 04/25/88 PAGES: 4
AUTHOR: J. R. BERAN/UNION PACIFIC RAILROAD
ADDRESSEE: TED WALL/EPA
DESCRIPTION: LETTER: DRAFT CONSENT AGREEMENT ON RI/FS. INCLUDES A
MEMORANDUM FROM COLLEEN LAMONT TO R. D. MARKWORTH
6. 1.
Frame Begins
Ends
l)
-------
UNION PACIFIC ADMINISTRATIVE RECORD INDEX
SUB-HEAD:
6. 2.
Consent Order
,()
- 0001 Microfilm Reel
DATE: 06/09/88 PAGES: 28
AUTHOR: CHARLES E. FINDLEY/EPA
ADDRESSEE: PAUL A. CONLEY, JR./UNION
DESCRIPTION: ORDER ON CONSENT
6. 2.
Frame Begins
Ends
)
PACIFIC RAILROAD
SUB-HEAD:
6. 2. 1.
Amendments
6. 2. 1. - 0001 Microfilm Reel
DATE: 05/01/89 PAGES: 3
AUTHOR: NANCY A. ROBERTS/UNION PACIFIC SYSTEM
ADDRESSEE: TED WALL/EPA
DESCRIPTION: COVER LETTER AND COPY OF FULLY EXECUTED AMENDED ADMINISTRATIVE
ORDER ON CONSENT NO. 1088-01-03-106 SIGNED BY CHARLES E.
FINDLEY, EPA, AND PAUL A. CONLEY, JR., UNION PACIFIC RAILROAD
Frame Begins
1
Ends
1
SUB-HEAD:
6. 3.
Notice Letters and Responses
DATE:
~ 0001 Microfilm Reel
01/08;8S PAGES:
CHARLES E. FINDLEY/EPA
ROBERT C. KUHN/UNION PACIFIC
LETTER: NOTICE OF POTENTIAL
Frame Begins
Ends
6. 3.
6
AUTHOR:
ADDRESSEE:
DESCRIPTION:
RAILROAD
LIABILITY
- 0002 Microfilm Reel
DATE: 02/24/88 PAGES:
AUTHOR: CHARLES E. FINDLEY/EPA
ADDRESSEE: ROBERT C. KUHN/UNION PACIFIC RAILROAD
. DESCRIPTION: LETTER: NOTICE OF POTENTIAL LIABILITY.
AND TO MAKE GOOD FAITH PROPOSALS
6. 3.
Frame Begins
Ends
2
PERMISSION TO NEGOTIATE
SUB-HEAD:
6. 4.
Risk Assessments - Human Health, Environmental
- 0001 Microfilm Reel
DATE: 11/01/90 PAGES: 414
AUTHOR: '/APPLIED GEOTECHNOLOGY INC.
ADDRESSEE: /UNION PACIFIC RAILROAD
DESCRIPTION: HUMAN HEALTH RISK ASSESSMENT
IDAHO
6. 4.
Frame Begins
1
Ends
1
POCATELLO SLUDGE PIT
POCATELLO,
("
-------
UNION PACIFIC ADMINISTRATIVE RECORD INDEX
I}
- 0002 Microfilm Reel
DATE: 11/01/90 PAGES: 427
AUTHOR: /APPLIED GEOTECHNOLOGY INC.,
ADDRESSEE: /UNION PACIFIC RAILROAD'
DESCRIPTION: ENVIRONMENTAL RISK ASSESSMENT
IDAHO
POCATELLO SLUDGE PIT
POCATELLO,
6. 4.
Frame Begins
1
Ends
1
'~
-"
SUB-HEAD:
6. 4. 1.
Addendum
6. 4. 1. - 0001 Microfilm Reel
DATE: 07/26/90 PAGES: 34
AUTHOR: /ENVIRONMENTAL TOXICOLOGY INTERNATIONAL, INC.
ADDRESSEE: /EPA
DESCRIPTION: OFFSITE WELL EVALUATION HUMAN HEALTH RISK ASSESSMENT ADDENDUM
POCATELLO SLUDGE PIT NPL SITE
Frame Begins
1
Ends
1
SUB-HEAD:
6. 4. 2. ,
Air Pathway Reassessment/Supporting Documentation
6. 4. 2. - 0001 Microfilm Reel
DATE: 03/12/91 PAGES: 14
AUTHOR: Douglas Hardesty/EPA
ADDRESSEE: Leigh Woodruff/EPA
DESCRIPTION: Memorandum regarding UPRR Superfund site Human Health Risk
Assessment Review
Frame Begins
1
Ends
1
6. 4. 2. - 0002
DATE: 03/13/91
AUTHOR: Bill Ryan/EPA
ADDRESSEE: Ann Williamson/EPA
DESCRIPTION: Memorandum concerning
Microfilm Reel
PAGES:
Frame Begins
1
Ends
1
3
UPRR Pocatello Sludge pit Air Monitoring
6. 4. 2. - 0003
DATE: 03/25/91
AUTHOR: /EPA
ADDRESSEE: /
DESCRIPTION: Handwritten
Microfilm Reel
PAGES:
Frame Begins
1
Ends
1
5
notes and tables concerning residential scenarios
~,
-------
UNION PACIFIC ADMINISTRATIVE RECORD INDEX
6. 4. 2. . - 0004
. DATE: 03/28/91
AUTHOR: /
ADDRESSEE: /
DESCRIPTION: Three tables: Future Residential RME Chronic,
RME Cancer, Future Residential RME Subchronic
Microfilm Reel
PAGES:
Frame Begins
1
Ends
1
i
3
Future Residential
)
6. 4. 2. - 0005 Microfilm Reel
DATE: 04/11/91 PAGES:
AUTHOR: Leigh (Woodruff)/EPA
ADDRESSEE: Ann (Wi11iamson)/EPA
DESCRIPTION: Handwritten note with attached recalculation of UPRR site risks
Frame Begins
1
Ends
1
4
6. 4. 2.
DATE:
AUTHOR:
ADDRESSEE:
DESCRIPTION:
- 0006 Microfilm Reel
04/24/91 PAGES:
Leigh (Woodruff)/EPA
Ann (Wi11iamson)/EPA
Handwritten note with attached
including combined risks
Frame Begins
1
Ends
1
3
recalculated site risks,
6. 4. 2.
DATE:
AUTHOR:
ADDRESSEE:
DESCRIPTION:
- Ce07
Microfilm Reel
,... .....
rrame Deg~ns
1
Ends
1
OS/29/91 PAGES: 29
Leigh Woodruff, Bill Ryan, Doug Hardesty/EPA
Ann Wi11iamson/EPA
Memorandum regarding UPRR Pocatello Sludge Pit, Air Pathway
Reassessment
~
-------
UNION PACIFIC ADMINISTRATIVE RECORD INDEX
1,
HEADING:
7. O.
HEALTH ASSESSMENTS
SUB-HEAD:
7. 2.
ATSDR Health Assessments
~
\
- 0001 Microfilm Reel
DATE: 07/27/88 PAGES: 4
AUTHOR: /U. S. PUBLIC HEALTH SERVICE
ADDRESSEE: FILE/EPA
DESCRIPTION: REPORT: HEALTH ASSESSMENT FOR UNION PACIFIC RAILROAD'S
POCATELLO SITE'
7. 2.
Frame Begins
1
Ends
1
,~
(
-------
. .
UNION PACIFIC ADMINISTRATIVE RECORD INDEX
HEADING:
8. o.
PUBLIC PARTICIPATION
SUB-HEAD:
Community Relations Plan
8. 1.
- 0001 Microfilm Reel
. DATE: 06/01/88 PAGES: 20
AUTHOR: TED WALL & GRECHEN SCHREIBER/EPA
ADDRESSEE: COMMUNITY OF POCATELLO, IDAHO/
DESCRIPTION! REPORT: COMMUNITY RELATIONS PLAN
8. 1.
Frame Begins
Ends
SUB-HEAD:
8. 2.
Public Notice(s)
8. 2.
Microfilm Reel
PAGES:
Frame Begins
Ends
- 0001
DATE: 04/12/88
AUTHOR: TED WALL/EPA
ADDRESSEE: GENERAL PUBLICI
DESCRIPTION: NOTICE: ANNOUNCEMENT OF NEGOTIATIONS BETWEEN EPA AND UNION
PACIFIC RAILROAD. FROM IDAHO STATE JOURNAL, 04/12/88, SECTION
B-] ..
1
SUB-HEAD:
8. 3.
Fact Sheets and Press Releases
- 0001 Microfilm Reel
DATE: 08/01/88 PAGES: 1
AUTHOR: TED WALL & GRECHEN SCHMIDT/EPA
ADDRESSEE: GENERAL PUBLICI .
DESCRIPTION: FACTSHEET: INFORMATION ON FIELD WORK AT UNION PACIFIC
. RAILROAD'S POCATELLO SITE
8. 3.
Frame Begins
Ends
8. 3.
Microfilm Reel
PAGES:
2
- 0002
DATE: 07/21/89
AUTHOR: /EPA
ADDRESSEE: /GENERAL PUBLIC
DESCRIPTION: UNION PACIFIC RAILROAD SUPERFUND SITE
FINDINGS OF REMEDIAL INVESTIGATION
Frame Begins
1
Ends
FACT SHEET REGARDING.
.,[
)
1
f~1
I
, ,
-------
~,
-r
/
,
'J
..
UNION PACIFIC ADMINISTRATIVE RECORD INDEX
8. 3.
Microfilm Reel
PAGES:
2
- 0003
DATE: 01/16/90
AUTHOR: /EPA
ADDRESSEE: /GENERAL PUBLIC
DESCRIPTION: UNION PACIFIC RAILROAD SUPERFUND SITE POCATELLO, IDAHO FACT
SHEET PROVIDING UPDATED INFORMATION RELATED TO ACTIVITIES AT THE
SITE
Frame Begins
1
Ends
-------
I '\ 1
I "
UNION PACIFIC ADMINISTRATIVE RECORD INDEX
HEADING:
9. o.
SUB-HEAD:
9. 1.
9. 1.
- 0001
DATE: 07/01/82
AUTHOR: /EPA
ADDRESSEE: /
DESCRIPTION: GUIDANCE:
9. 1.
- 0002
DATE: 07/01/82
AUTHOR: /EPA
ADDRESSEE: /
DESCRIPTION: GUIDANCE:
9. 1.
- 0003
DATE: 07/01/82
AUTHOR: /EPA
, ADDRESSEE:, /
DESCRIPTION: GUIDANCE:
TECHNICAL SOURCES AND GUIDANCE DOCUMENTS
EPA Headquarters Guidance
Microfilm Reel
PAGES:
Frame Begins
3
TEST METHOD 601, PURGEABLE HALOCARBONS
Microfilm Reel
PAGES:
Frame Begins
3
TEST METHOD 602, PURGEABLE AROMATICS
Microfilm Reel
PAGES:
Frame Begins
2
I~
Ends
j
Ends
Ends
TEST METHOD 610, POLYNUCLEAR AROMATIC HYDROCARBONS
~.\
------- |