~.
United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPNROD/R08-921058
September 1992
PB93-964406
&EPA
Superfund
Record of Decision:
Idaho Pole, MT
. MotordOus. Waste Collection
:..forrnotlol1. Resource Center
fFf.f$EPAReQI<)n .3 .
~I PA 19107
u . S. Environmentaf'15imeCflon Agency
Region III HazardouS Waste
Technical Information Center
841 Chestnut Street, 9th Floor
Philadelphia. PA 19107 .
, ~
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...,
NOTICE
The appendices listed in the index that are not found in this document have been removed at the request of
the issuing agency. They contain materiaJ which supptement. but adds no futther apptic:abIe information to
the content of the document. All supPemental material is, however. contained in the adm-bstk..ti1l'8 record
for this site.
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REPORT DOCUMENTATION 11. REPORT NO. I ~ 3. Recipient. Acceaalon No.
PAGE EPA/ROD/R08-92/058
4. TlUe ond SubtiUe 5. Report Dote
SUPERFUND RECORD OF DECISION 09/28/92
Idaho Pole, MT
6.
First Remedial Action - Final
7. Author(a) 8. Perfonning Organization Rept. No.
9. Perfonnlng Orgolnization Name and Addre.. 10. ProjectlTa8klWork Unit No.
11. Contract(C) or Grant(G) No.
(C)
(G)
12. Sponaorlng OrganizatJon Name and Addre.. 13. Type 01 Report & Period Covered
U.S. Environmental Protection Agency 800/000
401 M Street, S.W.
Washington, D.C. 20460 14.
15. Supplementary Notea
PB93-964406
15. Abstract (limit: 200 worda)
The 50-acre Idaho Pole Company site is an active wood treatment facility located in
Gallatin County, Bozeman, Montana. Land use in the area is light industrial. The site
lies within the 100-year floodplain, and wetlands are also located on site. The site
includes the Idaho Pole Company (I PC) pole plant, Burlington Northern Railroad
property, Montana Rail Link property, and land owned by the Montana Pole Company. The
IPC wOOd-treating facility began operation in 1945, using creosote to preserve wood.
In 1952, the company switched to pentachlorophenol in carrier oil (similar to fuel oil)
for the wood-treating solution. In 1978, the state found evidence that an oily
wood-treating fluid was being released from the plant and disposed of in ditches. IPC
stopped releasing this substance and attempted to clean up the land. In an attempt to
slow or eliminate movement of the oily wOOd-treating fluid through ground and surface
water and into private wells, IPC installed and operated an interceptor drain with a
sump and an interceptor trench. Absorbent pads also were used in the culverts and
ditches to intercept and collect the oily wood-treating fluid. Culverts under 1-90
were dammed to prevent runoff of contaminated surface water to Rocky Creek. The
spillage of oily wood-treating fluid has resulted in soil, ditch sediment, and ground
(See Attached Page)
17. Document Analysia .. De.criptOI'l
Record of Decision - Idaho Pole, MT
First Remedial Action - Final
Contaminated Media: soil, sediment, gw
Key Contaminants: organics (dioxins, PARs, pesticides, phenols), inorganics, oils
b. ldentifiera/Open-Ended Terms
c. COSA TI Field/Group
18. Availability Statement 19. Security CIa.. (Thia Report) 21. No. 01 Pagea
None 129
20. Security CIa.. (Thia Pege) ~ Price
None
e 272 (4-77)
50272.101
I~'
'"
(5 e ANSI Z39.18)
See InslrUcUolI8 on Reverse
(Formerty NTIS-35)
Depertment 01 Commerce
-------
EPA/ROD/R08-92/058
!daho Pole, MT
First Remedial Action - Final
Abstract (Continued)
water contamination both onsite and offsite in the surrounding vicinity. In addition,
since the oily wOOd-treating fluid is lighter or less dense than water, a product layer
exists beneath the site, above ground water. This ROD addresses contaminated onsite
soil, sediment, and ground water. The primary contaminants of concern affecting these
media are organics, including dioxins, oils, PAHs, pesticides, and phenolsi and
inorganics. .
The selected remedial action for this site includes excavating and consolidating
approximately 19,000 cubic yards of contaminated soil from the pasture area, ditch
sediment and bottoms, and the former round house areaipretreating the soil onsite using
an oil/solids separator to remove the oily wood-treating fluid, followed by biological
treatment of the contaminated soil and sediment in a land treatment unit (LTU), and
capping the LTU with a RCRA cap; treating 23,000 cubic yards of soil in inaccessible
locations contaminated with oily wood treatment fluids using in-situ soil flushing;
enhancing in-situ biological degradation of soil contaminants by the addition of oxygen
and nutrients; collecting the flushed water and skimming the oil; combining this oil with
recovered oil from the other site areas, followed by recycling or offsite disposal in
accordance RCRA; filling excavated areas with clean soil; pumping and onsite treatment of
approximately 1 billion gallons of contaminated ground water within the boundaries of the
oily plume, followed by transfer to an oil/water separator-clarifier/filtration planti
treating the water using a fixed film bioreactori consolidating the solids from the
separation process into the LTU for treatment along with the contaminated soil; treating
approximately 210 million gallons of contaminated ground water from under the pasture
area by in-situ biodegradation; reinjecting the treated ground water onsite or treating
~his using additional treatments, such as carbon polishing to meet POTW pretreatment
standards, if necessarYi monitoring ground water; providing any contaminated residential
wells with in-home carbon/reverse osmosis treatment system until MCLs are reached; and
implementing engineering and institutional controls, including deed, land, and ground
water use restrictions. The estimated present worth cost for this remedial action is
$9,074,962, which includes a total O&M cost of $928,790 for 10-30 years.
PERFORMANCE STANDARDS OR GOALS:
Soil and sediment goals are based on a site-specific risk analysis levels and will
correspond to a 10-4to 10-6 lifetime cancer risk. Chemical-specific clean-up goals for
soil include PCP 48 mg/kg (risk); total B2 PAHs 15 mg/kg (risk); total D PAHs 145 mg/kg
(HO); and TCDD TE 0.001 mg/kg. Ground water clean-up levels are based on SDWA MCLs and
proposed MCLs. Chemical-specific goals for ground water include pentachlorophenol 1 ug/l
(MCL); benzo(a)pyrene 0.2 ug/l (MCL); and 2,3,7,8-TCDD 3xlO-5ug/l (MCL).
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RECORD OF DECISION
IDAHO POLE NATIONAL
PRIORITIES LIST SITE
BOZEMAN, MONTANA
Montana Department of Health and Environmental Sciences
Solid and Hazardous Waste Bureau
Cogswell Building
Helena a 59620
ita
. ~ . hth
In cooper It e
United States Environmental Protection Agency
Region VIII - Montana Operations Office
Federal Building, 301 South Park Street, Drawer 10096
Helena, Montana 59626-0096
September 1992
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:J
L
RECORD OF DECISION
IDAHO POLE NATIONAL PRIORITIES LIST SITE
BOZEMAN, MONTANA
Montana Department of Health & Environmental Sciences
Solid & Hazardous Waste Bureau
Cogswell Building
Helena, Montana 59620
in cooperation with the
United States
Environmental Protection Agency
Region vm - Montana Office
Federal Bldg., 301 S. Park, Drawer 10096
Helena, MT 59626-0096
September 1992
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RECORD OF DECISION
IDAHO POLE COMPANY NATIONAL PRIORITIES LIST SITE
INTRODUCTION
Based on the Remedial Investigation/Feasibility Study, the Proposed Plan, the public
comments received, including those from the Potentially Responsible Parties, Environmental
Protection Agency comments, and other new information, the Montana Department of Health
& Environmental Sciences presents the Record of Decision for the Idaho Pole Company site
(the Site). The Record of Decision presents a brief outline of the Remedial
Investigation/Feasibility Study, actual and potential risks to human health and the
environment, and the selected remedy. The state followed EPA guidancel in preparation of
the Record of Decision. The Record of Decision has the following three purposes:
1.
Certify that the remedy selection process was carried out in accordance with the
requirements of the Comprehensive Environmental, Response, Compensation and
Liability Act (CERCLA), 42 U.S.C. 9601 et seq., as amended by the Superfund
Amendments and Reauthorization Act (SARA), and, to the extent practicable, the
National Contingency Plan (NCP);
2.
Outline the engineering components and remediation goals of the selected remedy;
and
3.
Provide the public with a consolidated source of information about the history,
characteristics, and risks posed by the conditions at the Site, as well as a summary of
the cleanup alternatives considered, their evaluation, and the rationale behind the
selected remedy.
The Record of Decision is organized into three distinct sections:
o
The Declaration functions as an abstract for the key information contained in
the Record of Decision and is the section of the Record of Decision signed by
the Director of the Mon~a Department of Health and Environmental Sciences
and the EP A Regional Administrator;
o
The Decision Summary provides an overview of the site characteristics, the
alternatives evaluated, and the analysis of those options. The Decision
Summary also identifies the selected remedy and explains how the remedy
fulfills statutory requirements; and
IGuidance on Preparing Superfund Decision Documents: The Proposed Plan, the Record of Decision,
Explanation of Differences, the Record of Decision Amendment, Interim Final, EPA/540/G, July 1989.
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2
,\
Idaho Pole Record of Decision
o
The Responsiveness Summary addresses public comments received on the
Proposed Plan, the Remedial Investigation/Feasibility Study and other
information in the administrative record.
-------
()
,!
DECLARATION
-------
SITE NAME AND LOCATION
Idaho Pole Company Site
Bozeman, Montana
STATEMENT OF BASIS AND PURPOSE
This decision document presents the selected remedy for the Idaho Pole Company site (the
Sit~), in Bozeman, MT. The Montana Department of Health & Envirorimental Sciences, in
consultation with the United States Environmental Protection Agency (EPA), selected the
remedy in accordance with CERCLA, as amended by SARA, and, to the extent practicable,
the NCP. The Environmental Protection Agency concurs in the selected remedy. The
attached index identifies the items that comprise the administrative record upon which the
selection of the remedial action is based.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from this site, if not addressed by
implementing the response action selected in this Record of Decision, may present an
imminent and substantial endangerment to public health, welfare, or the environment.
DESCRIPTION OF THE SELECTED REMEDY
This is the rmal action for the only operable unit for the Site. The operable unit includes all
known sources and contaminated media at the Site. This action addresses the principal .
threats remaining and provides for treatment of contaminated soils and ground water. Some
treatment residuals and soils contaminated at lower levels will remain onsite, such that the
Site will require longterm management.
The contaminants of concern at the Site are pentachlorophenol (PCP), polynuclear aromatic
hydrocarbons (PARs), polychJ.orinated dibenzo-p-dioxins and polychlorinated dibenzofurans.
This Record of Decision esta~lishes cleanup levels for those contaminants of concern at the
Site. The major components of the selected remedy include:
o
Excavation and surface land biological treatment of approximately 19,000
cubic yards of contaminated soils from the pasture area and the area between
Cedar street and U.S. Interstate Highway 90 (I-90) including ditch sediments
or bottoms, and the former roundhouse area;
o
Hot water and steam flushing of soils underlying the pole plant facility and 1-
90 in order to recover hazardous substances;
o
Separation and disposal of oily wood treating fluid extracted from soils;
1
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c1
2
Idaho Pole Record of Decision
o
Closure of onsite treatment units in compliance with RCRA Subtitle C
requirements;
o
Ground water cleanup using extraction and biological treatment and return of
water to the ground water aquifer to enhance in situ biological degradation and
to control potential migration of contaminants;
o
Treatment of contaminated residential wells exceeding maximum contaminant
levels (MCLs) or risk based concentrations pf the contaminants of concern at
the distribution point in addition to institutional controls preventing new access
to contaminated ground water; and
o
Continued residential and ground water monitoring to determine movement of
contaminants and compliance with. remedial action requirements.
Both soils and ground water will be remediated as one operable unit at the Site. Soils will be
excavated from three general areas: the area between Cedar Street and 1-90 (includes Cedar
Street ditch) and the pasture (includes the substation ditch) and the former roundhouse area.
Biological treatment will take place in land treatment units. The former roundhouse area
soils are predominantly P AH contaminated while the other soils are predominantly PCP
contaminated.
Ground water treatment will focus in the area underneath the oily wood treating fluid plume.
Extraction wells will be centrally located within the contaminated ground water and injection
wells will be placed along the perimeter of the oily wood treating fluid plume. Extracted
ground water will be biologically treated. Treated ground water will be injected in order to
deliver oxygen and nutrients back to the aquifer. Ideally this will create a hydraulic barrier
to reduce or eliminate continued transfer of hazardous substances from the oily wood treating
fluid plume to ground water. Additionally, nutrients will diffuse downgradient, providing for
biodegradation of the downgradient contaminated ground water plume. If it is not possible to
reinject all of the treated ground water, discharge to the publicly owned treatment works or
treatment and discharge to surface water under a Montana Pollutant Discharge Elimination
System (MPDES) permit may be required.
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 (or resource recovery) technologies to the maximum extent practicable and satisfies
the preference for remedies that employ treatment that reduces toxicity, mobility, or volume
as a principal element. Because this remedy may result in hazardous substances remaining
on site above health based levels, the five year review will be conducted within five years
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Declaration
3
after commencement of remedial action to ensure that the remedy continues to provide
adequate protection to human health and the environment.
~/.~A ~ ?JA2AA-a... - i/ZJf/tf?-
Dennis Iverson, Director Date
Mo~a Department of Health & Environmental Sciences
~
qi/~~ /1].,
( I
lac W. McGraw, Acting Regional Administrator
~rironmental Protection Agency, Region vm
Date
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DECISION SUMMARY
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I.
ll.
ID.
IV.
v.
Decision Summary
TABLE OF CONTENTS
VI.
SITE NAME LOCATION, AND DESCRIPTION. . . . . . . . . . . . . .. 1
SITE illS TORY ................................... 1
Enforcement Actions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 2
IllGHLIGHTS OF COMMUNITY PARTICIPATION. . . . . . . . . . .' .. 5
SCOPE AND ROLE OF RESPONSE ACTION. . . . . . . . '.' . . . . . .. 6
SITE CHARACTERISTICS. . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6
Site Geology and Hydrology. . . . . . . . .' . . . . . . . . . . . . . . . . . ., 6
Nature and Extent of Contamination. . . . . . . . . . . . . . . . . . . . . . .. 8
Contaminants of concern. . . . . . . . . . . . . . . . . . . . . . . . ., 8
Pentachlorophenol and other chlorinated phenols. . . . . ., 9
Polynuclear aromatic hydrocarbons. . . . . . . . . . . . . . .. 9
Polychlorinated dibe~o-p-dioxins and Polychlorinated
dibenzofurans ........................10
Contaminated media ........................ . . . . . 10
Sediments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Soils. . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . 14
Ground water. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
SUMMARY OF SITE RISKS. . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Human Health Risks. . . . . . . . . . . . . . . ; . . . . . . . . . . . . . . . . . 21
Selection of contaminants of concern. . . . . . . . . . . . . . . . . . . 21
Toxicity assessment summary. . . . . . . . . . . . . . . . . . . . . . . 21
Assumptions and exposure scenarios. . . . . . . . . . . . . . . . . . . 23
Risk characterization summary. . . . . . . . . . . . . . . . . . . . . . . 25
Cleanup Levels. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Ecological Risks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Selection of contaminants of concern. . . . . . . . . . . . . . . . . . . 32
Toxicity assessment summary. . . . . . . . . . . . . . . . . . . . . . . 32
Assumptions and exposure scenarios, . . . . . . . . . . . . . . . . . . . 32
Risk characterization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
DESCRIPTION OF ALTERNATIVES. . . . . . . . . . . . . . . . . . . . . . 36
Soil Alternatives. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Alternative 1: No Action. . . . . . . . . . . . . . . . . . . . . . . . . . 38
Alternative 2: Surface Capping. . . . . . . . . . . . . . . . . . . . . . 39
Alternative 3: Excavation And Treatment Using An Onsite or
Offsite Thermal Process. . . . . . . . . . . . . . . . . . . . . . 39
Alternative 4: Excavation, Oily Wood Treating Fluid Recovery,
and Solid-Phase (Surface Land) Biological Treatment Or
Slurry-Phase Biological Treatment. . . . . . . . . . . . . . . . 41
Slurry-Phase Biological Treatment. . . . . . . . . . . . . . . . 44
Solid-Phase Biological Treatment (Land Treatment) ..... 44
VIT.
1
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"
Idaho Pole Record of Decision
..
Alternative 5: Excavation, Oily Wood Treating Fluid Recovery,
and Critical Fluid Solvent Extraction. . . . . . . . . . . . . . 46
Alternative 6: Soil Flushing/In Situ Biological Treatment. . . . . . 49
Ground Water Alternatives. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Alternative 1: No Action. . . . . . . . . . . . . . . . . . . . . . . . . . 52
Alternative 2: Pump and Treat Using Activated Carbon
Adsorption. . . . . . . . . . . . . . . . . . . . . '.' . . . . . . . 54
Alternative 3: Pump and Treat Using A Fixed Film Biological
Reactor. . . . . . . . . . . . .' . . . . . . . . . . . . . . . . . . . 56
Alternative 4: In Situ Biological Treatment. . . . . . . . . . . . . . . 56
VIll. SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES.. 58
Evaluation and Comparison Criteria. . . . . . . . . . . . . . . . . . . . . . . . 58
Soil Alternatives. . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . 60
Ground Water Alternatives. . . . . . . . . . . . . . . . . . . . . . . . . . 69
IX. SELECTED REMEDY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Remedy for Soils and Sediments. . . . . . . . . . . . . . . . . . . '.' . . . . . 74
Remedy for Ground Water. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Estimated Costs of the Remedy. ... . . . . . . . . . . . . . . . . . . . . . . . . 77
Perfonnance Standards for Soils and Sediments. . . . . . . . . . . . . . . . . 77
Perfonnance Standards for Ground Water. . . . . . . . . . . . . . . . . . . . 78
Compliance Sampling Program . . . . . . . . . .. . . . . . . . . . . . . . . . . . 81
Points of Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Engineering and Institutional Controls. . . . . . . . . . . . . . . . . . . . . . . 82
Ground Water Uncertainty and Restoring Ground Water to Beneficial
Uses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
STATUTORY DETERMINATIONS. . . . . . . . . . . . . . . . . . . . . . . 83
Protection of Human Health and the Environment. . . . . . . . . . . . . . . 83
Compliance with Applicable or Relevant and Appropriate Requirements.. 84
Cost-Effectiveness. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
Utilization of Pennanent Solutions and Alternative Treatment
Technologies (or Resource Recovery Technologies) to the
Maximum Extent Practicable. . . . . . . . . . . . . . . . . . . . . . . . 87
Preference for Treatment as a Principal Element. . . . . . . . . . . . . . . . 88
XI. DOCUMENTATION OF SIGNIFICANT CHANGES. . . . . . ~ . . . . . . 88
XTI. REFERENCES..................................... 88
APPENDIX A Applicable or Relevant and Appropriate Requirements
APPENDIX B Administrative Record Index
x.
11
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Decision Summary
liST OF FIGURES
Figure 1 Bozeman and Vicinity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ., 3
Figure 2 Idaho Pole Site. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ., 4
Figure 3 Area Topography. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7
Figure 4 Site Conceptual Model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Figure 5 Oily Wood Treating Fluid Plume. . . . .. . . . . . . . . . . .. . . . . . . . . . . 17
Figure 6 Ground Water Plume. . . . . . . . . . . . . . . . . . . . ". . . . . . . . . . . . . . . . 20
Figure 7 Mobile Rotary Kiln Incinerator. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Figure 8 Large Scale Rotary Kiln Incinerator. . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Figure 9 Soil Slurry Reactor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Figure 10 Solid Phase Treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Figure 11 C~tical Fluid Solvent Extraction. . . ~ . . . . . . . . . . . . . . . . . . . . . . . . 50
Figure 12 Soil Flushing and Recovery. . . .". : . . . . . . . . . . . . . . . . . . . . . . . . . 53
Figure 13 Activated Carbon Adsorption. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Figure 14 Fixed Film Biological Reactor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Figure 15 In Situ Biological Treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Figure 16 Selected Remedy. . . . . . . . . . . . .". . . . . . . . . . . . . . . . . . . . . . . . . 80
liST OF TABLES
Table 1 Average and Maximum Summary For Ditch Sediments. . . . . . . . . . . . . .. 12
Table 2 Estimated Contaminated Areas and Volumes. . . . . . . . . . . . . . . . . . . . . 13
Table 3 Average and Maximum Summary For Creek Sediments. . . . . . . . . . . . . ., 15
Table 4 Average and Maximum Summary For Soils. . . . . . . . . . . . . . . . . . . . . . 16
Table 5 Average Concentrations Summary For Ground Water. . . . . . . . . . . . . . .. 19
Table 6 Human Health Contaminants of Concern. . . . . . . . . . . . . . . . . . . . . . . 22
Table 7 Toxicity Values of Contaminants of Concern. . . . . . . . . . . . . . . . . . . . . 24
Table 8 Reasonable Maximum Exposure Population. . . . . . . . . . . . . . . . . . . . . . 23
Table 9 Current Noncarcinogenic Health Hazards Summary. . . . . . . . . . . . . . . . . 27
Table 10 Current Carcinogenic Risks Summary. . . . . . . . . . . . . . . . . . . . . . . . . 28
Table 11 Future Noncarcinogenic Health Hazards Summary. . . . . . . . . . . . . . . . . . 29
Table 12 "Future Carcinogenic Risks Summary. . . . . . . . . . . . . . . . . . . . . . . . . . 30
Table 13 Risk Based Cleanup Levels For The Idaho Pole NPL Sites. . . . . . . . . . . . 31
Table 14 Aquatic Contaniinants Used For Ecological Risk Assessment. . . . . . . . . . . 33
Table 15 Terrestrial Contaminants Used of Ecological Risk Assessment. . . . . . . . . . . 34
Table 16 Ecological Risk Characterization Toxicological Data. . . . . . . . . . . . . . . . 35
Table 17 Ecological Risk Assessment Summary. . . . . . . . . . . . . . . . . . . . . . . . . 37
Table 18 Estimated Costs For Selected Remedy. . . . . . . . . . . . . . . . . . . . . . . . . 79
ill
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I.
SITE NAME WCATION. AND DESCRIPTION
Idaho Pole Company
Bozeman, MT
The Idaho Pole Company site (the Site) is located near the northern limits of Bozeman,
Montana (approximately 22,660 inhabitants) and occupies approximately 50 acres in the east
half of Section 6 and the west half of Section 5, Township 2S, Range 6E of Gallatin County.
The Site, illustrated in Figure 1, is located in a light industrial use area. The Site is bounded
by the Montana Rail Link railroad tracks to the south. Commercial property is west of the
Site. Rocky and Mill Creeks are to the north and east. North of the pole plant is a
semirural neighborhood of twelve residences with a population of about 30 individuals. Most
residences have a few acres of land used for pasture, hay or grass production and vegetable
gardens. Nine of the residences continue to use wound water for domestic purposes.
Rocky Creek flows along the northern edge of the Site. It combines with Bozeman Creek
about 1/2 mile from the Site to form the East Gallatin River. Wetlands exist within the Site
,
generally near Rocky Creek; the 100 year floodplain is close in towards Rocky and Mill
Creeks and is within Site boundaries. Figure.l shows the Site relative to the town and
surrounding area. . .
Significant features of the Site include the Idaho Pole Company (IPC) pole plant and
surrounding land as shown in the Site Plan, Figure 2. The !PC facility is currently in
operation to treat white wood poles. The Site also includes Burlington Northern Railroad
(BN) property, Montana Rail Link property, land owned by the Montana Power Company
(MPC), including the East Gallatin substation, privately owned land west and east of Rocky
Creek, and a portion of U. S. Interstate 90 (1-90).
ll.
SITE HISTORY
The !PC wood treating facility began operation in 1945 using creosote to preserve wood. In
1952, the company switched to pentachlorophenol in carrier oil (similar to fuel oil) for the
wood treating solution. !PC wood treating equipment has included butt and pole length
treating vats. In 1975, a pressurized heated retort was added for treating full length poles.
The pole length vats were removed in the early 1980's. There is also a drying area where
treated poles are stored prior to shipment. IPC continues wood treating with a pressurized
heated retort and butt diPPing vat.
In 1978, the Montana Department of Fish, Wildlife and Parks notified Montana Department
of Health & Environmental Sciences (MDHES) of a suspected release of oily wood treating
fluid from the plant. MDHES found evidence of a release in ditches near the facility and
near Rocky Creek. Consequently, MDHES issued a compliance order on September 29,
1978, notifying !PC of statutory violations and directing the company to stop uncontrolled
releases and to clean up spilled treating fluid.
1
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"
2
Idaho Pole Record of Decision
In an attempt to slow or eliminate mQvement of the oily wood treating fluid through ground
and surface water and into private wells, IPC installed and operated an interceptor drain with
a sump and an interceptor trench adjacent to 1-90. Absorbent pads were also used in the
culverts and ditches to intercept and collect oily wood treating fluid. Culverts under 1-90
have been dammed to prevent runoff of contaminated surface water to Rocky Creek.
However, during high runoff periods, discharge through the culverts has occurred.
In 1984, IPC conducted a remedial investigation without MDHES or EPA oversight to
identify the sources and extent of contamination at the Site. IPC drilled monitoring wells to
collect ground water samples and also collected soil and surface water samples. MDHES
and EPA concluded that IPC's remedial investigation report was not sufficient to identify
contaminant sources and to characterize the nature and extent of contamination.
EPA proposed the facility for the National Priorities List of Superfund sites in 1984. The
listing was final in 1986, making the site eligible for federal funds for enforcement,
investigation and remediation.
In 1989, MDHES assumed the lead agency role through a cooperative agreement with EPA
and began the remedial investigation and feasibility study (RIfFS) following the EP A
approved Work Plan and EP A guidance. The RI defmed the nature and extent of
contamination and provided data to complete the baseline health and Ecological Risk
Assessments. The FS included the development, screening and evaluation of potential site
remedies.
Enforcement Actions
EP A issued general notice letters and information requests to the potentially responsible
parties (pRPs), IPC and BN, in February 1988. The PRPs responded with general
information about their activities at the Site: IPC described treatment plant operations and BN
outlined historic railroad and roundhouse activities.
In June 1988, EPA issued special notice letters to IPC and BN to initiate RI/FS negotiations
between the PRPs, EPA and MDHES. Issuance of the special notice letters triggered a 60
day moratorium during which EPA would take no action to proceed with the RIfFS. Both
PRPs responded with good faith offers to conduct the RI/FS and the moratorium was
extended an additional 30 days. IPC prepared a draft RI/FS Work Plan and offered
comments on EPA's draft Administrative Order on Consent. BN assumed a secondary role
in the negotiations.
Negotiations ended unsuccessfully in January 1989. In March 1989, MDHES requested and
received the lead agency role for a Fund fmanced RI/FS for the Site.
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"
1
~
MONTANA
IaZDIAN
.
3
Figure 1 Bozeman and Vicini
I
I
T
T
i
T.
o 1000 2SIOO 3000
I . . I
SCALE IN. F'EET
aaa
INc.
ACAIJ#: IP10-0.40
REV: - DATE: 2./24/92-
DRAFTER: JW
VICINITY IoCAP .
IDAHO POLE COIoCPANY NPL SiTE: BOZEMAN, WONTAHA
-------
111$-8
o .
~~
APrllOXllIATt SCAU; I" rttt
I
o 100 200
"'*
11[$-1
o 0
RU-5
~oo
Figure 2 Idaho Pole Site
11[$-.
@ - R[COVUY W[U
J
100
ne;~
"CADI. IPIO-O~I
~r.J,[", D~[' 2/2~/12
SIUDY AAt/. P'-""
IDAIIO pot[ COIAI'All'f "rl Sn( bOIOWl. IIOtnAlIA
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c
Decision Summary
5
ID.
mGHLIGBTS OF CO~ PARTICIPATION
Public participation is required by CERCLA sections 113 and 117. These sections require
that before adoption of any plan for remedial action to be undertaken by the President (EP A)
or by a State (MDHES) or by anyone (pRPs), the lead agency shall:
1.
Publish a notice and brief analysis of the Proposed Plan and make such plan available
to the public; and.
2.
Provide a reasonable opportunity for submission of written and oral comments and an
opportunity for a public meeting at or near the Site regarding the Proposed Plan and
any proposed fIndings relating to cleanup standards. The lead agency shall keep a
transcript of the meeting and make such transcript available to the public. The notice
and analysis published under item #1 shall include sufficient information to provide a
reasonable explanation of the Proposed Plan and alternative proposals considered.
Additionally, notice of the fmal remedial action plan (Record of Decision) adopted shall be
published and the plan shall be made available to the public before commencing any remedial
action. Such a fmal plan shall be accompanied by a discussion of any significant changes to
the preferred remedy presented in the Proposed Plan along with the reasons for the changes
and a response (Responsiveness Summary) to each of the significant comments, criticisms,
and new data submitted in written or oral presentations during the public comment period.
MDHES has conducted required community participation activities through presentation of
the Proposed Plan, a 60 day public comment period, a public hearing and presentation of the
selected remedy in the Record of Decision. SpecifIcally included in the Record of Decision
is a Responsiveness Summary that summarizes public comments and MDHES and EPA
responses. The Record of Decision documents changes, if any, to the preferred remedy as a
result of public comments.
The Proposed Plan for the Site was released for public comment on April 16, 1992. The
Proposed Plan was made available to the public in both the administrative record located at
the Bozeman Public Library and at MDHES offices in Helena, MT, and information
repositories maintained at MDHES offices in Helena, the Bozeman Public Library, the
Gallatin County Environmental Health office and the State Library in Helena. The Proposed
Plan was distributed to the MDHES IPC Site mailing list. The notice of availability of the
Proposed Plan was published in the Bozeman Chronicle on April 16, 1992. A public
comment period was initially designated froIIi April 16, 1992 through May 16, 1992, but
requests from the PRPs resulted in a 30 day extension to June 16, 1992.
A public hearing was held in Bozeman, MT on April 30, 1992. At this hearing,
representatives from EP A and the MDHES answered questions about problems at the Site
and the remedial alternatives under consideration as well as the preferred remedy. A portion
of the hearing was dedicated to accepting oral comments from the public. A court reporter
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6
Idaho Pole Record of Decision
transcribed the entire hearing and MDHES made the transcript available to the public on
May 22, 1992. A response to the comments received during the public comment period is
included in the Responsiveness Summary, which is part of this Record of Decision. Also,
community acceptance of the selected remedy is discussed in section VII, Summary of
Comparative Analysis of Alternatives, of the Decision Summary.
IV.
SCOPE AND ROLE OF RESPONSE ACTION
To address potential threats posed by hazardous substances at the Site, MDHES organized
the Site into one operable unit and through the RI identified three specific types of
contaminated media. These are:
o
Contamination in the ditch & creek. sediments;
o
Contamination of the ground water aquifer; and
o
Cont;tmination in soils.
The contaminants of concern in these media include pentachlorophenol and other chlorinated
phenols, polynuclear aromatic hydrocarbons, polychlorinated dibenzo-p-dioxins and
polychlorinated dibenzofurans.
In order to develop an effective remedy two categories of alternatives have been defmed:
soils (including sediments) and ground water. The selected remedy will include both soil and
ground water alternatives and will address all contaminated media exceeding cleanup levels.
v.
SITE CHARACTERISTICS
Site Geolo!!\' and Hvdroloev
As shown in Figure 3, the Site is located near Rocky Creek. The Rocky Creek floodplain
lies in the Upper East Gallatin subarea. There are only a few delineated horizons at the Site:
a surficial clay, an intermediate silt at 25 feet below ground surface (bgs), a silty clay at 35
feet bgs and a second silty clay at 50 feet bgs.
Several feet of fill material have been placed in the pole plant area overlying the surficial
clay. Horizontal and vertical variations in the subsurface units play an important role in
ground water and contaminant movement. The horizons are of variable thickness and
permeability and are generally continuous but probably not over the entire Site. Aquifers are
associated with each of the permeable zones. Bedrock depth has not been established. The
principal surface water features are Rocky Creek and Mill Creek on the northern and eastern
edges of the Site. There are also several intermittently flowing ditches that carry surface
runoff from rain or snow melt and high ground water. Bozeman Creek is about 1/4 mile to
the west of the Site but is not in the direction of ground water flow from the Site. No
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7
Figure 3 Area Topography
1"
~
SCAlf:
,- - 500.
LEGEND
CONTOUR INT'ERVAL.: iEN r c.::.. I
STREAM
~_.:":":-
PROPERTI aOUlomARY (;)
IDAHO POLE: COMPANY SiTE TOPOGRAPHIC MAP
ACAD !IP1.3-001
RS'. A 6/25/92
P' -- 1=1
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8
Idaho Pole Record of Decision
attempt was made to evaluate Bozeman Creek's relationship to ground water.
The Rocky and Mill Creek 100 year floodplain is close to the streams while the 500 year
floodplain reaches near the IPC facility and into the nearby residential neighborhood.
Anticipated remedial activity will occur within the 500 year floodplain.
Ground water elevation at the Site is generally within 12 feet of ground surface. During
recharge times, levels may actually reach ground surface. The alluvial aquifers are fairly
transmissive. Ground water occurs in thin sand and grav~l seams that are laterally and
vertically discontinuous. The degree of interconnection is difficult to determine. .
There are 16 wells downgradient within 1/4 mile of the Site. Many other wells are
downgradient but are across potential hydrogeologic boundaries. Aquifer flow is basically to
the northeast at a gradient of .011 ft/ft. Currently, one ground water supply at an occupied
residence is contaminated with pentachlorophenol greater than the promulgated maximum
contaminant level (MCL) of 1.0 p.g/L.
Mill Creek is used during the irrigation season as an upstream diversion from Bozeman
Creek. Mill Creek remains bank full throughout the summer thereby creating a ground
water mound and limiting the amount of contaminated ground water that may flow into Mill
Creek.
Rocky Creek appears to form a hydrologic divide along the northern and eastern edges of the
Site. A series of flow monitoring stations were operated during the RI. Continuous
recorders on both stream stage levels and ground water levels indicated that ground water
discharges to Rocky Creek at least a portion of the year . Very low contaminant levels were
measured in Rocky Creek during low flow conditions but other sampling events showed
dilution of contaminants of concern to below detection limits.
Nature and Extent of Contamination
Wood treating operations at the Site are among the suspected sources of contamination. Past
disposal practices pertaining to the sludges accumulated in the thermal treatment vats are
unknown. Two boil overs of wood treating fluids occurred in 1981 and 1987. These spills
were associated with the retort building and the butt vat. One of the two long vats that was
decommissioned in 1978 was also reported to have leaked significant amounts of treating
fluids.
Contaminants of concern
Hazardous substances that have been released at the Site, include the following:
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Decision Summary
9
Pentachlorophenol and other chlorinated phenols
A mild acid with an hydroxyl group, pentachlorophenol is a hazardous substance as defmed
by CERCLA ~ 101(14). Pentachlorophenol ionizes in solution to form pentachlorophenate
anion. The pH dependent ionization leads to higher solubility for pentachlorophenol than its
nonnal aqueous solubility of 14.0 mg/L. Once pentachlorophenol dissolves in water, its
adsorptive behavior begins to control its fate. As aqueous solubility decreases, the
adsorption increases. Ground water Ph is generally in the neutral range at the Site,
rendering pentachlorophenol more mobile in ground water. than .the other contaminants of
concern. Site aquifers are comprised of fairly transmissive sands and gravels, resulting in
rapid migration of pentachlorophenol.
Pentachlorophenol is known to be biodegradable tinder both aerobic and anaerobic
conditions. Anaerobic degradation rates are generally 10 to 100 times slower than aerobic
degradation; therefore, if remediation time is critical, a method of oxygen enhancement is
recommended (Woodward-Clyde, 1988). Other related chlorinated phenols have been
identified at the Site. Chlorinated phe~ols are present in pentachlorophenol as manufacturing
byproducts. They may also result from breakdown of pentachlorophenol. Pentachlorophenol
is identified as a probable human carcinogen.
Polynuclear aromatic hydrocarbons
Several polynuclear aromatic hydrocarbons (pAHs), defmed as hazardous substances by
CERCLA ~ 101(14), have been identified at the Site. These include: anthracene,
benzo(a)pyrene, benzo(a)antbracene, benzo(k)fluoranthene, benzo(b)fluoranthene,
dibenzo(a,h)anthracene, indeno(c,d)pyrene, benzo(g,h,i)perylene, phenanthrene, chrysene,
fluoranthene, fluorene, naphthalene and pyrene. The majority of the compounds do not
contain active functional groups and have low aqueous solubilities.
The low molecular weight P AHs are comparatively more soluble in water than high
molecular weight P AHs and have lower organic carbon partition coefficients. This indicates
that these low molecular weight compounds will be more mobile in the environment than the
high molecular weight P AHs.
P AH compounds are known to be biodegradable under both aerobic and anaerobic
conditions. The rate of transformation of PAH compounds by soil microorganisms is related
to the compound's molecular weight as well as the acclimation of the soil microbes to the
P AH compounds. Thus, the low molecular weight P AHs biologically degrade at a faster rate
than the high molecular weight PAHs. The four and five ringed PAHs found at the Site are
suspected probable human (B2) carcinogens. The two and three ringed P AHs found at the
Site are not probable human carcinogens; however, they present noncarcinogenic health
hazards.
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L>
10
Idaho Pole Record of Decision
Polychlorinated dibenzo-p-dioxins and Polychlorinated dibenzofurans
Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are
hazardous substances as defmed by CERCLA ~ 101(14). PCDDs and PCDFs are a family of
aromatic compounds that appear to be primarily byproducts of chemical manufacturing or
combustion processes involving precursor compounds and heat.
The biological degradation rate of these compounds appears to be very slow when compared
to other organic compounds. Because PCDDs and PCDFs have very low vapor pressures,
they do not readily evaporate or volatilize to the atmosphere. The compounds adhere tightly
to soil particles and do not migrate readily or leach into ground water or surface water unless
the contaminated soil particles themselves migrate via erosion processes (Freeman, 1989).
The family of compounds are suspected probable human carcinogens of varying toxicity.
One isomer, 2,3,7,8-tetrachlorophenol dibenzo-p':dioxin (TCDD), has been determined to be
the most toxic. Concentrations of the other less toxic isomers must be multiplied by toxicity
equivalence factors to determine their risk relative to 2,3,7,8-TCDD. The toxicity
equivalence for each PCDD and PCDF analyzed for a sample is added together to result in
one concentration value and the summation is expressed as TCDD toxicity equivalence (TE).
Contaminated media
The estimated areas and volumes of contaminated media presented in this section were
calculated by determining the approximate volumes of media with contaminant concentrations
at or above the proposed Site-specific cleanup level for each media.
The spillage of oily wood treating fluid has resulted in soil, including ditch sediments, and
ground water contamination onsite and off site in the surrounding vicinity. In addition, since
the oily wood treating fluid is lighter or less dense than water, a product layer exists beneath
the Site, above ground water.
Site contamination exists in three media:
o
contaminated sediments in the Cedar Street ditch, the substation ditch, the L
Street ditch, a small stretch of Rocky Creek, and portions of the Bohart Lane
ditch;
o
contaminated surface and subsurface soils in the vicinity of the pole plant
facility extending north to the pasture and in the former roundhouse area; and
o
contaminated ground water that migrates from the pole plant area north and
northeast towards Rocky Creek and a residential area.
These contaminated media are illustrated in Figure 4, the Site Conceptual model. The
drawing visually describes contaminant movement from the treatment plant area, past 1-90
-------
Figure 4 Site Conceptual Model
IoIPC SUBSTAnoH
oncli ,ySUIl
7Z //
PAIt AQI/[OUS/PAATlCULATI U,U-hCP
pCP/2.s.41'-hcP/ .. AHD 3,4,5-TCP
..:---... ro......L/ ~ I~QU[~S) - ADWCT\OH ..
71 /~ ~/ / r-v :J.~:'----- <7777 // /L / ~
'\ CJ // .,Lf // // //.2b .'" GWfLO~~ // L/ /T7J
DCTAll OF cotffAloIlIlAHTS
II£TWUH CRAIlIS IH
AQulrER
1 ~GAwQU[OUS.)
DIlAPL p[poSmOIi (1) '-J ~
0'
POHDIIUI or
LDCAUUD HArl
8'
24'
U'
,/
/ .
pcp /P"" (AOUtOUS)
~
80'--
'00'
-- ,--.. ,-I ,.- ,.- ,.."
I, SURrAct SOILS AS SOURct OF p"RnCULAT[ (V\.I. FUGITIV[ 1.110 IoItCllAlIIl:.t.L IHlIWIIUIIIT)
1I0RIIOHTAl SCAU. '""100'
(APPRDXlum)
"U1lCAl SCA\£. 4X- or 1I0RIIOICTAl
(APP/IOXIUAII)
2. SPII,LS OF pcp 11"0 01l5"t PITCII S/Sttll MID REum" POIHT OF COIIJAUIHAJ(D stDIUEIIT DURIIIQ FUIIOFF MtfTS 1.110 OFF SIf( TIWISPORT
S. IilO/lWWAT[/I, IoInT'HAUR /lUll orF WlTtI stDIUUIT
lEGEHO
FILL f.Z1
[)JIlII ~
CL.l.Y L21
.. Q/lOUIIDWAnR/SOIL/PLAIIT PA1IIWAY WlTII /lODl1n-IW'TO/l. COW/UIU
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-
N
TABLE 1
A VERAGE AND MAXIMUM CONTAMINANT CONCENTRATION DATA SUMMARY FOR DITCH SEDIMENTS
(pg/kg)
Cedar Street MPC Substation Bohart Lane L. Street Groundwater Drainage
Contaminant Av'J.. (S.D.)" Max. AVf!. (S.D.) Max. Av'i!.. (S.D.) Max. Av'i!.. (S.D.) Max. Av'i!.. (S.D.) Max.
Pentachlorophenol 15,640(8,363) 22,000 10,667(9,783) 25,000 410 410 1,330(936) 2,400 640U
Fluoranthene 725(620)Jb 1, 700J 55J 55J 88(88)J 150 166(69)J 2601 75(27)J 94J
Benzo( a)pyrene 41O( 439)J 720J 41O(127)J 500J 621 621 85J 85J I10J 1101
Anthracene 346(204)J 520J 65(17)J 77J 27J 27J 38(16) 501 321 321
Pyrene 4,257(7, 783)J 20,OOOJ 84(37)J 1101 84(93)J 150 270(136) 460 l00J lOOJ
Benzo(a)anthracene 1,91O(2,361)J 4,6ooJ ----------- 510U 801 80J 115J 115J 66J 66J
Benzo(b )fluoranthene 766(364)J 1,2ooJ 228(243)J 400J 95(106)J 170 259(144) 440 120 120
Benzo(k)fluoranthene 1,900U 380J 380J 97U 320U 190U
Benzo(g,h,i)perylene 168(144)J 270J 210J 210J 54J 54J' 54J 54J 190U
Chrysene 2,920(3,664)J 7, lOOJ -------...--- 510U 120 120 197(70)J 270J 65J 65J
Indc;,no(l,2,3-cd)pyrene 172(124)J 260J 220J 220J 411 411 320U 190U
Phenanthrene 1,001(947) 2,300 205(78)J 260 69(72)J 120 182(89)J 280J 128(88) 190
TCDD TE 34.2 2.33 0.055'
Notes: a. Average concentration with standard deviation.
b. Data qualifier codes are as follows: J = an estimated quantity, U = compound was analyzed for, but was not detected.
Source: BaseJine Risk Assessment, MSE, March 1992
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u
Decision Summary
13
and the pasture and towards Rocky .Creek. The various compounds identified are assumed
transfonnations of pentachlorophenol to lesser chlorinated phenols. Potential pathways of
contaminant migration in addition to specific populations and environments that could be
affected by the contaminants are described in section VI, Summary of Site Risks.
Sediments
Contaminants of concern in ditch sediments are pentachlorophenol, 2,4,6-trichlorophenol,
PAlls (anthracene, benzo(a)pyrene, fluoranthene and pyrene), and PCDDs/PDCFs (TCDD
TE). Table 1 summarizes average and maximum concentrations of contaminants in ditch
sediments and includes data for other compounds evaluated.
Areas and volumes of contaminated intermittent ditcl). sediments or soils were estimated
assuming a depth of contamination of three feet below ground surface. There were two
ditches identified for remediation: the substation ditch that receives surface runoff from the
interceptor trench area and the Cedar Street ditch that receives runoff from the retort area.
The other intennittent ditches investigated did not have contaminants of concern exceeding
cleanup levels. Table 2 summarizes estimated areas and volumes of Site sediments and other
, contaminated media identified for remediation.
TABLE 2
ESTIMATED CONTAMINATED AREAS AND VOLUl\1ES
AREA (acres) VOLUME
sediments 0.6 2683 yd3
soils 7.4 39,304 yd3
ground water 61.4 210 million gal
Because only one sample to measure TCDD TE was taken from each ditch, the extent of
ditch sediments to be remediated is based upon pentachlorophenol and B2 PAll
contamination levels. Volumes for remediation were estimated assuming that the amount of
sediment in the two ditches that exceeded the preliminary remediation goal of 10 mg/kg
pentachlorophenol or 1.0 mg/kg for B2 PAlls was the same as the amount of sediment that
exceeded the cleanup level of 1.0 p.g/kg for TCDD TE.
Rocky Creek sediment volumes were not estimated due to low concentrations of contaminants
and the identified lack of adverse impact to surface water. Rocky Creek sediments are not
identified for remedial action. Table 3 summarizes average and maximum concentrations in
creek sediments and includes data for other compounds evaluated.
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14
Idaho Pole Record of Decision
Soils
Contaminants of concern for soils are pentachlorophenol, PAHs (anthracene, benzo(a)pyrene,
fluoranthene and pyrene), and PCDDs/PCDFs (TCDD TE). Table 4 summarizes average
and maximum concentrations in soils and includes data for other compounds evaluated.
The areal extent and volume of contaminated soil were determined by evaluation of analytical
results for the contaminants of concern, visual observations made while conducting specific
investigations and by computer modeling. The computer modeling evaluations were
conducted in the treatment plant area and in the former roundhouse area. Volumes of
contaminated soils were obtained by evaluating contaminant concentration data collected from
test pit samples. The evaluation produced contour maps of contaminant concentrations at
each zone or depth for which adequate discrete data was available. The estimated volume of
contaminated soils in the treatment plant area is approximately 6594 cubic yards over an area
of about 0.7 acres.
The RI determined that the majority of contaminated soils at the Site originate in the pole
plant area and extend northward in close association with the oily wood treating fluid plume.
Contamination of subsurface soils within the bounds of the oily wood treating fluid.
contamination area is due to smearing of oily wood treating fluid caused by the seasonally
fluctuating water table. During high water table conditions, the oily wood treating fluid has
reached ground surface in the pasture resulting in pools of oily wood treating fluid. The
approximate boundary of soils containing the oily wood treating fluid is presented in Figure
5. .
This area has been determined to be approximately 6.7 acres and was delineated primarily by
visual observations during the field investigations. Given the potential for a 3-foot seasonal
fluctuation of the static water level in this area, approximately 32,410 cubic yards of soil are
potentially contaminated with the oily wood treating fluid. Additionally, 300 yef of
contaminated soils has been estimated in the former roundhouse area. The total estimated
volume of contaminated soils is 39,304 cubic yards and 7.4 acres.
The oily wood treating fluid contains high concentrations of pentachlorophenol, B2 P AHs
and PCDDs/PCDFs (TCDD TE). Oily wood treating fluid was sampled very infrequently
but concentrations of 280 mg/kg, 283 mg/kg and 407 ug/kg, respectively, for
pentachlorophenol, B2 P AHs and TCDD TE, are representative of contamin::tnt levels. Oily
wood treating fluid is the principal source of contamination to soils, sediments and ground
WM&. .
Based on the results of an oily wood treating fluid plume investigation conducted as part of
the remedial investigation, the average thickness of the oily wood treating fluid area has been
determined to be approximately 0.5 feet. This value weighs free product pockets exceeding
1 foot in thickness in some areas and practically no product in others, and takes into account
significant amounts of product suspended in the soils due to the smearing effect. Given the
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"
TABLE 3
AVERAGE AND MAXIMUM CONTAMINANT CONCENTRATION FOR CREEK SEDIMENTS
(pg/kg)
Rockv Creek Mill Creek
Contaminants Avg. (S.D.)" Max. Avg. (S.D.) Max.
Pentachlorophenol 760Jb 760J 420J 420J
Fluoranthene 175(98) 310 205(120)J 290
Benzo(a)pyrene 730U 940U
Anthracene 180J 180J 940U
Pyrene 118(58)J 210 170(0)J 170J
Benzo(a)anthracene 621 621 94J 94J
Benzo(b )fluoranthene 82(23)J 120J 19O(14)J 200J
Benzo(k)fluoranthene 730U 180J 180J
Benzo(g,h,i)perylene 730U 940U
Chrysene 91(34)J 120J I 14(23)J 130J
Indeno(I,2,3-cd)pyrene 730U 940U
Phenanthrene 200( 105)J 400 182(124)J 270J
Notes: a.
b.
Average concentration with standard deviation.
Data qualifier codes are as follows: J = an estimated quantity, U = compound was analyzed for, but was not detected.
Source:
Baseline Risk Assessment, MSE, March 1992
-
U\
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.....
0\
TAULE 4
AVERAGE AND MAXIMUM DATA SUMMARY FOR SOILS
(pg/kg)
Former Roundhouse Area Wood Treating Soils (WTS) Other Potential Sources. IPC Pole Yard Areas
Soils (OPS) (lY A)
Contaminant Avg.(S.D.)' Max. AvdS.D.) Max. Avg.(S.D.) Max.- Avg.(S.D.) Max.
Pentachlorophenol 272(222)Jb 650J 50,456(101,297) 380,000 4,481(6,241) 10,000 713(506) 1,200
Fluoranthene 1,444(1,958) 5,300 2,093(3,275) 12,000 961 96J 122(94)J 230
Benzo(a)pyrene 1,066(1,561) 4,800 651(1,068) 4,100 49J 491 89J 89J
Anthracene 552(585) 1,500 864(1,860) 8,100 100U 28( 13)J 311
Pyrene 2,233(3,160) 8,500 1,654(2,714) 10,000 200(99)1 2701 119(10)1 200
Benzo(a)anthracene 1,212(1,846) 5,100 768(1,410) 5,800 59J 591 64(50) 100
Benzo(b )fIuoranthene 1,588(2,367) 6,700 1,574(2,978) 13 ,000 120i 120J 116(98)1 230
Benzo(k)fIuoranthene 1,552(2,363) 6,100 54(40)1 82J 120J 1201 98U
Benzo(g,h,i)perylene 553(652)1 1,700 462(616) 2,200 1,800U 68J 68J
Chrysene 1,555(2,096) 5,900 1,368(2,421) 10,000 801 801 108(87) /70
Indeno(I,2,3-cd)pyrene 462(552)J 1,500 536(154) 2,100 1,800U 68J 68J
Phenanthrene 1,312(2,010) 6,500 3,266(9,276) 46,000 1,800U 102(67) 180
TCDD 1'E 1.1g
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17
Figure 5 Oily Wood Treating Fluid Plume
WEll. 1 1
@
~
be..
Aa.IJ#: 1P10-0.42
REV: - DATE.: %/24/9
~DRAFTER: we
10~PlOT SCAU:: 1=150
APPROXIMATE I.NAPL CONTAMINATION AR£A
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18
Idaho Pole Record of Decision
oily wood treating fluid contamination area, a porosity of 0.3 and the average thickness of
0.5 foot, the estimated volume of oily wood treating fluid present is 327,000 gallons. This
volume may be less due to ongoing product recovery efforts and conservative estimation
methods.
Ground water
Contaminants of concern for ground water are pentachlorophenol, 2,4,6-trichlorophenol and
PAHs (anthracene, benzo(a)pyrene, fluoranthene, fluorene" naphthalene and pyrene). Table
5 summarizes average concentrations of contaminants in ground water and includes data for
other compounds evaluated.
The areal extent and volume of contaminated ground water associated with the dissolved
plume has been determined using ground water modeling results presented in the RI. Figure
6 presents an illustration of the approximate dissolved plume boundary.
The dissolved plume containing pentachlorophenol at 1.0 p.g/L or greater is approximately
61.4 acres. The average thickness of the contaminated ground water has been estimated at
35 feet, which includes the upper three aquifers. The average porosity value is 0.3. Based
on these values, approximately 210 million gallons of ground water are contaminated with
pentachlorophenol concentrations at or above 1.0 p.g/L. Ground water above 1.0 p.g/L was
used for the volume estimate because 1.0 p.g/L represents the promulgated Maximum
Contaminant Level (MCL) for pentachlorophenol as established by the Safe Drinking Water
Act. Ground water concentrations as high as 600 p.g/L have been identified at the
downgradient monitoring well furthest from the pole plant.
VI.
SUMMARY OF SITE RISKS
The baseline risk assessment provides the basis for taking action and indicates the exposure
pathways that need to be addressed by the remedial action. It serves as the baseline for
indicating what risks could exist if no action were taken at the Site. This section of the
Record of Decision reports the results of the baseline risk assessment conducted for this Site.
As part of the remedial investigation and feasibility study, human health and ecological risk
assessments, which together comprise the baseline risk assessment, were developed to help
MDHES and EP A determine actions necessary to reduce actual and potential risks from
hazardous substances at the Site. Risk assessments were conducted at the Site with the
following objectives:
o
provide an analysis of baseline risk (potential risk if no remedy occurs) and
help determine the need for action;
o
provide a basis for determining cleanup levels (concentrations) that are
protective of public health and the environment;
-------
,
"
l~
TABLE 5
AVERAGE CONCENTRATIONS OF CONTAMINANTS OF CONCERN IN GROUNDWATER (UGIL)aJ>
Contaminants UDl!l"ad.AUB DOWlU!l'ad. A VI!:.
A WELLS
PCP ~0.1O 3,799U
2,4,6 - TCP ~0.OO5 769J
Fluoranthene ~0.050 360U
Phenanthrene ~0.030 515U
Pyrene ~0.020 386U
Chrysene ~0.OO5 1981
Benzo(b )fluoranthene ~0.OO1 46J
Benzo(k)fluoranthene ~0.OO3 94J
Benzo(a)anthracene ~0.OO2 1461
Fluorene ~0.01O 165U
Anthracene ~0.01O 154J
Benzo( a)pyrene ~0.OO5 74J
Naphthalene ~0.020 140J
2, 3, 7, 8- TeCDD TE ~0.OOO5 :;;;0.05.
Contaminants UDI!l"ad.AUB DOWlU!rad. A VI!:.
B WELLS
PCP ~3 321U
2,4,6 - TCP ~2 4.81
Fluoranthene ~3 8.01
Phenanthrene ~5 8.9J
Pyrene ~3 13.3J
Chrysene ~5 82.4J
Benzo(b )fluoranthene ~4 0.30J
Benzo(k)fluoranthene ~2 3.11
Benzo( a) anthracene ~2 6.4J
Fluorene ~3 5.21
Anthracene ~3 5.3J
Benzo(a)pyrene ~2 0.57J
Naphthalene ~5 4.0J
2,3,7,8- TeCDD TE ~0.05 :;;;0.1d
Contaminants U~d.AUB DOWlU!l'ad. A VI!:.
C WELLS
PCP :;;;0.10 03.1U
2,4,6 - TCP ~0.OO5 (5.8U-12U)
Fluoranthene ~0.050 (0. 25U-2-1U)
Phenanthrene ~0.030 (0.25U-6.4U)
Pyrene ~O.020 (0. 50U-2. 7U)
Chrysene ~0.OO5 (0.38U-1.5U)
Benzo(b)fluoranthene ~0.OO1 (0.3U-O.18U)
Benzo(k)fluoranthene ~0.OO3 (0.OlU-O.17U)
Benzo(a)anthracene ~0.OO2 0.13+0U
Fluorene ~0.010 2.3J
Anthracene ~O.OlO (0.OlU-6.6U)
Benzo(a)pyrene ~0.OO5 (0.OSU-O.23U)
Naphthalene ~0.020 4.0U
2,3,7,8- TeCDD TE ~0.OOO5 No data (ND)
NOTES: . Based upon validated data from the May and August 1990 sampling plus the March and June 1991 sampling
episodes; AUB = assumed upper bound for contaminant-specific background level, based upon literature review.
J = estimated quantity, U = data with no qualifications attached, U = compound was analyzed for, but was not
detected.
Based upon August 1990 data from monitoring well9A.
Based upon May 1987 data from Well 16B.
Baseline Risk Assessment MSE March 1992.
b
SOURCE:
-------
20
Figure 6 Ground water plume
I
1
~
SCAL.E: 1" = 350'
"--
.--.,
~
e WElLS
AVERAGE OBSERVED
"i' PCP CONCDfiRATION
uv/1
PCP alNCDrTRATIOH
~ PREDICTD) aT WODEl.
IN uv/I
INc.
ACNJf: 1P10-045
REV: - DATE: 2/~/92
DRAFTER: JW
GROUNDWATER DISSOLVED PCP P~E.
BOUNDARY AND ASSOCIATC:D CDNa:NTRATION CONTOURS AS
DERIVED F'ROW THE CJ.USRATC:D TRANSPORT WODEL
-------
.:..
Decision Summary
21
o
provide a basis to compare potential public health and ecological impacts of
various cleanup alternatives; and
o
provide a consistent process to evaluate and document potential public health
and ecological threats at the Site.
The Baseline Risk Assessment indicates that the principal threats stem from subsurface soils,
oily wood treating fluid, and to a lesser extent surface soils. The low level threats stem from
ditch and creek sediments. This determination is based on concentrations and estimated
volumes of contaminated media. The primary pathways are ingestion of and direct contact
with contaminated ground water, ingestion of or direct contact with soils and inhalation of air
entrained soils; secondary pathways are ingestion of and direct contact with surface water
and ingestion of vegetation. Potentially affected receptors include human beings and
terrestrial and aquatic biota.
Human Health Risks
The Baseline Risk Assessment indicates that there are excessive human health cancer risks
and excessive non-cancer health hazards associated with hazardous substances at the Site:
Remedial action is required in order to reduce these potential risks.
Selection of contaminants of concern
The selection of contaminants of concern was based upon the presence of contaminants in
various media at the Site and the reference dose (RID) or cancer slope factor (SF) associated
with the cont;lminants.
This evaluation was completed for ditch and creek sediments, soils (including air entrained
soil particles), ground and surface water and oily wood treating fluid. The cont;lminants of
concern consist of semivolatile organic compounds. Volatiles and heavy metals were
eliminated from consideration after an initial round of sampling and analysis indiCated no
significant concentrations. Table 6 summarizes contaminants of concern identified for use in
the Baseline Risk Assessment.
Toxicity assessment SUIDIiJary
RIDs have been developed by EP A for indicating the potential for adverse health effects from
exposure to chemicals exhibiting noncarcinogenic effects. RIDs are expressed in units of
mg/kg-day. RIDs estimate (with uncertainty spanning an order of magnitude) daily exposure
to the human population (including sensitive subgroups) that is likely to be without an
appreciable risk of deleterious effects during a lifetime.
RIDs are derived from human epidemiological studies or animal studies to which uncertainty
factors have been applied (e.g., to account for the use of animal data to predict effects on
-------
TABLE 6
SUMMARY OF CONTAMINANTS OF CONCERN SELECTED FOR QUANTITATIVE
AND QUALITATIVE RISK ASSESSMENT
N
N
PART A. QUANTITATIVE RISK ASSESSMENT'
Media
Contaminants of Soils Sediment Groundwater
Concem
Pentachlorophenol x x x
.2,4,6-trichlorophenol x x
Anthracene x x x
Benzo(a)pyrene x x x
Fluomnthene x x x
Fluorene x
Naphthalene x
Pyrene x x x
(TCDD TE) x x x
PART B. QUAUTATIVE RISK ASSESSMENT"
Media
Contaminants of Soils Sediment Groundwater
Concem
Benzo(a)anthracene x x x
Benzo(b )fluomnthene x x x
Benzo(k)fluomnthene x x x
Benzo(g, h, i)pery lene x x
Chrysene x x x
Indeno(I,2,3- x x
cd)pyrene
Dibenzo(a, h) x x x
anthracene
Air IPC Pasture Soi1s
x x
x x
x
x
Air IPC Pasture Soi1s
T x
T x
T x
T x
T x
T x
x x
Notes:
. Compounds for which inhalation and/or oml reference doses plus inhalation and/or oml cancer potency factors exist in IRIS (EPA, 1991a)
or HEAST (EPA, 1991b).
b Compounds for which the above factors do not exist in IRIS (EPA, 199ta) or HEAST (EPA, 1991b).
C Tentative.
Baseline Risk Assessment MSE, March 1992.
Source:
-------
Decision Summary
23
. .
humans). These uncertainty factors help ensure that the RIDs will not underestimate the
potential for adverse noncarcinogenic effects.
SFs have been developed by EPA's Carcinogenic Assessment Group for estimating excess
lifetime cancer risks associated with exposure to potentially carcinogenic chemicals. SFs,
which are expressed in units of (mg/kg-day)-l, are multiplied by the estimated intake of a
potential carcinogen, in mg/kg-day, to provide an upper-bound estimate of the excess cancer
risk.
SFs are derived from the results of human epidemiological studies or chronic animal
bioassays to which animal-to-human extrapolation and uncertainty factors have been applied
(e.g., to account for the use of animal data to predict effects on humans). Use of this
approach makes underestimation of the actual cancer risk highly unlikely. Table 7 lists RIDs
and SFs for the contaminants of concern.' .
Assumptions and exposure scenarios
Reasonable maximum exposure scenarios were developed for onsite and offsite receptors for
current and future land use conditions. Two reasonable maximum exposure populations were
developed for each condition. These were determined by consideration of continuing pole
plant operations and a nearby residential neighborhood. The current onsite population was
identified as pole plant workers and intruders. The current offsite receptor point was
identified as the currently unoccupied residence in the contaminated ground water plume.
This residence is located in the nearby residential neighborhood and could be reoccupied.
The future reasonable maximum exposure on site and offsite populations were defmed by
assuming that a trailer court will exist on the pole plant grounds and that the residence
located in the ground water plume will be occupied. Table 8 summarizes the assumed
reasonable maximum exposure populations.
TABLE 8
ASSUl\1ED REASONABLE MAXIMUM EXPOSURE POPULATIONS
grmm
On site
Offsite
current
workers (adults)
intruders (6-18 yrs)
adults
children (6-12 yrs)
future
adults
children (1-6 yrs)
. adults
children (6-12 yrs)
A principal difference between the on site and offsite receptors was that only the offsite
receptors were assumed to be exposed to contaminated ground water through use of domestic
well water. This is a reasonable assumption since the pole plant facility is within the city
limits and currently receives city water. The residence used for the offsite scenarios is
-------
N
oJ::-
TABLE 7
TOXICITY VALUES FOR CONTAMINANTS OF CONCERN
CompourL
Cancer Slope Factor (mg/kg/day)'1
Oral Reference Dose(mg/kg/day)
Oral
Inhalation
Anthracene
----------
----------
Chronic SlIbchronic
0.03 0.03
0.30 3.0
Pentachlorophenol
1.2 X 10'1
ND
Benzo( a)pyrene
5.79 x 10°
6.1 X 10°
Filloranthene
----------
-----------
0.04
0.40
Pyrene
----------
-----------
0.03
0.30
TCDD TE
1.5 X 10'
1.5 x 10'
NOTES:
Baseline Risk Assessment, MSE, Inc., March 1992 and IRIS, EPA, 1992.
-------
Decision Summary
25
outside of the city and has used ground water for domestic purposes.
Reasonable maximum exposure point concentrations were developed for each of the exposure
populations identified in Table 8 for pentachlorophenol, PARs (anthracene, benzo(a)pyrene,
fluoranthene and pyrene), and TCDD TE. Reasonable maximum exposure point
concentrations are summarized in the baseline risk assessment.
Risk characterization summary
Excess lifetime cancer risks are determined by multiplying the intake level of a contaminant
with the SF. These risks are probabilities that are generally expressed in scientific notation
(e.g., lxlO-6 or lE-06). An excess lifetime risk of 1 x 10-6 indicates there is a one in one
million chance of developing cancer as a result of site-related exposure to a carcinogen over
a 70-year lifetime under the specific exposure conditions at a site.
For carcinogens, risks are estimated as the incremental probability of an individual
developing cancer over a lifetime as a result of exposure to the carcinogen. Excess lifetime
cancer risk is calculated from the following equation:
Risk = CDI x SF
where:
Risk = a unitless probability (e.g., 2 x 10-5) of an individual developing
cancer;
CDI = chronic daily intake averaged over 70 years (mg/kg-day); and
SF = slope-factor, expressed as (mg/kg-day)"l.
Potential concern for noncarcinogenic effects of a single contaminant in a single medium is
expressed as the hazard quotient (HQ) or the ratio of the estimated intake derived from the
contaminant concentration in a given medium to the contaminant's reference dose. By
adding the HQs for all contaminants within a medium or across all media to which a given
population may reasonably be exposed, the Hazard Index (HI) can be generated. The m
provides a useful reference point for gauging the potential significance of multiple
contaminant exposures within a single medium or across media.
The HQ is calculated as follows:
Non-cancer HQ = CDIIRfD
where:
CDI = Chronic Daily Intake expressed as (mg/kg-day) and
RID = reference dose expressed as (mg/kg-day).
-------
26
Idaho Pole Record of Decision
CD! and RID are expressed in the same units and represent the same exposure period (i.e.,
chronic, subchronic, or short-tenn).
Because of elevated levels of contaminants, a major concern is use of ground water
downgradient from the Site as a domestic water source. For example, arithmetic average
concentrations of B2 PARs relative to their reSPective, .proposed maximum contaminant
levels (MCL) standards result in excess cancer risk ranging from 2.6 x l
-------
TABLE 9
SUMMARY OF HEALTH HAZARD QUOTIENTS FOR NONCARCINOGENIC CONTAMINANTS OF CONCERN
ASSOCIATED WITH THE CURRENT LAND USE SCENARIOS..
PART A. ON-SITE INDIVIDUALS
Route of Exposure
Ingestion Inhalation Direct Contact
Contaminants of Concern Adults Intmdersb Adults Intmders Adults Intmders
Anthracene 1.7E-06 2.0E-08 NN' NA 3.1E-07 1.8E-07
Fluoranthene 5AE-05 6.3E-07 NA NA 9.9E-06 5.3E-06
PCP 8.9E-04 1. OE-05 NA NA 1. 6E-04 2.0E-02
Pyrene 4.3E-05 5. 6E-07 NA NA 7. 8E-06 4.7E-06
PART B. OFF-SITE INDIVIDUALS
Ingestion Inhalation Direct Contact
Contaminants of Concern Adults Children4 Adults Children Adults Children
Anthracene 9.9E-04 2.4E-03 NA NA 7. 6E-07 1.4E-06
Fluoranthene 1.1 E-02 2. 7E-02 NA NA 8.4E-06 4.6E-05
PCP 1.9E+OO 4.5E+OO NA NA 1.7E+OO 9.9E-Ol
Pyrene 2.5E-02 6.0E-02 NA NA 1.8E-05 IAB-05
SOURCE:
Source of these values are presented in Appendix A of the Baseline Risk Assessment; HQ values are calculated by dividing the
exposure estimates (Table 3-7) by Contaminants of Concern/route-specific reference dose values (Table 4-1).
Between the ages of 6 through 18 years.
NA - No RID available
Between the ages of 6 through 12 years.
Baseline Risk Assessment, MSE, March 1992.
NOTES: .
tV
....J
-------
TABLE 10
SUMMARY OF EXCESS INCIDENCE OF CANCER ESTIMATES FOR CARCINOGENIC
CONTMIINANTS OF CONCERN ASSOCIATED WITH THE CURRENT LAND USE SCENARIOS."
PART A. ON-SITE INDIVIDUALS
N
00
Adults
IntOldersb
Route of Exposure
Inhalation Direct Contact
Adults IntOlders Adults Intnaders
2.3E-08 4.6E-1O 3.IE-07 9. 6E-08
1.2E-06 2.3E-08 3.3E-05 8. 2E-06
NAo NA 2.IE-07 I .2E-05
Inhalation Direct Contact
Adullli Children Adults Children
2.4E-09. 1. 6E~09 1.9E-07 1.2E-07
1.5E-07 9. 8E-08 1.3E-04 5.3E-05
NA 2.6E-03 3.6E-04
Ingestion
Contaminants of Concern
Benzo(a)pyrene
TCDD TE
PCP
PART B. OFF-SITE INDIVIDUALS
1.7E-06
I .8E-04
I .2E-06
1. I E-08
I.OE-06
6.4E-09
Ingestion
Contaminants of Concern Adults Childrend
Benzo(a)pyrene 2.7E-04 4.9E-04
TCDD TE 3.0E-OI 5.6E-OI
PCP 4.9E-03 9.0E-03
NOTES: .
b
Source of these values are presented in Appendix A of the Baseline Risk Assessment; excess cancer risk values are calculated by
multiplying the lifetime exposure estimates (Table 3-8) by Contaminant of Concern/rate-specific carcinogenic potency factors (Table
4-1)
Between the ages of 6 through 18 years.
NA - No cancer slope factor available.
Between the ages of 6 through 12 years.
Baseline Risk Assessment, MSE, March 1992.
d
SOURCE:
-------
TABLE 11
SUMMARY OF HEALTII HAZARD QUOTIENTS FOR NONCARCINOGENIC CONTAMINANTS OF CONCERN
ASSOCIATED WITH THE FUTURE LAND USE SCENARIOS."
PART A. ON-SITE INDIVIDUALS
Ingestion
Route of Exposure
Inhalation
Contaminants of Concern Adults Young Childrenb Adults Young Children
Anthracene 1.3E-07 1.5E-07 NAo NA
Pluoranthene 7.0E-06 7. 8E-06 NA NA
PCP 4.0E-06 2. 6E-04 NA NA
Pyrene 4.5E-05 1.9E-05 NA NA
PART B. OFF-SITE INDIVIDUALS
Ingestion Inhalation
Contaminants of Concern Adults Childrend Adults Children
Anthracene 2.4E-04 5. 8E-04 NA NA
Fluoranthene 2.8E-03 6.8E-03 NA NA
PCP 4.7E-OI 1.IE+OO NA NA
Pyrene I .2E-02 3. OE-02 NA NA
Direct Contact
Adults Young Children
4.5E-09
3.0E-07
5.9E-07
2.0E-06
2.7E-08
1. 2E-06
5.2E-05
2.2E-06
Direct Contact
Adults
1. 9E-07
2.IE-06
4.2E-OI
9.0E~06
Children
1.0E-06
4.5E-05
2.5E-Ol
1.3E-05
Source of these values are presented in Appendix B of the Baseline Risk Assessment; values are calculated by dividing the exposure
estimates (Table 3-8) by Contaminant of Concern/route-specific reference dose values (Table 4-1).
Between the ages of 1 through 6 years.
NA - No RID available. .
Between the ages of 6 through 12 years.
NOTES: .
b
SOURCE:
Baseline Risk Assessment, MSE, March 1992.
N
\0
-------
TABLE 12
SUMMARY OF EXCESS INCIDENCE OF CANCER ESTIMATES FOR CARCINOGENIC
CONTAMINANTS OF CONCERN ASSOCIATED WITH TIlE FUTURE LAND USE SCENARIOS:
PART A. ON-SITE INDIVIDUALS
lH
o
Ingestion
Route of Exposure
Inhalation
Direct Contact
Adults _Young Childrenb
Contaminants of Concern Adults Young Childrenb Adults Young Childrenb
Benzo(a)pyrene 8.IE-07 1. 9E-06 4.IE-09 3.2E-09
TCDD TE 4. OE-OS 8.SE-OS 8.1 E-07 6.4E-07
PCP 6.2E-09 8.0E-08 NN NA
PART B. OFF-SITE INDIVIDUALS
Ingestion Inhalation
Contaminants of Concern Adults Chi!drend Adults Children
Benzo(a)pyrene 6. 6E-OS 1. 2E-04 3.0E-tO 2.0E-:tO
TCDD TE 7.3E-02 I.SE-OI 7.4E-08 4.9E-08
PCP 1.2E-03 2.2E-03 NA NA
3.SE-08
7.8E-06
9. IE-tO
3.IE-07
I .6E-OS
1.6E-08.
Direct Contact
Adults Children
4.8E-08 I.5E-07
3.2E-OS 3.3E-OS
6.4E-04 8. 8E-OS
NOTES: .
SOURCE:
Source of these values are presented in Appendix B of the Baseline Risk Assessment; values are calculated by multiplying the
lifetime exposure estimates (Table 3-9) by Contaminants of Concern/rate-specific carcinogenic potency factors (Table 4-1)
Between the ages of I through 6 years.
No cancer slope factor available
Between the ages of 6 through 12 years.
Baseline Risk Assessment, MSE, March 1992.
-------
Medium
Contaminant
TABLE 13
CLEANUP LEVELS AND CORRESPONDING RISKS
Cleanup level Basis Cancer Risk
(industrial use for
soil. residential use
for ground water}
Noncancer health
hazard qllotie.!11
Ground water (j.lg/L)
PCP
48.0 risk 1.0 x 10-<1 NDb
15.0" risk 1.0 X 10-<1 ND
145 hazard quotient NA 0.1
.001 risk 1 X 10-<1 NO
1.0 MCL 3 X 10-<1 ND
Soils and sediments
(mg/kg)
PCP
Total B2 PAHs
Total D PAHs
TCDD TE
B2 PAH~
2,3,7,8-TCDD (Dioxin)
0.2 MCL 2.7 X 10,5 ND
0.1 MCL 5.5 X 10,5 NA"
0.2 MCL 5.5 X 10.5 NA
0.2 MCL 5.5 X 10'5 NA
0.2 °MCL 5.5 X 10'5 NA
0.3 MCL 5.5 X 10'5 NA
0.4 MCL 5.5 X 10,5 NA
146 hazard quotient NA .9
3.0 x 10,5 MCL 1.3 x 10-4 NA
Benzo(a)pyrene
Benz(a)anthracene
Benzo(b )fluoranthene
Benzo(k)fluoranthene
Chrysene
Dibenz(a,h)anthracene
Jndeno(I,2,3-CD)pyrene
D PAHs
Source:
Adjusted for recently identified cancer slope factor of 5.79 (mg/kg/day)"..
ND - Not determined, cleanup level for carcinogenic effects results in noncarcinogenic health hazard of < 1.0.
NA - Not available, cleanup level established from proposed MCLs 54 Fed. Reg. 22062,22155-57 (May 22, (989), 55 Fed. Reg. 30370, 30445 (July 25,
1990) and promulgated MCLs 57 Fed. Reg. 31816 (July 17, 1992).
This contaminant has not been identified in ground water. If identified, the risk level achieved by compliance with the MCL would be higher (for this
contaminant) than the risk level specified in the ROD for ground water cleanup.
Defined by MDHES and EPA based on preliminary remediation goals presented in Peasibilily Study, MSE, April 1992.
l,,}
~
Notes: .
-------
32
Idaho Pole Record of Decision
Ecoloeical Risks
The Ecological Risk Assessment for the Site evaluated the potential for harm to terrestrial
and aquatic populations and food chains following the ingestion of contaminants. Deer, river
otter, beaver, waterfowl, skunk, songbirds and fishing birds reside within the area.
Endangered species using the Site, but not living or nesting there, are bald eagles and
peregrine falcons. Rainbow trout, brown trout, sculpin, whitefish and suckers are common
in Rocky Creek. The Baseline Risk Assessment found that fish occupying various portions of
Rocky Creek in the study area are more likely impacted by stream and riparian habitat than
by Site contaminants. A steady influx of contaminants has not been identified.
Selection of contaminants of concern
Pentachlorophenol, benzo(a)pyrene and TCDD TE were selected as the contaminants of
concern for use in the Ecological Risk Assessment for their identified toxic impacts to
mammals, avian and fish species. Concentrations of contaminants of concern found at the
Site used for the Ecological Risk Assessment are summarized in Table 14 for aquatic species
and in Table 15 for terrestrial species.
Toxicity assessment summary
The Ecological Risk Assessment focused on the oral exposure route using toxicological data
representative of species evaluated. Inhalation and direct contact were not evaluated due to a
lack of RIDs or SFs. Table 16 summarizes toxicological endpoints used in the Ecological
Risk Assessment. .
Assumptions and exposure scenarios,
Soils, vegetation, and surface oily wood treating fluid in the pasture and in sediments, and
ground and surface water are potential exposure points to the indicator species.
Three food chain scenarios were evaluated in the Ecological Risk Assessment: 1) Deer
mouse/falcon, 2) cow/milkIchild and 3) fish/fish fillet/child. The scenarios all represent
current conditions in the pasture area or creeks. The subsequent child receptor was added to
identify potential food chain impacts.
Effects on critical habitat and endangered species appear to be minimal. The surfacing of
oily wood treating fluid in the pasture is the only obvious soil impact resulting in no
vegetation. There is no indication that surface water habitat has been impacted. No
endangered species have been identified on Site, although there may be some in the area that
occasionally pass through the Site.
-------
c,
33
TABLE 14
AQUATIC DATA USED IN THE ECOLOGICAL RISK ASSESSMENr
PART A. ROCKY CREEK DATA
Contaminants of Concern
Surface Water (/Lg/U
Sediments( /Lg/kg)
PCP
B(a)P
TCDD TE
(IU-50U)b
0.037 .
No Analysis (NA)
1,605 + 1, 195J
(190U-51OU)
NA
PART B. :MPC SUBSTATION DITCH DATA
Contaminants of Concern
Surface Water
Sediments
PCP
B(a)P
TCD TE
88+74J
IOU
NA
10,667+9,783
410+ 127J
34.2
PART C. GROUNDWATER QUALITY FOR UVESTOCK WATERING
Contaminants of Concern
Res - lOA
Downgradient Arithmetic
Averages
PCP
B(a)P
TCDD TE
(5.9U-25U)
(0.05U-0.23U)
NA
3,799
74J
~0.OO3
NOTES:
Detailed discussions of sampling methodologies and consequent data interpretation for these
media are found in Section 2.1 of the Baseline Risk Assessment, MSE, 1992.
"U" data in parentheses indicates the range of undetects; "J" data are estimated.
b
SOURCE:
Ecological Risk Assessment, MSE, March 1992.
-------
TAnLJ~ 15 .
TERRESTRIAL DATA USED IN TIn~ ECOLOGICAL RISK ASSESSMENT K
PART A. PASTURE SOILS AND VEGETATION
COlllillUl na n~-l!f
CQn~
PCP
B(a)P
TCDD TE"
._Saillule Site fYeg.lSoi!L_._-
V2/R24
V3/R25
Ilackgrouncl Soil~
AIB
V tIR23
6,000Ub/I,100
1,800U/200U
0.57/0.43
5,000U1760U
1,500U1230U
0.31/0.42
10,000/350U
3,000U1260U
0.30/0.13
CQutal]1 iJ!ants of
Cn!1£!m!
PART B. SURFACE OiLY WOOD TREATING FLUID
Sample Site
PCP
B(a)P
TCDD TE4
NOTES: .
d
SOURCE:
m ill
280,000 . 170,000
14,00OJ 8,7001
407.2J 342.8
t.U
.r..
320U/370U
97U11 IOU
0.38/0.68
All data are in units of flg/kg; detailed discussion of sampling methodology and consequent data presentation/illteq)J"etation am
found in Section 2.1.5 of the Baseline Risk Assessment, MSE, 1992. .
Data qualifier codes used are as follows: . U = compound was analyzed for, but was not detected, J. = an estimated quantity;
otherwise, no qualifications are attached to the above data. .
Calculated using the 1989 toxicity equivalent factors (EPA, 1989c) and assuming that "U" values represent actual concentrations
(e.g., 1 U = 1 ~g/kg).
Calculated using the 1989 TEFs (BPA, 1989c) and using "non-U" data only.
Ecological Risk Assessment, MSB, March 1992.
. ,
-------
~\
TABLE 16
ECOLOGICAL RISK CHARACTERIZATION TOXICOLOGICAL DATA
PART A. MAMMALIAN SPECIES
Oral Route Toxicological End-Points (mg/kg.d)a
Mice (M. musculus)
Dairy Cows (B. taums)
CoC LD~ LDLo LDLo(Ter.) LDLo(Eta.) NOAEL LD~ ~ LOAEL NOAEL
PCP 65-252 NDb ND ND 3-10 140 15-20 0.2-2.0 0.05-0.5
B(a)P 50 ND ND 0.002 0.0002 ND ND 0.002 0.0002
TCDD TE 0.114-2.57 0.03 0.03 0.001 lE-06 ND 2E-06 ND ND
PART B. AVIAN SPECIES"
CoC
Oral Route
Toxicological End-Points (mg/kg.d)
LD».- LDLo NOAEL
PCP
B(a)P
TCDD TB
205-740
ND
0.01-0.8
~1 ~1O
0.002 ND
0.001-0.010 lE-06
PART C. AQUATIC SPECIES
Toxicological End-Points (lLg/L)
Macroinvertebratesd Trout (Salmo) Species
LCsol<24 hrs.) TD(96 hrs.) LCsc(24 hrs.) TD(>96 Ius.)
CoC
PCP
B(a)P
TCDD TB
NOTES:
48-55
~ 1 ,000
~0.2
. <3.2
~5.0
<0.2
20-40
~50
~0.01
10-20
~5
~0.001
Toxicological end-point codes are as folJows: LD$O = calculated dose of CoC which is expected to cause the death of 50
percent of the exposed population; LDLo = the lowest does (other than LDso) of a CoC introduced by any route (other
than inhalation) over any given period of time and reported to have caused death in the exposed population; TD = the
dose which results in some quantifiable adverse effect, other than death in the exposed indIvidual; LOAEL = lowest
observed adverse effect (dosage level; NOAEL = no observed adverse effect (dosage) level; Rep. = reproductive effects
(e.g., resorption of embryos); Ter. = teratogenic effects (e.g., cleft palate); Eta. = equivocal tumorigenic agent at the
given dose, and often resulting in weIJ defined neoplastic or carcinogenic effects at higher doses; LCso = lethal
concentration to 50 percent of the exposed population. ~
ND - no data
Species include Northern bobwhite, ringed turtle-dove, mallards and domestic chickens.
Species include freshwater snails, worms and Daphnia spp.
-------
36
Idaho Pole Record of Decision
Risk characterization
In order to evaluate adverse impacts, an environmental hann quotient (EQ) was developed
and used similarly to the HQ for human noncarcinogenic impacts. An EQ less than 1.0
represents no adverse impact while an EQ of 1.0 or greater represents adverse impact. SFs
were also used to evaluate cancer risk to children at the end of the food chain. The
Ecological Risk Assessment [mdings are summarized in Table 17. All of the EQs for the
species evaluated are less than 1.0 indicating no adverse impact. Additionally, food chain
carcinogenic impacts evaluated for the subsequent child receptor indicate no likely excess
cancer risk. Population level effects on terrestrial and aquatic indicator species are not
likely, at least through the oral route of exposure. However, adverse effects to particularly
sensitive individuals cannot be ruled out.
VIT. DESCRIPTION OF ALTERNATIVES
A brief description of the Site cleanup alternatives considered in the FS report follows. As
discussed in section IV, Scope and Role of Response Action, three general types of
contaminated media are found at the Site. Since soils and sediments provide sources of
continuing contamination to ground water, and soils and sediments are closely associated
with each other, one set of alternatives that addresses all soils and sediments was developed.
Separate remedial cleanup alternatives were developed for ground water.
There are some elements common to all of the alternatives. Institutional controls would be
used in conjunction with soil and ground water alternatives and may include restrictions on
ground water use, residential well drilling and residential and commercial land use.
Installation and maintenance of additional temporary residential water treatment systems may
be necessary if private well monitoring results indicate a potential health risk or exceedance
of cleanup levels. . .
The estimated cost of eacfCaIternative includes capital costs and annual operation and
maintenance costs. The estimated costs for the soil and ground water alternatives represent a
cleanup level protective for the current onsite and offsite scenarios as depicted in the Baseline
Risk Assessment and briefly discussed in section VI, Site Risks. The estimated costs for the
soil alternatives except Alternative 6 represent a cleanup level for residential land use that
would reduce the excess cancer risks to less than 1 in 100,000 (1 x 10-5) and for industrial
land use to less than 1 in 1,000,000 (1 x 1
-------
. TABLE 17
SUMMARY OF ECOWGICAL RISK CHARACTERIZATION ESTIMATES
Imlicotor Species
PART A. DEER MOUSE-PEREORINE FALCON SCENARIO
Inloke(mR/kR.d)
ToxicoloRicol End Point (mR/kR.d)
EO'
Deer Mouse
- PCP
- B(o)P
- TCDD TE
1.1 E-02
I.4E-03
3.6E-06
NOAEL' 3
LDLo(Eta},2E-03
LDLo(Eta.),1 E-03
Peregrine Falcon
- PCP
- B(o}P
- TCDD TE
PART B. COW-MILK-CHILD SCENARIO
I"dicotor Species
Dairy Cow
- PCP
- B(8)P
- TCDD TE
Y nung Child (1-7 yro)
- PCP
- B(o}P
- TCDD TE
J.I E-05
2.9E-08
5.7E-09
LDLo, I
LDLo, 2E-04
NOAEL, I E-06
3.7E-03
7.0E-01
3.6E-03
J.I E-05
I.4E-04
5.7E-03
Inlake(mR/kR ..1)
ToxicoloRical End Point (me/kR.d)
5.4E-03
9.8E-05
7.0E-07
NOAEL, 5E-02
NOAEL, 2E-04
TD' (monkeys) 2E-06
2.2E-08
5.6E-09
3.5E-II
Excess csncer incidence
Excess cancer incidence
Excess cancer incidence
Indicolor Species
PART C. FISH-FISH FILLET-CIIILD SCENARIO
Rainbow TWllt
- PCP
- B(o}P
- TCDD TE
Young Child (1-7 yrs)
- PCP
- B(o}P
- TCDD TE
NOTE:
b
d
SOURCE:
Surface Water
1'0(>96 hra.)
SI
0.037
sO.003
10
S5
~O.OOOI
Environmental hann quotient.
No observed adverse effect level.
Lethal dose (equivocal tumorigenic agent)
Toxic dose not resulting in death.
Ecological Risk Assessment, MSE, March 1992.
J.I E.OI
4.9E-OI
3.5E-01
IIQ~8.3E-06
Tnloke(me/kR.d)
--_...-----.--
---------.-.--
--------------
9.0E-08
7.9E-10
8.0E-10
EO
Toxicoloeical End Point
----------------
-.------...-------
---------------
Exces. cancer risk.
Excess cancer risk
Excess cancer risk
COlllmenls
---------------
EQ = 7E+00 for NOAEL, 2E-04
EQ = 3.6E+00 ror NOAEL, IE-
06.
------------
-------------
-------------
Excess Cancer Risk
-------------..--
----------------
----..-----------
2.6E-09
6.4E-08
5.2E-06
Excess Concer Risk
(Hllmons)
--------------
---------..----
--------------
J.I E-08
9.IE-09
1.2E-04
(Hllmons)
v~
-.1
-------
38
Idaho Pole Record of Decision
Soil Alternatives
Soil Alternative 2, Surface Capping, would only be considered for cleanup of the roundhouse
area because the roundhouse area is not a source of ground water contamination and all of
the identified direct contact risks posed by this area can be eliminated by surface capping.
Contaminated soils, exceeding cleanup levels, found in other locations of the Site, contribute
to ground water contamination and must undergo treatment to reduce soil and ground water
exposure risks to an acceptable level. Therefore, capping was not considered for other areas.
For purposes of cost comparison, however, the unit soil remediation costs of Alternatives 3,
4 and 5 have been calculated and have been used for comparison to the cost of Surface
Capping (Alternative 2) in section VIIT, Summary of Comparative Analysis of Alternatives.
Soil Alternatives 3 (Thermal Treatment), 4 (Biological Treatment) and 5 (Solvent Extraction)
would require excavation of all of the contaminated soils on the Site exceeding remediation
levels, including soils underneath 1-90 and the IPC treating plant structures. The excavated
soils would then be stockpiled and subsequently processed in the appropriate treatment unit.
The costs of these alternatives are directly comparable because each of the alternatives
remediate the same volume of contaminated soils:
Soil Alternative 6, In Situ Treatment Using Steam/Hot Water Flushing, would involve
treating all of the contaminated soils at the Site, exceeding remediation levels, except the
soils in the roundhouse area and in the drainage ditches. The contaminants in the soil in the
roundhouse area are not as amenable to soil flushing techniques as soils in the other areas of .
the Site. The primary contaminants in the roundhouse soils are P AHs that are very difficult
to separate from soil particles. The ditch sediments must be excavated for treatment, rather
than being treated in situ, because of the long narrow area in which the contaminated
sediments are located. Installation of a soil flushing system that would effectively reduce
contaminant levels in the ditch sediments was determined to be not practicable. Alternative 6
does not require excavation of soils from under the IPC structures or from beneath 1-90.
The estimated costs for soils remediation by Alternatives 3, 4, 5, or 6 have been calculated
and are contained in Section VIIT. The unit costs for treating one cubic yard of soil to the
Site remediation level may be calculated for Alternatives 3, 4, 5 and 6.
Alternative 1: No Action
Superfund law requires the consideration of a no action alternative. This alternative is used
as a baseline against which to compare the other alternatives. As defmed in the Idaho Pole
RIfFS, no action means that a remedy would not be conducted, and that remediation goals
would not be met. The quantity of untreated waste would remain at current levels and the
degree of risk posed by such waste would remain constant.
No ARARs, risk-based levels, or to be considered standards (TBCs) would be met under this
alternative.
-------
Decision Summary
39
Estimated cost: $0
Estimated time: 0 year
Alternative 2: Surface Cauuine
This alternative would involve covering contaminated areas with a clean, impenneable
material such as asphalt pavement.
Contaminated material would be stored in a unit similar to a landfill. This alternative was
only considered for the fonner roundhouse area. Under this alternative, neither the volume
nor the toxicity of contaminated soil would be reduced, since no treatment would occur.
Surface capping was considered for remediation of only the roundhouse soils because the risk
associated with the roundhouse soils is from direCt contact. The roundhouse soils are not a
source of ground water contamination and therefore would remain untreated under this
alternative without impacting risks from ground water. Contaminated soils in the other areas
of the IPC Site are contaminant sources for ground water and would require excavation
and/or treatment to allow the remediation goals for ground water to be met.
The surface cap would require one construction season to install. This alternative could be
implemented as a temporary measure in order to reduce health risks associated with direct
contact or ingestion of PAIl contaminated soils.
If this alternative were selected as a penn anent remedy, construction of the cap would
comply with RCRA perfonnance standards. RCRA landfill regulations would apply to this
alternative. The cap design and construction must withstand heavy equipment use at the IPC
facility throughout future wood treating operations in the roundhouse area.
To protect the integrity of.t~e cap, fencing, land use control, and deed restrictions would be
required. Capping would reduce risks associated with direct contact and ingestion pathways
and would potentially reduce the amount of infiltration that could impact ground water.
However, this alternative is not regarded as a solution to ground water contamination.
Estimated cost: $1,329,577
Estimated time: I year .
Alternative 3: Excavation And Treatment Usini! An Onsite or Offsite Thermal Process
Under this alternative all contaminated solid media would be excavated and incinerated
including soils in the roundhouse area, under 1-90 and in the IPC plant area. 1-90 would be
dismantled arid demolition of the treating plant structures would be required.
There are three different thermal processes that have been evaluated under this alternative:
1) onsite incineration using a mobile incinerator on a rent or lease basis; 2) design and
-------
40
Idaho Pole Record of Decision
construction of a transportable or stationary large scale incinerator, with incineration being
perfonned onsite; and 3) excavation and transport of contaminated materials to an offsite
incinerator.
The three different processes evaluated all involve the use of a rotary kiln type incinerator.
Rotary kiln incinerators are the most universally applicable incinerators for destruction of a
wide variety of waste types and characteristics. A rotary kiln incinerator can process wastes
having variable moisture content and variable clay content without a pretreatment step.
This alternative addresses all contaminated soils and secfunents exceeding cleanup levels
established for the Site. The alternative would involve incineration of approximately 42,000
yd3 of contaminated material.
In a properly operated incinerator at least 99.99% of all pentachlorophenol (PCP) and PAHs
and at least 99.9999% of polychlorinated dibenzo-p-dioxins and polychlorinated-
dibenzofurans (pCDDs and PCDFs) would be destroyed.
Process waste streams from an onsite incinerator including kiln ash, fly ash and purge water
would be sampled and the substantive requirements for a hazardous waste delisting petition
review would be met because the wastes being incinerated are RCRA listed hazardous waste
(F032 and F034) and wastes streams from incinerating these listed hazardous wastes are also
hazardous wastes. These waste streams are expected to meet standards for deli sting RCRA
waste and therefore would not require disposal as hazardous wastes. The ash materials would
be landfilled onsite in a unit designed to meet RCRA Subtitle D standards for solid waste
management. The amount of ash resulting from the incineration process would be
approximately 75 % of the original waste volume. Purge water would be discharged directly
to a publicly owned treatment works (pOTW) or to surface water.
Residual concentrations of PCDDs and PCDFs and other principal organic hazardous
constituents of concern (POHC) in by-product scrubber blowdown water and kiln ash are
typically found to be negligible (Le., less than one part per trillion ), while stack emissions
typically do not pose an unacceptable health threat to surrounding communities. The
methods used to measure the effectiveness of an incinerator and establish compliance are
very comprehensive and well proven; consequently, the uncertainty level of this alternative is
very low.
If an onsite incinerator is utilized, the substantive requirements for a RCRA pennitted
incinerator would be met. Offsite incineration requires compliance with both substantive and
procedural RCRA requirements, including obtaining all necessary permits for the offsite
incinerator. RCRA permit-by-rule requirements and Clean Water Act pretreatment
requirements would apply to discharges to publicly owned treatment works if excess process
water is to be disposed of offsite. Floodplain Management and Protection of Wetlands
requirements would be followed to ensure that construction of treatment units or the
excavation of contaminated soils does not encroach on the Rocky Creek and Mill Creek
-------
Decision Summary
41
floodplains and wetlands. Construction of a waste storage pile to stage soils for incineration
would require compliance with regulations for the safe operation of waste piles. For the
offsite incineration option, standards established in 40 CFR 263 for transport of hazardous
waste to the offsite incinerator would apply.
Treatability testing has not been conducted due to the proven capability of incineration;
however, initial startup testing would be necessary to ensure proper functioning of the
incinerator.
. Figures 7 and 8 present conceptual process flow diagrams for a mobile rotary kiln
incinerator, and an onsite, lafge scale rotary kiln incinerator, respectively. An offsite
incinerator would be identical to the unit represented in Figure 8. The conceptual process
flow diagrams also identify the waste streams associated with each process. Although the
volume of process waste to be managed varies depending upon the amount of contaminated
material that is incinerated, the waste streams are nearly identical.
On site Mobile Unit -
Feed Rate: 2 tons/hour
Estimated Cost: $63,000,000
Estimated Time: 5 years
On site Large Scale Unit -
Feed Rate: 9 tons/hour
Estimated Cost: $93,000,000
Estimated Time: 1.5 years
Offsite Lare:e Scale -
Feed Rate: 7 tons/hour
Estimated Cost: $211,900,000
Estimated Time: 2 years
Alternative 4: Excavation. Oily Wood Treatine: Fluid Recovery. and Solid-Phase
(Surface Land) Bioloi!ical Treatment Or Slurrv-Phase Biolo~cal Treatment
(Preferred Remedy for Accessible Soils only)
Under this alternative, all contaminated soils including the soil in the roundhouse area, under
1-90 and in the IPC plant area and ditch sediments would be excavated. 1-90 would be
dismantled and the treating plant structures would be demolished.
-------
DECONTAMINATE
. OR CRUSH
AND RE-FEED
Figure 7 Mobile rotary kiln incinerator
c:::::]ALfPL£/DEUST souDS::::>
. f ON-~ITE
.MH ---~-e-~ I LANDFILL'
2400 LB/HR 400 lB/HR. 50 lB/HR (2850 LB/HR)
DISCHARGE
DISCHARGE
AIR POlLUTION CONTROL EOUIPt.CEN'{
ROTARY
I..
N
SOUDS DISCHARGE
1(2-~~~PM) I...
I
t .
c:sAMPL£/DEUST WA~
LfOBIl[ INCINERATOR PROCESS FLOW DIAORALf FOR THE
. (1I5MLf BTU/HR.)
'_~k
ACADII IP t 0-022
REV, B DATEI 2/25/82
DRAnERI 1<8
/
-------
DECONTAMINATE
OR CRUSU
AND RE-FEED
OVERSIZE
MATERIAL
2"+
SCREEN
WASTE
AS"
10,800 Ib/hr
ROTARY
KILH
18,000 Ib/hr
Figure 8 Large Scale Rotary Kiln Incinerator
-------.---.--------.
~~~
I
I
SECONDARY I
COMBUSTION
CHAMBER
PROCESS
WATER
QUENCH
CHAMBER
SUMP
fLY ASU/
SOUOS
2,000+ Ib/hr
.Al8JP.u,.UJJQUjltnR.OLEQUI~EUI
ABSORBER
CONDENSOR
ENTRAINMENT
SEPARATOR
WAlER
1S0gpm
ON-SITE
LANDFILL
13,000. Ib/hr
~~v
I
I
WET
EtECTAOST A TIC
PRECIPITATOR
STACK
SUMP
POTW
50 gpm
STATIONARY ON-SITE ROTARY KILN INCINERATOR (SOM BTU/tlOUR)
"p= 'k.
ACAD,. IPIO-Ola
REVI B DATE. 2/2-4/82
DRAnERI KJB
~
V) .
-------
44
Idaho Pole Record of Decision
Excavated soil would be stored in a waste pile constructed for staging prior to treatment.
The soil would then be pretreated to remove the oily wood treating fluid. The recovered oily
wood treating fluid would be recycled or disposed offsite. The soil would then be treated
biologically in either a surface land treatment unit or a slurry-phase biological reactor to
reduce the contaminant concentrations in the soil.
This alternative addresses all contaminated soils, sediments and oily wood ~ting fluid
exceeding cleanup levels established for the Site. The alternative would biologically treat
approximately 42,000 yd3 of contaminated material.
Slurry-Phase Biological Treatment
The bioreactor would provide for treatment of soil contamination by providing contact
between microorganisms growing on a fIxed surface in the reactor and the slurry containing
soil contaminants. The microorganisms use the contaminants as an energy source and
degrade or destroy them to provide cell growth.
Excavated soils would undergo initial screening to remove debris by using stationary or
moving screens. Oversize materials would be washed with high pressure hot water to
remove contaminants. Materials passing through the screen would be washed and classified
by size. The cleaned, relatively coarse materials would be stockpiled while the more
contaminated silt/clay fraction would be slurried to a multistage, submerged fIxed-fIlm
bioreactor.
The treated soils would be remixed with the clean coarse materials and used to backfill the
excavated area if they meet remediation goals. If remediation goals are not fully achieved in
the bioreactor system, a small RCRA Subtitle C land treatment unit would have to be
constructed to provide additional contaminant reduction.
Effluent from the slurry units would be biologically treated in another treatment unit and
discharged to a POTW.
Slurry-phase treatment should reduce contaminant levels by 90 % for PCP, 85 % for B2
PAHs, 90% for D PAHs and 70% for PCDDs and PCDFs.
Solid-Phase Biological Treatment (Land Treatment)
The Solid-Phase Biological Treatment option.consists of an engineered land treatment unit
(LTU) for treatment of the soils from contaminated areas. If significantly different waste
types are excavated, an additional LTU would be considered because of the variable
contamination. This could happen if contamination from one area consists primarily of
PAR's and contamination from the other areas is primarily PCP. The LTU for the site soils
would cover approximately 4 acres.
-------
Decision Summary
45
A perimeter benn or dike would be constructed around the outer edge of each unit and, if
detennined necessary during the engineering design phase, a bottom liner and leachate
collection system would be installed. Excavated soil would be placed in the unit in layers up
to one foot deep and would be routinely plowed and irrigated. Areas where soil is excavated
would be backfilled with clean soil to eliminate any potential hazard associated with the open
excavations.
Treatment takes place in the unit by enhancing the conditions in which naturally occurring
microorganisms live and reproduce. Plowing adds oxygen to the soil and irrigation and
nutrient addition (nitrogen and phosphorus) serves to promote biodegradation. As with the
slurry option, the microorganisms use contaminants in the soil as an energy source and
degrade or destroy them.
Before additional layers of soil would be added to the L TU, soil remediation levels would
have to be achieved. When all of the contaminated soil has been applied to the LTU and
treatment is complete, the unit will be closed by capping.
The solid-phase process should reduce contaminant levels by 90 % for PCP, 85 % for B2
PAHs, 85% for D PAHs and 40% for PCDDs and PCDFs.
Land treatment would require compliance with RCRA requirements. Land disposal
restrictions would apply if treatment standards for F032 and F034 listed wastes are fmalized
prior to the Record of Decision.
RCRA pennit-by-rule requirements and Clean Water Act pretreatment requirements would
apply to discharges of treated slurry unit effluent to publicly owned treatment works. The
Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) requirements would apply to
reuse/recycling of recovered oily wood treating fluid. If the oily wood treating fluid did not
meet substantive FIFRA standards, the oily wood treating fluid would be transported to an
offsite RCRA Subtitle C disposal facility and disposed of in accordance with RCRA. RCRA
Subtitle C regulations for operation of waste piles would be followed.
There are different implementation requirements and time frames for each method. Solid
phase treatment will require a minimum of 10 years to reach remedial goals mainly due to
the restricted area available at the Site to place a land treatment unit. The slurry phase
biological treatment could be effected in 2 years.
Institutional controls required for this alternative include deed restrictions and land use
controls to prevent new well construction and to prevent interference with the treatment
units. Fencing would also be necessary to prevent access to LTUs.
Figures 9 and 10 provide conceptual process flow diagrams for the soil slurry reactor phase
and solid phase treatments respectively.
-------
46
Idaho Pole Record of Decision
Slurry-Phase -
Estimated Cost: $12,816,185
Estimated Time: 2 years
Solid-Phase -
Estimated Cost: $8,164,357
Estimated Time: 10 years
Alternative 5: Excavation. Oily Wood Treatine Fluid Recovery. and Critical Fluid Solvent
Extraction
Contaminated soil, including soil in the roundhouse area, under 1-90, and in the IPC plant area
and ditch sediments would be excavated and stored in a waste pile constructed in accordance
with RCRA Subtitle C requirements. 1-90 would be dismantled and the treating plant structures
would be demolished. .
Oily wood treating fluid would be recovered and recycled, treated or disposed offsite in
accordance with RCRA Subtitle C requirements. Hazardous substances would be extracted from
the soil using liquified propane in a series of tanks. After treatment, the soil would be returned
to the excavated area or a repository and recovered hazardous substances would be recycled or
disposed offsite in accordance with RCRA Subtitle C requirements.
This alternative addresses all contaminated soils and sediments exceeding cleanup levels
established for the Site, approximately 42,000 yd3. The process could treat as much as 200
tons/day with a 97% reduction in contaminant concentration.
The specific process evaluated under this alternative is the CF Systems Organics Extraction
Process. In this process, a series of reactors are designed to achieve the specified cleanup
levels. Within the extractor vessel of the reactor, at or near the solvent's critical pressure and
temperature, the hazardous organic substances in the contaminated media waste dissolve into the
solvent. Extracted organics are then removed with the solvent, while clean soils and water are
removed through an underflow. The. extracted organics and solvent then go to a second decanter
vessel, where the pressure and temperature are decreased, causing the hazardous substances to
separate from the solvent. The gaseous solvent is sent to a recovery column where it is liquified
by addition of heat and pressure and then recycled back to the extractor vessel. Addition of heat
may be required to maintain reactor temperatures above 60°F.
Treated soils would be used to backfill the excavated area if treatment levels are met. If
treatment levels were not achieved during the extraction process, additional treatment in an L TU
might be required. Recovered organics would be recycled if they meet FIFRA standards;
otherwise they would be disposed of offsite in accordance with RCRA Subtitle C requirements,
in a RCRA Subtitle C disposal facility.
-------
FUGITIVE DUST MUNICIPAL WATER
ExJVATE ---IwETStEEHIHO
SOilS ~. L::.:.- [
OVERS I E (2.18)
STOCKPILED
(E.O., DEBRIS,' STONES,
l:OARSE fRACTION)
SEE EXISTINO OW
TREATMENT SHEETS
-CUDOE
UNDERFLOW
POTW
Figure 9 Soil Slurry Reactor
-
MULTISTAGE ATIRITIOH/CLASSlflCATION ~IRCUIT
fiNE OVERSIZED .FRACTION (WASIIED)
WASUED, COARSE ORAIN
SOIL fRACTION (' SAND")
TO OHSITE 1H~'ILL .
SL RR't
.... FROTU FLOATATION . ---- C~SS.
----~-:----- . ~~~~fc{
FROTH
.EWATER'HO' ItiUclHER I.
EffUlENT ~ .
fiNE PARTICLE SLUDOE
fUGITIVE DUST.
flOCCULANT'SOLH. (CATIONIC POLyt.lER TYPE)
MIXINO/EQUAUZATION TANK
NUTRIENTS
WATER (SLURRY PREP.
TltREE STAOE, CONTINUOUSLY
STIRRED BIOREACTOR
(EIIoCCO Bloun Sys.)
AIR.
I ~~~T ~
NUTRIENTS -
AIR SPARO\HO (~02 ?)
T
HICKEHER
'--1------
TREATED
SLr
~~~ WATER -
TltICt~---- _---:-__h____'_-'-
SOLIDS OTHER TREATMENT ~~~
TO OHSITE LANDFilL - ~ IF STILL HAZARDOUS - III INc.
(AnER DELISTINO) (WORST CASE) ACADI' IP 10-013
REV. A DATEa 2/24/82
DRAnERa JW
~
EX SITU SOILS TREATt.lEHTI SLURRV OPTION
-------
Figure 10 Solid Phase Treatment
fUGITIVE DUST
VOC.(?)
C02
EXCAVATE --1
SOILS
SC~~ING I
I
OVERSIZE l>18)
DEBRIS. STONES.
ETC.
I . pH ADJUSTMENT
STOCKPilED . BULKING AGENT(S) If
l COMPOSTED
USE INI IN SITU EX SITUI WASH . BACTERIA AMENDMENTS? -,
INfiLTRATION GALLERY REMEDIATE WITH I
CONSTRUCTION HIGH PRESSURE -MAKE-UP" I
WAT£RISUjrACTAm _1< lEA~HATE . .' :
lEACHATE/RINSE' - ,t ~
WATER - - - - ..? - - - - - ~ TREATMENT - - - - RESIDUAL
(SEE EX SITU . SOUDS
GROUNDWATER
TRE" TMENT SHEET)
I
'V
POTW
ENGINEERED LAND TREATMENT
. MOISTURE MAINTENANCE
. N/P NUTRIENTS
TREATED
SOil
. AERATION
1:1 OPTIONAL PATHWAY(S)
.p..
00
CL£AN CLOSURE
(CoC. < ARAR.)
RCRA CLOSURE
(CoC. > ARAR.)
NOTES:
. .
. EVEN If LEACHATE fROM LTU 15 SENT TO BIOREACTOR. MONITOR COD. BOD TO ASSURE NO EXCESS NUTRIENTS AND EXCESS BIOMAS5
ARE NOT' SENT UlTIt.lATELY TO POTW. ALSO, 00 BIOASSAYS ON lEACHATE (ANP SOLIDS) TO CHECK fOR RESIDUAL TOXICITY DUE
TO PARTIAL DEGRADATION PRODUCTS. ETC. '
. ClEAN CLOSURE USED If RESIDUAL CoC CONCENTRATIONS AAE ~ RISK BASED REMEDIAL GOALS OR Io4EET
BOAT STANDARDS, RCRA CLOSURE If RESIDUAL CoC CONCENTRATIONS ARE> ABOVE THRESHOLDS. AND
WOULD REQUIRE TREATABILITY VARIANCE AND/OR NO Io4IGRATION PETITION.
EX SITU SOILS TREATMENT! SOLID PHASE OPTION
"
aaa
IHc.
ACADI: IP10-014
REV: A DATE: 2/2"/92
CRAnER: JW
-------
Decision Summary
49
Any land treatment occurring under this alternative would require compliance with RCRA
Subtitle C requirements. Land disposal restrictions would apply if treatment standards for
F032 and F034 wastes are fmalized prior to the Record of Decision.
Risks would be reduced to the I x 100 level for industrial use. Treatability testing has not
been conducted and the effectiveness of the extraction process has not been determined.
Process design testing would be required before full scale implementation.
RCRA permit-by-rule requirements and Clean Water Act pretreatment requirements would
apply to discharges from the extraction process dewatering system to a POTW. FIFRA
requirements would apply to reuse/recycling of recovered oily wood treating fluid. FIFRA
requires that a material used as a pesticide (wood treating fluid is classified as a pesticide by
FIFRA), meet the formulation requirements. RecOvered wood treating fluid would be
analyzed and that analysis would be compared to' the requirements to determine if the
recovered fluid could be reused. If it could not be reused, RCRA Subtitle C requirements
would apply to the offsite disposal of the oily wood treating fluid.
If an LTU is deemed necessary, deed restrictions 'would be required in order to prevent
development and well drilling in and around the land treatment unit. Fencing would be
required around the treating units to prevent unauthorized entry.
Figure 11 presents a simplified process flow diagram for CF System's Critical Fluid Solvent
Extraction process and specifies the waste streams associated with the process.
Estimated cost: $82,232,520
Estimated time: 1-112 years
Alternative 6: Soil Flushim!/ln Situ Bioloirlcal Treatment
(Preferred remedy for Soils Beneath the Treatment Plant and 1-90)
As analyzed in the FS, this alternative addresses all contaminated soils at the IPC Site with
the exception of soils in the roundhouse area and sediments in the drainage ditches. Soils in
the treating plant area and underneath 1-90 would not be excavated under this alternative.
Structures on the Site would not be demolished and 1-90 would not be temporarily removed.
Ditch sediments and former roundhouse soils would be addressed by one of the other soil
alternatives. This alternative treats approximately 39,000 yd3 of contaminated soil.
The contaminants in the soil in the roundhouse area are not as amenable to soil flushing
techniques as soils in the other areas of the Site. The primary contaminants in the
roundhouse soils are PARs that are very difficult to separate from soil particles. The ditch
-------
Figure 11 Critical Fluid Solvent Extraction
~u
PROPANE/ORGANICS
PROPANE
rEED
SCREEN
AND
WAS It
SEPARAToR
EXTRACToR
DEWATERING SYSTEM
.wAIE8
RECYCLE
SOILlsJOU.tEHTS
..I
. ON-SITE
LAtmnlL
PARTICULATE
FILTER
~I POrN I
Sll.tPUrlEO PROCESS rLOW DIAGRAM rOR cr SYSTEMS PROPANE EXTRACTION
VI
o
SOLVENT
RECOVERY
LNAPL RECYlE
OR STORAGE FOR
orF-SITE DISPOSAL
.~~~.~.
ACAOII IPtO-020
REVI A DATEI 2/25/92
DRAfTERI KJ8
-------
Decision Summary
51
sediments must be excavated for treatment, rather than being treated in situ, because of the
long narrow area in which the contaminated soils are located. Installation of a soil flushing
system that would effectively reduce contaminant levels in the ditch sediments was
determined to be not practicable.
Under this alternative, soil contaminated with oily wood treating fluid would be left in place
and flushed with hot water or steam and, if initial test or pilot runs indicated ,the need, a
nonhazardous surfactant which would cause the oily wood treating fluid to wash out would
be added. The nonhazardous surfactant would not have an adverse impact on domestic
ground water use. The flushed water, associated contaminants and flushed oily wood treating
fluid would be collected in a series of trenches on both sides of 1-90. The oily wood treating
fluid would be skimmed from the water for recycling or treatment and disposal and the water
'would be treated in a separate system along with ground water. An oxygen source such as
hydrogen peroxide and possibly nutrients would be added to the system to enhance biological
degradation of soil contaminants.
The soil flushing system would be designed to flood the soil pores in the soil above the water
table. Flushing solution would be distributed by an infIltration gallery designed to provide
maximum contact between the flushing solution and the course grained soils associated with
the pole plant area. Application of flushing solution would continue at a steady-state
condition until desired residual concentrations were reached. '
Oily wood treating fluid would be recycled or disposed of offsite. FIFRA requirements,
would apply to reuse/recycling of recovered oily wood treating fluid. FIFRA requires that a
material used as a pesticide (wood treating fluid is classified as a pesticide by FIFRA), meet
the formulation requirements. Recovered wood treating fluid would be analyzed and that
analysis would be compared to the requirements to determine if the recovered fluid could be
reused. If it could not be reused, RCRA Subtitle C requirements would apply to the offsite
disposal of the oily wood treating fluid.
With the exception of soil, removed for the installation of operating components, all
contaminated soils would be left in place. Soils removed for the installation of process
components, and the ditch sediments and former roundhouse soils will be addressed under
another soil alternative. '
Water used to recover contaminants during the soil flushing process could be treated in a
fIxed fIlm biological reactor to remove contaminants. A portion of the water would then be
reinjected within the contaminated zone to assist in the flushing process. The remaining
volume of treated water would be discharged to a POTW or to surface water in compliance
with Clean Water Act requirements.
About 40-80 % of the oily wood treating fluid would be removed by flushing and
approximately 70 % of the contaminants that adhere to the soils would be removed.
Recovery efficiencies would largely be dependent on how much oily wood treating fluid is
-------
52
Idaho Pole Record of Decision
cUITentIy present as free product versus the amount tied up as residual concentrations within
the soils. Mathematical modeling has been conducted to refme this estimation and is
summarized in the FS. However, testing would be necessary to provide site-specific
infonnation with sufficient accuracy to design and implement this process.
It has been estimated that the active in situ flushing and contaminant recovery activities
would take one year to complete and follow-up in situ biological treatment of soils would
take up to 10 years.
Safe Drinking Water Act requirements would apply to Class IV injection wells needed to
inject hot water or steam into the subsurface.
Figure 12 presents a conceptual process flow diagi'am for the soil flushing, steam/hot water
enhanced recovery process and specifies the waste streams associated with the process.
Estimated cost: $10,841,429
Estimated time: 10 years
Ground Water Alternatives
Costs for conducting the ground water alternatives were calculated in a manner similar to the
soil alternatives cost calculations. This was done so that costs of the ground water
alternatives could be comparect. The cost for each ground water alternative involving
extraction and treatment (Alternatives 2 and 3) was calculated assuming that each system
would treat 200 gallons of water per minute for approximately 10 years or a total volume of
1 billion gallons. The cost of the in situ ground water alternative (Alternative 4) was based
on treating a total volume of 210 million gallons.
Alternative 1: No Action
Superfund law requires the consideration of a no action alternative. This alternative is used
as a baseline against which to compare the other alternatives. As defmed in the Idaho Pole
RIlFS, no action means that a remedy would not be conducted. The quantity of untreated
waste would remain at current levels and the degree of risk posed by such waste would
remain constant.
The only activity that would occur under this alternative is routine ground water monitoring.
ARARs, risk based levels and TBCs would not be met.
Estimated cost: $45,000
Estimated time: annually
-------
IIUlliCIPAl
WAnR
IREA no
'RODUCID
WAT~R
WAnR SUPPLY
rOR
III SitU TREA"O/UIT
'ROCWU
..
J)£W(8'fJUJ.EW1
80IllR/SIIA" 'L.'II'
STORAOE/IIIXIHO 'AHKS
,IPIIIO IIOWORK
fiC.
. III SITU BIORECL.'IIATlOII IS A 'OST JRL""[lIf A"UCATIOH
(810 'OUSH/I/O) AND Will 11of II11UU nlE lllcovrRY rORTlDII
br 11115 AlfUHATM.
Figure 12 Soil Flushing and Recovery
'OfW
I
DROUIID
W",U
fRO. TWEH'
JlLSIJJLJOll nUSlIlHO
WOOD 'ROCISSINO uo.
UHsJ.TURAJtD SOILS
RUIDUAl coe.
-
..-
.,H 'iTU
IIOUCI ""I. 1I0It
DISSOLVED ..
RESIDUAL C.c.
I
IIIIIAIICIO mlRIIAL
BICOVIIIY fCROW) . Ju.w::ruuLSUItW
'A'l 'lUI/E SAT\JIUJtD SOILS -- VIRnCJ.l..
R([ II Rt$IDUAl rllASl UWl IIORIIOH'AL WlIU
COHC£PTVAl 'ROCESS n.ow olAOllA1oI rOR IH SITU SOil nUSIIiHOi/ mUIIAl £IUIAICC(O
WArl RlOOVtRY (CROW 'ROCESS) ,!JIO III SitU 10RICL.'IIAnOIl
Dm~~~
COllfAlIlHAJtD
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..
rwsllIIlO llIllIolIClllO
ADllfTS
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-
t
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COU£C'TIOII ..
UCT RAC'TIOII
01 WA'l
-
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I
DISPOSAL
ur:z: b~
ACAO,. 1'10-047
R[VI - DAI[I 2/25/81
DRAiUR, IIC
VI .
VJ
-------
54
Idaho Pole Record of Decision
Alternative 2: Pumo and Treat Usine Activated Carbon Adsorption
This alternative involves the design of a ground water extraction system to capture the
dissolved contaminant plume. Conventional activated carbon adsoIption units would be used
to remove contaminants from the ground water. Pretreatment of the extracted ground water
to remove suspended solids and oily liquid would be required to prevent the activated carbon
units from becoming overloaded.
Solid materials removed during the pretreatment process would be addressed through the
selected soils alternative and oily fluids would be either reused in the wood treating process
if FIFRA requirements were met, or disposed of offsite in accordance with RCRA Subtitle C
requirements at a RCRA Subtitle C facility.
Treatability data collected at the Site indicate that excessive carbon loading and plugging due
to dissolved organic and inorganic constituents will not significantly impact the operational
life of the activated carbon. .
Spent carbon would be reactivated using thermal or biological methods onsite or be sent
offsite to a commercial carbon reactivation process. Reactivation of carbon by either thermal
or biological methods destroys the contaminants adsorbed to the carbon. Transport of spent
activated carbon to an offsite reactivation facility would require compliance with RCRA
requirements because the carbon would contain the contaminants removed from the ground
water and would be classified as a hazardous waste.
Treated ground water would be reinjected through a series of wells or trenches depending on
which process is determined to be the more effective during design phase evaluations.
Excess water would be discharged to a POTW in compliance with Clean Water Act
pretreatment requirements. Injection wells used to return treated water to the aquifer are
classified as Class IV Wells and would have to meet Safe Drinking Water Act requirements.
The design of the extraction system would focus on the volume of ground water having high
contaminant concentrations. The alternative was evaluated with a conceptual extraction and
reinjection plan; however, specific criteria would be developed during remedial design.
Ideally, the treated extracted water would be reinjected. Pumping rates would remain low in
order to prevent draw down of the water table causing subsequent vertical enlargement of the
contaminated zone. The extraction and reinjection system would be designed to stimulate
flushing of contaminants and to limit migration of contaminants. . Figure 13 illustrates the
carbon adsoIption treatment process. .
Estimated cost: $4,413,555
Estimated time: 10 years
-------
FROM
EXTRACTION WELLS
l
~
!
OIL/WATER
SEPARATION
(;;;\
~
Figure 13 Activated Carbon Adsorption
~
RECOVERED NAPl
ODD
...
~
......
CARBON
ADSORPTION
orrslTE
CARBON
REGENERATION
CONCEPTUAL PROCESS fLOW DIAGRAM fOR
ACTIVATED CARBON ABSORPTION TEATMENT.
~~TO INJECTION
..... ~ WELLS
--- - : INc.
ACAD'I IP 1 0-039
REV: - DATE: 2/24/92
DRAnERI MC
UI
UI
-------
56
Idaho Pole Record of Decision
Alternative 3: Pump and Treat Usine A Fixed Film Bioloeical Reactor
(PrefeITed Remedy to be Used in Conjunction with Ground Water Alternative 4)
Contaminated ground water would be extracted by wells located along the axis or centerline
of the contaminated plume and would be sent for pretreatment in an onsite oil/water
separator-clarifier/fIltration plant. Suspended solids would be removed from the water in the
clarifier/fIltration plant. Solids removed during this phase of the ground water treatment
process would be addressed through the selected soils alternative and oily wood treatment
fluid removed by the oil/water separator would be recycled if FIFRA requirements were met
or disposed of offsite in accordance with RCRA Subtitle C requirements at a RCRA Subtitle
C facility.
After the pretreatment steps described above, the water would enter a mix tank where the pH
and temperature would be adjusted and microbes that have been acclimated to the
contaminants would be added. Water then would pass into the submerged fIxed fIlm
bioreactor. The water would remain in the reactor long enough for the contaminants to be
degraded to a level that would allow for reinjection or discharge to a POTW or to surface
water. The design of the extraction system would focus on the volume of ground water
having high contaminant concentrations. The alternative was evaluated with a conceptual
extraction and reinjection plan; however, specifIc criteria would be developed during
remedial design. Ideally, all of the treated extracted water would be reinjected. Pumping
rates would remain low in order to prevent a draw down of the water table and subsequent.
vertical enlargement of the contaminated zone. The extraction and reinjection system would
be designed to stimulate flushing of contaminants and to limit migration of contaminants.
Injection wells would comply with Safe Drinking Water Act requirements for Class IV
injection wells. Discharge to a POTW or to surface water would be in compliance with the
Clean Water Act. Figure 14 illustrates the biological treatment process.
Estimated cost: $2,519,235
Estimated time: 15 years
Alternative 4: In Situ Biolo!!ical Treatment
(prefeITed Remedy to be Used in Conjunction with Ground Water Alternative 3)
The principal objective of this alternative is to enhance the treatment of ground water and
soil beneath the water table in the pasture area north of 1-90 by adding oxygen and nutrients
to the subsurface environment. The oxygen and nutrients would be carried to the subsurface
in water that has been extracted from the aquifer and treated under one of the other remedial
ground water alternatives.
-------
IHrlU[HT 0
20-110 GPII.<50UO/L 0 " a
- UlAPL/SUSP[HD[D SDUDS
API 5£P,;Cu,Rlfln;nLlRAnOH
EXlRAClIOIt WtUjpuur
-
ow
l
Figure 14 Fixed Film Biological Reactor
IAClUlAl ".UHDUENTS
PII ADJUST.
HUTRIEUT "DDIIIOH
II~J[R
OIfT\/UD
1.[ nOH
1
r(cyCl~
~PENT OAA
SU8I1UGEO. PACK£D 8£0.
PUlo n.ow. nxED mu,
..UlhsrAGE II0RIAC'OR
(OECA'" IIODE 1)
6
P01W
[fTW£HTSI
- II[CYCU;' I TRIAT UlAPL .
- 'IECYCU; I IRIA' SPEHT OAC 111014 hiE [mUnt1 POUSI! AtlOloR 810AlAClOR VOC VtIIT. .
- UNO TRU.T SLUDOE FIIOW 1"0 nll£R--I/AlHLY 810lU.SS AHD IHOROAHICS WlJICH /oIA'" A£QUIR[ OW mHO
- PROCESS SIIOULD II[ET PRETRU,U£"T STAHOARDS fOR .DISCIIAROE '0 POTit, IU' WILL rROlA8lY REQUIRE
IIOHITORtHO fOR 800, HITRATtS, AIotI/OHIIA, PtlOSPllAIIS, Oil" ORUSE, AHD COD.
OUl[R Hom. IIAY HnD SEASOllAl APrUCAnOH Of IlIAT TO IIAIH1"IH OrnllA1810REACToR nUp[RA1\IRLS
. 8ACURIAl "IIUEHDIIENTS IIAY 8[ 8EHEnCIAL (rLAV08ACnRIUW sr.)
COt/CEPTUAl pROCESS flOW
DIAORAI/ or TII[ nXED-nlll "ORUCIOR
UE~ b~
ACAO,. IPIO-OII
REVa A O"Tta 2/25/82
DRAfURI JW
VI
-J
-------
58
Idaho Pole Record of Decision
The injection of this oxygen and nutrient rich solution into the contaminated ground water
plume would enhance oxidation and biodegradation of contaminants by native bacteria. The
bacteria utilize the contaminants in the ground water and in the saturated soil below the
ground water table as an energy source, destroying contaminants by converting them to other
nonhazardous forms. Injection wells used to transfer solution to the aquifer would comply
with Safe Drinking Water Act requirements for Class IV injection wells.
Treatability information fudicates that the addition of nutrients and an oxygen source will
enhance biological degradation of the contaminants in the ground water.
The extraction well locations and pumping rates would be determined during remedial design
by modelling. Modelling results may indicate the need for limited hydrologic plume
management to prevent spread of the plume boundaries. Field-scale process treatability
testing will be necessary to determine actual effeCtiveness of this technology. Figure 15
portrays the in situ biological treatment process.
Estimated cost: $1,878,447
Estimated time: 10 years
VIne SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
Section 300.430(e)(9) of the NCP requires that the agencies evaluate and compare the
remedial cleanup alternatives based on the nine criteria listed below. The ftrst two criteria
are threshold criteria and must be met. The selected remedy must represent the best balance
of the selection criteria.
Evaluation and Comparison Criteria
1.
Overall protection of human health and environment addresses whether or not a
remedy provides adequate protection and describes how potential risks posed through
each pathway are eliminated, reduced or controlled through treatment, engineering
controls or institutional controls.
2.
Compliance with applicable or relevant and appropriate requirements addresses
whether or not a remedy will comply with federal and state environmental laws
and/or provide grounds for invoking a waiver.
3.
Long-term effectiveness and permanence refers to the ability of a remedy to maintain
reliable protection of human health and the environment over time once cleanup goals
have been met.
4.
Reduction of toxicity. mobility and volume through treatment refers to the degree that
the remedy reduces toxicity, mobility and volume of the contamination.
-------
59
Figure 15 In Situ Biological Treatment
ASSU~E INSTALlATJON IN PERWo.su: (K > 10-3 em/SEC).
GRAVEL.L.Y F1L.L UPGRADIENT FROa.l TREATWENT PlANT AREA.
VENT
BACTERW. .wENDa.lENTS
SCUDS PH ADJUST NUTRIENTS
PROCESS
F1LTER
H20:?
Do?
SURF' ACT.urr?
(BIODEGRADASU:/
lOW TOXICITY)
API S£?ARATOR/c:uRJF1ER/FlLiER
I
EXTRACT10N WEU/PU~P
I EX SITU
TREA1\CENT
OF" BLEND
POTW
INJECT10N PUa.lP
.
<
GROUNDWATER f1.QW
GRAVELl.Y INRLTRATJON
GAU.E:RJES
(VADOSE ZONE)
Em..UENTS
F'ILTER CAKE WILL NE£D TaP .AlW.YSIS TO JJ.J.JJW DE1lST1NG. FCWJWED BY ON" SJTE "
TREATWENT/OISPOSAL.. TREA1\CENT REQUIRED IF' ORGANICS CONTAIN CoCa > AJWb
AU.OWANCE. OTHERWlS£ COULD BE LAND-Ftu.ED AS SOUD W~ "
SPENT GAC WAY NUJ) TC1..P ANALYSIS TO DELIST; RECYCL! PREFERRED.
St£ .BIOTROL."' SHEEi FOR DETAILS. RE: EXlST1NG iREJ.TWENT OF EXCESS WATER.
..t!CIC
ADDmON OF' .rer (0100-200 mv/L) TO 'THE INJECTED EFrUJENT WOULD STJWUu.n:
IN SITU TREA1"a.IENT OF'VJ.DOSE: ZONE SOILS BELOW INF"ILTRATJON GAU..ERJES.
NE::D DOWNGRADIENT WONrrORJNG (FROa.I E:XTRACT10N 'NEU.S) TO £VALUATE PROGRESS
IN REDUCNG COC CONCDn"RATJONS AND TO ASSURE NUTRIENT LEVElS (N/P) ARE NOT
FURTHER DEGRADING AQUIFa QUAUTYOR EXCEEDING WCls.
EXTRACTION PUa.lPING RATE > REJNJECT10N RATE (NYER. P. 17. BlOREJoCEDIATTON SD.IINAR).
THUS EXCESS WATER WAY HAVE TO BE DISQIARGED OFF SITE IF' NOT USED F'OR EX SITU
C1..£ANUP OF' VADOS[ ZONE. ErC-
aaa
IHc.
ACAIJf: 1P10-009
REV: A DATE: 2/2""/92
DRAFTER: JW
CONCEPTUAL PROcrss Ft.OW DIAGRAM
OF" THE IN SITU GROUNDWATER BIORECL" "'ATION
-------
60
Idaho Pole Record of Decision
5.
Short-tenn effectiveness addresses the period of time needed to complete the remedy,
and any adverse impact on human health and the environment that may be posed
during the construction and implementation period until cleanup goals are achieved.
6.
Implementability refers to the technical and administrative feasibility of a remedy,
including the availability of materials and services needed to carry out a particular
option.
7.
Cost evaluates the estimated capital costs, operation and maintenance costs and
present worth costs of each alternative.
8.
State agency aCcqJtance indicates whether, based on its review of the information, the
state (MDHES) concurs with, opposes or has no comment on the preferred
alternative. However, for the Site, the state (MDHES) is the lead management
agency. and EP A is the support agency. As such, the State has identified the selected
remedy and EP A has agreed with that identification.
9.
Community aCcqJtance is based on whether community concerns are addressed by the
selected remedy and whether or not the community has a preference for a remedy.
Although public comment is an important part of the final decision, MDHES and
EP A are compelled by law to balance community concerns with all of the other
criteria. A complete record of the responses to specific categories of comments is
summarized in the Responsiveness Summary.
The following summary of the evaluation and comparison of alternatives is presented in
greater detail in the FS. The initial discussion covers the soil alternatives, followed by a
discussion of the ground water alternatives. The alternatives are discussed in order of
relative rank, with alternatives ranking the highest discussed fIrst and alternatives ranking the
lowest, discussed last.
Soil Alternatives
Overall Protection of Human Health and the Environment:
This criterion evaluates how the alternatives provide human health and environmental
protection and describes how risks posed through each pathway are eliminated, reduced or
controlled through treatment, engineering controls or institutional controls.
All of the soil alternatives, except No Action, Surface Capping and Soil Flushing/In Situ
Biological Treatment, are expected to provide overall protection of human health and the
environment by eliminating, reducing or controlling risks associated with contaminated soils
at the Site. However, Surface Capping and Soil Flushing/In Situ Biological Treatment, could
provide adequate protection within limited areas of the Site. Each of the soil alternatives
with the exception of Surface Capping and No Action would use treatment to eliminate or
-------
Decision Summary
61
reduce risks. Institutional controls would be used to supplement each alternative's ability to
provide further protection.
Alternative 3: Excavation and Thermal Treatment, would be the most protective
alternative because the high temperature thermal process would destroy all (more than 99 %)
of the site contaminants in a single step, either onsite or offsite. Remaining risks for
residential land use would be less than 1 x 10-6 related to remaining untreated contaminants.
Alternative 5: Excavation and Critical Fluid Solvent Extraction. is slightly less effective
than incineration. This alternative has a 97 % contaminant removal efficiency. Oversize
materials must be pretreated prior to introduction into the extraction process to assure
complete contaminant reduction. Remaining risks for residential land use would be less than
1 x 10-5 resulting from untreated material and treatment residuals.
Alternative 4: Excavation and Bioloirlcal Treatment. would biologically remove or reduce
contaminant concentrations in the soil to protective remediation levels as has been
demonstrated at a number of wood treating sites currently undergoing remediation. Slurry
phase and solid phase processes are the two options under this alternative and result in nearly
identical ranking. Slurry phase treatment is somewhat better than solid phase treatment at
contaminant removal. Removal efficiencies for slurry phase for pentachlorophenol, B2
PAHs, D PAHs and PCDDs/PCDFs are 90%, 85%, 90% and 70%, respectively, and for
solid phase, 90%, 85%, 85%, and 40%, respectively. Remaining risks for residentia1land
use would be less than 1 x 10-5 for both options.
Alternative 6: Soil Flushinl!/ln situ Bioloirlcal Treatment. is ranked lower than the
previous alternatives because of lesser expected contaminant removal. The range of removal
is estimated to be from 40 % to 80 % . This alternative has been considered in order to avoid
the need to demolish and excavate the !PC facility and the highway. This alternative does
not directly address surface soils or ditch sediments. Since this alternative requires minimal
excavation during installation of system components any surface soil and sediments would be
treated along with the excavated material under another alternative. As a stand-alone
alternative, this alternative may not meet 1 x lQ4 risk level but in conjunction with other soil
and ground water alternatives remaining risks would be reduced to less than 1 x 1 Q4 for
residential use. The areas where this alternative would be implemented are sources of
ground water contamination that must be remediated to reach site cleanup levels.
Alternative 2: Surface CaotJin&:. would only provide protection where direct contact is the
primary risk to human health. Areas of ground water contamination would not be protected
by this alternative; therefore, Surface Capping is ranked lower than the other alternatives
except for Alternative 1, No Action. This alternative would not be as protective as
Alternatives 3, 5, 4 or 6 because it would not treat contaminants and would rely on the
continuing integrity of the cap to prevent exposure. Remaining risks relating to untreated
materials would be less than 1 x 10>5.
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Idaho Pole Record of Decision
Alternative 1: No Action. would not provide protection to human health and the
environment from site contaminants. All soil pathways would remain and no treatment
would occur. Without treatment, site contamination will persist indefInitely and will continue
to affect residential water supply wells. Risks would remain constant.
Compliance with Applicable or Relevant and Awropriate Requirements (ARARs)
Applicable requirements are those cleanup standards, and other substantive requirements,
criteria, or limitations promulgated under Federal or State .law that specifically address a
hazardous substance, pollutant, contaminant, remedial action, or location, at a CERCLA site.
Relevant and appropriate requirements are similar requirements that, while not applicable,
clearly address problems or situations sufficiently similar to those encountered at a CERCLA
site such that their use is well suited to the particular site. An evaluation of Federal and
State ARARs for the selected remedy is provided in Appendix A. Remedial action
Alternatives 3, 4, and 5 would comply with the ARARs. Alternative 2 would only meet
ARARs that are related to direct contact and inhalation exposures; ground water ARARs
would not be met; therefore surface capping will only be discussed for application in the
roundhouse area. Alternative 6 would not meet ARARs as a stand-alone alternative. It will
be discussed for use in conjunction with another alternative. Since the No Action alternative
does not meet the two threshold criteria, it will no longer be discussed in the comparative
analysis.
Long Term Effectiveness and Permanence
Long term effectiveness and permanence refers to the ability of a remedy to maintain reliable
protection of human health and the environment over time. This criterion includes the
consideration of residual risk and the adequacy and reliability of institutional controls.
Although institutional controls, consisting of land use restrictions and prohibitions on aquifer
use, would be implemented in conjunction with the remedy, the effectiveness and reliability
of institutional controls is considered to be less than that of engineered controls.
Because the soil cleanup levels established in this ROD for some areas of the Site are health
based standards for industrial use, and not unlimited use with unrestricted exposure, and
because the contaminants will remain onsite, the remedial action alternative selected requires
five year reviews under Section 121(c) of CERCLA, and Section 300.430(t)(4)(ii) of the
NCP, to assure the long term effectiveness of the remedy.
Alternatives 3: Excavation and Thermal Treatment. reduces the risks associated with site
contaminants by permanently destroying contaminants and achieves a higher destruction
efficiency than the other treatment alternatives. This alternative has been proven reliable and
would be adequate to address contaminants of concern. Treatment residuals would be clean
of hazardous substances resulting in minimal risks.
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Decision Summary
63
Alternative 5: Excavation and Critical Fluid Solvent Extraction. has good reliability, but
since residuals may have slightly greater contaminant levels than Alternative 3, this
alternative is ranked below Alternative 3. Long term management of residuals would be
necessary. There are also some uncertainties concerning the fate of extracted hazardous
substances, because contaminants of concern are concentrated in the extract but are not
destroyed and may pose residual risk.
Alternative 4: Excavation and Biolo!!ical Treatment. provides for long term effectiveness
through destruction of contaminants of concern, although ~t would be necessary to evaluate
the operational processes on a site specific basis to estimate efficiency. Long term
management of both solid phase and slurry phase treatment residuals would be necessary.
Uncertainties are greater with solid phase than slurry because of the time required to meet
cleanup levels and the area necessary to complete. the treatment process. Slurry phase would
rank ahead of solid phase due to slightly better reduction of concentration levels. This
alternative ranks below Alternatives 5 and 3 because residual contamination would be higher.
Alternative 2: Surface Cappine. would not provide permanent risk reduction even in a
limited area. Capping could meet performance specifications but the need for long term
maintenance and management is great. It is likely that replacement and repair of the cap
would be necessary to maintain protectiveness. The degree of long term effectiveness of the
capping alternative would depend on maintenance of the cap and on the effectiveness of
institutional controls protecting the cap. This alternative only ranks ahead of Alternative 6.
Alternative 6: Soil Flusbinl!lln situ Bioloeical Treatment. would require the
implementation of an additional ground water remedy to increase contaminant destruction for
long term effectiveness. If this alternative were used as a stand-alone alternative, remaining
risks could be greater than 1 x lQ4, which is higher than remaining risks for other
alternatives. This alternative is ranked lower than other alternatives. Longterm management
would be required to evaluate the effectiveness of Alternative 6. There would be
considerable design testing necessary to optimize this alternative. Contaminants would be
degraded to a lesser extent under this alternative than Alternatives 3, 4 or 5, although this
alternative has the capability of reaching soils other alternatives might not, especially soils
underneath structures. .
Reduction of Toxicity. Mobility and Volume
Congress has expressed a preference under CERCLA for selecting remedial actions that
employ treatment technologies that permanently and significantly reduce toxicity, mobility or
volume of hazardous substances as their principal element.
Alternative 3: Excavation and Thermal Treatment. would reduce the toxicity, mobility
and volume of soil contaminants at the Site better than other alternatives. This alternative
addresses all excavated material with an irreversible treatment process. Any treatment
residuals would have minimal risks and would meet treatment goals. This alternative
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Idaho Pole Record of Decision
satisfies the preference for treatment.
Alternative 4: Excavation and Bioloeical Treatment. would reduce the toxicity, mobility
and volume of soil contaminants on the Site. Slurry phase treatment would provide more
complete destruction than solid phase but the two options are ranked together after
Alternative 3. Alternative 4 would convert contaminants to nontoxic compounds. The
treatment process would be irreversible. The preference for treatment would be satisfied.
Alternative 5: Excavation and Critical Fluid Solvent Extraction. would reduce the
mobility and volume of soil contaminants at the Site better than Alternatives 2 and 6 but not
as well as Alternatives 3 and 4. Hazardous substances are not destroyed in this process but
are extracted in the form of a concentrate that would require additional treatment or
recycling. The preference for treatment is satisfied.
Alternative 6: Soil Flushing/In situ Bioloeical Treatment. would address the principal
threat by removing contaminants of concern from the environment and also by breaking them
down thus reducing toxicity, mobility and volume. However, this alternative does not
provide as great a percent of reduction as the previous alternatives do. Additionally there are
special requirements necessary for this alternative, such as a suitable soil matrix to flush oily
wood treating fluid and hazardous substances as well as hydrological controls to control the
flushing solution and the in situ bioremediation. This alternative meets the preference for
treatment.
Alternative 2: Surface Caopim!:. would reduce the mobility of soil contaminants by
covering them and by minimizing or eliminating surface water inIIltration and air
entrainment, but would not reduce the toxicity or volume of contaminants. The alternative
does not employ an irreversible treatment or destruction process and it does not meet the
preference for treatment as a principal element of the remedy. Therefore, this alternative is
ranked the lowest.
Short Term Effectiveness. --.
Short term effectiveness refers to the period of time needed to complete the remedy and any
adverse impacts on human health and the environment that may be posed during the
construction and implementation of the remedy.
Alternative 2: Surface Caopine. would rank the highest under this criterion, primarily
because it involves the least amount of work, can be completed in the shortest time and
results in minimal risks to workers and the community. It could be conducted in one
construction season and would present little risk to workers (less than I x Io-s) constructing
the cap and little risk to the community (less than I x 10-0) during construction.
Environmental impacts would be expected to be little, with some increased chance for
surface water runoff that previously infiltrated the soils.
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Decision Summary
65
Alternative 4: Excavation and Biololrlcal Treatment. would take longer to conduct
remedial action than Alternative 2. Slurry phase ranks higher than solid phase treatment but
both rank relatively close to one another. Slurry phase presents minimal risk to workers (1 x
10-5) and the community (1 x lQ-6).
Solid phase treatment would result in low worker risks (1 x 10-5) and community risks (1 x
10-6) but requires a much longer time frame, from 5 to 10 years to achieve remediation
levels. The size of the land treatment unit used for solid phase treatment would detennine
the length of the soils treatment period. A larger land treatment unit would require fewer
layers of soil and treatment would be completed in less time.
Exposure to dust from excavation of soils would be of concern for Alternatives 3, 4 and 5
but could be addressed through dust suppression techniques.
Alternative 6: Soil Flushin2/ In mu Biolo~cal'Treatment. would take a longer time than
other alternatives to achieve remediation levels. Alternative 6 would not pose any significant
risks to workers or others during implementation other than potential ground water impacts
that would require monitoring. This alternative results in a lower ranking than Alternatives 2
or 4 but ahead of Alternatives 3 and 5 because of limited worker risks. .
Alternative 3: Excavation and Thermal Treatment. would present the highest opportunity
for impacts to site workers and the environment from air emissions. There is also the
potential for adverse impacts to offsite populations from air emissions resulting from
emission control system malfunctions. There would also be potentially significant risks
associated with the offsite incineration option since large quantities of hazardous substances
would be transported over public roads. The time required to complete this remedy,
however, is relatively short: 1.5 years for an onsite large scale unit to 5 years for an onsite
mobile unit.
Alternative 5: Excavation and Critical Fluid Solvent Extraction. would only take
approximately 1.5 years to decontaminate site soils. However, it would pose a threat to
onsite workers if not properly designed or operated from air emissions and the use of
pressurized solvent. Community risks would be minimal as long as the system is operated
within specifications. Workers may also encounter risks from concentrated extract and from
treatment residuals. Environmental impacts would be limited.if correct design and operation
were followed. This alternative ranks lowest primarily due to worker risks.
Implementability
Implementability refers to the technical and administrative feasibility of a remedy, including.
the availability of materials and services needed to implement the remedy. This criterion
also includes coordination of Federal, State and local governments to clean up the Site.
Alternative 2: Surface Cappine. is considered to be a standard construction practice and
could be accomplished in a short period of time. Design methods are well understood and
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Idaho Pole Record of Decision
materials are readily available. Additional action to improve the cap woul~ be available. No
excavation of soils or sediments would be necessary. These factors all result in this
alternative being the most implementable.
Alternative 4: Excavation and Bioloeical Treatment. is somewhat less implementable than
Alternative 2, but more so than the remaining alternatives. A solid phase surface land
treatment unit would require no special equipment or treatment units. The land treatment
unit would be operated like an agricultural farm field and would be constructed in a short
time using standard earth moving equipment. The slurry reactor option of Alternative 4
would not be required to withstand high temperatures and pressures as equipment under
Alternatives 3 and 5, so it would be easier to construct. Alternative 4 would require some
planning with local government especially for the slurry option if discharges to a POlW
were found to be necessary. This alternative ranks as the second most easily implemented
alternative. .
Alternative 6: Soil Flushine/ln situ Biological Treatment. would require equipment and
services that are readily available. The drilling techniques required to introduce hot
water/steam into the area under 1-90 would be challenging, but not insurmountable. This
makes this alternative less implementable than 2 and 4 but more so than Alternatives 3 and 5.
Alterative 3: Excavation and Thermal Treatment. would likely be the most difficult to
implement other than Alternative 5, both admiiristratively and technically. There is not
currently an offsite commercial incinerator that is permitted to bum dioxin containing wastes.
There are a limited number of mobile incinerators available for onsite use. Construction of
an onsite incinerator is feasible and many vendors offer design, construction and training .
services for operation and maintenance of full scale units, however, thermal treatment has a
history of opposition by the public and local governments. This alternative would entail
considerable planning with local government. The offsite option would require coordination
with the Department of Transportation.
Alternative 5: Excavation and Critical Fluid Solvent Extraction. requires a specially
designed and constructed unit that would be used to contain the waste material during the
treatment process. This alternative would be the most difficult to implement. There is a
vendor available, but there may be delays in optimizing the process. This alternative would
require extensive system monitoring. Additional remedial action could be undertaken in the
form of additional excavation but capital investment in solvent extraction would make use of
another technology difficult. This alternative would require planning with the local
government.
Cost
This criterion evaluates the estimated costs for each remedial alternative. For comparison,
capital and annual operation and maintenance costs are used to calculate a present worth cost
for each alternative.
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Decision Summary
67
The alternatives' approximate present worth costs for site wide implementation are shown
below: .
Alternative 1. No Action
o
$0
Alternative 2. Surface CaWing,
o
$18,000,000 (cost for entire Site based on unit cost developed for former
roundhouse area soils)
Alternative 3. Excavation and Thermal Treatment,
o
$63,000,000
$93,000,000
$212,000,000
Mobile Onsite
Large Scale Onsite
Offsite
Alternative 4. Excavation and Biological Treatment,
o
$13,000,000
$8,000,000
Slurry Phase
Solid Phase (Land treatment unit)
Alternative 5. Excavation and Critical Fluid Solvent Extraction.
o
$82,000,000
Alternative 6. Soil Flushing/In situ Biological Treatment,
o
$11,000,000.
The alternatives, in order of increasing costs, are as follows: Alternative 1, No Action;
Alternative 4, Solid Phase Biological Treatment; Alternative 4 Slurry Phase Biological
Treatment; Alternative 6, Soil Flushing In Situ; Alternative 2, Surface Capping; Alternative
3, Thermal Treatment (onsite mobile) and Alternative 5, Solvent Extraction.
In order to evaluate the costs of the alternatives for implementation in only the roundhouse
area the following estimated costs have been prepared. The estimated costs in the FS for
Alternative 2 were only for the roundhouse area. The estimated costs for the other
alternatives were not in the FS comparative analysis and do not result in the same unit costs
as the costs described above because those costs do not include demolition or 1-90 disruption.
Alternative 1. No Action
o
$0
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Idaho Pole Record of Decision
Alternative 2. Surface CaWing,
o
$1,300,000
Alternative 3. Excavation and Thennal Treatment,
o
$7,800,000
Mobile Onsite
Alternative 4. Excavation and Biological Treatment,
o
$960,000
$600,000
Slu11)' Phase
Solid Phase (Land treatment unit)
Alternative 5. Excavation and Critical Fluid Solvent Extraction.
o
$55,000,000
Alternative 6. Soil Flushing/In situ Biological Treatment,
o
$1,100,000.
The Alternatives, in order of increasing costs, for the roundhouse area, are as follows:
Alternative 1, No Action; Alternative 4, Solid Phase; Alternative 4, Slu11)' Phase;
Alternative 6, Soil Flushing In Situ; Alternative 2, Surface Capping; Alternative 3, Thennal .
(onsite mobile) and Alternative 5, Solvent Extraction. Since the ranking of alternatives based
on cost estimates is the same over the Site and over the roundhouse area, the alternatives
retain their relative ranking regardless of area of implementation.
State Acc~tance
The State of Montana has been the lead agency for the development of this Record of
Decision and has selected the remedy contained herein. EP A has participated in the remedial
process as the support agency and has concurred with the remedy selection.
Community Acceptance
Public comment on the Remedial Investigation, Feasibility Study and Proposed Plan was
solicited during formal public commeIit periods extending from April 1, 1992 until June 16,
1992. Comments received from the community indicate no opposition to the preferred
remedy with the exception of a late comment expressing opposition to the remedy and
support for the remedy proposed by IPC. Additionally, at least one person and the local
government requested that the cleanup be expedited if possible. The City of Bozeman
expressed concern about possible discharges to the publicly owned treatment works.
Response to the community comments are found in the Responsiveness Summary.
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Decision Summary
69
During the public comment period, MDHES and EP A received extensive comments from
two Potentially Responsible Parties (pRPs) that have been identified for the Site. The PRP
comments object to the RI procedures, the Baseline Risk Assessment development and the FS
as well as the preferred remedy. As part of the written comments, the Idaho Pole Company
submitted their proposed remedy consisting primarily of in situ biological treatment of soils.
PRP comments with MDHES and EP A responses are also found in the Responsiveness
Summary .
Ground Water Alternatives
Ground water beneath the Site has become contaminated with oily wood treating fluid that
has been spilled, dripped or discharged onto the ground surface. The oily wood treating
fluid has migrated downward, contaminating the soil that it passed through, and has entered
the ground water. Some of the oily wood treating fluid is found at the surface of the ground
water, and some of the fluid is attached to soil particles above and below the water table. A
portion of the fluid has dissolved in the ground water and will have to be removed to reach
site remediation goals.
In order to assure long term protection of the ground water, the soil, acting as a source of
oily treating fluid contamination, must be cleaned up to a level that no longer contributes
contaminants to the ground water. If the source areas are not remediated, none of the
ground water alternatives would be considered permanent remedies. The effectiveness of
implementation of the ground water alternatives is dependent upon effective soil remediation.
Institutional controls preventing the construction of new water supply wells during site
remediation and installation of on-tap treatment devices at residences with contaminated wells
would provide additional protection.
Overall Protection of Human Health and the Environment
Alternative 2: Carbon Treatment. would be expected to provide protection of human
health and the environment by eliminating or reducing the risks posed by contaminated
ground water better than the other alternatives. Remaining risks would be less than 5 x IQ-6.
Alternative 3: Fixed Film Bioreactor. would also be expected to provide protection of
human health and the environment by eliminating or reducing the risks posed by
contaminated ground water although this alternative would not be as protective as Alternative
2. Remaining risks would be less than 5.5 x 10-5.
Alternative 4: In Situ Bioreclamation. would be expected to provide protection of human
health and the environment by eliminating or reducing the risks posed by contaminated
ground water only if it were used in conjunction with alternative 2 or 3. Alternative 4 would
not meet protective cleanup levels alone. However, Alternative 4 would enhance.
Alternatives 2 or 3 by reaching ground water that they can't reach. If Alternative 4 were
used with Alternative 3, for example, remaining risks would be less than 5.5 x 10-5.
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Idaho Pole Record of Decision
Alternative 1: No Action. would not provide protection of human health. since the untreated
ground water would continue to pose risks. Risk levels would remain constant. The only
activity identified under this alternative would be ground water monitoring.
Compliance with Applicable or Relevant and Appropriate Requirements (ARARs)
Applicable requirements are those cleanup standards, and other substantive requirements,
criteria, or limitations promulgated under Federal or State law that specifically address a
hazardous substance, pollutant, contaminant, remedial action, or location, at a CERCLA site.
Relevant and appropriate requirements are similar requireqlents that, while not applicable,
clearly address. problems or situations sufficiently similar to those encountered at a CERCLA
site such that their use is well suited to the particular site. An evaluation of Federal and
State ARARs for the selected remedy is provided in Appendix A. Alternatives 2 and 3
would meet ARARs for all ground water that is pumped to the surface for treatment.
Nevertheless, pump and treat systems have been shown to not be completely able to reach
cleanup levels in the ground water without additional in situ treatment. Alternative 4 would
meet ARARs only if used in conjunction with other ground water alternatives. Since the No
Action alternative does not meet the two threshold criteria, it will no longer be discussed in
the comparative analysis. .
Long Term Effectiveness and Permanence
Alternative 2: Carbon Treatment. would offer a high degree of permanence in the
reduction of risk associated with ground water if combined with a soil alternative that
effectively removes the potential for recontamination. This alternative would be expected to
attain MCLs and proposed MCLs in treated ground water, resulting in minimal risk from
contaminant residuals in ground water. Because of the length of time for remediation,
remedial action conducted under this alternative would require five year reviews and periodic
monitoring to assure the long term effectiveness of this remedy. In addition, there would be
need for long term maintenance of the treatment units and the need to treat or dispose of the
spent carbon that contains the contaminants would be required. This alternative would offer
the best long term effectiveness of any of the alternatives.
Alternative 3: Fixed Film Bioreactor. would offer a good degree of permanence in the
reduction of risk associated with the ground water if combined with a soil alternative that
effectively removes the potential for recontamination. This alternative would be expected to
attain MCLs or proposed MCLs in treated ground water, but not as quickly as Alternative 2
because the biologic system is not as efficient at removing contaminants as the carbon
treatment system. Operational momtoring would be required. Because of the length of time
for remediation, remedial action conducted under this alternative would require five year
reviews and periodic monitoring to assure the long term effectiveness of these remedies.
Alternative 4: In Situ Bioreclamation. would offer a lesser degree of permanence in the
reduction of risk associated with the ground water. The technology has been implemented at
other Sites but there would be uncertainties related to design and degree of contaminant
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Decision Summary
71
reduction. Because of the length of time for remediation, remedial actions conducted under
this alternative would require five year reviews and periodic monitoring to assure the long
term effectiveness of these remedies. An advantage that this alternative would offer is the
ability to treat residual ground water contaminants that could not be pumped to the surface
for treatment under alternatives 2 or 3.
Reduction of Toxicity. Mobility and Volume
Alternative 3: Fixed Film Bioreactor. would provide a reduction in toxicity, mobility and
volume of contaminants in ground water through treatment. This alternative degrades ground
water contaminants that are extracted by approximately 95 % . This alternative is ranked
higher than Alternative 2 even though it has a slightly lower per cent reduction in
concentrations, because this technology offers direct destruction of contaminants while
Alternative 2 only transfers contaminants from one medium (ground water) to another
(carbon). The contaminant breakdown under Alternative 3 is irreversible and treatment
residuals would be land disposed onsite. This alternative meets the preference for treatment.
Alternative 2: Carbon Treatment. would transfer contaminants from the ground water to
activated carbon which must be regenerated at regular intervals either onsite or offsite. This
alternative would meet the preference for treatment, with approximately 99 % contaminant
removal. The initial carbon treatment process is not irreversible, but the subsequent carbon
regeneration would be. This alternative ranks ahead of Alternative 4.
Alternative 4: In Situ Bioreclamation. would provide for treatment of contaminated ground
water to remove residual contamination in the aquifer. This alternative may not adequately
degrade contaminants by itself to remediation levels. An advantage of this alternative is that
no treatment residuals would be generated. This alternative results in irreversible
degradation and meets the preference for treatment.
Short Term Effectiveness
Alternative 4: In Situ Bioreclamation. would take about 10 years to reach remediation
levels in the ground water. Construction workers health risks associated with this alternative
would be minimal, less than 1 x 10.5. The principal hazard might be working with
concentrated hydrogen peroxide, if that compound is selected to provide the oxygen
enrichment source. Cominunity risks would be very low during implementation of this
alternative. Any potential risks presented by construction activities could be controlled or
eliminated by proper construction and health and safety practices. Due to the length of
treatment time and minimal risks this alternative ranks highest in short term effectiveness.
Alternative 3: Fixed Film Bioreactor. would take about 10 to 15 years to reach
remediation levels in the ground water. Construction workers health risks would be less than
1 x 10.5, with risks related to well installation, bioreactor operation and treatment residual
disposal. Any potential risks presented by construction activities could be controlled or
eliminated by proper construction and health and safety practices. This alternative ranks
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Idaho Pole Record of Decision
ahead of Alternative 2.
Alternative 2: Carbon Treatment. would take about 10 to 15 years to reach remediation
levels in the ground water. Construction workers health risks associated with this alternative
would be less than 1 x 10-5. However, there would be additional risks incurred during
regeneration of carbon, relating to either transportation or thermal regeneration. Any
potential risks presented by construction activities could be controlled or.eliminated by
proper construction and health and safety practices.
Implementability
Alternative 2: Carbon Treatment. would require preconstructed units that could be
installed very quickly. Since Carbon Treatment is well established and proven, it would be
easy to implement and operate this type of system~ Monitoring the effectiveness of the
system would be easily accomplished. Possible delays related to biofouling and to discharges
to the POTW or to surface water could occur under this alternative. Equipment for this
technology is readily available. There would be a need to coordinate with the local
government. for discharges to POTW. This alternative would be the most easily
implemented.
Alternative 3: Fixed Film Bioreactor. would require pilot testing; however, modular
treatment units are commercially available for full scale use. This alternative would require
specifically designed units that could be developed locally. Since Alternative 3 is relatively
well proven, it would be easy to implement and operate. Possible delays would relate to .
operational testing and the ability of the system design to handle the volume of ground water
for treatment. Other delays might relate to discharges to the POTW or to surface water.
There would be a need to coordinate with the local government for discharges to a POTW.
This alternative is more implementable than Alternative 4. .
Alternative 4: In Situ Bioreclamation. would require no special equipment for
implementation although the design of the system may require pilot testing. There have been
successful demonstrations of the in situ system, and this alternative has been implemented in
the state. System design would need to accommodate hydrogen peroxide if that compound is
selected for the oxygen enrichment source. Another operational delay might be the ability of
introducing oxygen and nutrient enrichment compounds to ground water zones of
contamination. Additional remedial action would be easily accomplished either by expanding
the network or by initiating a pump and treat technology. Monitoring effectiveness would be
relatively easy. This alternative may require out of state assistance in proper startup and
operation. No coordination with local government would be required.
Cost
The total 30 year present worth cost for each ground water alternative is estimated below:
Alternative 1. No Action
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Decision Summary
73
o
$45,000 (annually)
Alternative 2. Carbon Treatment
o
$4,400,000
Alternative 3. Fixed Film Bioreactor .
o
$2,500,000
Alternative 4. In Situ Bioreclamation
o
$1,800,000
State Acce.ptance
The State of Montana has been the lead agency for the development of this ROD and has
selected the remedy contained herein. EP A has participated in the remedial process as the
support agency and has concurred with the remedy selection.
Community Acceptance
Public comment on the Remedial Investigation, Feasibility Study and Proposed Plan was
solicited during formal public comment periods extending from April 1, 1992 until June 16,
1992. Comments received from the community indicate no opposition to the preferred
remedy with the exception of a late comment expressing opposition to the remedy and
support for the remedy proposed by IPC. Additionally, at least one person and the local
government requested that the cleanup be expedited if possible. The City of Bozeman
expressed concern about possible discharges to the publicly owned treatment works. .
Response to the community comments are found in the Responsiveness Summary.
During the public comment period, MDHES and EPA received extensive comments from
two potentially responsible parties that have been identified for the Site. The PRP comments
object to the RI procedures, the Baseline Risk Assessment development and the FS as well as
the preferred remedy. As part of the written comments, the Idaho Pole Company submitted
their proposed remedy consisting primarily of in situ biological treatment of soils and ground
water. Potentially Responsible Party comments with MDHES and EPA responses are also
found in the Responsiveness Summary.
IX.
SELECTED REMEDY
Based upon consideration of CERCLA requirements, the detailed analysis of alternatives, and
public comments, MDHES and EPA have determined that a combination of Soil Alternatives
4 (Excavation and Biological Treatment) and 6 (Soil Flushing and In Situ Biological
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Idaho Pole Record of Decision
Treatment) and Ground Water Alternatives 3 (Pump and Biological Treatment) and 4 (In Situ
Biological Treatment) is the most appropriate remedy for the Site. No single soil or ground
water alternative will provide complete remediation of soils or ground water over the entire
Site. It is necessary to combine several alternatives to achieve site wide cleanup.
Remedv for Soils and Sediments
Two soil alternatives have been selected to address the physical features of the Site. In
recognition of cost and the fact that the IPC pole plant is currently operating, MDHES and
EPA believe that Soil Flushing and In Situ Soil Biological Treatment (Alternative 6), under
treating plant structures and under 1-90 is appropriate. Excavation and Biological Treatment
(Alternative 4) has been selected as the remedy for soils that are accessible and will afford a
greater opportunity to achieve cleanup levels. The solid phase biological treatment option in
Alternative 4 has been selected over slurry phase bioremediation because of more proven
implementation at hazardous waste sites.
Alternative 6 is the only soil alternative evaluated that can be implemented in the active plant
area without requiring demolition of the existing structures and excavation of contaminated
soils and that provides a reduction in toxicity and mobility through treatment. Although
Alternative 6 is not as effective as a stand-alone remedy at meeting some of the selection
criteria as some of the other remedies, it will allow continued operation of the plant and will
reduce exposure risks to within the acceptable range. Surface Capping, Alternative 2, does
not provide reduction in toxicity or volume and was eliminated from consideration for
application in the plant area.
Remediation of soils under 1-90 without replacement of the highway can only be
accomplished by Alternative 6, Soil Flushing and In Situ Biological Treatment. MDHES and
EPA have determined that replacement of 1-90 is not practicable for this remedial action,
therefore soil treatment must take place without excavation.
Alternative 4, Excavation and Solid Phase Biological Treatment, will be implemented to
remediate all other areas. This alternative has been selected because it best meets the
selection criteria. Solid phase biological treatment is a proven remediation technology that
has met community acceptance at other sites, and is relatively inexpensive. In addition,
biological treatment in a surface land treatment unit is readily implementable and converts
contaminants to non-toxic compounds.
As discussed above, each of the soil alternatives will be implemented in separate areas of the
Site, generally determined by accessibility to contaminated soils or sediments. The
following summarizes the alternatives and implementation areas:
o
Soils Alternative 4 (Excavation and Solid Phase Biological Treatment) will be
implemented in the pole plant soils between Cedar Street and 1-90, round
house area soils, the pasture north of 1-90 and ditch sediments (or bottom
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Decision Summary
75
soils) from the Cedar Street and substation ditches.
o
Soil Alternative 6 (Soil Flushing and In Situ Biological Treatment) will be
implemented under and around the pole plant treatment facility south of Cedar
Street and under 1-90.
o
Institutional controls will be implemented to protect closed land treatment
units.
Contaminated soil will be excavated and will be stored in a waste pile constructed in
accordance with RCRA Subtitle C requirements. The soil will then be pretreated with an
oil! solids separator to remove the oily wood treating fluid. The recovered oily wood treating
fluid and material removed by the oil/water separator will be recycled if substantive FIFRA
requirements are met or disposed of offsite in acCordance with RCRA and other applicable
requirements. The soil will then be treated biologically in a surface land treatment unit to
reduce the concentrations of the contaminants of concern in the soil.
The LTU for the soils will cover approximately four acres. Excavated soil will be placed in
the unit in layers up to one foot deep and will be routinely plowed and irrigated. Areas
where soil is excavated will be back-filled with clean soil to eliminate any potential hazard
associated with the open excavations.
Before additional layers of -soil are added to the LTU, soil remediation levels will have to be
achieved. When all of the contaminated soil has been applied to the LTU and treatment is
complete, the unit will be closed by caPPing in accordance with RCRA Subtitle C
requirements.
Soil in inaccessible locations such as under buildings and 1-90 contaminated with oily wood
treating fluid will be left in place and flushed with hot water or steam. The flushed water,
associated contaminants and-.flushed oily wood treating fluid will be collected in a series of
trenches on both sides of 1-90. The oily wood treating fluid will be skimmed from the water
and will be recycled if substantive FIFRA requirements are met or disposed of offsite in
accordance with RCRA and other applicable requirements. The water will be treated with
ground water under Ground Water Alternative 3. In situ biological degradation of soil
contaminants will then be enhanced by addition of oxygen and nutrient sources to the soils.
Remedv for Ground Water
Two ground water alternatives have been selected in order to conduct a complementary
cleanup. In order to provide the most effective ground water cleanup, in situ bioremediation
was selected to complement the pump and treatment process. Biological pump and treat was
selected over caIbon adsorption because it costs much less to implement and it more fully
satisfies the preference for treatment and reduction in mobility, toxicity and volume, since
contaminants are degraded rather than transferred to another medium.
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Idaho Pole Record of Decision
The ground water alternatives will be conducted in concert with each other generally in and
around the oily wood treating fluid plume.
o
Ground Water Alternative 3 (Pump and Biological Treatment) will be
implemented within the boundaries of the oily wood treating fluid plume.
o
Ground Water Alternative 4 (In Situ Biological Treatment) will be implemented
along the boundaries of the oily wood treating fluid plume and downgradient
within the ground water plume. .
o
Institutional controls will be implemented to prevent access to contaminated
ground water.
Contaminated ground water will be extracted by wells located along the axis or centerline of the
contaminated plume and will be sent to an oil/water separator-clarifier/fIltration plant.
Suspended solids will be removed from the water in the clarifier/fIltration plant. Solids
removed during this phase of the ground water treatment process will be treated in the L TU
developed under Soil Alternative 4. Extracted ground water will then be treated in the fIxed
fIlm bioreactor described in Ground Water Alternative 3. The extraction and reinjection system
will be designed to stimulate flushing of contaminants and to limit migration of contaminants.
In situ biological degradation of ground water will enhance the treatment of ground water and
soil beneath the water table in the pasture area north of 1-90 by adding oxygen and nutrients to
the subsurface environment. The oxygen will be delivered to the subsurface in a manner
determined during remedial design. Nutrients will be carried to the subsurface in water that has
been extracted from the aquifer and treated in a bioreactor on the surface to remove
contaminants. .
If design and implementation of the ground water treatment prove to require a discharge of
water other than reinjection, then additional treatment such as carbon polishing may be
necessary to meet pretreatment standards prior to discharging to a publicly owned treatment
works or to meet surface water quality standards and nondegradation standards prior to
discharge to surface water. .
Sludge composed of exhausted microbes from the bioreactor will be captured in a bag ftlter and
applied to the L TU developed under Soil Alternative 4 for treatment.
Additionally, throughout the cleanup of the Site, ground water monitoring will be conducted to
evaluate cleanup efficiency and potential contaminant release. As part of the monitoring
program, residential wells in the potentially impacted neighborhood will be sampled not less
than quarterly for contaminants of concern. Residential wells exhibiting concentrations
exceeding MCLs or risk based cleanup levels shall have an in-home carbon/reverse osmosis
treatment system installed, operated and maintained until cleanup levels in ground water are
achieved. .
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Decision Summary
77
Estimated Costs of the Remedv
The estimated cost summary for this combination of alternatives is presented in Table 18. Costs
for Soil Alternatives 4 and 6, and Ground Water Alternatives 3 and 6 are less than those
presented in Sections vn and VIll of this document, because these alternatives will address
smaller areas and volumes than was assumed in Sections vn and VIll. Soil Alternative 4,
Excavation and Biological Treatment will address 19,000 cubic yards and Soil Alternative 6,
Soil Flushing/In Situ Biological Treatment will address 23,000 cubic yards. Ground Water
Alternative 3 will address up to 1.0 billion gallons and Ground Water Alternative 4 will address
up to 210 million gallons. The selected remedy cleanup areas are depicted in Figure 16.
The selected remedy may change as a result of engineering processes during remedial design.
Furthermore, specific design and startup testing will be necessary to fully evaluate the selected
remedy. .
Performance Standards for Soils and Sediments
For soils and sediments, the remedial goal is treatment so that the contaminant concentration
levels pose no unacceptable risk to human health or the environment. Since no federal or state
chemical specific ARARs exist for these media, cleanup levels were determined for
contaminants of concern through a site specific risk assessment and through development of
preliminary remediation goals.
The specific performance standards which will be used to insure attainment of the remediation
levels for these contaminated media are:
!;1
o
Excavation of all soil and sediments at the Site with contaminant levels exceeding
concentrations identified in Table 13; the exception being those inaccessible soils
under the pole plant structures and 1-90;
o
Recovery of oily wood treating fluid from excavated soils or from flushed soils to
a level that is technically practicable as determined by MDHES and EP A, and
recycling to active pole plant operations, or offsite disposal in accordance with
RCRA and other applicable requirements if the oily wood treating fluid does not
meet substantive FIFRA requirements;
o
Treatment of all excavated soils and sediments in land treatment units onsite to
cleanup levels identified in Table 13;
o
Placement of clean fill in all excavated areas;
o
Closure of the land treatment units in accordance with RCRA Subtitle C
requirements;
o
Implementation of engineering and institutional controls to prevent access, to limit
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Idaho Pole Record of Decision
the spread of contamination and to protect the integrity of ~e treatment units;
o
Flushing of the inaccessible soils under the pole plant structures and 1-90 for a
minimum period of one year or until oily wood treating fluid is no longer
recovered and contaminant levels have plateaued; and
o
Attainment. of all other ARARs identified in Appendix A for the remediation of
soils.
Sampling will be performed during the response action to verify that all media contaminated
above the cleanup levels are treated. Additional contaminated media will be moved to the
treatment areas prior to the completion of land treatment, as necessary, until attainment of soils
cleanup levels and protectiveness are ensured. The sampling program shall be developed during
remedial design. .
Performance Standards for Ground Water
Remediation goals for ground water include the restoration of contaminated ground water to its
potential future uses, protection of uncontaminated ground water by minimizing migration of
contaminants with the ground water, and ensuring that the level of contaminants remaining in
the ground water poses no unacceptable risk to human health or the environment. Since the
current and future use of the ground water aquifer is for domestic use, cleanup levels for
ground water are either promulgated or proposed MCLs established by the Safe Drinking Water
Act. Attainment of these cleanup levels will be protective of human health and the environment
and will restore the ground water to potential beneficial uses.
The specific performance standards which will be used to ensure attainment. of the remediation
goals for ground water are:
o
Reduction of contaminant levels in ground water within the attainment area to
cleanup levels identified in Table 13; the attainment area is the contaminated
ground water aquifer bounded by Rocky Creek, Bozeman Creek and 1-90;
o
Extraction of ground water at the Site with contaminant concentrations exceeding
the cleanup levels in Table 13;
o
Treatment of extracted ground water to cleanup levels in Table 13;
o
Reinjection of treated and nutrient enhanced ground water to the contaminated
ground water aquifer to stimulate in situ biological degradation of contaminants to
the cleanup levels in Table 13; and, if necessary, discharge to the publicly owned
treatment works or to surface water, in accordance with the applicable discharge
requirements;
o
Evaluation of monitoring well 17 abandonment procedures and, if necessary ,
reabandonment;
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79
TABLE 18
ESTIMATED COSTS FOR THE SELECTED REMEDY
Soils/Sediments
Alternative 4, Excavation and Biological Treatment (Roundhouse area)
Capital cost $107,562
Present worth, Pre-closure 13,550
(1 year at 10%)
Present worth, Closure
(1 years at 10%)
Present worth, Operation & Maintenance
(30 years at 10%)
TOTAL PRESENT WORlH COST
3,685
68.439
193,236
Alternative 4, Excavation and Biological Treatment
Capital cost
Present worth, Pre-closure
(2 years at 10 % )
Present worth, Closure
(2 years at 10 % )
Present worth, Operation & Maintenance
(30 years at 10 % )
TOTAL PRESENT WORTH COST
(Treatment plant and pasture)
$798,036
20,210
24,454
58,070
900,770
Alternative 6, Soil Flushing and In Situ Biological Treatment
Capital cost
Present worth, Pre-closure Operation & Maintenance
(10 years at 10%)
Present worth, Closure
(single payment in 10 years at 10%)
Present worth, Operation & Maintenance
(30 years at 10%)
TOTAL PRESENT WORlH COST
5,483,950
435,364
6,636
58,070
5,984,020
Ground water
Alternative 3, Pump & Biological Treatment
Capital Cost .
Present Worth, Operation & Maintenance
(2 years at 10 %)
TOTAL PRESENT WORlH COST
1,169,025
398.304
1,567,329
Alternative 4, In Situ Biological Treatment
Capital Cost
Operation & Maintenance (10 years at 10%)
TOTAL PRESENT WORlH COST
83,700
345,907
429,607
TOTAL ESTIMATED COSTS
$ 9.074,962
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80
Fi re 16 Selected Remedv
LEG~D
- - - LNAPL I='LUME BOUNDARY
----- GROUNDWAl"ER (DISSOLVED)
PLUME BOUNcAAY
. SECURITY FENC:NG/SIGNING
@ INJE.:i10N WE!..L. HZOz
o INJECTION WEll... STEAM (WITH SOURCE)
- RECOVERY 'TRENCH
PRODUCT RECOVSY SYSTEM
(rANK/PHYSICAL. SEPARATOR)
MONITORING W8...LS (EXISTING) 0
INsmJ SOIL FtUS"tiING 0
(lNALTRATION GA1..LER!ES)
SOILS ~TMENT Mf£A
.
1
~
EXCAVATE!) MATERIALS
.
8
.
C8J
II
r.::s1
Lj
.
STEAM INJEcnON Mf£A
. 0
NOT TO SCALE OR ACCJRAiE..Y PROPORTiONED
FOR 1I.l.USTRA11\IE PURPOSES ONLY
aaa
!Ie.
N;JJJf: IP10-007
REV: A DATE: 2/26/92
DRAFiER: JW
AREA f1, SCENARIO #2
INTEGRATED REMEDIATION CONCEPTUAL Pt.A.N VlEN
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Decision Summary
81
o
Attainment of all other ARARs identified in Appendix A for ground water
remediation;
o
Monitoring of residential wells within or proximate to the contaminated ground
water plume for contaminants of concern for ground water; residential wells
will be monitored not less than every three months until attainment of ground
water cleanup levels in the aquifer and in the wells has been achieved;
o
Implementation of institutional controls to prevent access to contaminated
ground water and to prevent spreading of the plume; and
o
Installation, operation and maintenance of carbon/reverse osmosis treatment
system for all residential wells that have ground water contaminant
concentrations exceeding cleanup levels in Table 13.
Ground water sampling will be performed during the response action to verify that
contaminated ground water above the cleanup levels is treated. Ground water will be
extracted, treated and reinjected until cleanup, levels are attained. If, during operation of the
ground water remediation system, contaminant levels cease to decline and remain constant at
concentrations higher that the cleanup levels, the remedy will be reevaluated.
Comoliance Sampline Proeram
A sampling program for monitoring the remedial action and determining compliance with the
performance standards shall be implemented during the remedial action. In addition, to
ensure that ground water performance standards are maintained, it is expected that ground
water will be monitored at least twice annually during the ground water seasonal high and
low for a period of at least three years following discontinuation of ground water
remediation. These monitoring programs will be developed during remedial design and shall
'include, at a minimum, the following: analytical parameters (focusing on the contaminants
of concern, but analyzing other contaminants, if any, that are not contaminants of concern
and are determined to be occurring at levels exceedingMCLs or proposed MCLs), sampling
points, sampling frequency and duration, and statistical methods for evaluating data. Specific
performance monitoring points shall be specified and approved by EP A and MDHES during
remedial design. '
Because the soils cleanup levels established in this Record of Decision are health based
standards for industrial use of the Site, that do not provide for unlimited use with unrestricted
exposure, and because residual hazardous substances may be left onsite and the cleanup is
expected to take 10-15 years, the selected remedy will require five year reviews under
Section l2l(c) of CERCLA, Section 300.430(t)(4)(ii) of the NCP, and applicable guidance,
to assure the long-term effectiveness of the remedy.
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Idaho Pole Record of Decision
Continued monitoripg of the treated materials remaining in the land treatment units will be
necessary until cleanup levels are attained.
Points of Compliance
Compliance with remediation levels for excavated soils and sediments must be achieved at
any point on the Site with the exception of under the plant and under 1-90. Soils under the
plant facility and under 1-90 must meet the performance standards. For ground water,
compliance with remediation levels must be achieved thro~ghout the contaminated ground
water plume, located downgradient of 1-90, extending to Rocky Creek. Additionally, runoff
that may be the result of ground water recharge, precipitation or snow melt, or release of
noncontact cooling water from the pole plant will meet the surface water standards as
identified in Appendix A, ARARs, where the release enters the surface waters. Surface
water not meeting those standards will be treated with ground water under Ground Water
Alternative 3.
En1rlneerin~ and Institutional Controls
These controls are required to maintain the protectiveness of the remedy. Since cleanup for
all media are not likely to be met in less than 10 years, measures must be instituted to ensure
that risks do not reach unacceptable levels. Fencing and posting of areas where active
remediation is occurring will be required to prevent unauthorized access to contaminated
media or to remedial action areas. Institutional controls will include the prevention of
domestic or commercial water well drilling in the contaminated ground water plume area to
prevent additional receptors of contaminated ground water or an expansion of the plume.
Land use and deed restrictions for the closed land treatment units will also be implemented to
preserve the integrity of the closed land treatment units.
Ground Water Uncertainty and Restorine Ground Water to Beneficial Uses
The goal of this remedial action is to restore the ground water to its beneficial use, which is
as an actual drinking water source. Based on information obtained during the RI and upon
careful analysis of all remedial alternatives, MDHES and EP A believe the remedy will
achieve this goal. It may become apparent, during implementation or operation of the
ground water extraction and in situ bioremediation system, that contamination levels have
ceased to decline and are remaining constant at levels higher than the remediation goals over
some portion of the contaminated plume. In such a case, the remedy may need to be
reevaluated. .
The selected remedy will include ground water extraction and in situ bioremediation for an
estimated period of 10-15 years, during which the system's performance will be carefully
monitored on a regular basis and adjusted as warranted by the performance data collected
during operation. Modifications may include any or all of the following:
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84
Idaho Pole Record of Decision
direct contact with or ingestion of contaminated soil. The current cancer risks associated
with these exposure pathways are as high as 1.8 x lQ4. By excavating the contaminated soils
and treating them, the cancer risks from exposure will be reduced to less than I x 1
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Decision Summary
83
o
At individual wells where cleanup goals have been attained, pumping may be
discontinued;
o
Alternating pumping at wells to eliminate stagnation points;
o
Pulse pumping to allow aquifer equilibration and to allow adsorbed
contaminants to partition into ground water; and
o
Installation of additional extraction wells to facilitate or accelerate cleanup of
the contaminant plume.
Finally, if active IPC pole treating operations cease at the Site, MDHES and EPA may
reevaluate the remedy concerning soils located under treatment facility structures.
x.
STATIJTORY DETERMINATIONS
Under CERCLA section 121, MDHES and EPA must select a remedy that is protective of
human health and the environment, complies with applicable or relevant and appropriate
requirements (unless a statutory waiver is justified), is cost-effective, and utilizes permanent
solutions and alternative treatment technologies or resource recovery technologies to the
maximum extent practicable. In addition, CERCLA includes a preference for remedies that
employ treatment that permanently and significantly reduce the volume, toxicity, or mobility
of hazardous wastes as their principal element. The following sections discuss how the
selected remedy meets these statutory requirements.
Protection of Human Health and the Environment
The selected remedy protects human health and the environment through a combination of
soil and ground water alternatives. Soil alternatives include excavation and biological
treatment of contaminated soil and soil flushing with in situ biological treatment under pole
plant structures and 1-90. Excavated areas will include portions of the pole plant, the pasture
and two ditches. Contaminated soils and sediments will be replaced by clean fill prior to
completion of the cleanup. Soil flushing with in situ biological treatment will be used in
those areas where excavation is not practicable or not cost effective in order to capture as
much of the mobile containination as possible and to reduce concentrations of contaminants
in those areas to levels that will be more susceptible to biological treatment.
Implementation of the soil flushing alternative in the active plant area around existing
structures and under 1-90 will eliminate the need for demolition of structures and
relocation/excavation of the interstate highway and will reduce the exposure risk in those
areas to within the acceptable range. The other soils alternatives evaluated were not
implementable in the plant area and under 1-90 without removing structures and the roadbed.
Biological treatment of the contaminated soil will eliminate the threat of exposure through
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Decision Summary
85
remedy will remediate existing ground water contamination to achieve these relevant and
appropriate MCLs. The selected remedy will also reduce levels of certain other
contaminants of concern to MCLs which have been proposed but not yet adopted. The
proposed MCLs have been identified as TBCs by EP A and MDHES.
Since no treatment standards have been set for the RCRA listed wastes on site (F032 and
F034 wastes) as of the date of this Record of Decision, RCRA Land Disposal Restrictions
will not apply to the remedy.
Location-specific ARARs
Location-specific ARARs establish requirements or limitations based on the physical or
geographic setting of the Site or the existence of protected resources on the Site. The area in
which the treatment is to be implemented is not located within a loo-year floodplain, and no
planned waste storage or treatment area is located within 200 feet of a fault. Thus the
selected remedy will comply with all requirements based on physical or geographic setting.
Regulations concerning the protection of wetlands, including those relating to the Fish and
Wildlife Coordination Act and Executive Orders 11,988 and 11,990, will apply to the
implementation of this remedy. The protected resource which has the potential to be
adversely affected by the selected remedy is a small wetland area. Consultation with the
U. S. Fish and Wildlife Service during the design and implementation phase will be required
to establish appropriate mitigative measures, such as reestablishing these wetlands as part of
the reclamation of excavated areas. Also in connection with EPA's consultation with the
U.S. Fish and Wildlife Service regarding the Endangered Species Act, the U.S. Fish and
Wildlife Service has requested that additional biological assessments regarding certain
endangered species (peregrine falcons, and. bald eagles) be conducted in conjunction with
remedial design.
Action-s.pecific ARARs
Action-specific ARARs generally provide guidelines for the manner in which specific
activities must be implemented. Thus, compliance with many action-specific requirements
must be ensured through appropriate design of the remedy.
The remedy will meet all action-specific ARARs, including the following RCRA
requirements: monitoring for releases from waste management units, closure and post-closure
standards, requirements for management of waste piles and land treatment units, recycling
requirements, and transportation requirements, if any hazardous waste is ultimately shipped
offsite for treatment or disposal, as well as all requirements for reclamation of excavated
areas
The remedy will also satisfy regulations under the Federal Insecticide Fungicide and
Rodenticide Act which establish allowable limits of certain constituents in pentachlorophenol
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86
Idaho Pole Record of Decision
products used in wood treating operations. Product which exceeds these limits must be
appropriately disposed of by a method other than recycling.
For any discharge to a POTW the remedy will comply with requirements, including the
pretreatment requirements under the Clean Water Act and the pennit-by-rule requirements
under RCRA. Compliance with the standards for discharges to POTWs would require
fulfilling the administrative, as well as the substantive portions of those requirements, since
any such discharge would occur offsite. .
In addition, the remedy, as designed, will meet other action-specific standards, including
Clean Air Act regulations for particulate matter, dust control practices that achieve ambient
air quality standards, Clean Water Act regulations requiring run-on and run-off controls that
prevent any discharge of contaminants from remedial actions that would violate surface water
standards, sufficient treatment before reinjection of ground water to ensure compliance with
ground water nondegradation standards, the requirements of the Underground Injection
Control program under the Safe Drinking Water Act and RCRA regulations associated with
the treatment, storage and transportation of hazardous waste.
The FS Report provides further support for the determination that the selected remedy
complies with ARARs. .
Cost-Effectiveness
MDHES and EPA have determined that the selected remedy is cost-effective in mitigating the
principal risks posed by the soils, sediments and contaminated ground water. Section
300.430(t)(ii)(D) of the NCP requires evaluation of cost-effectiveness. Cost-effectiveness is
determined by the following three balancing criteria to determine overall effectiveness: long-
term effectiveness and permanence; reduction of toxicity, mobility or volume through
treatment; and short-term effectiveness. Overall effectiveness is then compared to cost to
ensure that the remedy is cost-effective. A remedy is cost-effective if its costs are
proportional to its overall effectiveness. The selected remedy meets the criteria and provides
for overall effectiveness in proportion to its cost. The estimated cost for the selected remedy
is approximately $9,074,962
The selected remedy for the soils provides the best overall effectiveness of all alternatives
considered proportional to its cost. The selected remedy will greatly reduce the toxicity,
mobility, and volume of contaminated soils. Also the implementation of this remedy will
result in long-term effectiveness by reducing residual carcinogenic risks to within the
acceptable risk range through permanent treatment. Although in situ bioremediation, if
implemented by itself, is less expensive than the combination of soil alternatives comprising
the selected remedy, it does not provide as great a degree of long-term effectiveness or
reduction in toxicity, mobility or volume through treatment and therefore is only appropriate
for use in specific areas of the Site.
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Decision Summary
87 .
Alternative 6, soil flushing and in situ bioremediation is the only soil remedy identified that
will not .require demolition of existing structures at the IPC plant and will not require
excavation of 1-90. Thus, the costs of Alternative 6 for these parts of the Site are much less
than other alternatives, while still maintaining effectiveness.
The selected remedy for ground water provides the best overall effectiveness of all
alternatives considered proportional to its cost. The combination of Alternatives 3, Pump
and Biological Treatment; and 4, In Situ Biological Treatment, will reduce the toxicity,
mobility or volume of affected ground water and will be permanent solutions. The
combination of Alternative 2 and Alternative 4 might achieve cleanup levels more quickly,
but the additional cost of Alternative 2 compared to Alternative 3 is not warranted. The
combination of Alternatives 3 and 4 is believed necessary in order to reach MCLs because
pump and treat methods without an in situ component require longer remediation times.
The selected remedy assures a high degree of certainty that the remedy will be effective in
the long-term because of the significant reduction of the toxicity and mobility of the wastes
achieved through biological treatment of the soil. The ground water component of the
remedy ensures a high degree of certainty of effectiveness because the technology employed
is known to be effective for organic' contaminated wastewaters and will enhance the
degradation of contaminants remaining in situ. .
Utilization of Permanent Solutions and Alternative Treatment Technolocies (or Resource
Recoverv Technoloeies) to the Maximum Extent Practicable
MDHES and EP A have determined that the selected remedy represents the maximum extent
to which permanent solutions and treatment technologies can be utilized in a cost-effective
manner at the Site. Of those alternatives that are protective of human health and the
environment and comply with ARARs, MDHES and EPA have determined that this selected
remedy provides the best balance of trade-offs in terms of long-term effectiveness and
permanence, reduction in toxicity, mobility, or volume achieved through treatment, short-
term effectiveness, implementability and cost, while also considering the statutory preference
for treatment as a principal element and considering state and community acceptance. The
detailed evaluation of the balance of these criteria among the alternatives considered is set
forth in the FS Report and is summarized in section VIT, Description of Alternatives, of this
record of decision. .
The selected remedy includes treatment of contaminated media which will permanently and
significantly reduce the principal threats posed by the soils and ground water. The other
alternatives considered which could achieve similar or more substantial reductions, including
incineration, solvent extraction or offsite disposal, were significantly more expensive. Other
alternatives considered, including in situ biological treatment over the entire Site, did not
offer similar prospects for effectiveness in treatment.
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88
Idaho Pole Record of Decision
Preference for Treatment as a Principal Element
By biologically treating the contaminated ground water and the contaminated soils, the
selected remedy addresses. the principal threats posed by the Site through the use of treatment
technologies. By utilizing treatment as a significant portion of the remedy, the statutory
preference for remedies that employ treatment as a principal element is satisfied.
XI.
DOCUMENTATION OF SIGNIFICANT CHANGES
The Proposed Plan for the Site was released for public comment April 16, 1992.. The plan
identified a combination of Soil Alternatives (4, Excavation and Biological Treatment and 6,
Soil Flushing/In Situ Biological Treatment) and Ground Water Alternatives (3, Extraction
and Biological Treatment and 4, In situ Biological Treatment) as the preferred remedy for the
She. .
MDHES and EP A. have reviewed all written and oral comments submitted during the public
comment period. Upon review of the public comments, MDHES and EPA have determined
that two changes to the Proposed Plan are warranted.
First, MDHESand EP A are considering the possibility of discharging treated wastewater
from the Site into surface water if reinjection into the aquifer or discharge to a POTW are
not feasible. This change is the result of strong objections by the City of Bozeman to any
discharge of treated wastewater to the POTW.
Second, the roundhouse area soils have been identified as a significantly contaminated and
have been included for remedial action. However, due to recent regulatory changes this
conclusion may be subject to change. The rationale for this is that since preparation of the
Proposed Plan, the cancer slope factor for benzo(a)pyrene, upon which the B2 PAH cleanup
level of 7.5 mg/kg is based, has been reduced from 11.5 to 5.79 (mg/kg/day)"l. Therefore,
an adjusted cleanup level of 15 mg/kg B2 PAHs has been identified by MDHES as
representative of the 1 x 1 Q-6 risk level for industrial use. The currently determined highest
concentrations of B2 P AHs at test pit 3B (25 mg/kg) and at test pit 7 A (32 mg/kg) are much
closer to the adjusted cleanup level than they were to the initial cleanup level. Also, the
revised cleanup level reduced the number of data points above. the cleanup level.
Consequently, the amount of contaminated soil in the roundhouse area that is subject to
excavation and treatment may be significantly less than the earlier estimate of 4600 yd3.
XTI. REFERENCES
Freeman, Harry M., 1989. Standard Handbook of Hazardous Waste Treatment and
Disposal, McGraw Hill, New York, N.Y.
MSE, Inc., Remedial Investigation R~ort for Idaho Pole Site. Bozeman. MT, March 1992.
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Decision Summary
89
MSE, Inc., Remedial Investigation Report for Idaho Pole Site. Bozeman. MT, March 1992.
MSE, Inc., Feasibility Study for Idaho Pole Site. Bozeman. MT, April 1992.
MSE, Inc., Technical Memorandum 3 (Baseline Risk Assessment) for Idaho Pole Site.
Bozeman MT, March 1992.
MSE, Inc., Technical Memorandum 3 (Ecological Risk Assessment) for Idaho Pole Site.
Bozeman. MT, March 1992.
u.S. EPA, Guidance on Preparing Superfund Decision Documents, Office of Emergency and
Remedial Response, Interim Final, EPA/540/G, July 1989.
Woodward-Clyde, November 1988. Feasibility Study for Site Remediation. Libby. MT.
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v
"
APPENDIX A
FINAL DETERMINATION AND DESCRIPTION OF
APPliCABLE OR RELEVANT AND APPROPRIATE REQUIR.Ev1ENTS
IDAHO POLE NPL SITE
BOZEMAN, MONTANA
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TABLE OF CONTENTS
Page A-
APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS (ARARS) .. 1
ARARS FOR REM:EDIAL ACTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1
DETER1v.IINATION OF ARARS ................................ 1
ARARS FOR TIIE IDAHO POLE NPL SITE ........................ 3
FEDERAL ARARS . . . . . . . . . . . . . . . . . . . . . . .'. . . . . . . . . . . . . . . . . . .. 4
FEDERAL CONTAMINANT-SPECIF1C ARARS . . . . . . . . . . . . . . . . . . . . .. 4
Safe Drinking Water Act (Relevant and Appropriate) . . . . . . . . . . . . . . . . .. 4
FEDERAL LOCATION-SPECIF1C ARARS ......................... 5
Fish and Wildlife Coordination Act (Applicable) . . . . . . . . . . . . . . . . . . . .. 5
Floodplain Management Order (Applicable) . . . . . . . . . . . . . . . . . . . . . . .. 5
Protection of Wetlands Order (Applicable) ........................ 5
. Resource Conservation and Recovery Act (Applicable) . . . . . . . . . . . . . . . .. 6
Endangered Species Act (pending) ...,......................... 6
Archaeological and Historical Preservation Act (Applicable) . . . . . . . . . . . . .. 7
FEDERAL ACTION-SPECIFIC ARARS ........................... 7
Clean Water Act (Applicable) ................................ 7
Safe Drinking Water Act (Applicable) .........:................. 7
Clean Air Act (Applicable) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 8
Particulate Matter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... 8,
Resource Conservation and Recovery Act (Applicable) . . . . . . . . . . . . . . . .. 8
Standards Applicable to Transporters of Hazardous Waste (Applicable) .... 9
Standards for Owners and Operators of Hazardous Waste Treatment, Storage,
and Disposal Facilities (Applicable) ........................ 9
A. Releases from Solid Waste Management Units. . . . . . . . . . . . . . . ' 9
B. Closure and Post-Closure. . . . . . . . . . . . . . . . . . . . . . . . . . .. 9
C. Waste Piles (Applicable) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
D. Land Treatment (Applicable) ................ . . . . . . . . . . 10
E. Incineration (Applicable) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Discharge to POTWs (Applicable) . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Requirements for Recyclable Materials (Applicable) """""""" 12
Hazardous Materials Transportation Act (Applicable) . . . . . . . . . . . . . . . . .. 12
Federal Insecticide, Fungicide, and Rodenticide Act (Applicable) . . . . . . . . . .. 12
FEDERAL STANDARDS TO BE CONSIDERED. . . . . . . . . . . . . . . . . . . . . . 13
Safe Drinking Water Act. . . . . . . '. . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Proposed MCLs ...................................... 13
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STATE OF MONTANA ARARS .................................. 14
MONTANA CONTAMINANT-SPECIFIC ARARS ............""""" 14
Water Quality. .'. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
MONTANA LOCATION-SPECIFIC ARARS . . . . . . . . . . . . . . . . . . . . . . . . . 14
Floodplain and Floodway Management. . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Floodplain and Floodway Management Act (Applicable) . . . . . . . . . . . . .. 14
Floodplain Management Regulations (Applicable) . . . . . . . . . . . . . . . . .. 15'
MONTANA ACTION-SPECIFIC ARARS . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Water Quality. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Surface Water Quality Standards (Applicable) . . . . . . . . . . . . . . . . . . . . 16
Montana Groundwater Pollution Control System (Applicable) .......... 18
Groundwater Act (Applicable) ............................. 19
Air Quality. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Air Quality Regulations (Applicable) .......................... 20
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ARAR
ATSDR
BAT
BCT
BPCTCA
BPJ
CERCLA
DNRC
DSL
EPA
FIFRA
HWM
IPC
LNAPL
MCL
MCLG
MDHES
MGWPCS
MPDES
NCP
NESHAPS
NPL
NPDES
PAR
PCP
POHC
POTW
PSD
RCRA
RIfFS
ROD
SHPO
SIP
TBC
TU
VIC
liST OF ACRONYMS
Applicable or Relevant and Appropriate Requirements
Agency of Toxic Substances and Disease Registry
Best Available Technology Economically Achievable
Best Conventional Pollutant Control Technology .
Best Practicable Control Technology Currently Available
Best Professional Judgment
Comprehensive Environmental Response, Compensation, and Liability Act of
1980
Department of Natural Resources and Conservation (Montana)
Department of State Lands (Montana)
U.S. Environmental Protection Agency
Federal Insecticide, Fungicide, and Rodenticide Act
Hazardous Waste Management
Idaho Pole Company
Light Non-aqueous Phase Liquid
Maximum Contaminant Level.
Maximum Contaminant Level Goal
Montana Department of Health and Environmental Sciences
Montana Groundwater Pollution Control System
Montana Pollutant Discharge Elimination System
National Contingency Plan
National Emissions Standards for Hazardous Air Pollutants
National Priorities List
National Pollutant Discharge Elimination System
Polynuclear Aromatic Hydrocarbon
Pentachlorophenol
Principal Organic Hazardous Constituents
Public Owned Treatment Works
Prevention of Significant Deterioration
Resource Conservation and Recovery Act
Remedial Investigation/Feasibility Study
Record of Decision
State Historic Preservation Officer (Montana)
State Implementation Plan
To Be Considered
Turbidity Unit
Underground Injection Control
'A-ill
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APPLICABLE OR RELEVANT AND APPROPRIATE REOUIREMENTS (ARARS)
ARARS FOR REMEDIAL ACTIONS
I
Section 121(d)(2) of CERCLA, 42 U.S.C. ~ 9621(d)(2), requires that cleanup actions
conducted under CERCLA achieve a level or standard of control which at least attains "any
standard, requirement, criteria or limitation under any Fedei'al environmental law ... or any
[more stringent] promulgated standard, requirement, criteria or limitation under a State
environmental or facility siting law... [which] is legally applicable to the hazardous
substance concerned or is relevant and appropriate under the circumstances of the release of
such hazardous substance or pollutant, or contaminant... " . The standards, requirements,
criteria or limitations identified pursuant to this section are commonly referred to as
"applicable or relevant and appropriate requirements," or ARARs.
Tbe cleanup of the Idaho Pole NPL site must comply with or attain all ARARs unless
specific ARAR waivers are invoked. See CERCLA 9 121(d)(4), 42 U.S.C. 9 9621(d)(4),
and the NCP, 40 CFR 300.430(f)(1)(ii)(C). ARARs must be met both during the conduct of
on site cleanup activities and at the conclusion of the cleanup activity, unless specifically
exempted. 1
DETERMINATION OF ARARS
ARARs may be either "applicable" requirements or "relevant and appropriate" requirements.
Compliance with both is equally mandatory under CERCLA.2
Applicable requirements are those standards, requirements, criteria or limitations
promulgated under federal environmental or state environmental or facility siting laws that
specifically address a hazardous substance, pollutant, contaminant, remedial action, location,
or other circumstance found at a CERCLA site.
RelevaIit and appropriate requirements are those standards, requirements, criteria or
limitations promulgated under federal environmental or state environmental or facility siting
laws that, while not "applicable" to hazardous substances, pollutants, contaminants, remedial
actions, locations, or other circumstances at a CERCLA site, address problems or situations
sufficiently similar to those encountered at the CERCLA site that their use is well suited to
the particular site. Factors which may be considered in making this determination, when the
factors are pertinent, are presented in 40 C.F.R. 9 300.400(g)(2). They include, among
other considerations, examination of: the purpose of the requirement and the purpose of the
CERCLA action; the medium and substances regulated by the requirement and the medium
. 40 CFR ~ 300.435(b)(2); Preamble to the Proposed NCP, 53 Fed. Reg. 51440 (December 21, 1988); Preamble to the Final
NCP, 55 Fed. Reg. 8755-8757 (March 8, 1990).
See CERCLA ~ 121(d)(2)(A).42 U.S.C. ~ 9621(d)(2)(A).
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and substances at the CERCLA site; the actions or activities regulated by the requirement
and the remedial action contemplated at the site; and the potential use of resources affected
by the requirement and the use or potential use of the affected resource at the CERCLA site.
ARARs are divided into contaminant-specific, location-specific and action-specific
requirements. Contaminant-specific requirements govern the release to the environment of
materials possessing certain chemical or physical characteristics or containing specific
chemical compounds. Contaminant-specific ARARs generally set human or environmental
risk-based criteria and protocols which, when applied to site-specific conditions, result in the
establishment of numerical action values. These values establish the acceptable amount or
concentration of a chemical that may be found in, or discharged to, the ambient environment.
Location-specific ARARs relate to the geographic or physical position of the site, rather than
to the nature of site contaminants. These ARARs place restrictions on the concentration of
hazardous substances or the conduct of cleanup activities due to their location in the
environment.
Action-specific ARARs. are usually technology- or activity-based requirements, or are
limitations on actions taken with respect to hazardous substances. A particular remedial
activity will trigger an action-specific ARAR. UIilike chemical-specific and location-specific
ARARs, action-specific ARARs do not, in themselves, determine the remedial alternative.
Rather ,action-specific ARARs indicate how the selected remedy must be achieved.
On-site actions are required to comply with ARARs, but need comply only with the
substantive provisions of a requirement. 3 Off-site actions need comply only with legally
applicable requirements, but must comply fully with both the substantive and administrative
portions of such requirements. See EPA OSWER Dir. 9234.2-Q2FS. Administrative
requirements are those which involve consultation, issuance of permits, documentation,
reporting, recordkeeping, and enforcement. The CERCLA program has its own set of
administrative procedures which assure proper implementation of CERCLA. The application
of additional or conflicting administrative requirements could result in delay or confusion.4
Provisions of statutes or regulations which contain general goals that merely express
legislative intent about desired outcomes or conditions but are non-binding are not ARARs.s
Only those state standards that are identified in a timely manner and are more stringent than
federal requirements may be applicable or relevant and appropriate. To be an ARAR, a state
40 CPR ~ 300.5 (Definitions of "Applicable requirements" and "Relevant and appropriate requirements.") See also Preamble to
the Final NCP, 55 Fed. Reg. 8756-8757 (March 8, 1990).
Preamble to the Fmal NCP, 55 Fed. Reg. 8756-8757 (March 8, 1990); Compliance with Other Laws Manual, Vol. I. pp. 1-11
through 1-12.
Preamble to the Final NCP, 55 Fed. Reg. 8746 (March 8, 1990).
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standard must be "promulgated," which means that the standards are of general applicability
and are legally enforceable. 6
Additional documents may be identified as To Be Considered (TBCs). The TBC category
. consists of advisories, criteria, or guidance that were developed by EPA, other federal
agencies, or states that may be useful in developing CERCLA remedies. These may be
considered as appropriate in selecting and developing cleanup actions.7
Laws which are not environmenta1laws or state facility siting laws are not ARARS, but, if
applicable, must be observed and complied with in any action at the site. CERCLA ~ 121
exempts any action conducted entirely on-site from any local, state or federal permit
requirement, including any permit requirements of these other laws. However, all other
applicable requirements of these other laws, including the administrative as well as the
substantive requirements, apply to actions conducted at the site.
ARARS FOR THE IDAHO POLE NPL SITE.
This document constitutes MDHES' and EPA's fmal determination and detailed descriptions
of federal and state ARARs for remedial action at the Idaho Pole NFL site. The descriptions
are provided to allow the user a reasonable understanding of the requirements without having
to refer constantly back to the statute or regulation itself. However, in the event of any
inconsistency between the law itself and the summaries provided in this document, the
applicable or relevant and appropriate requirement is ultimately the requirement as set out in
the law, rather than any paraphrase of the law provided here.
The ARARs analysis is based on section 121(d) of CERCLA, 42 D.S.C. ~ 9621(d);
"CERCLA Compliance with Other Laws Manual, Volume I," OSWER Dir. 9234.1-01
(August 8, 1988); "CERCLA Compliance with Other Laws Manual, Volume IT," OSWER
Dir. 9234.1-02 (August, 1989); the Compendium of CERCLA ARARs Fact Sheets and
Directives, OSWER Dir. 9347.3-15 (October 1991); the Preamble to the Proposed National
Contingency Plan, 53 Fed. Reg. 51394, et. ~. (December 21, 1988); the Preamble to the
Final National Contingency Plan, 55 Fed. Reg. 8666-8813 (March 8, 1990); and the Final
National Contingency Plan, 40 C.F.R. Part 300 (55 Fed. Reg. 8813-8865, March 8, 1990)
(hereinafter referred to as the NCP). All references to 40 C.F.R. Part 300 contained in this
document refer to the fmal NCP, unless noted.
40 C.F.R. ~ 300.400(g)(4).
40 C.F.R. ~ 300.400(g)(3); 40 C.F.R. ~ 300.415(i); Preamble to the Final NCP, 5S Fed. Reg. 8744-8746 (March 8, 1990).
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FEDERAL ARARS
FEDERAL CONTAMINANT-SPECIFIC ARARS
Safe DrinJdng Water Act (Relevant and Appropriate)8
The National Primary and Secondary Drinking Water Standards (40 CPR Parts 141, 143),
better known as "maximum contaminant levels" (MCLs), are not applicable to remedial
activities at the site because the aquifer underlying the site does not serve a public water
supply system. These drinking water standards are, however, relevant and appropriate to all
groundwater alternatives because groundwater in the area is a domestic water source for off-
site residences not connected to city water.
Ten residences located downgradient and within 1/2 mile of the site use groundwater for
domestic, irrigation, and stock watering purposes." These wells are typically between 30 and
60 feet deep and are completed within transmissive sand and gravel seams.
Pentachlorophenol, a contaminant of concern at the site, has been repeatedly identified in one
of these wells. There are approximately 400 other wells within a 2-mile radius of the site.
. The determination that the drinking water standards are relevant and appropriate at the site is
fully supported by EPA regulations. The Preamble to the National Contingency Plan (NCP)
clearly states MCLs are relevant and appropriate for groundwater that is a current or
" potential source of drinking water, 55 Fed. Reg. 8750 (March" 8, 1990), and this
determination is further supported by requirements in the RIfFS section of the NCP, 40 CPR
~ 300.430(e)(2)(i)(B). In addition to the MCLs, non-zero maximum contaminant level goals
(MCLGS)9 for any contaminants at the site would be relevant and appropriate for remedial
actions that will be considered for this site. See 55 Fed. Reg. 8750-8752 (March 8, 1990).
None of the contaminants for which MCLs and MCLGs are currently in effect have been
identified as contaminants of concern at the Idaho Pole site. Relevant proposed MCLs are
discussed in the federal standards "To Be Considered" (TBCs), Section 3.4, below.
An EPA rulemaking establishing an MCL for pentachlorophenol at 0.001 mg/l has been
promulgated. The new MCL will be effective January 1, 1993. See 56 Fed. Reg. 30280
(July 1, 1991), to be codified at 40 CFR ~ 141.61. This MCL should be considered a
EPA has granted to the State of Montana primacy in enforcement of the Safe Drinking Water Act. Thus the law commonly
enforced in Montana is the state law, rather than the federal law . The state regulations under the state Public Water Supply Act,
~~ 75-6-101~, MCA, substantially parallel the federal law. The MCLs are currently identical, ~ ARM 16.20.203, and
will remain so until certain federal rule changes become effective on luly 1, 1992, and lanuary 1, 1993. The state requirements
are not separately identified, since they are not more stringent. This note is provided only to clarifY the primacy issue, i.e.,
which law is commonly enforced in Montana. .
Effective lanuary I, 1993, pentachlorophenol will be included in the group of highly toxic chemicals for which the MCLG is
zero. See 56 Fed. Reg. 30280 Quly I 1991), to be codified at 40 CFR ~ 141.50(a). The zero MCLGs are not generally
considered "appropriate" requirements for CERCLA cleanups, primarily for reasons of practicability. See 40 CFR ~
300.430(e)(2)(i)(C); ~ Preamble to the Final NCP, 55 Fed Reg. 8750-8753 (March 8, 1990).
A-4
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relevant and appropriate requirement for this action. When a regulation with a delayed
effective date is known at the time of issuance of a record of decision, and the remedy will
not be performed until after the effective date of the regulation, EP A will consider the
standard to be an ARAR.IO .
Similarly, the newly promulgated MCL's of 3 X 10-8 mg/l for 2,3,7,8-TCDD (Dioxin) and
0.0002 mg/l for Benzo(a)pyrene, 57 Fed. Reg. 31778 (July 17, 1992), are relevant and
appropriate requirements for this action.
FEDERAL LOCATION-SPECIFIC ARARS
Fish and Wildlife Coordination Act (Applicable)
This standard (16 U.S.C. ~~ 1531-1566, 40 CFR ~ 6.302(g» requires that federal agencies
or federally-funded projects ensure that any modification of any stream or other water body
affected by any action authorized or funded by the federal agency provides for adequate
protection of fish and wildlife resources. Compliance with this ARAR requires consultation
with the U. S. Fish and Wildlife Service and the Wildlife Resources Agency of the affected
State to ascertain the means and measures necessary to mitigate, prevent and compensate for
project-related losses of wildlife resources and to enhance the resources. Consultation will
occur during the remedial design and implementation phase and specific mitigative measures
may be identified in consultation with the appropriate agencies, if remedial action, as
designed, will affect a stream or creek.
Floodplain Management Order (Applicable)
This requirement (40 CFR Part 6, Appendix A, Executive Order No. 11,988) mandates that
federally-funded or authorized actions within the 100 year floodplain avoid, to the maximum
extent possible, adverse impacts associated with development of a floodplain. Compliance
with this requirement is detailed in EPA's August 6, 1985 "Policy of Floodplains and
Wetlands Assessments for CERCLA Actions." Specific measures to minimize adverse
impacts will be identified and incorporated into the remedial design following consultation
with the appropriate agencies.
Protection of Wetlands C;>rder (Applicable)
This requirement (40 CFR Part 6, Appendix A, Executive Order No. 11,990) mandates that
federal agencies and PRPs avoid, to the extent possible, the adverse impacts associated with
10
The new MCL does not have to be currently in effect to be considered relevant and appropriate. But for the delayed effective
date, the new MCL would clearly constitute a relevant and appropriate requirement. The considerations specified in 40 CFR ~
3oo.400(g)(2) for evaluating whether a requirement is relevant and appropriate a11 weigh in favor of observing this requirement as
an ARAR.
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the destruction or loss of wetlands and to avoid support of new construction in wetlands if a
practicable alternative exists. The wetlands inventory for the site identified the following
wetlands: drainage ditches along Cedar Street and 1-90; lowland areas along Mill Ditch; a 6-
acre willow/sedge grove situated immediately west of the MPC Substation and located on
pasture land owned by the IPC; and the Rocky Creek floodplain. Alternatives for soil and
sediments and ground water cleanup could impact these areas, so this requirement would be
applicable.
. Compliance with this ARAR requires consultation with the U. S. Fish and Wildlife Service
(USFWS) to determine the extent of impact on wetlands and to ascertain the means and
measures necessary to mitigate, prevent and compensate for project-related losses of
wetlands. EPA consulted the USFWS during the RI/FS. The USFWS has submitted
suggestions for developing a wetlands mitigation plan. This plan will be prepared in
conjunction with the design phase of the remedy. .
Resource Conservation and Recovery Act (Applicable)
The requirements set forth at 40 CFR ~ 264.18(a) and (b)1l provide that (a) any hazardous
waste facility must not be located within 61 meters (200 feet) of a fault (see Appendix VI of
Part 264), and (b) any hazardous waste facility within the 100 year floodplain must be
designed, constructed, operated and maintained to avoid washout. Although the site is not
located within 61 meters of a fault, a portion of the site lies within the 100 year floodplain.
Any discrete disposal or storage facilities which remain on-site as part of remedial activities
will be located outside the 100 year floodplain.
Endangered Species Act (pending)
This statute and implementing regulations (16 USC ~~ 1531-1543, 50 CFR ~ 402, 40 CFR ~
6.302(h» require that any federal activity or federally-authorized activity may not jeopardize
the continued existence of any threatened or endangered species or destroy or adversely
modify critical habitat.
Compliance with this requirement involves consultation with the u.S. Fish and Wildlife
Service to determine whether there are listed or proposed species or critical habitats present
on the site, and, if so, whether any proposed activities will impact such wildlife or habitat.
To date the U.S. Fish and Wildlife Service has not identified any threatened or endangered
species or critical habitats on the site. However, a final determination will be made during
the design phase of the remedial action. The U. S. Fish and Wildlife Service has
recommended that certain biological assessments be conducted in conjunction with remedial
design to determine the exact extent of any impact on endangered species.
11
These requirements are applicable through their incorporation by reference in Montana's regulations for its authorized RCRA
program. ARM 16.44.702.
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"
G
Archaeological and Historical Preservation Act (Applicable)
This statute and implementing regulations, 16 V.S.C. ~ 469, 40 CPR ~ 6.301(c), establish
requirements for the evaluation and preservation of historical and archaeological data, which
may be destroyed through alteration of terrain as a result of a federal construction project or
a federally licensed activity or program. This requires a survey of the site for covered
scientific, prehistorical or archaeological artifacts. Such a survey was conducted by GCM
Services, Inc., of Butte, Montana, on April 25 and 26, 1990, and revealed no prehistoric
sites at the facility. See Final Cultural Resource Inventory of the Idaho Pole. Site, MSE,
Inc., September 1990. Preservation of appropriate data concerning any artifacts actually
discovered would be required, however, during the implementation of this remedial action.
FEDERAL ACTION-SPECIFIC ARARS
Clean Water Act (Applicable)
Under the Clean Water Act, all discharges by nondomestic users into POTWs must meet
pretreatment standards. Under' 40 CPR Part 403, 'standards are set to control pollutants
which contact publicly-owned treatment works (POTWs) or which may contaminate sewage
sludge. 40 CPR Part 421 limits discharges to POTWs. If groundwater that is pumped and
treated is discharged to a POTW, these requirements will be applicable. Because the POTW
is off-site, both administrative and substantive pennit requirements specified in these
regulations must be met.
There are three categories of limitations for discharges into a POTW. The fIrst is the
general standard that applies to all discharges into a POTW. Second, POTW s may issue
discharge permits to industrial users to enforce specific limits for a particular facility. Third,
BFA has established pretreatment standards for specific industrial subcategories. All three
of these standards may be applicable to a particular wastewater stream. Generally,
discharges into a POTW cannot cause pass through or interference with a POTW. "Pass
through" means a discharge which exits the POTW causing a violation of the POTW's
National Pollutant Discharge Elimination System ("NPDES") permit. "Interference" is a
discharge which inhibits or disrupts a POTW's treatment process or operation, causing a
violation of the POTW's NPDES permit. .
Safe Drinking Water Act (Applicable)
The underground injection control (UIC) program requirements found at 40 CPR Part 144
would be applicable for alternatives that involve reinjection of pumped and treated
groundwater. The program divides wells into classes for permitting purposes. Class IV
wells are used to dispose of hazardous waste into or above a formation which contains,
within one-quarter mile of the well, an underground source of drinking water. These wells
are generally prohibited, except for reinjection of treated groundwater into the same
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formation from which it was withdrawn, as part of a CERCLA cleanup or RCRA corrective
action.
The aquifer underlying the site would be considered an underground source of drinking
water, so any well injecting above the aquifer would be a Class IV well. Generally, the
construction, operation, and maintenance of a Class IV well is prohibited by 40 CFR ~ .
144.13. However, wells used to inject contaminated ground water that has been treated and
is being reinjected into the same formation from which it was withdrawn are not prohibited if
such injection is approved by EP A pursuant to provisions for cleanup of releases under
CERCLA, or pursuant to requirements and provisions under RCRA.. 40 CFR ~ 144.23
requires that Class IV wells be plugged or otherwise closed in a manner acceptable to the
EP A Regional Administrator.
Clean Air Act (Applicable)
Section 109 of the Clean Air Act, 42 USC ~ 7409, and implementing regulations found at 40
CFR Part 50 set national primary and secondary ambient air quality standards. National
primary ambient air quality standards defme levels of air quality which are necessary, with
an adequate margin of safety, to protect the public health. National secondary ambient air
quality standards defme levels of air quality which are necessary to protect the public welfare
from any known or anticipated adverse effects of a pollutant. The standards for particulate
matter at 40 CFR ~ 50.6 are applicable for all alternatives involving the excavation, land
treatment, incineration and transportation of soils. These standards must be met during both
the design and implementation phases of the remedial action.
Particulate Matter
The ambient air quality standard for particulate matter of less than or equal to 10
micrometers in diameter (PM-I0) is 150 micrograms per cubic meter, 24 hour average
concentration; 50 micrograms per cubic meter, annual arithmetic mean for particulate matter
of less than or equal to 10 micrometers in diameter.12
In addition, state law provides an ambient air quality standard for settled particulate matter.
Particulate matter concentrations in the ambient air shall not exceed the following 30-day
average: 10 grams per square meter. ARM ~ 16.8.818 (Applicable).
Resource Conservation and Recovery Act (Applicable)
As noted above, EPA has listed new RCRA hazardous wastes consisting of waste waters,
process residuals, preservative drippage, and spent formulations of wood preserving
processes generated at plants using chlorophenolic and creosote formulations for wood
12
The state air quality regulations provide an equivalent standard, ~ ARM 16.8.821, which is enforceable in Montana as part of
the State Implementation Plan.
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preserving waste nos. F032 and F034. 55 Fed. Reg. 50,450, 50,482, to be codified at 40
CFR ~ 261.31(a). Because the site is a wood treating site that uses pentachlorophenol (PCP)
and has used creosote, these newly-listed wastes are found in various locations throughout the
site, and RCRA regulations concerning the treatment, storage and disposal of hazardous
wastes apply to activities involving these materials.
Standards Applicable to Trans.porters of Hazardous Waste (Applicable)
The regulations at 40 CFR Part 263 establish standards that apply to persons that transport
hazardous waste within the United States. If hazardous waste is transported on a rail-line or
public highway on-site, or if transportation occurs off-site,. these regulations will be
applicable.
Standards for Owners and Operators of Hazardous Waste Treatment. Storage. and Disposal
Facilities (Ap'plicable) .
A.
Releases from Solid Waste Management Units
The regulations at 40 CFR 264, Subpart F, 13 establish requirements for groundwater
protection for RCRA-regulated solid waste management units (Le., waste piles, surface
impoundments, land treatment units, and landfills). These requirements will apply to the
land treatment units containing the PCP contaminated wastes and media at the site. Subpart
F provides for three general types of groundwater monitoring:' detection monitoring (40
CFR ~ 264.98); compliance monitoring (40 CFR ~ 264.99); and corrective action monitoring
(40 CFR ~ 264.100). Monitoring wells must be cased according to ~ 264.97(c).
Monitoring is required during the active life of a hazardous waste management unit. At
closure, if all hazardous waste, waste residue, and contaminated subsoil is removed, no
monitoring is required. If hazardous waste remains, the monitoring requirements continue
during the 40 CFR ~ 264.117 closure period.
B.
Closure and Post-Closure
40 CFR Part 264, Subpart G, 14 establishes that hazardous waste management facilities,
including laDd treatment units treating hazardous wastes, must be closed in such a manner as
to (a) minimize the need for further maintenance and (b) control, minimize or eliminate, to
the extent necessary to protect public health and the environment, post -closure escape of
hazardous wastes, hazardous constituents, leachate, contaminated runoff or hazardous waste
decomposition products to the ground or surface waters or to the atmosphere.
13
These regulations are incorporated by reference and are implemented by DHES as part of Montana's authorized RCRA program.
~ ARM 16.44.702.
14
These regulations are incorporated by reference and are implemented by DHES as part of Montana's authorized RCRA program.
See ARM 16.44.702.
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Facilities requiring post-closure care must undertake appropriate monitoring and maintenance
actions, control public access, and control post-closure use of the property. to ensure that the
integrity of the final cover, liner, or containment system is not disturbed. 40 CPR ~
264.117. In addition, all contaminated equipment, structures and soil must be properly
disposed of or decontaminated unless exempt. 40 CPR ~ 264.114. A survey plat should be
submitted to the local zoning authority and to the EP A Regional Administrator indicating the
location and dimensions of landfill cells or other hazardous waste disposal units with respect
to permanently surveyed benchmarks. 40 CPR ~ 264.116. 40 CPR ~ 264.228(a) requires
that at closure, free liquids must be removed or solidified, the wastes stabilized, and the
waste management unit covered. .
C.
Waste Piles (Applicable)
40 CPR Part 264, Subpart L, applies to owners and operators of facilities that store or treat
hazardous waste in piles.ls Implementation of th.e remedy may include placement of
hazardous waste contaminated soils and sediments in piles as part of pretreatment (separation
of rocks, etc.) prior to the placement of the soils in the land treatment unit. The regulations
require the use of run-on and run-off control systems and collection and holding systems to
prevent the release of contaminants from waste piles.
D.
Land Treatment (Awlicable)
The requirements of 40 CPR Part 264, Subpart M,16 regulate the management of "land
treatment units"l7 that treat or dispose of hazardous waste; these requirements are applicable
for any land treatment units established at the site.
The owner or operator of a land treatment unit must design treatment so that hazardous
constituents placed in the treatment zone are degraded, transformed, or immobilized within
the treatment zone. "Hazardous constituents" are those identified in Appendix VIII of 40
CPR Part 261 that are reasonably expected to be in, or derived from, waste placed in or on
the treatment zone. Design measures and operating practices must be set up to maximize the
success of degradation, transformation, and immobilization processes. The treatment zone is
the portion of the unsaturated zone below and including the land surface in which the owner
or operator intends to maintain the conditions necessary for effective degradation,
transfonnation, or immobilization of hazardous constituents. The maximum depth of the
treatment zone must be no more than 1.5 meters (five feet) from the initial soil surface; and
more than one meter (t:hree feet) above the seasonal high water table.
"
"Pile" means any non-containerized accumulation of solid, nonflowing hazardous waste that is used for treatment or storage. 40
CFR ~ 260.10.
'6
These regulations are incorporated by reference and are implemented by DHES as part of Montana's authorized RCRA program.
See ARM 16.44.702.
I7
Land treatment occurs when hazardous waste is applied onto or incorporated into the soil surface.
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Subpart M also requires the construction and maintenance of control features that prevent the
ron-off of hazardous constituents and the ron-on of water to the treatment.unit. The unit
must also be inspected weekly and after storms for deterioration, malfunctions, improper
operation of ron-on and ron-off control systems, and improper functioning of wind dispersal
control measures.
An unsaturated zone monitoring program must be established to monitor soil and soil-pore
liquid to determine whether hazardous constituents migrate out of the treatment zone.
Specifications related to the monitoring program are contained in section 264.278.
E.
Incineration ( Applicable)
The regulations at 40 CFR ~~ 264.340 - 351 and 40 CFR Part 265, Subpart 0,18 will be
ARARs for any remedial action involving incineration of hazardous waste. The standards
require an owner or operator of a hazardous waste incinerator to conduct a waste analysis in
conjunction with obtaining a treatment, disposal, and storage permit for the incinerator. A
permit designates one or more Principal Organic Hazardous Constituents (PORCs) from
those constituents listed in 40 CFR Part 261, Appendix vm. A PORC designation is based
on the degree of difficulty of incineration of the organic constituents in the waste feed from
trial bums. Organic constituents that represent the greatest degree of difficulty are most
likely to be designated a PORCo Incineration of PORCs designated in the permit must
achieve a 99.99 % destruction and removal efficiency. Incineration of dioxins must achieve a
destruction and removal efficiency of 99.9999% (40 CFR ~ 264.343(a)).
An incinerator burning hazardous waste and producing stack emissions of more than 1.8
kilograms per hour (4 pounds per hour) of hydrogen chloride (Rcl) must control Rcl
emissions such that the rate of emission is no greater than the larger of either 1.8 kilograms
per hour or 1 % of the RCI in the stack gas prior to entering any pollution control equipment
(40 CFR ~ 264.343(b)). A permitted incinerator must not emit particulate matter in excess
of 180 milligrams per dry standard cubic meter (40 CFR ~ 264.343(c)). The owner or
operator must monitor combustion temperature, waste feed rate, CO emissions, and
combustion gas velocity. The incinerator must be visually inspected daily, and the
emergency waste feed cutoff system and associated alarms must be tested weekly. At
closure, all hazardous waste residues must be removed from the incinerator site.
18
These regulations are incorporated by reference and are implemented by DHES as part of Montana's authorized RCRA program.
See ARM 16.44.702 and 16.44.609 (Interim status).
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Discharge to POTWs (Awlicable)
All discharges of RCRA hazardous wastes to POTWs must comply with the RCRA permit-
by-rule requirements at 40 CPR ~ 270.60. The regulations require that the waste meet all
federal, state, and local pretreatment requirements which would be applicable to the waste if
it were being discharged into the POTW through a sewer, pipe, or sUnilar conveyance.
Requirements for Recyclable Materials (Awlicable)
Hazardous wastes that are recycled are subject to the requirements for generators,
transporters, and storage facilities set forth in 40 CPR ~ 261.6(b) and (c), unless the wastes
are excluded from regulation in 40 CPR ~ 261.6(a).
40 CPR ~ 261.6(b) subjects generators and transporters of recyclable materials to the
applicable requirements of 40 CPR Part 262,undet which generators must comply with
specified accumulation times and methods for storing hazardous waste on-site. Both time and
storage method vary depending upon the quantity of hazardous waste generated.
Owners or operators of facilities that store recyclable materials before they are recycled must
comply with 40 CPR Part 270. Part 270 establishes EPA's Hazardous Waste Pennit
Program, and sets forth basic permitting requirements, standard pennit conditions, and
moriitoring and reporting requirements. While a permit is not required for on-site
remediation, the substaittive portions of the permitting requirements must be followed.
Hazardous Materials Transportation Act (Applicable)
The Hazardous Materials Transportation Act (49 use ~~ 1801-1813), as implemented by the
Hazardous Materials Transportation Regulations (49 CFR Parts 10, 171-177), regulates the
transportation of hazardous materials. The regulations apply to any alternatives involving the
transport of hazardous waste off-site, on public highways on-site, or by rail line.
Federal Insecticide, Fungicide,. and Rodenticide Act . (Applicable)
This statute (7 U.S.C. ~ 136 et ~.) regulates the sale, distribution and use of all pesticide
products in the United States, and is applicable to any alternative involving the recycling and
reuse of recovered wood treating fluid, since the fluid contains the pesticide
pentachlorophenol. Under FIFRA, use of a registered pesticide product in a manner
inconsistent with its labeling is a violation of the Act (7 U.S.C. ~ 136j). Recovered
pesticides may be reused provided they meet new product labelling specifications, which
include concentration limits for pesticides in solution.
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FEDERAL STANDARDS TO BE CONSIDERED (TBC's)
Safe Drinking Water Act
Proposed MCLs
Proposed Maximum Contaminant Levels are unpromulgated versions of the MCLs discussed
in the ARARs section. MCLs apply to public water systems. However, they may be
relevant and appropriate to surface or groundwater if those waters are used as drinking
water. Because the aquifer underlying the site is a drinking water source, and current or
adopted MCL's are ARARs, the proposed MCLs are TBCs. The contaminant levels
identified below have been proposed as MCLs. See 54 Fed. Reg. 22062, 22155-57 (May
22, 1989) and 55 Fed Reg. 30370, 30445 (July 25, 1990), (to be codified at 40 CFR ~
141.61).
Compound
Proposed MCL (mg/l)
PARs:
Benz(a)anthracene
Benzo(b )fluoranthene
Benzo(k)fluoranthene
Chrysene
Dibenz( a, h) anthracene
Indeno(I,2,3-CD)pyrene
0.0001
. 0.0002
0.0002
0.0002
0.0003
. 0.0004
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STATE OF MONTANA ARARS
MONTANA CONTAMINANT-SPECIFIC ARARS
Water Quality
Surface water quality standards, including the requirement that any discharge to surface
waters such as Rocky or Mill Creek must meet Gold Book levels, are specified in the action-
specific ARARs below.
MONTANA LOCATION-SPECIFIC ARARS
. Floodplain and Floodway Management
The 100 year floodways and floodplains of Rocky and Mill Creeks are near the site. The
areas proposed for excavation and for placement. of the land treatment units are located
outside these floodplains~ Compliance with these floodway and floodplain ARARs can be
attained by avoiding conducting any of the remedial activities within the floodplain
boundaries.
Floodplain and Floodway Management Act (Applicable)
Section 76-5-401, MCA, (Applicable) specifies the uses permissible in a floodway and
generally prohibits penn anent structures, fill, or pennanent storage of materials or
equipment.
Section 76-5-402, MCA, (Applicable) specifies uses allowed in the floodplain, excluding the.
floodway, and allows structures meeting certain minimum standards.
Section 76-5-403, MCA, (Applicable) lists certain uses which are prohibited in a designated
floodway, including:
1.
any building for living purposes or place of assembly or pennanent use by
human beings, .
2.
any structure or excavation that will cause water to be diverted from the
established .floodway, cause erosion, obstruct the natural flow of water, or
reduce the carrying capacity of the floodway, or
3.
the construction or pennanent storage of an object subject to flotation or
movement during flood level periods.
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Floodplain Management Regulations (Awlicable)
ARM 36.15 .216 (Applicable) specifies factors to consider in determining whether a permit
should be issued to establish or alter an artificial obstruction or nonconforming use in the
floodplain or floodway. While permit requirements are not directly applicable to activities
conducted entirely on site, the criteria used to determine whether to approve establishment or
alteration of an artificial obstruction or nonconforming use should be applied by the decision-
makers in evaluating proposed remedial alternatives which involve artificial obstructions or
nonconforming uses in the floodway or floodplain. Thus the following criteria are relevant
and appropriate considerations in evaluating any such obstructions or uses:
1.
the danger to life and property from backwater or diverted flow caused by the
obstruction;
2.
the danger that the obstruction will be swept downstream to the injury of
others; .
3.
the availability of alternative locations;
4.
the construction or alteration of the obstruction in such a manner as to lessen
the danger;
5.
the permanence of the obstruction;
6.
the anticipated development in the foreseeable future of the area which may be
affected by the obstruction.
ARM 36.15.604 (Applicable) precludes new construction or alteration of an artificial
obstruction that will significantly increase the upstream elevation of the flood of 100-year
frequency (1fz foot or as otherwise determined by the permit issuing authority) or
significantly increase flood velocities.
ARM 36.15.605 (Applicable) enumerate artificial obstructions and nonconforming uses that
are prohibited within the designated floodway except as allowed by permit and includes" a
structure or excavation that will cause water to be diverted from the established floodway,
cause erosion, obstruct the natural flow of water, or reduce the carrying capacity of the
floodway ... ." Solid and hazardous waste disposal and storage of toxic, flammable,
hazardous, or explosive materials are also prohibited.
ARM 36.15.703 (Applicable) is applicable in flood fringe areas (Le., areas in the floodplain
but outside of the designated floodway) of the site and prohibits, with limited exceptions,
solid and hazardous waste disposal and storage of toxic, flammable, hazardous, or explosive
materials.
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MONTANA ACTION-SPECIFIC ARARS
In the following action-specific ARARs, the nature of the action triggering applicability of
the requirement is stated in parenthesis as part of the heading for each requirement.
Water Quality
Surface Water Quality Standards (Applicable) (Discharge to surface water)
Under the state Water Quality Act, ~~ 75-5-101 et seq., MCA, the state has promulgated
regulations to preserve and protect the quality of surface waters in the state. These
regulations classify state waters according to quality, place restrictions on the discharge of
pollutants to state waters, and prohibit the degradation of state waters. The requirements
listed below would be applicable to any,discharge19 to surface waters in connection with the
remedial action. Compliance with these requirements may be achieved by avoiding any such
discharge. ' ' ,
ARM 16.20.607(1) provides that specified waters in the Missouri River drainage, including
Rocky Creek and Mill Creek, are classified "B-1" for water use. The standards for "B-1"
classification waters are contained in ARM 16.20:618 (Applicable) of the Montana water
quality regulations. These standards place limits on fecal coliform content, dissolved oxygen
concentration, Ph balance, turbidity, water temperature, sediments, solids, oils, and color. 20
Concentrations of toxic or deleterious substances which would'remain in the water after
.9
"Discharge" is defined in the state Surface Water Quality Standards as "the injection, deposit, dumping, spilling, leaking,
placing, or failing to remove any pollutant so that it or any constituent thereof may enter into state waters, including ground
water.' ARM 16.20.603(6).
20
The B-1 classification standards in ARM 16.20.618 include the following limitations:
1. During periods when the daily maximum water temperature is greater than 60°F, the geometric mean number of
organisms in the fecal coliform group must not exceed 200 per 100 milliliters (mI), nor are 10 % of the total samples during
any 30-day period to exceed 400 fecal coliforms per 100 mi.
2. Dissolved oxygen concentration must not be reduced below 7.0 milligrams (mg) per liter (I).
3. Induced variation of hydrogen ion concentration (Ph) within the range of 6.5 to 8.5 must be less than 0.5 Ph unit.
Natural pH outside this range may not be altered and natural pH above 7.0 must be maintained above 7.0.
4. Temperature variations are specifically limited, depending upon the temperature range of the receiving water. See ARM
16.20.618(2)(e).
5. No increase in naturally occurring concentrations of sediment, settleable solids, oils, or floating solids is allowed which
will or is likely to create a nuisance or render the waters harmful, detrimental, or injurious to public health, recreation,
safety, welfare, livestock, wild animals, birds, fish or other wildlife.
6. True color must not be increased more than five units above naturally occurring color.
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conventional treatment cannot exceed MCLs, and concentrations of toxic or deleterious
substances cannot exceed Gold Book levels. 21
Additional restrictions on any discharge to surface waters are included in:
ARM 16.20.631 (Applicable), which requires that industrial waste22 must receive, as
a minimum, treatment equivalent to the best practicable control technology currently
available (BPCTCA) as defmed in 40 CFR Subchapter N and subsequent amendments.
This section also requires that in designing a disposal system, stream flow dilution
requirements must be based on the minimum consecutive 7-day average flow which
may be expected to occur on the average of once in 10 years.
ARM 16.20.633 (Applicable), which prohibits discharges containing substances that
will:
(a) settle to form objectionable'sludge deposits or emulsions beneath the
surface of the water or upon adjoining shorelines;
(b) create floating debris, scum, a visible oil fIlm (or be present in
concentrations at or in excess of 10 milligrams per liter)' or globules of grease
or other floating materials; ,
(c) produce odors, colors or other conditions which create a nuisance or
render undesirable tastes to fish flesh or make fish inedible;
(d) create concentrations or combinations of'materials which are toxic or
harmful to human, animal, plant or aquatic life;
(e) create conditions which produce undesirable aquatic life.
ARM 16.20.925 (Applicable), which adopts and incorporates the provisions of 40
C.F.R. Part 125 for criteria and standards for the imposition of technology-based
treatment requirements in MPDES permits. Although the permit requirement would
not apply to on-site discharges, the substantive requirements of Part 125 are
applicable, Le., for toxic and nonconventional pollutants treatment must apply the best
available technology economically achievable (BAT); for conventional pollutants,
application of the best conventional pollutant control technology (BCT) is required.
Where effluent limitations are not specified for the particular industry or industrial
category at issue, BCTIBAT technology-based treatment requirements are determined
on a case by case basis using best professional judgment (BPJ). See CERCLA
Compliance with OtherLaws Manual, Vol. I, August 1988, pp. 3-4 and 3-7.
11
ARM 16.20.603(10) defines Gold Book levels as "the freshwater acute or chronic levels or the levels for water and fish ingestion
that are listed in Update Number Two (511187) of Quality Criteria for Water 1986 (EPA 44015-8
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The Water Quality Act and regulations also include nondegradation provisions which require
that waters which are of higher quality than the applicable classification be maintained at that
high quality, and discharges which would degrade that water are prohibited. Montana's
standard for nondegradation of water quality is applicable for all constituents for which
pertinent portions of Rocky Creek and Mill Creek are of higher quality than the B-1
classification. This standard will also be applicable if any remedial action constitutes a new
source of pollution or an increased source of pollution to high-quality waters to require the
degree of waste treatment necessary to maintain that existing water quality.
ARM 16.20.701 (Applicable) defmes "degradation" and provides that "nonpoint source
pollutants [e.g., runoff] from lands where all reasonable land, soil and water managements or
conservation practices have been applied are not considered degradation."
ARM 16.20.702 (Applicable) applies nondegradation requirements to any activity which
would cause a new or increased source of pollution to state waters. This section states when
exceptions to nondegradation requirements apply; except that in no event may such
degradation affect public health, recreation, safety, welfare, livestock, wild birds, fish and
other wildlife or other beneficial uses.
ARM 16.20.703 (Applicable) establishes the substantive nondegradation standard (quality of
receiving waters whose quality is higher than established water quality standards is not to be
degraded by the discharge of pollutants), and requires that water quality permits incorporate
nondegradation standards. In accordance with CERCLA ~ 121(e), if the discharge occurs
entirely on-site, only the substantive nondegradation standard, and not the permit
requirement, would apply. However, if the discharge occurs off-site, the permit and
administrative requirements would also be applicable. This rule also provides that
determination of degradation is to ensure that baseline quality of the receiving waters will not
be degraded at any flow greater than the 7-day, 1O-year low flow of the receiving waters.
Montana Groundwater Pollution Control System (Apj)licable) (Discharge to groundwater)
ARM 16.20.1002 (Applicable) classifies groundwater into Classes I through IV based on the
present and future most beneficial uses of the groundwater, and states that groundwater is to
be classified according to actual quality or actual use, whichever places the groundwater in a
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It
higher class. Class I is the highest class; class IV is the lowest. Based upon its specific
conductance, the bulk of the groundwater at the site should be considered. Class I
groundwater. ~
ARM 16.20.1003 (Applicable) establishes the groundwater quality standards applicable with
respect to each groundwater classification. Concentrations of dissolved substances in Class I
or n groundwater or any groundwater which is used for drinking water supplies may not
exceed Montana MCL values for drinking water. However, no Montana MCL's have been
established for the contaminants of concern at the Idaho Pole site. Thus for the Idaho Pole
site, concentrations of dissolved or suspended substances must not exceed levels that render
the waters harmful, detrimental or injurious to public health. Maximum allowable
.concentration of these substances also must not exceed acute or chronic problem levels that
would adversely affect existing or designated beneficial uses of groundwater of that
classification.
ARM 16.20.1011 (Applicable), the nondegradation requirement, provides that any
groundwater whose existing quality is higher than the standard for its classification must be
maintained at that high quality unless the Board of Health is satisfied that a change is
justifiable for economic or social development and will not preclude present or anticipated
use of such waters. Thus any groundwater which is to be reinjected as part of the remedy
must be treated sufficiently to prevent additional degradation of the aquifer, Le., the
reinjected groundwater cannot be of lower quality than the receiving groundwater for any
constituent. .
Groundwater Act (Apj>licable) (Construction and maintenance of groundwater wells)
Section 85-2-505, MCA, (Applicable) precludes the wasting of groundwater. Any well
producing waters that contaminate other waters must be plugged or capped, and wells must
be constructed and maintained so as to prevent waste, contamination, or pollution of
groundwater.
:>
ARM 16.20.1002 provides that Class I groundwaters have a specific conductance ofless than 1000 micromhos/cm at 25° C;
Class II groundwaters: 1000 to 2500; Class ill groundwaters: 2500 to 15,000; and Class IV groundwaters: over 15,000. The
groundwater at the Idaho Pole site ranges from 586 to 1370 micromhoslcm, with the majority of the wells testing at below 1000.
See Final Draft Remedial Investigation Report, Vol. II, Appendix E, MSE, Inc., March 1992.
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)
Air Quality24
Air Duality Regulations (Applicable) (Excavation/earth-moving; transportation; incineration;
storage of petroleum distillates)
Dust suppression and control of certaiI:t substances likely to be released into the air as a result
of earth moving, transportation and similar actions may be necessary to meet air quality
requirements. The ambient air standards for specific contaminants and for particulates are
set forth in the federal contaminant-specific section above. Additional air quality regulation&
under the state Clean Air Act, ~~ 75-2-101 et~, MCA, are discussed below.
ARM 16.8.1404 (Applicable) states that "no person may cause or authorize emissions to be
discharged in the outdoor atmosphere... that exhibit an opacity of twenty percent (20 %) or
greater averaged over six consecutive minutes. "
:u
The air quality AR.ARs included in this analysis are identified on the assumption that no remedial action at the site will constitute
a "major stationary source," or "major modification," as defined in ARM 16.8.921. Should any part of a remedy constitute such
a source, some additional requirements would be applicable, including the ambient air increments of ARM 16.8.925~.
Similarly, if any part of a remedy should constitute a new or altered source of air pollution which has the potential to emit more
than 25 tons per year of any pollutant addressed by the Clean Air Act regulations, the owner or operator must install the
maximum air pollution control capability which is technically practicable and economically feasible, as provided by ARM
16.8.1103 (bestavailable control technology shall be utilized).
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