PB97-963136
EPA/541/R-97/101
January 1998
EPA Superfund
Record of Decision Amendment:
Hanford Site - 200 Area (USDOE)
Benton County, WA
9/25/1997
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United States Environmental Protection Agency
Region X ,
1200 Sixth Avenue
Seattle, Washington 98101
U.S. Department of Energy
Environmental Restoration Disposal Facility
Hanford Site - 200 Area
Benton County, Washington
Amended Record of Decision
Decision Summary and Responsiveness Summary
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TABLE OF CONTENTS
SECTION PAGE NUMBER
DECLARATION
Site Name and Location i
Statement of Basis and Purpose i
Assessment of the Site i
Description of the Amendment to the Remedy i
Declaration ii
DECISION SUMMARY
Introduction 1
Site History 2
Remedy Selected in the ROD 6
Description of the Modified Remedy 8
Evaluation of Alternatives 9
Selected Amended Remedy for the ERDF 12
Statutory Determination 12
Documentation of Significant Changes 12
RESPONSIVENESS SUMMARY 13
FIGURES
Figure 1. Hanford Site Map 4
Figure 2. Existing Disposal Cells and Phase II Expansion 5
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DECLARATION OF THE RECORD OF DECISION
SITE NAME AND LOCATION
U.S. Department of Energy
Environmental Restoration Disposal Facility
Hanford Site - 200 Area
Benton County, Washington
STATEMENT OF BASIS AND PURPOSE
This Record of Decision (ROD) Amendment has been developed in accordance with the
Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA), as
amended by the Superiund Amendments and Reauthorization Act of 1986 (SARA), 42 U.S.C.
Section 9601 et.seq. and to the extent practicable, the National Oil and Hazardous Substances
Pollution Contingency Plan (NCP), 40 Code of Federal Regulations (CFR) Part 300. This ROD
Amendment is based on the Administrative Record for the Environmental Restoration Disposal
Facility.
The State of Washington concurs with the ROD Amendment.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from the operable units on the Hanford Site,
if not addressed by implementing the response action selected in the ROD, as changed by this ROD
Amendment, may present an imminent and substantial endangerment to the public health, welfare, or
the environment.
DESCRIPTION OF THE AMENDMENT TO THE REMEDY
The changes to the original ROD addressed in this Amendment are explained in the following
sections.
ERDF Expansion. The ERDF ROD specifies that expansion of the facility would be authorized as-
needed through the ROD amendment process. Based on estimated remediation waste volumes.
presented in the ERDF ROD, additional disposal cells were anticipated. This Amendment authorizes
two additional ERDF cells to be constructed and operated for disposal of Hanford Site remediation
waste. The Phase II construction shall be located entirely within the 4.1 square kilometer (1.6 square
miles) area selected for ERDF, as defined in the ERDF ROD.
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The approved design of ERDF is a single, 70-ft-deep trench consisting of two side-by-side cells with
final dimensions of 1,420-ft long by 720-ft wide at the top of the trench. The facility is equipped with
a RCRA double-liner and leachate collection and recovery system. The same RCRA design selected
for the existing ERDF disposal cells shall be used for the Phase II cells. The design phase shall also
include an evaluation of vadose zone monitoring. The detailed design shall be submitted to the EPA
for approval prior to construction of the ERDF facility.
Treatment at ERDF. The selected remedial alternative in existing 100 and 300 Area waste site
remediation RODs is removal, treatment if required, and disposal at ERDF. Treatment would be
required if the concentration of contaminants in the waste is above land disposal restriction standards
found in the Federal and State hazardous waste regulations or above the ERDF waste acceptance
criteria. This Amendment provides the option of conducting remediation waste treatment in
containers at ERDF instead of the operable unit, prior to disposal. This option does not preclude
treatment at the operable units. Treatment at ERDF would be limited to stabilization in containers
and encapsulation. In addition, all substantive federal and state requirements governing hazardous
waste treatment in containers, such as secondary containment, shall be met as part of treatment at
ERDF. The decision whether to perform remediation waste treatment, and the specific treatment
needed, will be documented as part of the remedy selection and remedial design process for the
operable unit or waste site of origination. The decision concerning where treatment occurs would
be made in coordination with ERDF.
DECLARATION
Although this ROD Amendment changes components of the remedy selected in the original ROD,
the remedy, as modified, continues to be protective of human health and the environment.* The
remedy, as amended, complies with Federal and state requirements that are legally applicable or
relevant and appropriate and is cost effective. This remedy utilizes permanent solutions to the
maximum extent practicable for this site. Treatment of wastes will be addressed in the operable unit
decision documents. As a consequence, the statutory preference for treatment as a principal element
will be addressed in those current and future documents rather than in this ROD.
Because this remedy will result in hazardous substances remaining on site above health-based levels,
a review will be conducted at least every five years after the commencement of remedial actions to
ensure that the remedy continues to provide adequate protection of human health and the
environment.
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Signature sheet for the Amendment to the Record of Decision for the USDOE Hanford
Environmental Restoration Disposal Facility between the United States Department of Energy and
the United States Environmental Protection Agency, with concurrence by the Washington State
Department of Ecology.
Chuck Clarke Date
Regional Administrator, Region 10
United States Environmental Protection Agency
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Signature sheet for the Amendment to the Record of Decision for the USDOE Hanford
Environmental Restoration Disposal Facility between the United States Department of Energy and
the United States Environmental Protection Agency, with concurrence by the Washington State
Department of Ecology.
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J/Shn D. Wagoner' / Date
nager, Richland Operations
United States Department of Energy
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Signature sheet for the Amendment to the Record of Decision for the USDOE Hanford
Environmental Restoration Disposal Facility between the United States Department of Energy and
the United States Environmental Protection Agency, with concurrence by the Washington State
Department of Ecology.
Michael Wilson
Program Manager, Nuclear Waste Program
Washington State Department of Ecology
Date
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DECISION SUMMARY
USDOE Environmental Restoration Disposal Facility
Record of Decision Amendment
I INTRODUCTION
This document presents an Amendment to the Record of Decision (ROD) for the Environmental
Restoration Disposal Facility at the Hanford Site.
Site Name and Location
USDOE Hanford Environmental Restoration Disposal Facility
Hanford Site - 200 Area
Benton County, Washington
Lead and Support Agencies
The lead regulatory agency for this action is the U.S. Environmental Protection Agency (EPA). The
U.S. Department of Energy (DOE) and the Washington Department of Ecology (Ecology) both
concur with the need and justification to increase the size of the disposal facility and allow for
stabilization and encapsulation capabilities at the ERDF site. The three agencies participated jointly
in the decision and preparation of this document.
Statutory Citation for a ROD Amendment
The Environmental Restoration Disposal Facility (ERDF) ROD was signed by the EPA, Ecology, and
the DOE in January 1995. In 40 CFR §300.435(c)(2) the National Contingency Plan provisions are
specified for addressing and documenting changes to the selected remedy after issuance of a ROD.
An Explanation of Significant Differences (ESD) was issued in August of 1996. This ROD
Amendment documents fundamental changes to the remedy set forth in the 1995 ERDF ROD. Public
participation and documentation procedures have been followed as specified at 40 CFR
300.43 5(c)(2)(ii).
Need for the ROD Amendment
This amendment is necessary for the following reason:
The ERDF is currently identified in the 100 Area ROD and ROD Amendment, the 300 Area
ROD, and several Removal Action Memoranda as the location to dispose of waste resulting
from actions in these areas. The estimated waste volume to be generated from these actions
is 1.5 to 2.0 million cubic yards. The total capacity of the existing disposal facility is
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approximately one million cubic yards. Expansion is necessary to continue remediation of the
Hanford Site.
Public Involvement
A newspaper notice was placed in the Tri-City Herald on August 3, 1997 announcing the availability
of the proposed amendment and the start of the public comment period. Approximately fourteen
hundred copies of a fact sheet describing the amendment proposal were mailed out. A public
comment period was held from August 4 through September 3, 1997. No requests were received for
a public meeting, therefore, no public meeting was held. Copies of the proposed plan were provided
to the Hanford Advisory Board (HAB) Environmental Restoration (ER) Committee members. The
proposed amendment was discussed with the HAB and the HAB-ER Committee at meetings in June,
July, August, and September of 1997. The decision to amend the ROD is based on the
Administrative Record for the ERDF. Locations where the Administrative Record may be found are
listed below.
Administrative Record
This ROD Amendment will become part of the Administrative Record for ERDF, as required by 40
CFR 300.825(a)(2), and will be available to the public at the following locations:
ADMINISTRATIVE RECORD (Contains all project documents)
U.S. Department of Energy - Richland Operations Office
Administrative Record Center
2440 Stevens Center
Richland, Washington 99352
INFORMATION REPOSITORIES (Contain limited documentation)
University of Washington Gonzaga University, Foley Center
Suzzallo Library E. 502 Boone
Government Publications Room Spokane, Washington 99258
Seattle, Washington 98195
Portland State University DOE Richland Public Reading Room
Branford Price Millar Library Washington State University, Tri-Cities
SW Harrison and Park 100 Sprout Road, Room 101L
Portland, Oregon 97207 Richland, Washington 99352
H. SITE HISTORY
In 1988, the Hanford Site was scored using the EPA's Hazard Ranking System. As a result of the
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scoring, the Hanford Site was added to the NPL in July 1989 as four sites (the 1100 Area, the
200 Area, the 300 Area, and the 100 Area). Each of these areas was further divided into operable
units (a grouping of individual waste units based primarily on geographic area and common waste
sources). These operable units contain contamination in the form of hazardous waste,
radioactive/hazardous mixed waste, and other CERCLA hazardous substances.
In anticipation of the NPL listing, DOE, EPA, and Ecology entered into the Hanford Federal Facility
Agreement and Consent Order in May 1989. This agreement established a procedural framework and
schedule for developing, implementing, and monitoring remedial response actions at Hanford. The
agreement also addresses RCRA compliance and permitting.
The fundamental objective of ERDF is to support the timely removal and disposal of contaminants
from various locations within the Hanford Site. Several Hanford Site remediation RODs and
Removal Action Memoranda identify ERDF as the location for disposal of resulting waste. The
Hanford Site and ERDF location are shown on Figure 1.
Construction of the first two ERDF disposal cells began in February 1995, and the first waste was
placed in ERDF on July 1, 1996. As of June 30, 1997, ERDF has received 248,256 cubic yards of
waste. The ERDF is scheduled to accept approximately 360,000 cubic yards of waste material in
fiscal year 1997. The two operating disposal cells have a total maximum waste capacity of
approximately one million cubic yards. In addition to the disposal cells, the ERDF site contains a
transportation staging area, an administration building, worker offices and a change trailer, a waste
container staging area, leachate collection tanks, a spoils pile used for daily operational cover, an
employee parking area, a truck scale, and haul roads.
The layout and size of the existing and proposed Phase n cells are shown in Figure 2. The deep,
single-trench configuration used for the first two cells and selected for Phase II construction
minimizes the area! extent of the waste facility and offers the following advantages in comparison to
other configurations:
Less habitat disruption
Reduced material needs
Reduced leachate generation
Lower costs for the trench liner and the interim and final covers.
The operation of ERDF has proven to be a cost-effective means to handle Hanford Site remediation
waste. To date, the operating cost to dispose of waste at ERDF has averaged approximately $30 per
cubic yard from the start of operation. The total life-cycle costs for the facility equate to
approximately $80 per cubic yard. No other more cost-effective waste disposal alternative has yet
been identified to handle Hanford Site remediation waste.
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FIGURE 1
HANFORD SITE MAP
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FIGURE 2
LEGEND
PROPOSED PHASE II EROF TRENCH
CONSTRUCTION/SUPPORT AREAS
EXSITING AND PROPOSED
ERDF PHASE II
DISPOSAL CELLS
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m. REMEDY SELECTED IN THE ROD
The major components of the selected remedy implemented as a result of the 1995 ERDF ROD
include the following:
Initial construction and operation of the first two disposal cells. These cells are expected to
provide an approximate waste disposal capacity of one million yd3. The cells are designed and
constructed to RCRA minimum technological requirements (MTRs) (40 CFR Part 264,
Subpart N). The decisions to expand the landfill in the future will be documented by
amending the ERDF ROD or as part of the RODs for the Hanford operable units.
The ERDF site will cover a maximum of 4.1 km2 (1.6 mi2) on the Central Plateau, southeast
of the 200 West Area and southwest of the 200 East Area. The initial construction of the
facility required 165 acres of this area.
The ERDF facility will provide sufficient leachate storage capacity to ensure uninterrupted
operations, and will comply with 40 CFR Part 264, Subpart N.
Surface water run-on/run-ofFwill be controlled at the landfill and other areas of the facility
that are potentially contaminated.
Air monitoring will be accomplished by placement at ERDF of real-time air monitors for
radioactive contaminants and air samplers for hazardous and radioactive constituents to detect
any offsite migration of contaminants. The current air monitoring system satisfies this
requirement.
Groundwater monitoring will be performed in accordance with 40 CFR Part 264, Subpart F.
The current monitoring system complies with these requirements.
Appropriate measures to protect facility workers and the public will continue to be employed
during ERDF operations, including contamination control and dust mitigation, and protection
of personnel from industrial hazards presented by ERDF operations. Protective measures
shall comply with applicable requirements found in the Occupational Safety and Health Act
(OSHA), Washington Industrial Safety and Health Act (WISHA), and other safety regulations
or ERDF-specific safety requirements. Energy shall also comply with 40 CFR §300.150.
Waste acceptance criteria have been developed by DOE and approved by EPA in accordance
with applicable or relevant and appropriate requirements (ARARs), risk/performance
assessments, ERDF-specific safety documentation, and worker protection requirements.
Operable unit-specific waste disposal and treatment decisions will continue to be made as part
of the remedy selection and cleanup decision process for each operable unit.
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The ERDF landfill will be closed by placing a modified RCRA-compIiant closure cover over
the waste. The cover will prevent direct exposure to the waste and will include a vegetated
surface layer of fine-grained soils to retain moisture and encourage evapotranspiration,
thereby minimizing infiltration and vadose zone transport of contaminants to groundwater.
The upper 50 cm (20 in.) of the soil cover system will be composed of an admixture of silt
and gravels. This layer is intended to both reduce infiltration through the cover and enhance
the resistance of the cover to burrowing animals and long-term wind erosion. The RCRA-
compliant cover will be modified by providing a total of approximately 15 feet of cover
material to deter intrusion. It is anticipated that additional research into closure covers may
result in site-specific enhancements to RCRA-compliant designs. Prior to cover construction,
closure cover designs will be evaluated and the most appropriate closure cover design will be
selected for construction. Construction of the cover will occur on an incremental basis, as
the trench is expanded. The design will, at a minimum, comply with applicable RCRA
requirements found at 40 CFR Part 264, Subpart N. Basalt from Hanford Site borrow pits
will not be required for construction of the ERDF closure cover.
Institutional controls shall be imposed to restrict public access to the landfill. Current
Hanford Site access restrictions are in place.
Wash water used to decontaminate site equipment shall be managed in accordance with
appropriate requirements. The approved operations plan addresses handling of
decontamination waters.
An ERDF operations plan has been approved by EPA.
DOE commits to the implementation of the Mitigation Action Plan developed in coordination
with the Natural Resource Trustees for additional mitigation measures.
The Explanation of Significant Differences to the ERDF ROD, issued in July of 1996, documented
authorization of the following changes:
Any Hanford environmental cleanup waste generated as a result of CERCLA or RCRA
cleanup actions (IDW, decontamination and decommissioning wastes, RCRA past-practice
wastes) is eligible for disposal provided it meets the ERDF Waste Acceptance Criteria and
provided that the appropriate decision documents are in place. Additionally, nonprocess
waste (e.g., contaminated soil, debris) generated from closure of inactive RCRA TSD units
may be placed in ERDF provided that the units (1) are within the boundaries of a CERCLA
or RCRA past-practice operable unit, (2) the closure wastes are sufficiently similar to
CERCLA or RCRA past-practice wastes placed in ERDF, (3) the ERDF waste acceptance
criteria are satisfied, and (4) the appropriate CERCLA decision documents are in place.
Revision of the RCRA Permit and closure plans may be required.
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The ERDF leachate may be collected and stored at the ERDF for use within the trench, as
appropriate. Appropriate uses are limited to dust suppression and waste compaction. The
leachate must be sampled prior to use to ensure compliance with Land Disposal Restrictions
(LDRs), ERDF waste acceptance criteria, and other health-based limits (whichever is more
restrictive). Leachate in excess of ERDF recycling capacity or acceptable contaminant levels
will be sent to the Effluent Treatment Facility or another approved facility for management.
IV. DESCRIPTION OF THE MODIFIED REMEDY
The changes to the original ROD addressed in this Amendment are explained in the following
sections.
ERDF Expansion. The ERDF ROD specifies that expansion of the facility would be authorized as-
needed through the ROD amendment process. Based on estimated remediation waste volumes
presented in the ERDF ROD, additional disposal cells were anticipated. Two additional ERDF cells
shall be constructed and operated for disposal of Hanford Site remediation waste. Remediation
volume estimates in final and planned cleanup decision documents, prepared since the ERDF ROD
was issued, support the need for additional capacity. The Phase II construction shall be located
entirely within the 4.1 km2 (1.6 mi2) area selected for ERDF, as defined in the ERDF ROD.
The current design of ERDF is a single, 70-ft-deep trench consisting of two side-by-side cells with
final dimensions of 1,420-ft long by 720-ft wide at the top of the trench. The facility is equipped with
a RCRA double-liner and a leachate collection and recovery system. The same RCRA design selected
for the existing ERDF disposal cells shall be used for the Phase n cells. The design phase shall also
include an evaluation ofvadose zone monitoring. The detailed design shall be submitted to the EPA
for approval prior to construction of the ERDF.
Treatment at ERDF. The selected remedial alternative in existing 100 and 300 Area waste site
remediation RODs is removal, treatment if required, and disposal at ERDF. Treatment would be
required if the concentration of contaminants in the waste is above land disposal restriction standards
found in the Federal and State hazardous waste regulations or above the ERDF waste acceptance
criteria. This Amendment provides the option of conducting remediation waste treatment at ERDF
instead of the operable unit, prior to disposal. This option does not preclude treatment at the operable
units. Treatment at ERDF would be limited to stabilization and encapsulation in containers. In
addition, all substantive federal and state requirements governing hazardous waste treatment in
containers, such as secondary containment, shall be met as part of treatment at ERDF. The decision
whether to perform remediation waste treatment, and the specific treatment needed, will be
documented as part of the remedy selection and remedial design process for the operable unit or
waste site of origination. The decision concerning where treatment occurs would be made in
coordination with ERDF.
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V. EVALUATION OF ALTERNATIVES
The NCP establishes nine criteria for evaluating remedial action alternatives. These criteria are
divided into three categories of weighted importance which include: threshold, balancing, and
modifying criteria. All remedies must meet the threshold criteria to be considered. The seven
balancing and modifying criteria help describe relative differences between the alternatives. A
discussion of the original remedy and the modified'remedy relative to the nine criteria evaluation is
required by CERCLA.
Summary of Alternatives
The key elements of each alternative are described and briefly discussed below.
Alternative 1 - No Action. The no action alternative consists of not constructing the Phase
II expansion of the ERJDF trench to accommodate additional waste from waste site
remediation.
Alternative 2 - ERDF Phase II Construction. Two additional cells would be constructed
at ERDF to provide additional capacity for ongoing remediation of the 100, 200 and 300
Areas.
The ERDF Phase II construction would use the same design as the first two disposal cells;
therefore, the previous evaluation of the threshold and balancing criteria in the 1995 proposed
plan and ROD remains applicable.
Alternative 3 - Treatment at the Operable Unit. Treatment would continue to be
performed only at the operable unit.
Alternative 4 - Treatment at ERDF. Treatment of waste coming from 100, 200 and 300
Area remedial actions and from deactivation and decommissioning activities would be
performed at the ERDF. Treatment determinations would still be documented as part of the
remedy selection process for the operable unit or decontamination and decommissioning
activity. This option does not preclude treatment at the operable units.
Threshold Criteria
1. Overall Protection of Human Health and the Environment
The no action alternative does not satisfy the criterion of overall protection of human health and the
environment. Once the original ERDF capacity was utilized, remediation of the 100 and 300 Areas
would cease unless alternative disposal options could be.developed. For this reason, the no action
alternative is not evaluated further.
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The construction of the expansion would satisfy overall protection of human health and the
environment. The same approach to treatment would be implemented whether treatment was
conducted at ERDF or at the operable unit where the waste originated. Therefore, both alternatives
will be equally protective of human health and the environment, effective in the short-term and
long-term, and implementable.
2. Compliance with Federal or State Environmental Standards (ARARs)
The existing ERDF ROD and this amendment will both comply with ARARs. The key ARAR for
the facility is the Resource Conservation and Recovery Act - Title 42 USC 6901 et seq., Subtitle C.
The Resource Conservation and Recovery Act (RCRA) regulates the generation, transportation,
storage, treatment, and disposal of hazardous waste. These regulations also provide authority for the
cleanup of spills and environmental releases of hazardous waste to the environment as a result of past
practices. Hazardous waste management regulations promulgated pursuant to RCRA are codified
at 40 CFR Part 260 through 268. Washington State Dangerous Waste Regulations implement the
federal hazardous waste regulations and are administered by Ecology. These state regulations are
codified in Chapter 173-303 of the Washington Administrative Code ("WAC"). Regulations
established under RCRA are applicable to the ERDF because the facility is expected to receive
hazardous waste and operation of the facility may generate hazardous waste.
The most significant ARARs for construction and operation of the disposal facility receiving
hazardous/dangerous waste include federal RCRA landfill requirements specified in 40 CFR Part 264,
Washington State dangerous waste landfill requirements specified in WAC 173-303-665, RCRA
LDRs specified in 40 CFR Part 268 and WAC 173-303-140, and Toxic Substances Control Act
(TSCA) requirements specified in 40 CFR Part 761.
The key ARARs for the storage and treatment of waste at the ERDF are specified in 40 CFR Part 268
Subpart E - Prohibitions on Storage; and 40 CFR Part 264 Subpart I and WAC 173-303-630 - Use
and Management of Containers.
Balancing Criteria
3. Long-term Effectiveness and Permanence
Expansion of the ERDF would provide long term isolation of waste coming from remedial actions
at the Hanford Site.
The effectiveness of treatment by stabilization or encapsulation would be the same, regardless of
where treatment is performed.
4. Reduction of Toxicity, Mobility, and Volume Through Treatment
Treatment of the incoming waste at ERDF is part of this ROD amendment and only includes
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stabilization and encapsulation. Waste treatment will generally be considered in the feasibility studies,
proposed plans, RODs, and design documents for the individual operable units. Waste coming to
and treated at the ERDF shall meet all ARARs and satisfy ERDF waste acceptance criteria prior to
disposal.
The goal of treatment by stabilization or encapsulation is reduction of mobility and subsequent
reduction of toxic elements released to the environment. The same reduction of mobility and toxicity
would be accomplished regardless of the location where treatment is performed.
5. Short-Term Effectiveness
The existing ERDF ROD and this amendment have the same approach to construction of the facility.
Therefore, both are essentially the same with respect to meeting this criterion.
Risks posed to the community, workers, or the environment as a result of the treatment location
would be negligible. Environmental risk would be lower at the operable unit due to treatment being
done prior to shipment.
6. Implementability
Similar to Phase I, the Phase n expansion has a double liner. Therefore, the complexity of the task
ranks low in terms of technical implementability.
Stabilization or encapsulation treatment technology is considered implementable regardless of the
location. A single centralized treatment location is considered more efficient and, therefore, less
difficult to implement than providing separate treatment units at each remedial action site. An added
advantage would likely be consistency of the treatment technology when applied at a central location
rather than at several different locations.
7. Cost
The estimated cost in the existing ERDF ROD was $65 million. The actual cost for the facility design
and construction was $45 8 million. It is estimated the construction of the next two disposal cells
would cost approximately $18 million from design through the start of operation.
Costs for conducting treatment activities at ERDF are considered to be less than conducting
treatment at each operable unit based on the amount of material to be shipped. AJso, a centralized
treatment area would reduce the need for multiple treatment systems and associated contracts and
operating expenses. A reduction in transportation and handling costs would also be realized as the
treatment agents (e.g., cement), which increase the volume and weight, would be added to the waste
after shipment to ERDF. The cost to transport to and handle waste at ERDF is approximately
$50/ton.
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Modifying Criteria
8. State Acceptance
The State of Washington has concurred with this amendment.
9. Community Acceptance
Newspaper notices, a fact sheet, and a proposed plan were issued to support starting public comment
on August 4, 1997. Several comments were received during the 30-day public comment period. The
comments were generally in support of the amendment and are included in the Responsiveness
Summary that is attached to this Amendment.
VI. SELECTED AMENDED REMEDY FOR THE ERDF
A combination of alternatives two and four is considered the best option because these options
provide for continuous remediation of the Hanford Site in accordance with current RODs and Action
Memoranda and provide a cost-effective option for treatment of waste materials being sent to the
ERDF under those RODs and Action Memoranda. A detailed description of the selected amended
remedy is found in Section IV (Description of the Modified Remedy) of this Amended Record of
Decision for the ERDF. The ARARs for this amended remedy are unchanged from those specified
in the 1995 ERDF ROD.
Vn. STATUTORY DETERMINATIONS
The EPA and Ecology believe that the amended ROD remains protective of human health and the
environment, complies with Federal and State requirements that are applicable or relevant and
appropriate to this remedial action, and is cost-effective. This remedy utilizes permanent solutions
to the maximum extent practicable for this site. Treatment of wastes will be addressed in the operable
unit decision documents. As' a consequence, the statutory preference for treatment as a principal
element will be addressed in those current and future documents rather than in this ROD.
Vm. DOCUMENTATION OF SIGNIFICANT CHANGES
DOE and EPA reviewed all written and verbal comments submitted during the public comment
period. Upon review of these comments, it was determined that no significant changes to the
amended remedy, as originally identified in the Proposed Plan, were necessary.
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DC. RESPONSIVENESS SUMMARY
U.S. Department of Energy
Environmental Restoration Disposal Facility
Hanford Site
Benton County, Washington
Amended Record of Decision
Introduction
This responsiveness summary meets the requirements of Section 117 of the Comprehensive
Environmental Response, Compensation, and Liability Act (CERCLA) as amended. The purpose of
this responsiveness summary is to summarize and respond to public comments on the proposed
amendment for the January 1995 Record of Decision (ROD) for the Hanford Environmental
Restoration Disposal Facility. The proposed plan for the Amendment, issued on August 4, 1997, was
presented for public comment on the proposed changes to components of the remedy set forth in the
January 1995 ROD.
The Tri-Parties announced the issuance of the proposed plan in the community newspaper. A thirty-
day comment period was provided for the public to read the proposed plan, review documents in the
administrative record, and submit written comments. No request was made for a public meeting,
therefore, no meeting was held. The proposed plan discussed expansion of the Environmental
Restoration Disposal Facility by two additional cells and included the option of waste treatment at
the facility, limiting it to stabilization and encapsulation of waste.
Community Involvement
The proposed amendment was presented to the Hanford Advisory Board (HAB) and the HAS
Environmental Restoration Committee in June, July, August, and September 1997.
Comments and Responses
The following advice was received from the Hanford Advisory Board.
1. The HAB supports both elements of the Proposed Plan for an Amendment to the Environmental
Restoration Disposal Facility Record of Decision: (a) construction of Phase II of ERDF for disposal
of Hanford Site waste only, and (b) authorization for treatment of Hanford Site waste at ERDF.
Response: Thank you for your comment.
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2. The HAB recommends that the DOE report the full cost for disposal of waste at ERDF including
costs of design, construction, maintenance, monitoring, mitigation, and closure. U.S. DOE should
use the full cost of disposal at ERDF when comparing the costs of other remediation technologies.
Response: The cost of $30 per cubic yard noted in the Proposed Plan reflects operating costs only.
When the additional costs of design, construction, transportation, operation, monitoring, and
closure are factored in, the life cycle cost of the facility is approximately $80 per cubic yard. Both
of these numbers are reflected in the ROD Amendment. A formal response has been prepared to
address the costs in detail and -will be submitted to the HAB.
The following comments were received from the Confederated Tribes and Bands of the
Yakama Indian Nation.
The Yakama Indian Nation cannot endorse the proposed ERDF expansion until a number of technical
questions are answered. We expect that many of the following questions have been addressed in
previous documents and could be answered by providing us with the citation and the actual document
where the issues were addressed. However, in order to meet your deadline for comment of
September 3, we are responding to the proposed expansion with a series of questions to be followed
later by a letter accepting or rejecting the proposal depending on the answers to the questions.
Response: A formal response addressing the questions provided by the Yakama Indian Nation has
been prepared by the Department of Energy (DOE) and Environmental Protection Agency (EPA).
Many of the comments do not focus on the expansion of the facility. Rather, the comments deal with
the facility as a whole. DOE and EPA will continue to work with the Yakama Indian Nation in
resolving the concerns.
1. Do excavated soil volume estimates still match the original estimates? What are those volumes,
and what is the process for feeding new information about disposal needs into ERDF containment
performance requirements and waste acceptance criteria?
Response: Estimates of the total volume of waste have decreased since the ROD was published.
The ROD states the following, "The total volume of waste is expected to be less than 21.4 million
m3 . . . ". The current estimate of total waste volume is four million m3. Risk and performance
analyses were based on the higher volumes published in the ROD and were modeled at higher
concentrations than are actually being encountered. Thus, no plans exist at this time for updating
the ERDF containment performance requirements and waste acceptance criteria. Waste acceptance
criteria revisions will be performed, as appropriate and when needed, to address additional
information as it becomes available.
2. What is the total amount (inventory) in cells 1&2 (volumes, contaminants, concentrations, total
curies and quantities)? What is anticipated for cells 3&4? What was used as the original analysis in
the RI/FS?
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Response: The total volume in cells 1&2 is approximately 204.900 m3 as of August 29, 1997. The
total curies disposed at ERDF is approximately 1,800 Ci. This value is conservative in that where
a "non-detect" is identified in the waste profile, the detection limit is used as the curie content for
that radionuclide. Radionuclide and dangerous waste constituents are being tracked in a site-
specific database managed by Waste Management Federal Services. Remediation is being focused
first on waste sites with the highest anticipated concentrations of contaminants in the 100 and 300
Areas. Therefore, it is anticipated the total curies in cells 3&4 will be less than what will exist in
cells 1&2. The original analysis used the maximum concentrations reported and assumed this
concentration for the total volume of the waste being disposed in ERDF.
3. What exactly has been put into ERDF so far (soil, rubble, debris, etc.)? How is it mapped in case
something specific needs to be retrieved?
Response: The predominant waste form received by the ERDF has been soil. Additionally,
contaminated concrete rubble and steel debris has been received. The ERDF trench has. a 30ft grid
system that is used to record the location of each container or discrete objects placed in the trench.
4. What containment assumptions are most current? What updates are there on the barrier testing
program? If that program is slated for discontinuance (and the probes removed), how will long-term
performance be validated? Is any monitoring planned as long as the test barrier is there?
Response: The final cover will be a RCRA-compliant, Subtitle C cover that has a permeability less
than that of the liner. The Hanford Prototype Barrier testing program has completed three years
of field testing. EPA and DOE have agreed to continue with the testing program in fiscal year 1998
at a reduced level of monitoring. A site-wide evaluation of barrier performance needs is being done
and additional funding from other programs within DOE is being discussed.
5. Do any of the following items need revisiting for analysis or underlying assumptions:
a. The Native American subsistence scenario was not developed thendoes it need to be added
now? If not now, when?
Response: The risk scenarios developed for ERDF were based on current regulations and guidance
for evaluating human and ecological risk. Further evaluation may be expanded to include the
subsistence scenario at closure.
b. If a 500 year intruder scenario was used, we also need a 100 year intruder scenario;
Response: A performance analysis specified that inadvertent intrusion (post-closure drilling
scenario) cannot occur until loss of institutional control, which was defined as 100 years. If the
facility contains contaminants that are persistent beyond 100 years, and relics on passive controls
for the deterrence of intruders, the time of compliance was defined as 500 years. Although the
ERDF is assumed to use passive controls (making the time of intrusion 500 years post-closure fur
the drilling scenario), total dose calculations for the post-drilling scenario were clone for 100, 300.
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and 500 years.
c. How does ERDF fit into the 200 Area composite source term and the entire Sitewide source
term?
Response: ERDF is considered as a single source term that is integrated into the final composite
analysis. The composite analysis uses the current volume estimates (see response to #J) and
maximum concentrations reported in the ERDF Remedial Investigation and Feasibility Study
(RI/FS). The 200 Area composite analysis is synonymous with the sitewide and assumes all areas
outside the 200 Area plateau are cleaned up.
d. What kind of composite risk profile was done (including socio-cultural risks, impacts, and
values)? Was anything done beyond simple dose calculations?
Response: A baseline risk assessment was conducted to determine the human and ecological impacts
associated with waste disposal in ERDF under various scenarios. Risks are expressed in terms of
incremental cancer risk and hazard quotients for both radiological and non-radiological
contaminants, as appropriate.
The scope of the ERDF RI/FS was expanded to address NEPA values not normally considered, such
as socioeconomic and cultural resources. Socio-cultural risks were not specifically addressed.
e. What is the groundwater point of compliance for ERDF? How does that POC fit into other
POCs?
Response: The point-of-compliance (POC) for ERDF is the point where groundwater intersects a
vertical plane projected from the surface at the edge of the facility. For the composite analysis the
POC is the edge of the 200 Area buffer zone, and for the Hanford Site low-level waste burial ground
it is 100 meters down gradient of the facility.
6 What is the total time frame of analysis? What is the total long-term risk profile?
Response: Both performance dose calculations and the risk analyses were done based on a time
frame of 10,000 years. Because of the various scenarios considered, the reader is referred to the
RI/FS and Performance Assessment for a detailed discussion of long-term risk profiles. v
7. Are the original groundwater and vadose models still adequate for predicting environmental
releases and waste acceptance criteria? What process is there for refining the WAC and containment
performance assessments as the groundwater and vadose models are further refined?
Response: Ground\vater and vadose models used in the ERDF RJ/FS are still considered to bv
representative of predicted conditions. Characterization of the vadose zone at the ERDF site
quantified both stratigraphic profiles and physical properties. Ongoing groundwater monitoring
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at the site has demonstrated an increase in the depth to groundwater beneath the site due to
dissipation of 200 West Area mounding. Original predictions for environmental releases and -waste
acceptance are very conservative and therefore still considered to be well within acceptable limits
being applied to ERDF waste receipt. The most stringent ERDF acceptance limits are derived
primarily from the more conservative regulatory requirements (e.g., land disposal restrictions,
TSCA, radionuclide waste classification) rather than by calculated risk limits.
8. What performance assumptions were used to set the original waste acceptance criteria? On what
additional factors were WAC based? Were the WAC based on a composite Sitewide analysis
evaluating long-term (post-closure) releases and impacts from ERDF as well as all other 200 Area
and Sitewide (including the 100 Area) sources? What is the process for refining the WAC as more
complete information is received?
Response: The waste acceptance criteria for radioactive constituents were developed to ensure that
waste accepted for disposal could not result in potential doses in excess of the performance
objectives. The primary waste acceptance criteria are radionuclide-specific concentration limits
(Ci/m3)for isotopes with half-lives greater than five years and total-activity limits (Ci)for long-lived
environmentally mobile radionuclides. Second, compliance with performance objectives was
evaluated by estimating potential dose resulting from the disposal of the entire projected inventory
of low-level waste in the ERDF. This evaluation included a long-term (post-closure) evaluation for
the ERDF source term only.
A risk-based screening process and comparison to applicable or relevant and appropriate
requirements was used to identify contaminants of potential concern. The risk-based screening
process involved the calculation of risk-based screening concentrations that correspond to a hazard
quotient ofO. 1, or incremental cancer risk of JxJO'7 using residential scenario exposure parameter
values. These screening values are an order of magnitude less than the Comprehensive
Environmental Response Compensation and Liability Act (CERCLA) risk-based criteria.
WAC revisions will be performed, as appropriate and when needed, to address additional
information as it becomes available.
9 What waste treatment is anticipated?
Response: The only treatment currently identified is for lead encapsulation. However, other waste
streams may need to be treated to meet applicable regulatory limits. The most likely treatment
alternative would be stabilization or encapsulation to allow the waste to be disposed of at ERDF,
Thus, the Proposed Plan discusses both stabilization and encapsulation as potential treatment
methods at ERDF.
10. Please provide a copy of the Safety Analysis (BHI-00370, Rev. 2).
Response: A copy was provided on September 15, 1997.
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11. What are the total volume projections and how many total cells will be needed? How will DOE
guarantee that only on-site waste will be disposed of, and how are the ultimate total limits determined
and enforced?
Response: The total volume projections are provided in response to question #J above. Currently,
it is anticipated that a total of eight cells will be needed to accommodate this volume.
The authorization basis for the ERDF is the ROD. The ROD states that only waste originating from
the remediation of operable units within the 100, 200, and 300 Area National Priorities List (NPL)
sites ofHanford is eligible for disposal at ERDF. Each remediation originating waste for disposal
at ERDF must have approved CERCLA authorization documentation before ERDF will accept it.
DOE has developed, and EPA has approved, the ERDF Waste Acceptance Criteria (WAC). This
WAC requires a waste profile for all waste entering ERDF. This profile is reviewed by ERDF
operations prior to disposal.
12. What is the process by which other projects guarantee that their wastes will be characterized
adequately to be accepted by ERDF? How does ERDF know exactly what other projects are planning
to send ERDF? Do the current ERDF volume estimates include those plans of other projects?
Response: According to the waste acceptance criteria (see response to #11), each waste generator
must characterize their waste sufficiently to produce a waste profile. A combination of process
knowledge, historic information, characterization data, and ongoing field characterization during
remediation are used to profile the waste. The ERDF compares the waste profile to the waste
acceptance criteria to verify that the waste is acceptable for placement in the ERDF.
All waste received for disposal in ERDF must have an approved CERCLA decision document in
place. In addition, projected waste volumes from all projects are rolled up in the detailed work
plan. This plan is the basis for long-range volume forecasts for the ERDF.
1 3 . What natural resources mitigation has been planned in response to the total area impacted by
ERDF'>
Response: For the current expansion, an Inter-Agency Agreement between DOE and the U. S.
Department of Fish and Wildlife has been drafted and is expected to be issued by the end of
September 1997. The agreement will provide the basis for planting sagebrush on naturally
disturbed areas of the Arid Lands Ecology reserve. In addition, a Natural Resources Trustee
Council Subcommittee has been formed to provide input to the development of the revegetation plan.
Although the total area impacted by ERDF will not be known until remediation is completed, it i.\
anticipated that any further expansions would follow a similar process.
The following comments were received from Richard Ozanich, President of Berkeley
Instruments, Inc.
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1) It is unknown whether sufficient soil analysis is being done to identify the particular chemicals in
contaminated soil. This leads to the following problems:
A) Clean soil may be being removed - taking up valuable and costly ERDF disposal space (I would
hope that environmental restoration progress and performance is not evaluated by the volume of dirt
moved).
Response: Sampling of waste sites is done prior to excavation in order to determine contaminants
of concern. Field screening during excavation is done to better define the area between clean and
contaminated soil and to verify the waste profile.
B) Soil with different contaminants present may be mixed. While various chemical reactions are
possible, the most potentially concerning is the mixing of complexant containing soil (e.g., EDTA -
tons used at Hanford) with toxic species such as heavy metals or radionuclides (e.g., Pu), thus
dramatically increasing the mobility of these otherwise immobile toxic species.
Response: Reactivity is evaluated as [Kir t of the waste acceptance process for ERDF. Additionally,
the double liner configuration of the facility is such that the leachate is collected during the
operational period. The data collected thus far indicate that little contamination is being released
from the material disposed in the facility.
The following comment was received from Len Clossey, a private citizen.
I believe ERDF is a great step forward in the safe disposal of radioactive (dry) waste. I therefore
recommend that two .more cells for the ERDF Site be approved for construction, providing a safe
storage facility thus minimizing adverse impacts to the environment.
DOE, Bechtel, and the Regulatory Agencies should be congratulated for the way this program was
designed and in the way it is being carried out.
Response: Thank you for your comment.
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