[Federal Register Volume 85, Number 218 (Tuesday, November 10, 2020)]
[Notices]
[Pages 71640-71644]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-24908]


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DEPARTMENT OF ENERGY


Record of Decision for Final Environmental Impact Statement for 
Remediation of Area IV and the Northern Buffer Zone of the Santa Susana 
Field Laboratory, California

AGENCY: Office of Environmental Management, U.S. Department of Energy.

ACTION: Record of decision for groundwater remediation, Area IV, Santa 
Susana Field Laboratory.

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SUMMARY: The U.S. Department of Energy (DOE) announces its decision to 
initiate groundwater remediation in Area IV of the Santa Susana Field 
Laboratory (SSFL). DOE-EM will implement the preferred alternatives for 
groundwater remediation identified in the SSFL Area IV Final 
Environmental Impact Statement (EIS), with the exception of Building 
4100/Building 56 Landfill Trichloroethylene (TCE) Plume, for which DOE 
will implement monitored natural attenuation. This alternative is a 
combination of the Treatment Alternative and the Monitored Natural 
Attenuation Alternative. This action will be taken in accordance with 
applicable federal, state, and local laws and regulations, and 
approvals made by the California Department of Toxic Substances Control 
(DTSC). This action will also be taken consistent with agreements and 
decisions resulting from interagency consultations conducted in 
accordance with applicable federal, state, and local laws and 
regulations, including the Programmatic Agreement executed with the 
California State Historic Preservation Officer pursuant to the National 
Historic Preservation Act and the Biological Opinion issued by the U.S. 
Fish and Wildlife Service pursuant to the Endangered Species Act.

ADDRESSES: This Record of Decision (ROD), the SSFL Area IV Final EIS, 
and related National Environmental Policy Act (NEPA) documents are 
available at the DOE SSFL Area IV website (http://etec.energy.gov) and 
the DOE NEPA website (http://energy.gov/nepa).

FOR FURTHER INFORMATION CONTACT: For further information on the SSFL 
Area IV Final EIS, the ROD, and DOE cleanup actions within Area IV of 
SSFL, please contact, Mr. John Jones, Energy Technology Engineering 
Center (ETEC) Federal Project Director, U.S. Department of Energy at 
[email protected]. For general information on DOE's NEPA 
process, please contact Mr. Bill Ostrum, NEPA Compliance Officer, U.S. 
Department of Energy, Office of Environmental Management, 1000 
Independence Avenue SW, Washington, DC 20585-0103; Telephone: (202) 
586-2513; or Email: [email protected].

SUPPLEMENTARY INFORMATION:

Background

    DOE prepared the SSFL Area IV Final EIS (DOE/EIS-0402) in 
accordance with NEPA (42 U.S.C 4321 et seq.), Council on Environmental 
Quality (CEQ) NEPA regulations (40 CFR parts 1500-1508), and DOE's NEPA 
Implementing Procedures (10 CFR part 1021).\1\ DOE announced its intent 
to prepare an EIS on May 16, 2008, (73 FR 28437) and conducted public 
scoping. DOE prepared a Draft EIS and distributed it to interested 
parties. Following the U.S. Environmental Protection Agency (EPA) 
notice of availability of the SSFL Area IV Draft EIS (82 FR 4336; 
January 13, 2017), DOE conducted public hearings and invited comment on 
the Draft EIS. After considering comments received on the Draft EIS, 
DOE addressed the comments and prepared a Final EIS that was issued 
with EPA's Notice of Availability (83 FR 67282; December 28, 2018). On 
September 27, 2019, DOE announced its decision to demolish the 18 
buildings it owns in Area IV of the SSFL and to dispose of or recycle 
the resulting building materials off-site (84 FR 51149; September 27, 
2019).
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    \1\ The CEQ published on July 16, 2020 the ``Final Rule Update 
to the Regulations Implementing the Procedural Provisions of the 
National Environmental Policy Act''. The SSFL Area IV EIS was 
started prior to September 14, 2020 (the effective date for CEQ's 
updated NEPA regulations). DOE completed the EIS and is issuing this 
ROD pursuant to DOE's NEPA regulations and the 1978 CEQ regulations.
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    The California Department of Toxic Substances Control (DTSC) is in 
the process of completing its Program Environmental Impact Report for 
the Santa Susana Field Laboratory, Ventura County, California (SSFL 
EIR), prepared under the California Environmental Quality Act (CEQA). 
The DTSC SSFL EIR also assesses proposed groundwater remediation 
actions at SSFL. Should DTSC--in its CEQA Findings of Fact and/or 
Resource Conservation and Recovery Act (RCRA) Statement of Basis for 
groundwater cleanup--make a decision inconsistent with the DOE NEPA EIS 
and this ROD, DOE will confer with DTSC and determine whether 
modifications or additional actions related to groundwater cleanup in 
Area IV and the Northern Buffer Zone (NBZ) are required.
    SSFL, located on approximately 2,850 acres in the hills between 
Chatsworth and Simi Valley, California, was developed as a remote site 
to test rocket engines and conduct nuclear research. Rocket engine 
testing by North American Aviation (later Rockwell International 
[Rocketdyne]) began in 1947. In the mid-1950s, the Atomic Energy 
Commission (AEC), a predecessor agency to DOE, funded nuclear research 
on a 90-acre parcel within Area IV of SSFL. The Energy Technology 
Engineering Center (ETEC) was established on this parcel as a ``center 
of excellence'' for liquid metals research. A total of 10 small 
reactors were built and operated as part of nuclear research that ended 
in 1982. DOE-directed liquid metals research continued until 1988.
    DOE initiated the investigation of groundwater at Area IV in 1986 
when the first monitoring well was installed. Since that time DOE has 
installed more than 130 monitoring wells to identify the presence and 
type of groundwater contamination. The investigation work was 
summarized in the Final RCRA Facility Groundwater Remedial 
Investigation Report, Area IV (August 2019). The groundwater 
investigation work involved the 14 solid waste management units 
assigned to DOE in the DTSC 2007 Consent Order for Corrective Action 
(2007 CO) and areas adjacent to these units including the NBZ and the 
Brandeis property. The investigation identified seven areas in Area IV 
with differing groundwater impact issues related to solvents,

[[Page 71641]]

metals, and radionuclides, released from the years of energy and liquid 
metals research. Proposed groundwater remedies were identified in the 
Area IV groundwater corrective measures study that was conducted at the 
same time the Final EIS was developed. Impacts of implementing the 
measures are described in the Final EIS.
    The DOE/ETEC SSFL Area IV locations with impacted groundwater are:

 Former Sodium Disposal Facility (FSDF) Volatile Organic 
Compound (VOC) Plume
 Building 4100/Building 56 Landfill Trichloroethylene (TCE) 
Plume
 Building 4057 Tetrachloroethylene (PCE) Plume
 Hazardous Materials Storage Area (HMSA) TCE Plume
 Building 4010 Tritium Plume
 Radioactive Materials Handing Facility (RMHF) Leach Field 
(Strontium 90 and TCE)
 Metals Clarifier/DOE Leach Field 3 TCE Plume

Purpose and Need for Agency Action

    The DOE Office of Environmental Management's (DOE-EM) purpose and 
need for action remains as stated in the SSFL Area IV Final EIS. DOE-EM 
needs to complete remediation of Area IV and the NBZ to comply with 
applicable requirements for cleanup of radiological and hazardous 
substances. Pursuant to this ROD, and upon consideration by DTSC of the 
Groundwater Corrective Measures Implementation Plan (CMIP), DOE-EM will 
initiate remediation of groundwater in a manner that is protective of 
the environment and the health and safety of the public and its 
workers.

Proposed Action

    DOE-EM's proposed action is to remediate groundwater at seven 
locations in Area IV. DOE will also continue the ongoing groundwater 
monitoring of other locations in Area IV and the NBZ in accordance with 
the 2007 CO to confirm no groundwater contamination. The final 
groundwater cleanup goals will be established by DTSC as it evaluates 
the corrective measures and reaches its conclusions in the RCRA 
Statement of Basis. DTSC will confer with DOE regarding DTSC's 
decisions regarding groundwater remediation.
    This ROD addresses only DOE's decision for groundwater remediation. 
DOE previously announced its decision to demolish the 18 buildings it 
owns in Area IV of the SSFL and dispose of or recycle the resulting 
building materials off-site (84 FR 51149; September 27, 2019). DOE will 
issue subsequent ROD(s) to document its decision for soil remediation.
    The actions DOE will undertake to remediate groundwater are 
presented below.

FSDF VOC Plume

    The FSDF groundwater is impacted by VOCs (chlorinated solvents) and 
metals contained in bedrock fractures primarily between 15 feet and 60 
feet below ground surface. In November 2017 DOE initiated an interim 
measure to extract groundwater from the fractures. The interim action 
reduced VOC concentrations from 10,000 micrograms per liter ([micro]g/
L) to approximately 1,000 [micro]g/L. The maximum contaminant level 
(MCL) for TCE is 5 [micro]g/L. DOE plans to continue the action of 
dewatering the fractures and evaluating bedrock back-diffusion effects 
for 5 years. Extracted groundwater will be temporarily stored in an on-
site tank and then transported off-site for treatment and disposal. 
After 5 years of action, DOE will evaluate the effectiveness of the 
fracture dewatering, and then evaluate additional actions if necessary, 
based on the effectiveness of the remedy at reducing chemical 
concentrations, and the assessment of the back-diffusion rate of the 
contaminants from bedrock into the fracture groundwater.

Building 56 Landfill

    One well at the landfill is impacted by TCE above 5 [micro]g/L. 
Trend data for the last six years demonstrates a continued decline of 
TCE concentration at the well from 56 [micro]g/L in 2015 to 22 
[micro]g/L in 2020. DOE's evaluation of data for the landfill area 
indicates that the landfill is not the source for the TCE. The decline 
in TCE at the landfill also indicates that the observed contamination 
reflects the presence of a leading edge of a plume, originating 
upgradient to the landfill. DOE proposes to continue monitoring the 
impacted well to confirm the decline in TCE at the landfill site.

Building 4057 PCE Impacted Groundwater

    One well in the vicinity of Building 4057 is impacted by the 
chlorinated solvent PCE. DOE proposes to install additional extraction 
wells near the impacted well and pump the water for temporary storage 
into an on-site tank. The impacted groundwater will be transported off-
site for treatment and disposal. The effectiveness of the remedy in 
reducing chemical concentrations will be evaluated on a five-year 
basis. If the pumping remedy is determined to not be effective, DOE 
will assess the need for an alternative remedy.

HMSA TCE Plume

    The HMSA represents the largest groundwater impact in Area IV. TCE 
is present in alluvium and weathered bedrock material and in competent 
bedrock. DOE is considering two remediation options for the MHSA: Pump 
and treat and in situ chemical/biological oxidation. Due to the large 
volume of impacted groundwater, DOE will determine whether it is 
possible to reuse the treated groundwater (such as for dust control) or 
discharge it locally. If reuse or discharge is not feasible, DOE 
proposes conducting a pilot study to assess whether the plume can be 
treated in situ by chemical and/or biological means to reduce the TCE 
levels. If successful, the in-situ treatment would be extended to 
address the entire area of impacted groundwater. The success of in situ 
treatment would be assessed on a five-year basis.

Building 4010 Tritium Plume

    An area of groundwater in the north central portion of SSFL Area IV 
is impacted by the radioactive isotope of hydrogen, termed tritium. 
Seven wells in this area have been sampled for tritium for 16 years and 
the concentrations of tritium have declined from 119,000 picocuries per 
liter (pCi/L) in 2004 to 26,000 pCi/L in 2020. Only two wells remain 
above the MCL of 20,000 pCi/L. This decline is consistent with the 
12.5-year half-life of tritium. The wells with the highest tritium 
concentrations are within Area IV and the leading edge of the plume at 
about 1,000 pCi/L is observed in the NBZ. Due to the tight bedrock 
conditions, groundwater flow is slow in this area and the plume has 
moved less than 1,000 feet since its release 30 years ago. DOE proposes 
to continue to monitor the natural attenuation of the tritium in 
groundwater through annual sampling of several wells. Concentrations of 
tritium are anticipated to be below the drinking water standard (MCL) 
of 20,000 pCi/L within the next 10 years.

RMHF TCE and Strontium 90 Impacted Groundwater

    A small area north of the RMHF exhibits TCE contamination near the 
applicable MCL of 5 [micro]g/L. DOE proposes to continue to monitor the 
natural attenuation of TCE concentrations at this location; data 
collected from wells at this location show a decline of TCE from 20 
[micro]g/L in 1998 to 5.4 [micro]g/L in 2020. Bedrock beneath the 
former RMHF leach field is impacted by the radionuclide Strontium-90. 
When

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groundwater elevation rises in wet rainfall years, the groundwater 
comes into contact with the impacted bedrock. DOE proposes to excavate 
for off-site disposal at a mixed low-level waste facility the bedrock 
containing the Strontium-90. Monitoring wells installed near the former 
leach field site will then be sampled to demonstrate the effectiveness 
of the bedrock removal in protecting groundwater.

Metals Clarifier/DOE Leach Field 3 TCE

    A small area in the south-central portion of Area IV is impacted by 
TCE near the applicable 5 [micro]g/L MCL. This area has been monitored 
for 20 years and the data demonstrate a continued decline in TCE 
levels. DOE proposes to continue monitoring the wells with TCE to 
provide data demonstrating the continued attenuation of TCE at this 
location (Monitored Natural Attenuation).

Alternatives

    In the SSFL Area IV Draft and Final EIS, DOE-EM evaluated No 
Action, monitored natural attenuation, pump and treat, bedrock vapor 
extraction, source isolation, and bedrock removal as groundwater 
remediation alternatives. In the Area IV Corrective Measures Study, DOE 
evaluated these technologies plus in situ groundwater treatment using 
biological and chemical oxidation, thermal remediation, and bedrock 
fracturing.

Potential Environmental Impacts

    In the SSFL Area IV Final EIS DOE-EM analyzed environmental issues 
and the potential impacts related to land resources, geology and soils, 
surface water, groundwater, biology, air quality and climate change, 
noise, transportation and traffic, human health, waste management, 
cultural resources, socioeconomics, environmental justice, and 
sensitive-aged populations. DOE-EM also evaluated the potential impacts 
of the irreversible and irretrievable commitment of resources, the 
short-term uses of the environment, and the maintenance and enhancement 
of long-term productivity. These analyses and results are described in 
the SSFL Area IV Final EIS, including the Summary and Section 2.8.
    In identifying the preferred alternative for groundwater 
remediation, for each of the impacted areas, and in making the 
decisions announced in this ROD, DOE-EM considered the potential 
impacts that would result from the groundwater pumping, in situ 
treatment, bedrock removal, and monitored attenuation actions. Table S-
9 of the SSFL Area IV Final EIS Summary provides a summary and 
comparison of potential environmental consequences associated with each 
groundwater remediation alternative. The impacts of all preferred 
groundwater remediation alternatives to the physical, social, and 
natural environments will be minimal and manageable.

Environmentally Preferable Alternatives

    The environmentally preferable alternatives are the groundwater 
Treatment Alternatives, Bedrock Removal, and Monitored Natural 
Attenuation. Groundwater pumping and in situ treatment technologies, 
and monitored natural attenuation have the least severe environmental 
impacts compared with other alternatives considered for each impact 
area at most locations. Bedrock excavation reduces by approximately 150 
years groundwater monitoring, groundwater control, and investigation 
work at the former RMHF leach field site.

Permits, Consultations, and Notifications

    DOE-EM will implement the proposed groundwater remediation 
activities in accordance with the Groundwater CMIP to be approved by 
California DTSC. If local discharge of treated groundwater is 
considered, DOE will coordinate water release with the Los Angeles 
Regional Water Quality Control Board. DOE will obtain necessary permits 
for any potential installation and operation of groundwater treatment 
systems. DOE-EM is complying with Section 106 of the National Historic 
Preservation Act through completion and implementation of the 
Programmatic Agreement (PA) with the California State Historic 
Preservation Officer (September 13, 2019). DOE will follow the 
requirements of the PA as it develops and eventually implements the 
Groundwater CMIP. DOE also consulted with the U.S. Fish and Wildlife 
Service (USFWS) for compliance with Section 7 of the Endangered Species 
Act. Area IV of SSFL includes federally designated critical habitat for 
the endangered Braunton's milk-vetch. USFWS issued its Biological 
Opinion related to DOE's proposed actions on August 28, 2018. (http://www.ssflareaiveis.com/documents/feis/Biological%20Opinion.pdf).

Public and Agency Involvement

    Following the 2007 federal court decision resulting from a legal 
challenge to the DOE 2003 Environmental Assessment (EA) and its 
subsequent Finding of No Significant Impact (FONSI), DOE published in 
the Federal Register an Advanced Notice of Intent (ANOI) to prepare an 
EIS (72 FR 58834; October 17, 2007). The ANOI was issued to request 
early comments and to obtain input on the scope of the EIS. The NOI to 
prepare an EIS and to announce scoping meetings was published in the 
Federal Register on May 16, 2008 (73 FR 28437). The public scoping 
period started on May 16, 2008, and continued through August 14, 2008. 
Scoping meetings were held in Simi Valley, California (July 22, 2008), 
Northridge, California (July 23, 2008), and Sacramento, California 
(July 24, 2008).
    Preparation of the Draft EIS was delayed due to the need to collect 
soil and groundwater characterization data for Area IV and the NBZ. The 
lack of characterization data was an issue raised in EPA's and the 
State of California's comments on the 2003 EA. EPA collected 
characterization data for radionuclides from October 2010 to December 
2012. DOE (under DTSC oversight) collected characterization data for 
chemicals from October 2010 to June 2014. While the characterization 
data were being collected, DOE ETEC continued public involvement 
through release of newsletters and conducting Community Alternatives 
Development Workshops in 2012. Due to the length of time between the 
2008 NOI and completion of characterization, DOE ETEC published in the 
Federal Register on February 7, 2014, an Amended NOI for the SSFL Area 
IV EIS (79 FR 7439). Additional scoping meetings were held in Simi 
Valley, California on February 27, 2014, and in Agoura Hills/Calabasas, 
California on March 1, 2014. The scoping period ended on March 10, 
2014. The Notice of Availability of the SSFL Area IV Draft EIS was 
published in the Federal Register on January 13, 2017 (82 FR 4336). An 
Amended Notice Extending the Comment Period to April 13, 2017 was 
published in the Federal Register on March 17, 2017 (82 FR 14218).

Comments Received on the Final Environmental Impact Statement for 
Remediation of Area IV and the Northern Buffer Zone of the Santa Susana 
Field Laboratory

    The Notice of Availability of the SSFL Area IV Final EIS was 
published in the Federal Register on December 28, 2018 (83 FR 67282). 
DOE-EM distributed the SSFL Area IV Final EIS to Congressional members, 
State and local governments; other federal agencies; culturally 
affiliated American Indian tribal governments; non-governmental 
organizations; and other stakeholders,

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including members of the public who requested the document. Also, the 
SSFL Area IV Final EIS was made available via the internet (http://www.SSFLAreaIVEIS.com). In the SSFL Area IV Final EIS, DOE-EM announced 
the preferred alternatives for groundwater remediation as a combination 
of the Treatment Alternative and the Monitored Natural Attenuation 
Alternative. Preferred treatment technologies included groundwater pump 
and treat, bedrock removal, and monitored natural attenuation.
    DOE-EM received 885 letters or emails regarding the SSFL Area IV 
Final EIS. DOE-EM considered all comments contained in the letters and 
emails received during the review period. Some of the comments 
reiterated issues raised during the comment period on the SSFL Area IV 
Draft EIS. DOE previously evaluated all comments submitted on the SSFL 
Area IV Draft EIS and provided responses to those comments in the SSFL 
Area IV Final EIS, Volume 3, Comment Response Document. The ROD for 
Building Demolition (84 FR 51149) addressed the general comment issues 
(as well as those specific to building demolition) received on the 
Final EIS. Comments related to groundwater remediation are summarized.
    DOE-EM received comment letters from EPA, Region IX; DTSC; The 
Boeing Company; City of Los Angeles; Natural Resources Defense Council/
Committee to Bridge the Gap; Physicians for Social Responsibility--Los 
Angeles; Rocketdyne Cleanup Coalition; Southern California Federation 
of Scientists; and the SSFL Community Advisory Group. DOE-EM also 
received 876 comment emails from individuals. DOE reviewed and 
responded to all comments received through March 28, 2019. There were 
no comments received after that date.
    Active Remediation Comment--Commenters alleged that DOE was not 
proposing active groundwater remediation and was planning to leave 
groundwater with contaminants above permissible levels.
    Response--The commenters misstated DOE's proposed groundwater 
actions presented in the Final EIS. The Final EIS states that the 
maximum contaminant level (MCL or drinking water standard) would be the 
goal for locations requiring active remediation. The Final EIS states 
that active remediation is proposed to address contamination for the 
FSDF, PCE Plume, HMSA, and RMHF Strontium-90 bedrock. The cleanup 
actions would be continued until concentrations reach the cleanup goal.
    Monitored Natural Attenuation Comment--Commenters also objected to 
DOE's proposal to use monitored natural attenuation as a process for 
groundwater remediation.
    Response--In the Final EIS DOE states that monitored natural 
attenuation would be considered only for those locations with 
concentrations near the contaminant's MCL and with data demonstrating 
continued decline in concentration. The Final EIS states that monitored 
natural attenuation would be considered for the Tritium Plume, RMHF TCE 
Plume, and the Metals Clarifier TCE Plume as contaminants at those 
locations are either at or near their MCLs and are anticipated to be at 
MCLs within 10 years.
    Compliance with the 2007 CO--Commenters stated that DOE was not 
following the 2007 CO. The commenters did not state what aspects of the 
2007 CO were not being met.
    Response--DOE has been compliant with the 2007 CO, working in 
coordination with California DTSC. This includes the sampling of Area 
IV monitoring wells in accordance with the SSFL Water Quality Sampling 
and Analysis Plan (SSFL WQSAP; Haley and Aldrich, 2010). DOE developed 
and DTSC approved the work plan for groundwater characterization. DOE 
implemented the work plan installing 33 new wells, bringing the total 
number of monitoring wells in Area IV to over 130 wells. This network 
is adequate to assess groundwater remedies for each location of Area 
IV. As DOE designs the groundwater remedies to be described in the 
Groundwater CMIP, DOE will be identifying additional locations for new 
monitoring wells to be installed in Area IV. In compliance with a 
directive from DTSC, DOE implemented the groundwater interim measure at 
the FSDF, which is already reducing VOC concentrations. DOE collected 
over 500 groundwater samples during the last five years consistent with 
the 2007 CO requirements. The results of the efforts were reported in 
the RCRA Facility Groundwater Remedial Investigation Report (August 
2019), reviewed by and conditionally approved by DTSC. Finally, in 
accordance with the 2007 CO, DOE prepared the Area IV Groundwater 
Corrective Measures Study Report, which has been reviewed by DTSC. With 
the issuance of this ROD, DOE will prepare the Groundwater CMIP which 
will describe the technical details of the groundwater remedies 
identified herein. DTSC in turn will review and comment on the 
Groundwater CMIP.

Groundwater Remedy Changes Since the Final EIS

    The Final EIS DOE identified pump and treat as the preferred 
treatment technology for the Building 56 Landfill TCE Plume. Data 
collected since issuance of the Final EIS has determined that the 
Building 56 Landfill is not the source of observed TCE contamination. 
The source appears to be upgradient of the landfill. The groundwater 
data for the landfill location show a continuous decline in TCE 
concentrations, indicative of the leading edge from a plume from 
another location. DOE will continue to monitor the declining TCE 
concentrations at the landfill site. Under these conditions, continued 
groundwater monitoring near the landfill would have less environmental 
impact than a pump and treat action, which could draw additional 
contaminants from the source to the landfill.

DOE Comment Review and Changes Conclusion

    DOE has considered the above mentioned comments and changes and 
concludes that they do not present ``significant new circumstances or 
information relevant to environmental concerns and bearing on the 
proposed action or its impacts'' within the meaning of 40 CFR 1502.9(c) 
and 10 CFR 1021.314(a) and therefore does not require preparation of a 
supplement analysis or a supplemental EIS.

Decision

    DOE-EM has decided to implement pump and treat for the FSDF VOC and 
Building 4057 PCE plumes; conduct an in situ treatment pilot study for 
the HMSA TCE plume; perform a bedrock removal action for RMHF 
Strontium-90 impacted bedrock; and implement monitored natural 
attenuation for the Building 56 Landfill, Tritium Plume, RMHF Leach 
Field TCE, and Metals Clarifier/DOE Leach Field 3 Plume. These actions 
reflect DOE's Preferred Alternatives for groundwater remediation as 
described in the SSFL Area IV Final EIS, with the one exception of the 
change to the Building 56 Landfill noted above. Under this alternative, 
DOE-EM will prepare a Groundwater CMIP describing for each groundwater 
impact area the details for each remedial action, handling and disposal 
of treatment residuals created during the actions, monitoring 
requirements, and the goal for completion of the actions.
    The DOE Groundwater CMIP will be subject to DTSC review under the 
CEQA. In October 2017, DTSC released

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a draft Programmatic Environmental Impact Report (EIR) describing 
cleanup actions for the entirety of SSFL. Approval of remedies and 
selection of goals will be identified in the DTSC RCRA Statement of 
Basis. DOE-EM will implement the groundwater actions consistent with 
DTSC's EIR findings and approval of the Groundwater CMIP. DOE will 
continue to perform interim monitored natural attenuation, which does 
not require a final EIR, of the FSDF plume, metals clarifier plume, 
tritium plume, and building 56 landfill plume, until final remedies are 
concurred upon with DTSC. Other actions, such as the Sr-90 removal of 
bedrock, will not be performed until the final EIR is published.
    In reaching this decision, DOE-EM balanced the environmental 
information in the Final EIS with potential environmental impacts of 
groundwater remediation, current and future mission needs, technical 
and security considerations, availability of resources, and public 
comments on the SSFL Area IV Draft and Final EIS. Groundwater 
remediation supports DOE-EM's program initiatives for site cleanup and 
closure. Groundwater contaminant concentrations exceed levels 
considered safe for human health and ecological receptors. The current 
and future land use of the Area IV property is open space/recreational 
in accordance with the Grant Deed of Conservation Easement and 
Agreement (Ventura County 2017) and the Ventura County General Plan. 
The groundwater remediation actions presented in this ROD are 
consistent with the current and future land use. Implementing the 
Preferred Alternative will allow DOE-EM to continue its progress of 
cleaning up and eliminating liabilities for legacy nuclear research 
properties.

Mitigation Measures

    The installation of monitoring wells has the potential for 
temporary air quality emissions from diesel powered equipment. The 
transport of treatment residuals and extracted groundwater also has the 
potential for diesel exhaust emissions. Temporary water storage and 
treatment systems will be installed in already disturbed areas and 
operations are anticipated to be powered by solar systems. Overall, the 
groundwater remediation impacts are anticipated to be minimal. This 
decision adopts the mitigation and monitoring measures relevant to 
groundwater remediation that are identified in Chapter 6 of the Final 
EIS, the Programmatic Agreement, and the Biological Opinion. 
Practicable means to avoid or minimize environmental harm from the 
selected alternatives have been, or will be, adopted. Prior to active 
groundwater remediation, DOE-EM will prepare a mitigation and 
monitoring plan that will address how DOE-EM will minimize air 
emissions. Diesel emissions will be controlled using well installation 
and bedrock removal equipment and highway trucks fitted with pollution 
control equipment maintained to manufacturer specifications. Hazardous 
chemicals and radionuclides captured in treatment media will be 
packaged to prevent releases during transport. Occupational safety 
risks to workers will be minimized by adherence to federal and state 
occupational safety laws, and DOE requirements, regulations, and 
orders. Workers will also be protected by use of engineering and 
administrative controls. Emergency preparedness will also include an 
Accident Preparedness Program to address protection of the public 
during transport of groundwater treatment residuals. Stormwater control 
best management practices will be implemented to prevent surface water 
runoff from demolition sites. The plan will also incorporate by 
reference the monitoring and mitigation measures relevant to 
groundwater remediation established in the Programmatic Agreement and 
Biological Opinion.

Signing Authority

    This document of the Department of Energy was signed on November 2, 
2020, by William I. White, Senior Advisor for Environmental Management 
to the Under Secretary for Science, Office of Environmental Management, 
pursuant to delegated authority from the Secretary of Energy. That 
document with the original signature and date is maintained by DOE. For 
administrative purposes only, and in compliance with the requirements 
of the Office of the Federal Register, the undersigned DOE Federal 
Register Liaison Officer has been authorized to sign and submit the 
document in electronic format for publication, as an official document 
of the Department of Energy.
    The administrative process in no way alters the legal effect of 
this document upon publication in the Federal Register.

    Signed in Washington, DC, on November 5, 2020.
Treena V. Garrett,
Federal Register Liaison Officer, U.S. Department of Energy.
[FR Doc. 2020-24908 Filed 11-9-20; 8:45 am]
BILLING CODE 6450-01-P