&EPA
United States
Environmental Protection
Agency
Office of Superfund Remediation and Technology
EPA542-F-14-001 May 2014
Climate Change Adaptation Technical Fact Sheet:
andfills and Containment as an Element of Site Remediatio
In February 2013, the U.S. Environmental Protection Agency (EPA) released the draft U.S. Environmental Protection Agency
Climate Change Adaptation Plan.1 The plan examines how EPA programs may be vulnerable to a changing climate and how the
Agency can accordingly adapt in order to continue meeting its mission of protecting human health and the environment.
Under the Agency's Superfund Program, existing processes for planning and implementing contaminated site cleanup provide
a robust structure that allows consideration of climate change impacts. Climate change vulnerability analyses and adaptation
planning leading to increased remedy resilience may be integrated throughout the Superfund process, including feasibility
studies, remedial designs and remedy performance reviews or the equivalent in other cleanup programs. Due to wide
variation in the location and hydrogeologic characteristics of contaminated sites, the nature of remedial actions at those sites,
and local or regional climate and weather regimes, the process of considering climate change impacts and potential
adaptation measures is most effective through use of a site-specific strategy.
This fact sheet addresses contaminated site
remedies involving source containment
systems. It is intended to serve as an
adaptation planning tool by(l) providing an
overview of potential climate change
vulnerabilities and (2) presenting possible
adaptation measures that may be considered
to increase a remedy's resilience to climate
change impacts. This tool was developed in
context of the Superfund Program but its
concepts may apply to site cleanups
conducted under other regulatory programs
or through voluntary efforts, [a]
The adaptation strategies for containment
remedies build on concepts detailed in EPA's
introductory Climate Change Adaptation
Technical Fact Sheet: Groundwater
Remediation Systems (EPA 542-F-13-004).2
Supplemental information available online
includes:
• Additional background information
• Definitions of key terms such as
"vulnerability" and "resilience"
• Links to key sources of information.
Materials acting as a source of environmental contamination often
consist of contaminated soil or sediment. A source also could involve
sludge, debris, solid waste, non aqueous-phase liquids, equipment,
drums, or storage tanks.3 Remediation of contaminated sites often
involves containment systems to address the contaminant source(s).
Containment systems may operate ex situ and/or in situ.
Ex situ processes may involve excavating contaminated source material
and placing it in an engineered containment area (cell) that is lined, such
as a landfill, or an area designated as a consolidation unit that is typically
unlined. An ex situ source containment system often includes a cover
(cap), which is required for a closed landfill. A hazardous waste landfill
constructed under the Resource Conservation and Recovery Act also
requires a leachate collection and removal system. In addition, some
landfills have an active landfill gas collection and removal system, which
may vary from simple flaring to recovery of the gas to produce electricity
and/or useable heat. Other ex situ source containment remedies may
involve subaqueous contaminated sediment or mining waste. At mining
sites, contaminant sources such as waste rock, tailings, process areas,
and heap and dump leach operations may be consolidated in open pits
and capped in underground workings.
www.epa.gov/superfund/climatechange
In contrast, in situ processes may involve placing a cover on
contaminated material that is stabilized and left in place, such as an aged
landfill. Other techniques may involve constructing vertical barriers (walls) made of clay (typically bentonite) and/or
cement slurry poured into one or more subsurface trenches, synthetic materials such as geomembranes placed in
trenches, or sheet piles driven into the subsurface. The barriers are designed to prevent movement of contaminants
existing in a dissolved or free-phase form and often operate with a groundwater extraction and treatment system.
(
Figure 1. Climate Change Adaptation Management
Evaluate System Vulnerability
Assess Exposure ] [ Assess Sensitivity ]
Implement Adaptation Measures
[ Identify Options ]
Monitor and
•^•^^^ periodically re-evaluate ^^^. —
Select Measures
Climate change adaptation for an
existing or planned containment system
focuses on (1) evaluating the system's
vulnerability to climate change and (2)
implementing adaptation measures,
when warranted, to ensure the remedy
continues to prevent human or
environmental exposure to contaminants of concern (Figure 1). The adaptation strategy should include monitoring of
implemented measures, periodic re-evaluation of the system's vulnerability, and incorporating any needed changes.
[a] In manners consistent with existing regulations, including those under the Comprehensive Environmental Response, Compensation, and Liability Act; the National Oil and
Hazardous Substances Pollution Contingency Plan; the Resource Conservation and Recovery Act; and the Small Business Liability Relief and Brownfields Revitalization Act.
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Evaluation of Containment System Vulnerability
Evaluation of a containment system's vulnerability to climate change may involve:
• Identifying climate change hazards of concern
• Characterizing the system's exposure to those hazards of concern
• Characterizing the system's sensitivity to the hazards of concern
• Considering factors that may exacerbate system exposure and sensitivity, such as a long operating period; for
example, ex situ containment systems typically operate as long as the material remains hazardous, which in some
cases may exceed 100 years.
Climate Change Impacts
Temperature:
• Increased occurrence of extreme temperatures
• Sustained changes in average temperatures
• Decreased permafrost
Precipitation:
• Increased heavy precipitation events
• Increased flood risk
• Decreased precipitation & increasing drought
• Increased landslides
Wind:
• Increased intensity of hurricanes
• Increased intensity of tornados
• Increased storm surge intensity
Wildfires:
• Increased frequency & intensity
Sea level rise
A climate-change exposure assessment
identifies climate change hazards of
concern for a remediation system in
light of a range of potential climate and
weather scenarios. One climate change
hazard that is relatively unique to
landfill/containment systems involves
precipitation changes that could
degrade the covers. These systems also
may be adversely affected by land-cover
changes associated with climate
impacts, such as increased sinkholes.
At some sites, other hazards may relate
to the system's original siting or to potential lapses in the system's long-term stewardship. Landfills at or near sea
level in coastal areas, for example, might be subject to saltwater intrusion and increased groundwater salinity, which
may increase permeability of a clay liner and consequently decrease its performance.
Exposure assessment should include evaluating potential anthropogenic stressors, such as future land development
that could remove natural protective barriers or cause infill subsidence in low-lying areas. Exposure assessment
should also recognize near-term use of a covered landfill/containment area; for example, EPA and other federal
agencies are evaluating opportunities to install renewable energy facilities on current or formerly contaminated
lands, landfills and mine sites.6 Site managers are encouraged to work closely with future-use planning entities when
assessing site-specific exposure to climate change hazards.
Office of Solid Waste and Emergency Response Climate Change Adaptation Plan (draft),5
Appendix A (adaptation)
Dynamic information concerning specific locations is readily
available from several federal agencies to help screen
potential hazards and identify those of concern. More
information may be available from state agencies, regional or
local sources such as watershed and forestry management
authorities, non-profit groups and academia. At some sites,
installation of a meteorological station may be warranted to
monitor the need for response measures and to aid predictive
modeling for targeted vulnerabilities.
Federal agencies such as EPA, the National Oceanic and
Atmospheric Administration (NOAA) and the Federal
Emergency Management Agency (FEMA) offer dynamic
online information to help evaluate vulnerability to
climate change impacts; links for key information
resources are available at:
www.epa.gov/superfund/climatechange/resources
A climate-change sensitivity assessment evaluates the likelihood for the climate change hazards of concern to reduce
effectiveness of a landfill/containment system. Potential direct impacts of the hazards include power interruption,
physical damage, water damage and reduced accessibility. Potential indirect impacts may include petroleum oil or
chemical spills, accidental fire, explosions and ecosystem damage. Depending on the type and size of a system, overall
system failures may result in:
• Damage to liner or cover materials and potential washout of contaminated contents
• Damage to or loss of a leachate collection/removal system
• Damage to or loss of a landfill gas (LFG) management system, which may involve one or more flares to destroy
excess gas or a facility to recover and convert the gas to useable energy
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• Loss of subaqueous cover integrity due to increased erosion associated with intense water currents and waves
• Loss of surface grade integrity and potential spread of contaminants
• Unexpected and additional costs for repairing or replacing a cover system, a leachate or LFG management
system, or infrastructure components such as power lines, maintenance corridors and buildings.
Points of potential vulnerability correspond to the landfill/containment system components (including any leachate
and/or LFG management systems), site operations and infrastructure (Table 1). Site operation vulnerability may
include disruption of critical activities such as scheduled inspections of a landfill cover or sampling of LFG.
Table 1. Considerations for Sensitivity Assessment of a Source Containment System
Potential Vulnerabilities
Examples of System Components
Synthetic materials such as geomembrane in a
composite liner or cover system, geonet for
drainage, and/or geotextile for leachate filtration
Underground
and At-Grade
Components
Power
Interruption
Bottom layer of unlined waste
Vegetative layer integral to an evapotranspiration
cover or overlaying a conventional cover
Vertical and horizontal wells for LFG extraction
Pipe networks for leachate and/or LFG collection
Wells for monitoring groundwater or LFG
Vertical barriers
Physical
Damage
Water
Damage
Reduced
Access
Electrical controls for leachate and LFG
management systems
Pipe systems for leachate treatment and disposal
and for LFG collection and transfer
Transfer pumps for leachate and LFG
Flow-through leachate treatment units for
coagulation/flocculation, aerobic treatment,
chemical precipitation, ozonation, or reactive
carbon absorption
Aboveground
Components
Leachate treatment pond
LFG pre-treatment equipment such as blowers,
coolers and condensers
LFG flares
LFG-to-energy turbines
Chemical storage containers
Treatment residuals disposal system
Treated leachate discharge system
Auxiliary equipment powered by electricity,
natural gas or fossil fuel
Monitoring equipment
Buildings, sheds or housing
Electricity and natural gas lines
Site
Operations
and
Infrastructure
Liquid fuel storage and transfer
Water supplies
Exposed machinery and vehicles
Surface water drainage systems
Fencing for access control and litter prevention
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Techniques for compiling information on exposure and sensitivity
and assessing overall vulnerability of a containment system may
include:
• Collecting qualitative information, including photographs of
system components and existing field conditions
• Extrapolating quantitative information from data in existing
resources
• Conducting quantitative modeling through use of
conventional software or commercially available risk
assessment software for engineered systems
• Developing summary maps, tables and matrices.
Ex situ soil/waste containment systems rely on
effective control of water entering or exiting the
system. As a result, these systems are commonly
vulnerable to flooding that could cause cover
material erosion, side slope failure or contaminant
washout. Damaging floods from extreme
precipitation events may be exacerbated if
preceded by severe heat and drought. Source
containment systems in coastal areas also are
particularly vulnerable to saltwater intrusion caused
by sea level rise and associated flooding.
Adaptation measures are underway at the American Cyanamid Superfund site along the Raritan River in Bridgewater,
New Jersey, which experienced significant flooding in 2011 due to Hurricane Irene. Measures have already been
implemented for general site operations, such as installing submersible pumps in bedrock wells to maintain hydraulic
control during future flood events and elevating critical onsite electrical infrastructure (shown above on left). A remedy
selected in 2012, which calls for treatment and capping of contaminated wastes, will also incorporate a number of flood
adaptation measures, such as designing engineered covers to withstand a 500-year flood event. The berms (shown
above at right) surrounding two highly contaminated waste impoundments have been reinforced to increase their
strength and prevent scouring until a remedy for the impoundments can be developed and implemented.
Implementation of Adaptation Measures
Results of a vulnerability evaluation may be used to develop a strategy for increasing a landfill/containment system's
resilience to climate change. Strategy development involves:
• Identifying measures that potentially apply to the vulnerabilities in a range of weather/climate scenarios
• Selecting and implementing priority adaptation measures for the given containment system.
Identification of potential measures involves the screening of
steps that may be taken to physically secure the system, provide
additional barriers to protect the system, safeguard access to the
system, and alert project personnel to system compromises
(Table 2). Depending on the scenario, modifications may enable
many measures to address more than one aspect of an overall
containment system. Some measures also may be scaled up to
For new containment systems to be constructed,
evaluation of the vulnerability and adaptation
measures may be integrated into project designs.
For systems already operating, subsidence and
slope instability may signal the need to closely
examine subsurface components of the system and
re-evaluate their vulnerabilities.
encompass multiple remediation systems and critical field
activities. Yet others may provide a degree of desired redundancy; for example, access to an onsite or mobile
renewable energy system could provide a redundant power source that enables continued treatment of leachate
and/or LFG despite disruptions to the local power grid.
For a new remediation system, selecting optimal measures during the design phase may maximize the system's
resilience to climate change impacts throughout the project life and help avoid costly retrofits. Designs for
aboveground remedial components that are vulnerable could include, for example, structural reinforcement to
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protect buildings from high winds, secondary containment systems to capture hazardous liquids escaping from flood-
damaged containers, and closed or elevated housing to protect leachate pumps or monitoring equipment from high
winds or flooding. Designs for vulnerable subsurface remedial components such as leachate/LFG pipe networks or in
situ barriers could include extra precautions for potential conditions such as surface mounding, desiccation or
groundwater flow changes.
Climate change considerations are particularly important in designs and
associated modeling for containment systems anticipated to operate
for 30 years or longer. If an area is
predicted to experience
increasingly frequent flooding or
storm surge activity or be subject to
rising sea levels, disposal of
contaminated soil offsite in an area
not subject to these problems may
be an option.
Resilience of a covered landfill at the Davisville Naval Construction Battalion Center Superfund site, which is located along the
Narragansett Bay in Rhode Island, is strengthened by an armored base to prevent erosion. Intertidal wetlands and a seawall
work together below the base to reduce wave energy during storm surge from the adjacent Allen Harbor. Prior to installation
of the landfill cover, the wetlands were reconstructed by replacing the adjacent polluted mudflat with a layer of rocks topped
by dredge spoils (from the harbor entrance channel) and planting deep-rooted cordgrass (Sport/no) on the modified surface.
Underground
and At-Grade
Components
of the
Containment
System
nate Change
Impacts
Table 2. Examples of Adaptation Measures
Potential Adaptation Measures for System Components
Brief descriptions of engineered structures integral to many of the measures are available on the
Superfund Climate Change Adaptation website.
Construction at grade
Designing a new containment system to be built at rather than below ground surface, in
order to minimize potential contact between groundwater and targeted waste (or an
engineered liner) due to consistent rising of the water table
Dewatering well system
Installing extraction wells at critical locations and depths to prevent or minimize
groundwater upwelling into the waste zone of an aged landfill, waste consolidation unit,
or lined engineered landfill
Leachate extraction upgrades
Installation of additional wells (and aboveground pumps) for leachate extraction in
vulnerable areas
Liner system reinforcement
Selection of geomembranes with a maximum feasible thickness for new liner systems, use
of a secondary liner or geotextile, or extension of geosynthetic materials to vulnerable
sides of a waste cell
Pipe burial
Installation of pipes below rather than above ground surface where feasible, particularly
for LFG transfer
Run-on controls
Building one or more earthen structures (such as vegetated berms, vegetated swales, or
stormwater ponds) or installing fabricated drainage structures (such as culverts or French
drains) at vulnerable locations to prevent stormwater accumulating at higher elevations
from reaching a landfill/containment system
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Aboveground
Components
of the
Containment
System
Climate Change
Impacts
emperature
+
+
recipitation
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•
+
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A/ildfires
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Potential Adaptation Measures for System Components
Armor
Fixed structures placed on or along the shoreline of flowing inland water or ocean water to
mitigate effects of erosion and protect site infrastructure; "soft" armor may comprise
synthetic fabrics and/or deep-rooted vegetation while "hard" armor may consist of riprap,
gabions and segmental retaining walls
Coastal hardening
Installation of structures to stabilize a shoreline and shield it from erosion, through "soft"
techniques (such as replenishing sand and/or vegetation) or "hard" techniques (such as
building a seawall or installing riprap)
Concrete pad fortification
Repairing cracked pads or replacing inadequate pads (of insufficient size or with
insufficient anchorage), particularly those used for monitoring purposes, and integrating
retaining walls along a concrete pad perimeter where feasible
Containment fortification
Placement of riprap adjacent to a subsurface containment barrier located along moving
surface water, to minimize bank scouring that could negatively affect barrier integrity; for
soil/waste capping systems vulnerable to storm surge, installation of a protective vertical
wall or armored base to absorb energy of the surge and prevent cap erosion or destruction
Entombment
Enclosure of vulnerable equipment or control devices in a concrete structure
Evapotranspiration cover modification
Replacement of existing vegetation with a plant mix more tolerant of long-term changes in
precipitation or temperature, and/or soil addition to increase water storage capacity
Fire barriers
Creating buffer areas (land free of dried vegetation and other flammable materials)
around vulnerable remediation/monitoring components and installing manufactured
systems (such as radiant energy shields and electrical raceway fire barriers) around heat-
sensitive components
Flare enclosure
Industrial-strength protective material that surrounds equipment used to ignite and
combust excess LFG
Ground anchorage
One or more steel bars installed in cement-grouted boreholes (and in some cases
accompanied by cables) to secure an apparatus on a ground surface or to reinforce a
retaining wall against an earthen slope
Relocation
Moving selected system components to positions more distant or protected from potential
hazards; for flooding threats, this may involve elevations higher than specified in the
community's flood insurance study
Retaining wall
A structure (commonly of concrete, steel sheet piles or timber) built to support earth
masses having a vertical or near-vertical slope and consequently hold back loose soil, rocks
or debris
Tie down systems
Installing permanent mounts that allow rapid deployment of a cable system extending
from the top of a unit to ground surface
Well-head housing
Building insulated cover systems made of high density polyethylene or concrete for control
devices and sensitive equipment situated abovegroundfor long periods
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Site Operations
and
Infrastructure
Climate Change
Impacts
Potential Adaptation Measures for System Components
Alarm networks
Integrating a series of sensors linked to electronic control devices that trigger shutdown of
selected remediation/monitoring components, or linked to audible/visual alarms that alert
workers of the need to manually shut down the components, when specified operating or
ambient parameters are exceeded
Building envelope upgrades
Replacing highly flammable materials with (or adding) fire- and mold/mildew-resistant
insulating materials in a building, shed or housing envelope
Flood controls
Building one or more earthen structures (such as vegetated berms, vegetated swales,
stormwater ponds, levees, or dams) or installing fabricated drainage structures (such as
culverts or French drains) to retain or divert floodwater spreading from adjacent surface
water or land surface depressions
Hurricane straps
Integrating or adding heavy metal brackets that reinforce physical connection between the
roof and walls of a building, shed or housing unit, including structures used for leachate
and LFG management
Pervious pavement
Replacing impervious pavement that has deteriorated or impeded stormwater
management with permeable pavement (in the form of porous asphalt, rubberized
asphalt, pervious concrete or brick/block pavers) to filter pollutants, recharge aquifers and
reduce stormwater volume entering the storm drain system
Plantings
Installing drought-resistant grasses, shrubs, trees and other deep-rooted plants to provide
shading, prevent erosion, provide wind breaks and reduce fire risk
Power from off-grid sources
Constructing a permanent system or using portable equipment that provides power
generated from onsite renewable resources, as a primary or redundant power supply that
can operate independent of the utility grid when needed
Remote access
Integrating electronic devices that enable workers to suspend pumping or selected
activities during extreme weather events, periods of impeded access, or unexpected
hydrologic conditions
Renewable energy system safeguards
Extended concrete footing for ground-mounted photovoltaic (PV) systems, additional
bracing for roof-top PV or solar thermal systems, and additional masts for small wind
turbines or windmills; for utility-scale systems, safeguards to address climate change
vulnerabilities may be addressed in the site-specific renewable energy feasibility study
Utility line burial
Relocating electricity and communication lines from overhead to underground positions,
to prevent power outages during and often after extreme weather events
Weather alerts
Electronic systems that actively inform subscribers of extreme weather events or provide
Internet postings on local/regional weather and related conditions
The process of selecting potential measures and determining optimal measures for a landfill/containment system in
a given scenario may consider:
•/ Size and age of aboveground components of the system and auxiliary equipment
•S Complexity of any associated leachate and/or LFG management systems
•S Anticipated duration of remedial system operations
•/ Existing infrastructure components such as roads, power and water supplies
•S Primary and back-up means of access
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•/ Project aspects affecting future land use or development
•S Anticipated effectiveness and longevity of the potential measures
•S Capital cost and operations and maintenance (O&M) cost.
A sample structure for documenting
evaluation of site-specific vulnerabilities,
prioritizing potential adaptation measures,
and monitoring implemented measures is
available in Climate Change Adaptation
Technical Fact Sheet: Groundwater
Remediation Systems (EPA 542-F-13-004).2
Selected measures may be integrated into primary or secondary
documents supporting existing landfill/containment systems, such as
monitoring plans, optimization evaluations, five-year reviews and close-
out planning materials. For new systems to be constructed, the measures
also may be integrated into the site's feasibility study and remedy design process. Significant or fundamental changes
may need formalization through a decision document (such as a record of decision amendment) or a permit
modification. In general, implementation of adaptation measures during early rather than late stages of the cleanup
process may expand the universe of feasible options, maximize integrity of certain measures, and in some cases
reduce implementation costs.
To be most effective, adaptation should be an iterative and flexible process that involves periodically re-evaluating
the source containment system's vulnerability, monitoring the measures already taken, and incorporating newly
identified options or information into the adaptation strategy. Periodic re-evaluations should include verifying key
data; for example, predictions for increased frequency of intense inland surface water currents and tides may prompt
upgrades to subaqueous soil/sediment capping systems, as could the changing patterns of ice versus non-ice
conditions. As another example, updated floodplain mapping could lead to installation of engineered structures to
protect a landfill in an area previously considered a 500-year floodplain but now classified as a 100-year floodplain.
Effective adaptation planning also considers how climate change may affect short- and long-term availability of clean
water and ecosystem services that may be critical to maintenance of a source containment system as well as future
land use.7 Information about related data and government and/or private sector partnerships is available to the site
cleanup community, local or regional planners, and the general public through the recently launched U.S. Climate
Data Initiative.8
References
[Web access date: May 2014]
U.S. EPA; Climate Change Adaptation Plan (draft); June 2012; http://epa.gov/climatechange/pdfs/EPA-climate-change-adaptation-plan-final-for-public-
comment-2-7-13.pdf
U.S. EPA; Climate Change Adaptation Technical Fact Sheet: Groundwater Remediation Systems; EPA 542-F-13-004; December 2013;
http://www.epa.gov/superfund/climatechange/cca-tech-fact-sheet-gw-remediation-systems.pdf
3 U.S. EPA; Superfund Remedy Report; Fourteenth Edition; EPA 542-R-13-016; November 2013; http://www.clu-in.org/asr/
U.S. Geologic Survey; The Science of Sinkholes; http://www.usgs.gov/blogs/features/usgs_top_story/the-science-of-sinkholes/
U.S. EPA; Office of Solid Waste and Emergency Response Climate Change Adaptation Implementation Plan (draft); June 2013;
http://epa.gov/climatechange/Downloads/impacts-adaptation/office-of-solid-waste-and-emergency-response-plan.pdf
The White House; Presidential Memorandum - Federal Leadership on Energy Management; Decembers, 2013; http://www.whitehouse.gov/the-press-
office/2013/12/05/presidential-memorandum-federal-leadership-energy-management
U.S. EPA; Climate Impacts on Water Resources; http://www.epa.gov/climatechange/impacts-adaptation/water.html
8 The White House; The President's Climate Data Initiative: Empowering America's Communities to Prepare for the Effects of Climate Change; March 19,
2014; http://www.whitehouse.gov/the-press-office/2014/03/19/fact-sheet-president-s-climate-data-initiative-empowering-america-s-comm
To learn more about climate change adaptation at Superfund sites and access new
information and decision-making tools as they become available, visit:
www.epa.gov/superfund/climatechange
Contacts
Questions about climate change adaptation in EPA's Superfund Program may be forwarded to:
Carlos Pachon (pachon.carlos@epa.gov), Anne Dailey (dailey.anne@epa.gov) or Ellen Treimel (treimel.ellen@epa.gov
EPA is publishing this document as a means of disseminating useful information regarding approaches for adapting to climate change. This document does not impose legally
binding requirements on EPA, states, tribes or the regulated community and does not alter or supersede existing policy or guidance for contaminated site cleanup. EPA, federal,
state, tribal and local decision-makers retain discretion to implement approaches on a case-by-case basis.
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