United States
Environmental Protection
\r ^1 *mAgency
Climate Resilience Technical Fact Sheet:
Contaminated Waste Containment Systems
In June 2014, the U.S. Environmental Protection Agency (EPA) released the 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 Superfund
Program, existing processes for planning and implementing site remedies provide a robust structure that allows consideration of
climate change effects. Examination of the associated implications on site remedies is most effective through use of a place-based
strategy due to wide variations in the hydrogeologic characteristics of sites, the nature of remediation systems operating at
contaminated sites, and local or regional climate and weather regimes. Measures to increase resilience to a changing climate may be
integrated throughout the Superfund process, including feasibility studies, remedy designs and remedy performance reviews.
Office of Superfund Remediation and Technology Innovation
EPA 542-F-19-004	October 2019 Update
As one in a series, this fact sheet addresses
the climate resilience of Superfund remedies
involving waste containment systems. It is
intended to serve as a site-specific planning
tool by (1) describing an approach to
assessing potential vulnerability of a
containment system, (2) providing examples
of measures that may increase resilience of a
containment system, and (3) outlining steps
to assure adaptive capacity of a containment
system as climate conditions continue to
change. Concepts described in this tool may
also apply to site cleanups conducted under
other regulatory programs or through
voluntary efforts.
Remediation of contaminated sites often involves waste containment
systems to address sources such as contaminated soil or sediment,
sludge, solid waste, nonaqueous-phase liquids or storage tanks. In many
cases, the waste exists in abandoned landfills or industrial waste piles.
Onsite waste containment systems may operate ex situ or in situ. Ex situ
systems may involve excavating and placing the source material in other
onsite areas, such as a newly engineered containment area (cell) with a
bottom liner consisting of compacted clay, geotextiles or both. At other
sites, excavated source material may be placed in an unlined
consolidation unit. Such systems typically include a cover (cap) placed
above the waste and in some cases processes for collecting and treating
leachate and managing landfill gas (LFG).
In situ containment systems focus on stabilizing contaminated waste to be left in place. For example, a final cover
utilizing impervious geosynthetic fabric may be placed over assorted wastes; in contrast, a composite soil cover may
be placed over certain materials such as waste rock. In situ systems also could involve one or more subsurface
barriers constructed at strategic locations to prevent movement of dissolved or free-phase contaminants. Such
barriers commonly consist of clay (typically bentonite) or cement slurry poured into a trench, geosynthetic materials
placed in trenches, or sheet piles driven into the subsurface. Containment barriers often operate in conjunction with
groundwater extraction and treatment systems.
Climate resilience planning for a waste containment system generally
involves:
(1)	Assessing vulnerability of the system's elements and associated site
infrastructure.
(2)	Evaluating measures potentially increasing the system's resilience to a
changing climate.
(3)	Assuring the system's capacity to adapt to a changing climate, which helps the cleanup remedy continue to be
protective of human health and the environment (Figure 1).
Resilience: A capability to anticipate,
prepare for, respond to, and recover from
significant multi-hazard threats with
minimum damage to social well-being, the
economy, and the environment.2
Assess System
Vulnerability
^^"Ixposure*^^
Sensitivity
Evaluate Measures to
Increase Resilience
{^jdentifi catior^
Prioritization
Assure Adaptive
Capacity
implementation
Of Measures ^
Periodic
Reassessment
Figure 1. Climate Change Adaptation Management

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Assessment of Waste Containment System Vulnerability
Assessing a waste containment system's vulnerability to the effects of
climate change involves:
•	Determining the system's exposure to climate or weather hazards.
•	Determining the system's sensitivity to the hazards.
Vulnerability: The degree to which a
system is susceptible to, or unable to cope
with, adverse effects of climate change,
including climate variability and extremes.
Vulnerability is a function of the character,
magnitude, and rate of climate variation to
which a system is exposed; its sensitivity;
and its adaptive capacity.2
A climate change exposure assessment identifies particular hazards of
concern and characterizes exposure to those hazards in light of various climate
potential hazards for a waste containment system include high floodwater, soil
unexpected changes in the water table.
and weather scenarios. Examples of
washout in sloped areas, or
The hazards may arise abruptly due to extreme weather events, which are
expected to occur at increasing intensities, durations and frequencies as
long-term climate conditions continue to change. Depending on a site's
location and attributes, hazards associated with an extreme weather event
may generate different outcomes and degrees of severity in onsite or
offsite areas and infrastructure. For example, a heavy rainfall within a 24-
hour period across an urban industrial area could generate stormwater
flow that inundates a site and overloads an aged combined sewer system
into which leachate treatment wastewater discharges. In contrast, a
comparable rainfall across a steep mountain valley could lead to onsite
flooding that disrupts the critical water balance of a containment system
and generates runoff contributing to flash flooding in downgradient areas.
Changing climate conditions include
sustained changes in average
temperatures, increased heavy
precipitation events, increased coastal
flooding, increased intensity of storm
surge, sea level rise and increased wildfire
severity.3 A vulnerability assessment helps
project decision makers:
•	Understand which conditions may
change at a site.
•	Understand how altered conditions may
affect the site remedy.
Climate parameters that significantly influence hydrologic processes and
ultimate performance of a containment system include precipitation,
ambient temperatures, wind speeds and solar radiation.4 For example, a
prolonged rainfall event could lead to water seepage at vulnerable edges
of a cover. In contrast, drought conditions could cause desiccation and
associated cracking of compacted clay lining the bottom of a waste cell.
Similarly, cracking or general deterioration of subsurface vertical barriers could result from more frequent or extreme
wet-dry or freeze-thaw cycles or heat stress.
Climate-related hazards potentially
affecting performance of compacted clay
liners include desiccation, freeze-thaw,
thermally induced moisture movement
leading to desiccation, and subsidence.
Potential hazards also might concern the LFG management process required for waste containment cells constituting
a landfill.5 Associated equipment such as aboveground gas-transfer pipes as well as gas flares or gas-to-energy
turbines are commonly exposed to weather on a year-round basis. Modifications to an LFG management process are
typically made over time to accommodate the gradual decrease in LFG production due to bacterial decomposition of
the waste's organic matter.
Other hazards at landfills could relate to the particular content of a cover.
Conventional covers use layers of material with low hydraulic conductivity,
such as geomembranes, to serve as a barrier that minimizes percolation of
water through the waste. Precipitation- or wind-generated erosion or
abrupt washout of soil above a geomembrane could result in its exposure
to ultraviolet radiation, which is a major contributor to the degradation of
geosynthetic materials. In contrast, evapotranspiration (ET) covers
minimize percolation by relying on the capability of multiple soil layers to
store water until it evaporates or is transpired through vegetation.
Sustained changes in onsite precipitation or temperatures could reduce
viability of the assorted long-rooted plant species originally selected on
the basis of their expected survival under historic climate conditions.
Designs for site-specific stormwater
management depend on accurately
estimating peak stream flow within the
local watershed, including contributions
from snowmelt. Regions that historically
accumulated seasonal snowpackare
expected to experience a shift from snow-
to rain-dominated 100-year precipitation
events. This shift affects the rainfall
intensity, duration, and frequency (IDF)
curves typically used to model potential
flooding.6'7
2

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At some sites, hazards may concern the system's original siting or
potential lapses in the system's long-term stewardship. Landfills at or
near sea level in coastal areas, for example, might be vulnerable to
saltwater intrusion and increased groundwater salinity, which may
increase permeability of a clay liner. Other potential hazards may concern
onsite or offsite anthropogenic stressors, such as land development that
removes natural protective barriers or causes infill subsidence in low-lying
areas. Land cover changes also could increase a system's vulnerability to
sinkholes triggered by intense rainstorms or floods.8
Final cover systems for contained waste are intended to remain in place and maintain their functions for periods of
many decades to hundreds of years. As a result, a vulnerability assessment typically considers future use of a covered
landfill or other type of containment area. For example, the U.S. EPA and other federal agencies are evaluating
opportunities to install renewable energy facilities on current or formerly contaminated lands, landfills and mine
sites.9 Site managers are encouraged to work closely with future-use planning entities when assessing site-specific
exposure to climate change hazards.
Dynamic information about climate and weather variabilities and trends across the United States is available from
several federal agencies to help screen potential hazards in a given spatial area and identify those of concern. Web-
based platforms and tools include:
•	National Oceanic and Atmospheric Administration (NOAA) resources such as Digital Coast and Sea Level Trends.
•	National Weather Service resources such as National Storm Surge Hazard Maps and Sea, Lake, and Overland
Surges from Hurricanes (SLOSH).
•	U.S. Geological Survey (USGS) resources such as the National Climate Change Viewer and StreamStats.
Information also 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.
A climate change sensitivity assessment for a planned or operating waste containment system evaluates the
likelihood for the climate change hazards of concern to reduce the system's effectiveness. Potential direct effects of
the hazards associated with an extreme weather event include power interruption, physical damage, water damage
and reduced accessibility. Potential indirect effects include petroleum oil or chemical spills, accidental fire, explosions
and ecosystem damage. System failures due to exposure to one or more hazards could result in:
•	Washout of covered waste at or near surface grades.
•	Migration of subsurface contaminants to areas that were previously uncontaminated.
•	Leakage from various depths of the contained waste or from damaged leachate-control equipment, which could
affect underlying groundwater or nearby surface water.
•	Atmospheric release of untreated LFG, which typically comprises about 50 percent methane and 50 percent
carbon dioxide.
•	Unexpected and additional costs for repairing or replacing portions of the containment system or site
infrastructure such as power lines, maintenance corridors and buildings.
Vulnerable points of a containment system due to extreme weather events may physically exist below, at or above
surface grades or involve the site's general operations and infrastructure (Table 1). For example, reduced access to a
site due to road washout could disrupt a critical activity such as scheduled inspection of a waste cover or sampling of
leachate.
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.
3

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Table 1. Considerations for Sensitivity Assessment of a Waste Containment System
Potential Vulnerabilities Due to Extreme Weather
Examples of System Components
Physical
Damage
Water
Damage
Power
Interruption
Reduced
Access
Underground
and At-Grade
Components
Synthetic materials such as geomembrane in a
composite liner or cover system, geonet for
drainage, or geotextile for leachate filtration
~
~


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
~


~
Aboveground
Components
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 units for leachate treatment
processes such as coagulation/flocculation,
chemical precipitation or ozonation
~
~
~
~
Leachate treatment or evaporation 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 diesel fuel
~
~
~
~
Monitoring equipment
~
~
~
~
Site
Operations
and
Infrastructure
Buildings, sheds or housing
~
~
~
~
Electricity and natural gas lines
~
~

~
Liquid fuel storage and transfer
~
~
~
~
Water supplies
~
~
~
~
Exposed machinery and vehicles
~
~

~
Surface water drainage systems
~
~

~
Fencing for access control and litter prevention
~


~
Techniques for assessing potential vulnerability of a waste containment system may include:
•	Collecting qualitative information such as photographs of system components and current field conditions.
•	Extrapolating quantitative data documented in resources such as NOAA or USGS mapping systems.
•	Modeling that uses predictive weather and climate data, through use of conventional software or commercially
available risk assessment software for engineered systems.
•	Developing site-specific maps and matrices that can aid decision-making.
Detailed information about climate-related vulnerability assessment and access to associated tools is provided in
resources such as the:
•	U.S. Climate Resilience Toolkit for exploring hazards and assessing
vulnerability and risks.
•	Climate Change 2014: Impacts, Adaptation and Vulnerability report
from the Intergovernmental Panel on Climate Change, which includes a
chapter (19) on assessing emergent risks and key vulnerabilities.
More examples of relevant tools and other
resources are described online at
Superfund Climate Resilience:
Vulnerability Assessment.
4

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As an illustration, Figure 2 highlights results of a preliminary vulnerability assessment for a waste containment system
currently deployed at a Superfund site. The illustration identifies potential disruptions to the system due to extreme
weather events and provides a sample structure for documenting high-priority resilience measures that could be
implemented in the near term. Planning tools such as this also may be used to build additional adaptive capacity over
time.
This sample cleanup scenario involves a 30-acre Superfund site located on an island of an inland river. Contaminants
remain from the site's past use for disposal of industrial waste, domestic trash and construction debris. The remedy
components involve covering historic waste disposal trenches with a multi-layer cap; covering other areas with an
erosion cap consisting of asphalt, concrete paving or a vegetative layer; installing a passive gas collection system;
constructing a stormwater runoff and erosion control system that includes subsurface vertical barrier walls; and
monitoring natural attenuation in the groundwater plume. Portions of the area covered with the multi-layer cap are
anticipated for reuse supporting roadways, parking areas or other developed structures.
Public information sources indicate that potential hazards for this scenario include flooding, high winds, cold
temperatures and an elevated water table. In combination with site-specific data existing in materials such as site
investigation reports and the Superfund record of decision, professional judgment is used to identify and prioritize
resilience measures for this remedy.
Potential Points of
Potential System Disruption Due to
Extreme Weather
Resilience Measures for
System Vulnerability
Power
Interruption
Physical
Damage
Water
Damage
¦¦¦¦¦¦ i-iign-riioiiiy
¦¦HI Vulnerabilities
Underground
and At-Grade
Components
Geosynthetic layer(s) in
cover system

•
•

Upgrade rock armor system
Install dewatering system
Vegetative layer of
erosion caps

•
•

Install runoff channels
Plant flood-resistant species
Wells for LFG extraction
or groundwater
monitoring

o

O

Leachate collection pipes

o
o
O

Cement vertical barriers

•

O
Emplace supporting gabions
Aboveground
Components
Leachate transfer pumps
o
•
c

Build well-head housing
LFG well vents

•
c

Fortify concrete pad
Enclose exposed piping
Leachate evaporation
pond

«

O
Increase holding capacity
Groundwater monitoring
equipment
o
•
c
C
Add remote access system
Site
Operations
and
Infrastructure
Equipment housing
o
€
c
€

Site fencing

O

O

Water supplies

O

O

Surface water drainage
systems

•
•
€
Construct vegetated swales
^ high priority ^ medium priority O low priority
Figure 2. Illustrative Superfund Site Scenario: Vulnerability Assessment Results and Prioritized Adaptation Measures
5

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Evaluation of Potential Climate Resilience Measures
Results of a vulnerability assessment may be used to develop a strategy for increasing a waste containment system's
resilience to a changing climate and extreme weather events. Development of the strategy entails:
•	Identifying resilience measures potentially applying to the hazards of concern under various climate and weather
scenarios.
•	Prioritizing resilience measures for the given system.
Identification of potential resilience measures involves screening of steps
that may be taken to physically secure the system, provide additional
barriers to protect the system, safeguard access to the system or alert
project personnel of system compromises (Table 2). Some of the measures
may address more than one climate or weather scenario. For example,
extending the geosynthetic layer of a waste cell's top liner outward to
cover vulnerable sides of the cell may increase the containment system's resilience to intense rainfall or rapid
snowmelt as well as high winds.
Some of the measures also may be scaled up to increase the resilience of co-located remediation systems, such as a
groundwater extraction and treatment system operating in conjunction with a subsurface containment barrier. Other
measures may provide a degree of desired redundancy. For example, installation of a small-scale photovoltaic (PV)
system could help assure a steady source of power for LFG or groundwater monitoring systems during 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 hazards throughout the project life and help avoid costly retrofits. Designs for a waste
containment system could include specifications to meet particular vulnerabilities. For example, the design could
involve surface drainage criteria that use a worst-case storm scenario based on most recent and longer-term climate
predictions; integration of more sumps to handle potentially higher volumes of leachate accumulating above a liner
due to a higher water table; or additional intermediate berms to prevent
water- or wind-related erosion or landslides in steep areas bordering a
waste cell. 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 hazards may be an
option.
The process of identifying and prioritizing potential measures for a waste containment system may consider:
•	Size and age of an existing system's components and auxiliary equipment.
•	Complexity of the waste containment system.
•	Local or regional climate adaptation plans or ordnances affecting sites with landfills or other waste
containment classifications.
•	Status of infrastructure components such as power and water supplies.
•	Existing and critical means of access.
•	Relevant aspects of future land use or development.
•	Anticipated effectiveness and longevity of the resilience measures.
•	Capital cost and operations and maintenance cost of the measures, as well as costs associated with potential
system repair or replacement due to climate-related damage in the future.
Prioritization of resilience measures also may necessitate professional judgements regarding other aspects such as:
•	Critical versus non- or marginally-critical equipment, activities or infrastructure.
•	Minimum performance thresholds for system or site operations.
•	Levels of tolerance for operational disruptions.
Effective mitigation of climate change
hazards for a waste containment
remediation system involves a site-specific
analytical approach rather than a broad
prescriptive plan.
Descriptions of engineered structures
commonly used in climate resilience
measures are available online at
Superfund Climate Resilience: Resilience
Measures.
6

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Table 2. Examples of Climate Resilience Measures
Climate Change
Effects

Precipitation
Wind
Sea Level Rise
Potential Climate Resilience Measures for System Components
Underground
and At-Grade
Components
of the
Containment
System

~



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
Installing additional wells (and aboveground pumps) for leachate extraction in vulnerable
areas
~
~

~

Liner system reinforcement
Selecting geomembranes with a maximum feasible thickness for new liner systems, using a
secondary liner or geotextile, or extending geosynthetic materials to vulnerable sides of a
waste cell

~
~


Pipe burial
Installing 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
~




Thermal insulation
Covering composite liners and barriers made of geosynthetics with a layer of insulating
material such as chipped tires to prevent liner/barrier desiccation due to heating orfreeze-
thaw action, or wrapping pipes with insulating material
Aboveground
Components
of the
Containment
System

~

~

Armor
Placing fixed structures 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
Installing structures to stabilize a shoreline and shield it from erosion through use of soft
engineering techniques, such as replenishing sand and/or vegetation, or hard engineering
techniques, such as building a seawall or emplacing riprap
~
~

~

Concrete pad fortification
Repairing cracked pads or replacing 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
Emplacing 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, installing a protective vertical wall
or armored base to absorb energy of the surge and prevent cap erosion or destruction

~
~

~
Entombment
Enclosing vulnerable equipment or control devices in a concrete structure
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Climate Change
Effects

Precipitation
Wind
Sea Level
Potential Climate Resilience Measures for System Components
Aboveground
Components
of the
Containment
System
~
~



Evapotranspiration cover modification
Replacing existing vegetation with a plant mix more tolerant of long-term changes in
precipitation or temperature, or adding soil 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
Add industrial-strength protective material around equipment used to ignite and
combust excess LFG

~



Ground anchorage
Installing one or more steel bars 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
Building a structure (commonly of concrete, steel sheet piles or timber) 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 aboveground for long periods
Site
Operations
and
Infrastructure
~
~
~
~
~
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
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Climate Change
Effects


Temperature
Precipitation
Wind
Sea Level Rise
Wildfires
Potential Climate Resilience Measures for System Components
Site
Operations
and
Infrastructure
~
~
~
~
~
Plantings
Installing a mix of flood- and drought-resistant grasses, shrubs, trees and other deep-
rooted plants to 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 periods of impeded access or unexpected hydrologic conditions
~
~
~
~

Renewable energy system safeguards
Extending concrete footing for ground-mounted PV systems, adding bracing for roof-top
PV or solar thermal systems, and adding masts for wind turbines or windmills
~
~
~

~
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
Subscribing to open-access electronic networks that actively inform subscribers of
extreme weather events
Assurance of Adaptive Capacity
Assuring the adaptive capacity of a waste containment system involves:
•	Implementing new or modified measures to increase climate
resilience of the system or site operations and infrastructure, as
needed.
•	Establishing plans for periodically reassessing the system and site vulnerabilities, to determine if additional
capacity is needed as cleanup progresses and climate conditions change.
Climate resilience measures that are selected for implementation may be integrated into primary or secondary
documentation supporting existing containment systems. Key documentation includes monitoring plans, optimization
evaluations, five-year reviews and close-out planning materials. For new projects, the measures also may be
integrated into the site's feasibility study and remedy design. Resilience planning also may involve incorporating
specific requirements to be met in cleanup service contracts. In general, implementation of climate resilience
measures during early, rather than late, stages of the cleanup process might expand the universe of feasible options,
maximize integrity of certain measures and reduce implementation costs. Upfront planning also could enable the
selected measures to benefit the site's anticipated reuse. For example, climate-resistant plantings above a waste cell
cover could intercept precipitation while providing a suitable substrate for
future recreational or ecological use.
Assurance of sufficient adaptive capacity is an iterative and flexible
process. It involves periodically reassessing the system's vulnerability,
monitoring the measures already taken and incorporating newly identified
options or information. Periodic reassessments typically include verifying
key data. Established plans for the timing of vulnerability reassessment
may involve a predetermined schedule or use triggers such as an extreme
weather event.
Adaptive Capacity: The ability of a system
to adjust to climate change (including
climate variability and extremes), to
moderate potential damages, to take
advantage of opportunities, or to cope
with the consequences.2
A regional wildfire event could trigger
reassessment of a containment system's
potential vulnerability associated with:
•	Stormwater controls needing
modification due to altered land cover.
•	Invasive species moving into the
system's vegetative layer.
•	Changes in the system's hydrologic
balance due to loss of nearby tree
canopy.10
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Resources to help understand climate resilience planning and implementation are available through online
compendiums such as:
m ARC-X (EPA's Climate Change Adaptation Resource Center), which provides online access to tools that help
communities anticipate, plan for and adapt to the changing climate.
~	The NOAA National Centers for Environmental Information, which provide climate and weather data and monthly
summaries of U.S. temperatures and precipitation.
~	EPA's Addressing Climate Change in the Water Sector website, which
provides access to the State Water Agency Practices for Climate
Adaptation Database.
The general concepts, tools and examples provided in such compendiums may be used to tailor climate resilience
planning for a specific waste containment remediation system. Resources such as these also may serve as a guide in
assuring that the measures align with climate adaptation actions taken by relevant state, regional or local agencies.
More tools to help assure adaptive
capacity are described online at Superfund
Climate Resilience: Adaptive Capacity.
The Malone Services Company Superfund Site along Galveston Bay,
Texas, borders open water and extensive wetlands and marshes.
Remedial action at this site, which was formerly used for waste oil and
chemical reclamation, storage and disposal, has involved placing the
waste in two onsite cells and monitoring of groundwater. The
remedy's vulnerability to flooding due to hurricane storm surge or sea
level rise was addressed in the remedy's design and construction by:
•	Using NOAA's SLOSH model and historical weather data to analyze
storm surge and wave runup under various hurricane scenarios and
sea level rise predictions, to establish design storm criteria.
•	Armoring the bay-facing boundary of a levee surrounding the site.
•	Installing riprap armor along vulnerable portions of the waste cells.
Following Hurricane Harvey in 2017, recently emplaced topsoil and
hydromulch above one cell were replenished in areas that experienced
erosion or washout.
Consolidated waste cells at the Malone Services
Company Superfund Site in Texas City, Texas.
References
[Web access date: October 2019]
1	U.S. EPA; Climate Change Adaptation Plan; June 2014; https://www.epa.gov/greeningepa/climate-change-adaptation-plans
2	U.S. EPA; Vocabulary Catalog: Topics: Climate Change Terms;
https://ofmpub.epa.gov/sor_internet/registry/termreg/searchandretrieve/glossariesandkeywordlists/search.do
3	U.S. EPA; Climate Change Indicators in the United States 2016; Fourth Edition; EPA 430-R-16-004; https://www.epa.gov/climate-indicators
4	U.S. EPA; Assessment and Recommendations for Improving the Performance of Waste Containment Systems; EPA 600/R-02/099, December 2002;
https://cfpub.epa.gov/si/si_public_record_report.cfm?Lab=NRMRL&dirEntryld=63351
5	U.S. EPA; Landfills; https://www.epa.gov/landfills
6	Strategic Environmental Research and Development Program. Developing Adaptation Strategies to Address Climate Change and Uncertainty. Webinar
#92, June 20, 1019; https://www.serdp-estcp.org/Tools-and-Training/Webinar-Series/06-20-2019
7	U.S. Department of Energy, Pacific Northwest National Laboratory; Distributed Hydrology Soil Vegetation Model (DFLSVM); https://dhsvm.pnnl.gov/
8	U.S. Geological Survey; Sinkholes; https://water.usgs.gov/edu/sinkholes.html
9	U.S. EPA; RE-Powering America's Land; https://www.epa.gov/re-powering
10	Current Forestry Reports; Assessing Landscape Vulnerability to Wildfire in the USA; Vaillant, Nicole M. et al.; 2:201-213 (2016);
https://www.fs.fed.us/pnw/pubs/journals/pnw_2016_vaillant001.pdf
To learn more about climate resilience at Superfund sites and access new information
and decision-making tools as they become available, visit:
www.epa.gov/superfund/superfund-climate-resilience
Contacts
Questions about climate resilience in EPA's Superfund Program may be forwarded to:
Carlos Pachon (pachon.carlos@epa.gov) or Hilary Thornton (thornton.hilary@epa.gov)
EPA is publishing this document as a means of disseminating useful information regarding approaches for assuring climate resilience. 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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