Superfund Climate Resilience: Resilience Measures
Resilience Measures
Measures to maintain remedy protectiveness under future climate conditions may be integrated into the design or operation of a site remedy. A remedy may include multiple remediation systems intended to address contaminated groundwater, soil or sediment. Adaptive actions commonly involve:
- Physically securing the systems.
- Providing additional barriers to protect the systems.
- Safeguarding access to the site and individual systems.
- Alert project personnel of system compromises.
Certain climate resilience measures address a system’s operating parameters, such as installing equipment that enables offsite workers to remotely adjust or suspend operations during extreme weather events. Other measures involve installing engineered structures that address vulnerabilities such as onsite power supplies and erosion controls. Engineered structures also may help prevent transport of contaminated material across a site or to offsite areas during heavy or prolonged precipitation and avoid site recontamination due to stormwater runoff from offsite sources.
Site remediation decision makers are encouraged to apply nature-based solutions that weave natural features or processes into the built environment. Relevant practices are described in resources such as:
- Building Community Resilience with Nature-Based Solutions, a guide developed by the Federal Emergency Management Agency to support local communities.
- Compendium of Federal Nature-Based Resources for Coastal Communities, States, Tribes, and Territories, a resource compilation by the federal Coastal Resilience Interagency Working Group.
| Engineered Structures Commonly Used in Climate Resilience Measures | |
|---|---|
| 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; "hard" armor may consist of riprap, gabions and segmental retaining walls. |
| Berm | A low, impermanent, nearly horizontal ledge or narrow terrace made of earthen material to retain or divert floodwater. |
| Bulkhead | A structure or partition to retain or prevent land sliding and to protect uplands against damage from wave action. |
| Coastal hardening | Installation of structures to stabilize a shoreline and shield it from erosion. Techniques for “soft” stabilization involve replenishment of sand and/or vegetation or placement of other natural materials. "Hard" stabilization typically involves bulkheads, concrete sea walls, riprap, jetties or groins. |
| Dam | An earthen, rock, concrete and/or steel barrier constructed across a flowing water channel to impound water and, as needed, divert floodwater. |
| Dike | A wall, generally made of earthen materials, designed to prevent permanent submergence of lands below sea level, tidal flooding of lands between sea level and spring high water, or storm-surge inundation of a floodplain. |
| Fire barrier | A network of buffer areas (land free of dried vegetation and other flammable materials) and/or manufactured systems (such as such as radiant energy shields and electrical raceway fire barrier systems) to prevent spread of fire. |
| Gabion | A wire mesh basket or mattress filled with rocks or in some cases masonry materials to stabilize banks and/or beds of surface water channels, divert floodwater away from certain sections of a channel, or retain land slopes. |
| Groin | A structure typically made of concrete, timbers, steel or rock, and oriented perpendicular to a coastline to accumulate littoral sand by interrupting long-shore transport processes. |
| Ground anchor | A steel bar installed in a cement-grouted borehole to secure an apparatus on a ground surface or to reinforce a retaining wall against a sloped earth mass. |
| Hurricane strap | A heavy metal bracket that reinforces physical connection between the roof and walls of a building or housing unit. |
| Jetty | A structure of concrete and/or rock at the mouth of a river or tidal inlet to help stabilize a navigation channel, by preventing channel shoaling due to littoral materials and directing and/or confining the river or tidal flow. |
| Levee | A wall, generally made of earthen materials, designed to prevent the flooding of a river after periods of exceptional rainfall. |
| Retaining wall | A structure that supports earth masses having a vertical or near-vertical slope (such as 70 degrees). The structure may consist of material such as concrete, gabions, steel sheet piles or timber (and may include a reinforcement element such as geosynthetic material) forming a gravity wall, cantilevered wall, anchored wall or mechanically stabilized wall. |
| Riprap | A layer, facing or protective mound of stones randomly placed along stream or river banks, a shoreline or a structure to prevent erosion, scour or sloughing. |
| Seawall | A structure typically built parallel to a coastal shore to prevent erosion and other damage by wave action, often retaining the earth against its shoreward face. A "hard" seawall is often made of concrete or stone and is more massive than – and therefore capable of resisting greater wave forces than – a bulkhead. A “soft” seawall consists of replenished sand and/or vegetation. |
| Stormwater pond | A constructed basin intended to retain or detain stormwater runoff; a retention pond ("wet pond") holds a permanent pool of water throughout the year (or at least throughout the wet season) while a detention pond ("dry pond") is designed to detain runoff for a minimum time (such as 24 hours) during storm events. |
| Tie down | A permanent mount that allows rapid deployment of a cable system extending from the top of a unit to the ground surface. |
| Vegetated swale | A broad, shallow channel with a dense stand of vegetation covering the side slopes and bottom of an earthen structure to retain or divert floodwater. |
[Descriptions of these engineered structures are extracted or adapted from resources such as the: (1) U.S. EPA Office of Air and Radiation/Office of Atmospheric Protection/Climate Change Division; Vocabulary Catalog: Coastal Sensitivity to Sea-level Rise Glossary and Acronyms; (2) U.S. EPA; National Menu of Stormwater Best Management Practices; (3) U.S. Army Corps of Engineers; Coastal Engineering Manual Part I: Introduction, with Appendix A: Glossary of Coastal Terminology; and (4) NOAA; National Weather Service; Glossary]