Revegetating Landfills and Waste Containment Areas Fact Sheet Introduction This Fact Sheet The U.S. Environmental Protection Agency (EPA) Office Discusses the Following: of Superfund Remediation and Technology Innovation (OSRTI) is developing a series of fact sheets on ecological • It is possible to plant on restoration and revegetation of contaminated sites. landfill surfaces Former landfills, abandoned dumps, mines, and other contaminated sites throughout the U.S. - once thought • Native plants are recommended to be of limited or no value - are being reclaimed for a when revegetating sites variety of productive uses. These new uses include revegetation of land where plants and animals can once • Technical factors to consider when again flourish. For example, as of 2005, thousands of revegetating acres of land on Brownfields, Superfund, and Resource Conservation and Recovery Act (RCRA) sites have been • References and additional assessed or cleaned up and revegetated. In particular, resources more than 50 Superfund sites have been cleaned up and returned to ecological use. Aesthetic and final land use considerations are becoming more common during cover design. Some increasingly common end uses include parks, hiking trails, wildlife habitat, sports fields, and golf courses. This fact sheet provides information Keys to Success when on revegetation of landfill surfaces for EPA site managers, consultants, and others interested in the revegetation of Revegetating Landfill landfill surfaces. Surfaces: Contaminated material may be left on the property in • Ensure proper planning, containment systems designed to protect people and the environment from exposure and prevent design, and funding contaminant migration. In deciding how to support • Provide adequate soil quality the revegetation of these sites, however, there are and depth questions about whether it is appropriate to plant on the landfill surface. Grasses are typically used to • Determine appropriate target help stabilize the landfill surface and prevent runoff, habitat and native plant but shrubs and trees are selected less frequently because of concerns that the root systems could selection damage the surface. Based on the location of the • Allow for appropriate containment area, site-specific approaches should be planting and establishment used and a general approach has been discussed in this fact sheet. Former landfills, abandoned dumps, • Conduct routine monitoring mines, and other waste containment areas will be and management referred to as landfill surfaces throughout the fact sheet. 1 Is it Possible to Plant a result (Robinson and Handel 1995). The on Landfill Surfaces? key factors that affect the feasibility of planting on a containment system include the characteristics of the landfill surface Yes, it is possible to plant trees, shrubs, (such as soil depth and soil quality), the and other types of vegetation on the desired plant habitat, and the physical containment system at many sites without setting of the site (for example, topography affecting its integrity and protectiveness. and climate). In fact, many sites have been revegetated with a variety of plants on a containment system. For example, grains, wild­ Why Use Native Plants? flowers, and other carefully selected flora were planted at • Native plants provide a beautiful, the Army Creek Landfill in hardy, low maintenance, and drought Delaware to create a meadow to attract migratory birds resistant landscape ( http://www.epa.gov/ • Native plants can develop into a self- superfund/programs/recycle/ sustaining ecosystem, eliminating the success/casestud/armycsi.htm). need for fertilizers, pesticides, and water The primary concern in planting on landfill surfaces is ensuring the integrity of the containment system, Can Native Plants be particularly the potential for roots to Used on a Landfill penetrate and physically damage the cap, thereby creating entry points for water, or Surface? to open fissures in the protective barrier by excessive moisture reduction. However, Although a variety of plant species can be ongoing research and a growing body of used on a landfill surface, native plants are experience indicate that, if it is properly recommended when possible. While each designed and implemented, the integrity project is site-specific, plants are typically of the landfill surface can be maintained selected based on the design of the landfill while it supports a variety of plants. Root surface, the role of the vegetative cover, growth depends on the characteristics of the depth of plant roots, irrigation and the soil, and the presence of a clay liner drainage requirements, geographic and or geomembrane influences its growth. atmospheric conditions, long-term Research at the Brookfield Sanitary Landfill maintenance requirements, and costs to in New York showed that roots, including acquire and install materials and plants. taproots, grow laterally once they reach A single species of grass has commonly the clay cap. No significant damage to been planted as a monoculture to control the clay cap was observed as erosion of landfill surfaces, but the species For more information on the design of landfill caps, please visit the following Web sites: • http://www.epa.gov/ORD/NRMRL/pubs/600r02099/600R02099.pdf • http://www.epa.gov/epaoswer/non-hw/muncpl/landfill/techman/subpartf.txt 2 may or may not be indigenous to the surrounding habitat and are more vulnerable to disturbance (Harper 1987). Native Plants – Ecological Values However, planting native species that have been selected over thousands of years in • Native plants do not require fertilizers that area are best adapted to disturbances • Native plants do not require pesticides and climate change (Waugh 1994). Species diversity helps reduce disease • Native plants require less water dispersal or blights and encourages wider (no watering once established) biological diversity in the restored habitat, than turf grass (lawns) making it more like a natural ecosystem, in turn reducing long-term operation and • Native plants provide shelter and food maintenance (O&M) and promoting a self- for wildlife sustaining ecosystem (Handel et al 1994). • Native plants are critical to a diverse Even sites that currently support monocultures number of pollinators can be converted to diverse native plant communities through careful planning and • Native plants reduce air pollution monitoring. The site can be prepared for native seeding or planting by prescribed • Native plants provide biodiversity and burning, using herbicide, or removing a thin stewardship of our natural heritage layer of soil along with the monoculture vegetation. Native plants can even be • Native plants save money seeded through existing cover with a no-till • Native plants can offer economic values drill; periodic burning would also be beneficial in controlling the monoculture (medicinal, herbals, landscaping vegetation. For example, the Christian and food) County Landfill was converted from a sparse monoculture with eroding areas to a thriving native prairie (http://www.epa.state.il.us/ environmental-progress/v25/n1/ adapted to the geography, hydrology, and abandoned-landfill.html). climate (see http://www.epa.gov/ greenacres/). Native plants found in the A major consideration when selecting plants surrounding natural areas will have the most for a site is Executive Order (EO) 13148, chance of success, require the least which promotes use of native species on maintenance, and are the most cost-effective revegetated sites. EPA defines native plants in the long term. Ideally, revegetation of a as plants that have evolved over thousands of site will create natural conditions that years in a specific region and that have encourage re-population by native animal For more information on plant types, please visit the following Web site: http://www.ciwmb.ca.gov/LEACentral/Closure/Revegetate/. To identify the type of general land use in your area, please visit the following Web site: http://www.nrcs.usda.gov/technical/land/cover_use.html. For examples of natural habitat restoration on landfills, please see page 63 of the following Web site: http://www.epa.gov/tio/tsp/download/dctechnical.pdf. 3 The species that are appropriate for local habitat conditions can be selected with support Native Plants - Ecosystem Integrity from EPA's regional Biological Technical Assistance Groups, EPA's Environmental • Native plants support a complex web of Response Team (http://www.ert.org), the life, and provide a critical component to Natural Resources Conservation Service ensure balance in our ecosystems (NRCS) (http://www.nrcs.usda.gov), and local native plant societies, such as the • Only native plants can provide long-term following: http://michbotclub.org/links/ sustainability of the landscape native_plant_society.htm. Yet: What Types of Plants • more than 200 plants have become Can be Used on a extinct since the early 1800's Landfill Surface? • nearly 5,000 native plants are "at risk" Each project has site-specific considerations, and the plant types listed below are not • one in ten plants face extinction applicable to every site. • Grasses and Wildflowers are generally herbaceous and are limited to prairie-like habitats or appearances, with species and that are consistent with the wildflowers providing a broad selection surrounding land. Furthermore, using non­ of plant heights, root depths, and aesthetic native plants located close to native plant choices. Considerations when selecting environments could displace