Closure/Postclosure of Disposal Sites

Environmental Restoration

A typical landfill can involve the disruption of a significant area of land, and along with that land the accompanying habitat. Upon closure, a landfill may undergo a postclosure use, as a business park, recreational park or, it may be restored, either as mitigation or as a final planned outcome as an environmental habitat. Cases of environmental restoration on closed landfills are covered and exemplified by Coyote Canyon Landfill, Orange County, Crescent City Landfill, and Del Norte County.

Title 27 California Code of Regulations (CCR) require a landfill to be closed and a final step is the installation of the final cover, which includes the vegetative cover. Landfills must be closed in compliance with the minimum requirements for vegetative cover according to 27CCR, section 21090.

The closure of landfills anticipates the potential postclosure status of a landfill with regard to postclosure land use, which may be, among other uses or classifications, "nonirrigated open space," "irrigated open space," or "commercial/industrial" in the closure plan.

Landfills that are identified as "open space" may be brought to a state of satisfactory compliance with 27CCR or to a state beyond the minimum requirements of 27CCR, including golf courses, natural preserves, or mitigative projects involving environmental restoration.

Several significant landfill postclosure land use projects have involved such restorative techniques and several cases can be noted.

• Revegetation involves the placement of plants, horticultural or native, on a project site. Relatively few, if any, other environmental restoration techniques will be applied. The plants can be an arbitrary choice of the project coordinator, with no regard for native species, their distribution or plant community design. A landfill configured to engineering specifications and planted with non-native grasses in regulatory compliance illustrates simple revegetation. Consideration for county approval of species should be made, though.
• Environmental Restoration will invariably involve revegetation. But, it also involves the extensive design and naturalization of project site contours, soil content and vegetative communities. The intent of environmental restoration is to create a seamless “repair” by emulating and supporting the native floral and faunal communities adjacent to and on the project site. The ultimate aim is for the project to be “assimilated” back into the natural surrounding environment.

Environmental restoration is characterized by these elements:

• A detailed reconstruction of the project site topography (elevations).
• Site geomorphology (surface features).
• Soil types conducive to the native plants of the project area.
• Surface hydrology (water features).
• Native plant species, their diversity, and distribution.

More Information

Further information can be found in:

A Guide to the Revegetation and Environmental Restoration of Closed Landfills
by Jacques Graber, October 1999

• Order the CIWMB Publication.
• View the web page.

Water Use Classification of Landscape Species (WUCOLS) A Guide To Estimating Irrigation Water Needs of Landscape Plantings in California, WUCOLS III

Guide to Vegetative Covers for California Landfills, California Integrated Waste Management Board

California Association of Resources Conservation Districts

California Native Grass Association

Cornflower Farms
9811 Sheldon Rd. Elk Grove, CA 95624
(916) 689-1015, ext 10.

Sacramento Wetlands Action Group (SWAG): A 501(c)(3) nonprofit public-benefit corporation established to put watershed restoration dollars "on the ground" using cost-effective technology and local work forces.

US EPA's Glossary of Terms Used in Environmental Restoration

Cal Poly's School on Studying Alternative Technologies including integrated waste management and alternative energy production.

Case Studies

• Coyote Canyon Landfill, chaparral (30-AB-0017)
• Crescent City Landfill, dune, wetlands (08-AA-0006)

Last updated: April 18, 2008