Closure/Postclosure of Disposal Sites
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.
Further information can be found in:
A Guide to the Revegetation and Environmental Restoration of Closed
by Jacques Graber, October 1999
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 (now CalRecycle)
9811 Sheldon Rd. Elk Grove, CA 95624
(916) 689-1015, ext 10
Sacramento Watersheds 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.
Cal Poly's School on Studying Alternative Technologies including integrated waste management and alternative energy production.
Low IMPACT Development Considerations (LID): LID is an alternative site design strategy that uses natural and engineered infiltration and storage techniques to control stormwater runoff where it is generated. The objective of LID is to disperse water forces through using low impact dispersal systems to minimize runoff. LID serves to preserve the natural hydrologic and environmental functions altered by conventional stormwater management. LID techniques provide temporary surface runoff water retention areas, increase surface runoff water infiltration, allow for pollutant removal and control the release of excessive stormwater into adjacent waterways.
Closure and Technical Services, http://www.calrecycle.ca.gov/SWFacilities/TechServices/
Mike Wochnick: Michael.Wochnick@calrecycle.ca.gov (916) 341-6318