Santiago Canyon



    The site is located off Santiago Canyon Road, east of the intersection of the SR 261 and SR 241, adjacent and westerly of Irvine Lake. The physical address is 3099 Santiago Canyon Road.

Dates of Operation and Closure

    The County operated the site as a municipal solid waste landfill from 1968 to 1993 with reduced operations for three additional years. The County ceased accepting waste at the site in mid 1996.

Size and Types of Waste

    The site is a closed Class III landfill approximately 113 acres in size, containing approximately 23.7 million cubic yards of municipal solid waste.


  • 1968-2002 County leased the site from The Irvine Company (TIC).
  • 1968-1993 County operated site as a Class III landfill.
  • 1993-1996 County operated the landfill with reduced operations.
  • 2002 County commenced final closure construction under a Mitigated Negative Declaration (MND No. 378).
  • 2002 County obtained fee ownership of the refuse mass from TIC, with easements of approximately 1,000’ from the refuse mass for environmental system monitoring. Upon completion of TIC’s development adjacent to site, the easements will convert to County fee ownership.
  • 2004 County final closure construction was completed, and Coastal Sage Scrub (CSS) planted as pre-mitigation for the County’s Habitat Management Program.
  • 2005 Interests were expressed to develop the site into an equestrian center or for use as a model airplane airfield. The Final Post Closure Maintenance Plan (FPCMP) was approved by regulatory agencies.
  • 2007 County conducted an investigation of existing site landfill gas probes to determine whether they comply with new compliance probe regulations.
  • 2008 Revisions to the FPCMP were submitted for approval by regulatory agencies.
  • 2009 The revised FPCMP was approved.
  • 2010 No activity of note to report.
  • 2011 A Request for Proposals was sent out for landfill gas utilization projects. Flex OC Energy LLC received an option agreement to construct a 1.5 – 2 megawatt plant.
  • 2012 The Flex OC Energy option agreement was extended to December 2012 to allow the company to complete the CEQA process and to obtain an agreement for sale of the energy to Edison. Construction of the physical plant is scheduled to begin in early 2013.

Current Owner

    County of Orange.

Current Land Use

    Natural Community Conservation Plan mitigation site; open space

Environmental Control Measures

    County maintains landfill cover; landfill gas collection, monitoring and destruction systems; and monitors ground and surface water quality.

Click here for property location

Click here for closed site information on Cal Recycle's website.


View Santiago Canyon Landfill in a larger map.

Please contact us at 714-834-4000 if you have any questions regarding this site.