Palomar Closed Landfill Work 

Palomar Airport Landfill UnitsClick on map to enlarge.

The County of San Diego manages a closed landfill that is located beneath portions of the McClellan-Palomar Airport. This municipal solid waste landfill operated from 1962-1975. This includes three landfill units and a system that extracts gases, including methane, that occurs naturally as organic materials decompose.

The health and safety of our staff, community, and airport visitors are our first priority. To support this, monthly maintenance and monitoring is conducted for the closed landfill to ensure safety and protect public and environmental health.

As part of our regular inspections on October 17, 2022, staff noticed unusual settlement of the landfill in a small area of Unit 3 (northeast of the runway). Upon further inspection, we discovered elevated temperatures in an underground vault that houses components of the landfill gas system. The elevated temperatures are limited to a small, localized underground area of Unit 3. This poses no risk to the public as there have not been any emissions from Unit 3 above regulatory thresholds since the elevated temperatures were first observed.

In consultation with regulatory agencies, the County has initiated a response and investigation plan that follows standard protocols of the solid waste industry. The County’s response includes ongoing and future investigations, repairs, and improvements to the landfill infrastructure including the gas collection system.  The underground temperatures, which have decreased significantly since mid-November 2022, and other monitoring data indicate that event is diminishing. However, we remain committed to the health and safety of our staff, community, and Airport visitors by fully resolving the incident.

The area identified in the County’s inspection is secure, and the County continues to work closely with the San Diego Air Pollution Control District (APCD), Solid Waste Local Enforcement Agency (LEA), and Regional Water Quality Control Board (RWQCB) to collaborate on our response plan and ensure compliance with all regulatory requirements. If you have questions about this work, please contact Melissa Porter noted below. 


Related Agencies and Contacts ·

County Staff: Melissa Porter, REHS at 

Air Pollution Control District (APCD): APCD Hearing Board ·

Solid Waste Local Enforcement Agency (LEA)/ CalRecycle: Solid Waste Information System 

Regional Water Quality Control Board (RWQCB): GeoTracker (

Palomar Airport Advisory Committee (PAAC): Palomar Airport Advisory Committee (