Methane Inspection


Methane Inspection for Soil Gas Mitigation


The purpose of a Methane Inspection (also known as a Soil Inspection or Soil Gas Survey) is to test a property for subsurface methane and hydrogen sulfide hazards, in order to determine the proper methane mitigation design parameters for future development.

Methane is a colorless and odorless gas that can migrate underground (through soil and structure foundations), and accumulate inside buildings. Accumulations of these gasses are associated with oil and gas fields, natural gas extraction wells, coal mines and landfills. Awareness on the hazards of methane soil gas rises from methane gas explosions in Los Angeles during 1985. Since then, various building departments and public works agencies recommend a methane soil gas survey and/or a mitigation plan within specific methane hazard zones.

After a methane inspection has been completed at a job-site, a methane mitigation plan is prepared in effort to eliminate the hazards of methane  gas intrusion. In addition to methane soil gas investigation, Geo Forward, Inc. also provides methane mitigation design services and methane mitigation plans for all types of construction projects.

Call us at (888) 930-6604 to speak with a licensed geologist and get a free estimate!  


Click Here For LADBS Methane Barrier Deputy Inspection


Where would a Methane Inspection be Required? 

Methane Inspection "The first oil district in Los Angeles, Toluca Street, ca.1895-1901"

The first oil district in Los Angeles, Toluca Street, California.1895-1901 (CHS-3686)

During the late 1800s and early 1900s, oil and gas production was predominantly practiced in central and southern California. The northernmost areas of California were primarily used for natural gas production.

In recent years, the City of Los Angeles established high-risk “Methane Zones” which require methane soil gas surveys before undergoing construction or demolition. Various public works entities are beginning to follow the same standards.  Citywide methane mitigation requirements can be reviewed in Ordinance No. 175790 and Ordinance No. 180619.

Unincorporated cities in Los Angeles County fall under the jurisdiction of the Los Angeles County Methane Mitigation Unit, and generally require methane soil gas surveys on construction sites within 1,000 feet of a landfill or 300 feet of a oil & gas well. Please Click Here to view the County of Los Angeles Building Code.

Huntington Beach and other portions of Orange County also require a methane investigation to assess methane risk.


Typical Soil Gas Probe Set schematic for a Methane InspectionBuilding Department Standards – Methane Inspection for Soil Gas

Geo Forward offers methane inspection services to meet the requirements of all building jurisdictions in California (including Los Angeles City, Los Angles County, Huntington Beach, Ventura County and more). Our sampling and testing plans include determining site design level, locating nearby zone boundaries or hazards, installing soil gas probes, and air quality analysis. A standard methane inspection tests the shallow soil gas underlying a property, for fast results from the field.


Limited Methane Inspection for Real Estate Due Diligence 

When a comprehensive methane inspection is NOT required by the local building departments, property owners can request a limited methane inspection for due diligence and risk assessment purposes.  In such cases, Geo Forward offers Limited Methane Investigations.  IF the findings of a limited soil gas investigation warrant a follow-up comprehensive methane inspection, costs can be credited towards the comprehensive scope.


Methane Inspection Probe Set

Photo by: Azad Kaligi

Methane Mitigation Plans (after the Methane Inspection process) 

Local building departments may also require methane mitigation plans to reduce health-related dangers such as asphyxiation or explosion.  Geo Forward offers a variety of methane mitigation services in all areas of California. Click here to learn more about Methane Mitigation Plans/Reports. 


For more information about methane inspection or mitigation, please call (888) 930-6604 to speak with a licensed professional geologist, engineer or environmental scientist. 


Geo Forward, Inc.

Forward-Thinking Geologists, Engineers & Contractors

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