Methane Mitigation System for Buildings


Methane Mitigation Systems for Buildings


A methane mitigation plan eliminates the hazards of methane soil gas intrusion. Without proper methane mitigation, vapors can migrate through foundations and into buildings. This causes an accumulation of methane gas and leads to explosive and asphyxiation hazards.

In Los Angeles, these plans are created for projects within Methane Zones or Methane Buffer Zones. Additionally, plans require review and approval of the building department. Furthermore, design parameters of a methane mitigation system are based on the results of a methane soil gas test.

The geologists and engineers at Geo Forward, Inc. are experienced with the latest design standards and building codes. Geo Forward, Inc. specializes in designing these systems for commercial and multi-tenant residential projects.  Moreover, Geo Forward, Inc. specializes in subterranean parking garages, underground vaults, basements and more. Comprehensive mitigation plans summary reports are provided. Lastly, Geo Forward, Inc. provided construction support and oversight. Call us at (888) 930-6604 to speak with a licensed geologist or engineer.

Methane Mitigation Barrier System. Methane Barrier Deputy Inspection Photo.

Methane Mitigation Barrier System. This photo taken during methane deputy inspection.


City of Los Angeles Methane Mitigation Requirements

The City of Los Angeles established high-risk “Methane Zones” and “Methane Buffer Zones.” For properties in a Methane Zone or Buffer Zone, there is a requirement to comply with Los Angeles Department of Building and Safety (LADBS).  Site design parameters are based on the data from a methane soil gas test.

There are various LADBS mitigation design parameters. Accordingly, the methane mitigation requirements increase with each level of methane gas concentration. As a result, the plans can include specialized ventilation systems that are either “Passive” or “Active.”

Methane Mitigation Methane Barrier Installation

© MTA Capital Construction


Passive Vapor Mitigation Systems

Passive ventilation systems can be engineered to remove methane gas from the subsurface.  A passive system relies on the natural rising characteristics of methane gas to capture the accumulations underground. The system is engineered to direct the gas upwards into the atmosphere.

Passive Methane Mitigation Subsurface Piping

Passive Methane Mitigation System


Active Vapor Mitigation Systems

Active methane mitigation systems are comprised of subsurface gas extraction systems. These systems are blower or pump activated. Moreover, HVAC systems accelerate indoor ventilation. Additionally, an active system includes methane gas sensors and an alarm system. This warns occupants of peaking methane concentrations.

Active Methane Mitigation Systems Include a Methane Gas Alarm

Active Methane Mitigation System – A Methane Gas Alarm


Dewatering & Waterproofing in Methane Mitigation

Dewatering systems lower the groundwater table to a level below the bottom of a soil-gas ventilation system. Waterproofing barriers prevent groundwater from passing through a methane barrier. Geo Forward specializes in designing dewatering systems and waterproofing barriers.


For more information about methane mitigation plans, call (888) 930-6604 to speak with an expert. 


Geo Forward, Inc.

Forward-Thinking Geologists, Engineers & Contractors!

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