Methane Testing and Soil Gas Survey 4


Methane Testing and Soil Gas Survey

Methane testing is the environmental engineering process that examines the in situ soil gas under a property for explosion hazards. This physical process consists of drilling, vapor implant installation, sampling, laboratory work and a report stamped by a professional geologist. In fact, the data from a methane test aids building departments in health and safety determinations, and mitigation requirements. Methane testing and methane mitigation systems are essential for properties inside “special hazard zones.” For example, the City of Los Angeles has “Methane Buffer Zones” and “Methane Zones.” Whereas the City of Huntington Beach has “Methane Districts.” And these special zones are a result of petroleum fields and landfills. Updated December 5, 2018.

Methane Testing Drilling via Direct-Push Rig

Methane Testing Drilling via Direct-Push Rig

About Methane Soil Gas

Methane has chemical formula of “CH4,” and is the predominant chemical compound (by volume) of natural gas. Methane soil gas is flammable, colorless and odorless. Soil gas and can migrate through geological formations into confined structures above ground. As a result, the gas accumulates inside buildings, and can concentrate to combustible levels overtime. Typically, this hazard is a consequence of historical oil drilling, natural crude oil surfacing, and landfill activities. As a result, a methane test determines the concentrations of in situ CH4 at a property, and a methane mitigation system eliminates the risk of combustion.

Methane Test Containers

Methane Test Containers

Methane testing is usually the prerequisite to the methane mitigation system design. Awareness on the hazards of combustible soil gas rises from a series of explosions in Los Angeles during the 1980s. Consequently, the Los Angeles Department of Building and Safety (LADBS) implement methane testing and mitigation requirements in these special zones. Similarly, other agencies, such as the County of Los Angeles, County of Orange, City of Huntington Beach, and more enforce LADBS codes. Please Click Here to view the County of Los Angeles Building Code.

Methane testing at the first oil district in Los Angeles

The first oil district in Los Angeles – Methane Testing

Moreover, various local, State and federal agencies, under the jurisdiction of the United Stated Environmental Protection Agency, have recently formed departments and units in charge of methane mitigation. In fact, the growing concern for hazardous methane gas and other subsurface contaminants is prompting these agencies to strengthen the environmental policies for developments moving forward. For example, the Texas Commission for Environmental Quality implements a Landfill Gas Management program comprised of soil gas monitoring, reporting and mitigation.

Methane Soil Gas Survey Probe Set

Permanent Methane Testing Probe Set

Methane Buffer Zone vs Methane Zone

Historical oil fields, storage ponds and oil wells are the typical root causes of natural gas in soil. Consequently, properties with oil wells usually yield higher methane gas concentrations. Moreover, landfills are also common sources of methane gas hazards in shallow soil. Although without documentation, there is speculation that Methane Buffer Zones and Methane Zones are a reflection of a standard proximity from landfills and petroleum wells, pipelines, fields, etc.

The City of Los Angeles established high-risk boundaries which define “Methane Buffer Zones” and “Methane Zones.” Furthermore, these zones require a methane soil inspection and potential methane mitigation system when undergoing development. Other government agencies similarly apply the same mitigation standards. Los Angeles Mitigation requirements can be reviewed in Ordinance No. 175790 and Ordinance No. 180619. The diagram in the section below is a snapshot of the official LA City Methane Zone and Methane Buffer Zone Map. As indicated per the legend, the purple areas represent “Methane Buffer Zones.” And the pink areas represent “Methane Zones.

Methane Testing Agency Roster

Most building departments and oversight agencies refer consumers to an official roster of certifiable testing consultants. Without valid certification, consultants are not authorized to perform methane testing and mitigation design services. Typically, agency rosters disclose each laboratory license number, specialized area of practice and contact information. Furthermore, the rosters display each laboratory license expiration date for consumer review.

The City of Los Angeles tends to compile all certifiable testing laboratories (of various trades) into one roster. Often times, consumers are mislead into contacting welders or concrete tests when in need of methane testing. Thus, it is advised to use the “Find Tool” on your browser (Ctrl+f) to search the words “Methane Field Testing.” Additionally, consumers should also know the agency rosters lineup consultants in alphabetic order, and NOT the order of preference. Best practice suggests obtaining bids and price quotes from a variety of companies throughout the LADBS Methane Testing Consultant List.

Geo Forward is an official methane soil gas testing and mitigation design consultant for various oversight agencies and building departments across the nation. Methane test services include locating hazardous conditions, field drilling and constructing, periodic sampling, technical reporting and more. Furthermore, Geo Forward subsurface assessments are fast, reliable and include an open dialog with clients.

Methane Buffer Zone Los Angeles

Methane Buffer Zone Los Angeles vs. Methane Zone Los Angeles

Huntington Beach Methane District Testing

The City of Huntington Beach and the Orange County Fire Authority oversees engineering projects within the local “Methane District.”  The Huntington Beach Methane Overlay District is a portion of the city area which has a high methane soil gas hazards. This area is determined by historical methane testing data and information from the Huntington Beach Oil Well Finder Database. Some of the methane gas occurrences are reportedly natural, and as a result of decaying shallow surfacing crude oil. However, the primary of the hazards are a reflection of the current and historical crude oil production wells. As a result, the City of Huntington Beach enforces methane soil testing and methane mitigation plan review for all proposed projects within the “Methane District.”

Methane Testing Landfill

Methane Testing Landfill

Additionally, some portions of Yorba Linda are similarly reported as hazard zones due to historical oil production. And the City of Santa Fe Springs (in Los Angeles County) also regulates high methane soil gas testing zones as a result of the petroleum and landfill activities.

Methane Mitigation Design

A methane mitigation system prevents methane soil gas from entering a structure. The professional service is a branch of the environmental engineering industry, and involves intensive planning to protect the occupants above ground, or underground. Each mitigation plan must be custom designed and site-specific, per the structural plans for development. Moreover, the mitigation plans must achieve building department approval, per the results of the prerequisite methane test data and respective building codes.

Click here to learn more about Mitigation Design Options. 

Geo Forward is the chief provider of methane testing services and methane mitigation design services, throughout the nation. Geo Forward designs strive to meet all agency requirements, as well as developer budgets for construction. For more information or a private consultation, call (888) 930-6604. 

Sources of Information:
U.S. EPA
U.S. EPA Guidance for CH4 Landfill Gas Sampling & Testing
City of Los Angeles, Department of Building & Safety
The CH4 Zone – The Land Developer’s Guide


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4 thoughts on “Methane Testing and Soil Gas Survey

    • Project Geologist II Post author

      Unfortunately not. Typical Los Angeles basin soils are known to be “non-homogeneous.” The means the soils underlying your neighbor’s lot are not likely to be exactly like yours. Especially in regards to depths, gas-mobility, moisture, gas-content, and more. As a result, methane test results at your neighbor’s lot are likely to differ from yours. We’ve been hearing complaints from callers, about one company out there saying they can “predict methane test results” with “30 years of experience.” This seems to just be a sales hook, and an unethical business tactic. The reality is that these results differ from site to site.

  • David Erickson

    Is repetitive soil gas testing a requirement for commercial buildings with permanent subslab methane testing sensors?

    • Project Geologist II Post author

      Typically yes. However, this ultimately depends on your site specifics. In general, the fire department and your methane mitigation engineer determine this necessity. It may be quarterly, semi-annual or annual.