Methane Testing and Soil Gas Survey 20

Methane Testing and Soil Gas Survey

Methane testing is performed to screen soil gas underground. This is additionally required to determine whether a mitigation plan is needed to reduce combustion hazards.  The process includes drilling, constructing sample probes, sampling and a final report.

CH4 is a colorless and odorless gas, and moves through soil and foundations. Additionally, CH4 accumulates inside buildings overtime. This hazard is usually associated with historical oil and gas fields, and landfills. A methane test is required for all construction projects in a Methane Zone or Buffer Zone.

Furthermore, if test results are high, a mitigation system will be required. Geo Forward, Inc. provides soil testing and mitigation design services.

Methane Testing in Special Zones 

Historical oil fields, storage ponds and production wells are the main sources of natural gas hazards in shallow soil. Additionally, landfills and the areas surrounding them are another cause of CH4 in soil gas. Awareness on the hazards of natural gas rises from explosions in central Los Angeles during the 1980s. Since then, the Los Angeles Department of Building and Safety (LADBS) and other local agencies have required testing in special zones.

The first oil district in Los Angeles

Los Angeles Methane Buffer Zone

The City of Los Angeles established high-risk boundaries which define a Methane Zone or a Buffer Zone. These zones require soil inspections when undergoing development. Other local agencies apply similar standards. Mitigation requirements can be reviewed in Ordinance No. 175790 and Ordinance No. 180619.

Geo Forward is a licensed soil testing agency and mitigation consultant for the City of Los Angeles Department of Building and Safety, also referred to as the LADBS. Methane test services are provided to meet the requirements of LADBS. LADBS survey includes locating hazards, drilling, setting soil gas probes, sampling, reporting and concluding.  Furthermore, the assessments are fast and include an open dialog with clients.

Photograph of a Permanent Methane Testing Probe Set

Methane Testing Probe Set

Landfill Gas

Unincorporated cities under the jurisdiction of the Los Angeles County – CH4 Mitigation Unit (such as Santa Fe Springs and more) require soil gas surveys.  Typically, an assessment is needed on construction sites within 1,000 feet of a landfill, or 300 feet of an oil & gas well.  Please Click Here to view the County of Los Angeles Building Code.

CH4 - Landfill Soil Gas Survey

CH4 – Landfill Soil Gas Survey

Huntington Beach

Huntington Beach and other Cities in Orange County require a CH4 assessment to address explosion hazard risk. Geo Forward offers hydrogen sulfide and CH4 survey services for the City of Huntington Beach. Sampling and testing procedures include all of the elements required by the Huntington Beach Fire Department.

Methane Test Containers

Methane Test Containers

Mitigation Design

A mitigation plan may be required to eliminate health-related dangers such as asphyxiation or explosion.  Moreover, mitigation plans are designed based on the “LADBS Site Design Level,” which is determined from the soil gas test. There are five LADBS Site Design Levels, (Site Design Level I though V). And mitigation design requirements increase with each Site Design Level.  Click here to learn more about Mitigation Design Options. 

For more information call us at (888) 930-6604 to speak with a licensed professional geologist, engineer or environmental scientist. 

Geo Forward, Inc.

Forward-Thinking Geologists, Engineers & Contractors!

 Sources of Information:
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

Leave a comment

Your email address will not be published.

20 thoughts on “Methane Testing and Soil Gas Survey

  • Brian Johannes

    Our property in los angeles needs a methane zone inspection. Is it smart to get one proposal for both a soil gas survey and also to design the mitigation system?

    • Azad A. Kaligi, PG Post author

      Hi Brian. Yes the Los Angeles Building Department will require a test if your property is in either zone. But I recommend you request the soil gas test proposal separately from the mitigation plan design.

      The survey results are what determine the level of mitigation design-parameters. Lower level systems cost less to design than the higher levels.

      One simply can’t predict the results of a test before actually drilling and sampling at the site… Thus, it is difficult to accurately estimate a cost for designing a mitigation system without already having test results in-hand. Chances are that these combined proposals are created to lock you into a lower up-front cost. One could expect increases during design and construction.

      Hope this helps.


      Azad A. Kaligi, PG

  • Jon Ramos

    I got a few prices for the soil assessment. but after asking around i learned the cheaper companies don’t do the test to the city of los angeles standards. Looks like they shortcut on drilling and sampling. And then us developers have to take on the risk with LADBS if it gets turned down. Your soil gas survey and mitigation report was approved by LA city fast. Thanks again.

  • Travis B

    Our phase 1 esa report concluded that our property was inside a los angeles mathane zone. Do we need a survey now? Or is it possible to do the inspection at the same time as the phase 2?

    • Azad A. Kaligi, PG Post author


      You are only required to conduct a CH4 assessment if you are planning for construction onsite. Results are used to set up design parameters for the development. And a CH4 test can be fixed into a Phase 2 scope for a combined lower cost. If you do intend to redevelop the property and need a Phase 2 anyways, I would recommend doing both tests together.


      Azad A. Kaligi, PG

    • Azad A. Kaligi, PG Post author

      Hi Gregg. Each methane testing project should be planned such that the deepest soil gas probe is set above the groundwater table. However, if groundwater levels are discovered at different heights during the drilling fieldwork, adjustments are to be made directly from the field, and accordingly reported.

    • Azad A. Kaligi, PG Post author

      Hello Devin,

      Although they are generally similar across the country, there are slight differences between the survey and mitigation procedures per building department. The City of Los Angeles has the leading standard.

    • Azad A. Kaligi, PG Post author

      HI Kristen,

      Yes. The standards require drilling to specified depths below the proposed footing. Thus, proposed subterranean features will require deeper drilling compared to slab-on-grade developments.

      For more questions, feel free to call us anytime.


      Azad Kaligi, PG
      (888) 930-6604 extension 700.

    • Azad A. Kaligi, PG Post author

      Hello Tyson,

      Specific areas of San Bernardino require this assessment. It is based on proximity to oil fields or landfills. Furthermore, areas within Santa Fe Springs, Riverside, Huntington Beach and Yorba Linda also require soil gas surveys. The scope of the assessment varies by jurisdiction.

      Feel free to call anytime to schedule an methane zone test at your next property.


      Azad A. Kaligi, PG
      (888) 930-6604 extension 700

    • Azad A. Kaligi, PG Post author

      Hi Arthur,

      The testing standards in Los Angeles Methane Buffer Zones are the same as they would be in Los Angeles Methane Zones. Although, the methane mitigation parameters are different between the two Los Angeles Zones.

      Feel free to call anytime for a detailed explanation.


      Azad A. Kaligi, PG
      (888) 930-6604 extension 700

    • Azad A. Kaligi, PG Post author

      For jobs in the Los Angeles City area, we can provide verbal results directly from the field on the first day of sampling. Fieldwork altogether takes about two days. And the final report is usually delivered after fieldwork is completed.