Perimeter gas probes – Brawley landfill

Methane extraction system

Nested gas casing in probe

Installing new gas probe

Gas measurement with GEM 2000

Dynamic methane survey with geoprobe

The Bodhi Group performed quarterly monitoring of perimeter gas probes at 9 landfill sites (Brawley, Calexico, Holtville, Hot Spa, Imperial, Niland, Ocotillo, Palo Verde, and Picacho) to keep the landfills in compliance with California Code of Regulations (CCR) Title 27 requirements for perimeter landfill gas monitoring and reporting.

The Bodhi Group:

• Measured methane and non-methane organic compounds in 103 wells nested in 53 probes at 9 landfill sites.
• A total of 5,463 readings were collected and incorporated in a geospatial database.
• A calibrated Landtec Gas Analyzer and Extraction Monitor Model 2000 (GEM™) was used to record methane concentration (CH₄), oxygen (O₂), carbon dioxide (CO₂), and balance gases as % by volume, atmospheric pressure, relative probe pressure, and the date and time of reading; the readings were incorporated in the geospatial database.
• Installed new nested gas probes to replace older probes that were no longer needed.
• Collected landfill gas samples for laboratory analysis based on GEM instrument readings.
• Performed dynamic methane soil gas survey (based on results a methane extraction system as installed).
• Installed piezometers and performed water-level analysis to determine possible source of shallow perched groundwater.