for compliance to NSPS Subparts WWW, XXX, and EG (Subpart Cf)

Sniffer provides manual surface emissions monitoring (SEM) used to monitor landfill gas emissions in compliance with 40 CFR Part 60, Subparts WWW, and XXX.

Our technicians are required to walk the landfill to visually inspect the site while monitoring fugitive gas emissions with a hand-held methane detector.  The methane emission concentrations are measured and manually collected using a detector compliant to 40 CFR Part 60, Subpart WWW Appendix A (Method 21). 


Measured methane emissions above 500 ppm are flagged and reported. Subsequent re-inspections are required 10-days post the initial inspection, then within another 10 days following. A final inspection is required 30 days after the initial.  

Our methodical approach


Our technicians are properly trained on the specifics of the regulatory requirements. 

These requirements include calibration of the equipment, monitoring of weather

conditions, equipment set-up and utilization, walking path requirements, identification

of additional areas to inspect, reporting methods, and others.  Technicians utilize

Sniffer's designed apps on their mobile devices to record their walking path,

and to record locations where exceedances (methane emissions above threshold)

are found.  Details of the location and the cause of the exceedances, along with additional

information are recorded onsite at the location when observed.

Inspection reports are provided to customers promptly at the end of each daily

inspection.  The report contains:


  • Methane concentration (PPM)

  • GPS coordinates

  • Further location details (e.g. distance to gas well)

  • Potential cause and/or suggested corrective action

  • Photograph of exceedance location

  • Additional notes

  • Detector calibration report(s)


At the end of the 30-day inspection, a formal report is provided

for regulatory compliance purposes.

SEM details are also reported in SnifferVIEW™ for customer viewing.  This online,

secure portal provides rich data and imagery within a dynamic mapping tool and

can be used operationally to aid in onsite remediation and to monitor remediation



SEM data can further be combined with advanced imagery and additional

data collection services for a complete landfill cover integrity assessment.  

Daily Report Sample.png