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Air Quality Division uses high-tech tools to conduct enhanced inspections
October 23, 2024
Air quality inspections are one of the primary ways the Michigan Department of Environment, Great Lakes, and Energy’s Air Quality Division (AQD) determines a company's compliance with air quality rules and regulations. The bread and butter of an inspection is the inspector's eyes, nose, attention to detail, and investigative abilities. In some cases, the inspector’s natural tools can be enhanced by technology to ensure they get the whole facility story. Over the last few years, several pieces of high-tech equipment have been added to AQD’s technology toolbox. These tools have helped to identify methane leaks and to sample for hydrogen sulfide, smoke, and volatile organic compounds, among others.
EGLE staffer uses handheld monitor during landfill inspection.
Although this technology may be used at any facility where pollutants may be released in ways not normally observable by sight or smell, they are primarily used for landfill and oil and gas facility inspections. Identifying issues with these facilities is important. Early identification can minimize pollutants entering the air which may impact communities and contribute to climate-related issues. These pollutants can be large contributors to ozone formation. In particular, methane is a powerful greenhouse gas and an outsized contributor to climate change effects. Timely identification and prevention of leaks is critical to cleaner, healthier air and reductions in greenhouse gases.
When inspecting a landfill, looking for potential releases of landfill gas, which contains approximately 50% methane, is essential. Methane is created when garbage and other waste break down in a landfill. As methane is formed, gas pressure builds and forces it to rise to the top of the landfill. Once there, it is collected by a series of pipes called a gas collection system or it may escape as fugitive gas. Landfills are large and the gas collection system can effectively collect gas from much of the ground. Landfills typically collect and burn off the gas in a flare, reuse the methane to create electricity, or convert it into pipeline-quality natural gas. Landfills are subject to state and federal air quality rules and regulations that require gas collection and associated control systems to be operated so that surface methane concentrations are less than 500 parts per million (ppm).
Air Quality inspectors use a combination of devices, including a surface emission monitor (SEM) called a SEM 5000, to check for surface concentrations of methane. This sampling device has been used to indicate where leaks in the surface cover of the landfill may be present. An inspector uses the SEM 5000 to walk a grid of the investigated area. The monitor will take readings as fast as one per second along with global positioning system or GPS coordinates to help the inspector see where higher methane concentrations are located After the data has been collected, a report is prepared and sent to the landfill company highlighting the leaks and identifies any problems discovered in the associated gas collection system.
In addition to landfills, oil and gas facilities are also subject to state and federal air quality regulations. Inspectors also use a forward-looking infrared or FLIR camera to detect leaks from landfills and oil and gas extraction facilities. The FLIR camera shows leaks the naked eye cannot detect by creating an image that highlights specific wavelengths of light that are characteristic of the pollutant being observed. In addition to landfills, oil and gas facilities are also subject to state and federal air quality regulations. The FLIR camera is useful for facilities, subject to the leak detection and repair program, known as LDAR.
When leaks are detected with the SEM 5000 or the FLIR camera, the inspector can use a flame ionization detector (FID) to measure certain hydrocarbons and volatile organic compounds. The FID is a handheld device that gives real-time information on those pollutants. Inspectors may use another hand-held device called a Jerome Analyzer to measure hydrogen sulfide concentrations. Hydrogen sulfide is an air pollutant that can have strong odors even at low concentrations and can be of concern for nearby residents.
If concerns are noted, the inspector will communicate with the facility regarding the sampling results. The inspector and the facility will discuss corrective actions and any next steps with the facility. Using technology to conduct enhanced inspections is useful for air quality inspectors and facility personnel. It leads to better compliance with LDAR and other air quality rules. This technology reduces the release of pollutants into the air and the potential impacts on the surrounding community.
If you are looking for more information on landfills – how they work and how they are regulated – these resources may help:
- How Michigan samples for methane – the SEM5000
- How Landfills Work interactive story map (printable factsheet: How Landfills Work)
- Talking Trash - Landfills - part of EGLE's new "Talking Trash" video series
- Landfill and Recycling EnviroScape- part of the "EGLE Classroom" video series