A burning question: how much does gas pollute?

by Nadia Steinzor and Pete Dronkers

For the last several months, Earthworks has been field-testing a quantification tool designed specifically for use with the FLIR GF 320 optical gas imaging (OGI) camera. Just like the camera, the QL 320 by Providence Photonics allows us to document and better understand oil and gas pollution. While the camera captures images of pollution, the quantification tool measures what’s seen in those images.

We’ve taken this work on as part of the growing quest to put numbers to the amount of pollution the oil and gas industry causes. With the recent expansion of our Community Empowerment Project (CEP), Earthworks has joined this effort by seeking to measure the pollution we see with OGI cameras.

As the saying goes, “Numbers don’t lie”—but that’s because they mean nothing unless interpreted by a person. Currently, various methods are being developed and tested to measure methane coming from wells, compressor stations, processing plants, and other oil and gas pollution sources, and to understand what the results mean.

Measuring pollution matters because numerical thresholds—representing volumes of pollution—are the basis for the current system of air permits and regulations. If an operator pollutes above a certain limit, it’s a violation. If pollution levels get too high, then air quality standards can’t be met and health is impacted. Lower levels of pollution can still harm health and the environment, but regulators tasked with overseeing the industry cannot legally ignore these thresholds.

As CEP visits oil and gas sites nationwide, we identify many large and small pollution releases and file complaints with regulators on those we think warrant a response. Some are from everyday operations and some are the result of operator neglect and mechanical errors, like open tanksunlit flares, and leaking valves.

Earthworks can use measurements to push regulators to take action in response to the complaints we file—making it harder for them to dismiss the pollution in OGI videos as “standard operating procedure” or as being “below allowable limits.” Many regulators don’t go to the sites and measure pollution themselves—although federal and state requirements to detect and fix leaks are making inspections harder to avoid.

The QL320 can be calibrated only for single gases (such as propane, methane, or butane). The tool measures the volume of total gas released, with the one selected by the user in effect  serving as a proxy for the complex mix of gases that oil and gas operations actually release. Earthworks currently sets the tool to “methane” because we know that the pollution sources we document with OGI release that gas. (Over time we hope to work with Providence Photonics to make our calibrations pinpoint specific gases.)

To date, Earthworks has successfully used the QL320 to measure emissions from storage tanks, pipe fitting leaks, pneumatic controller exhaust, unlit flares, and other smaller sources. The results are concerning.

For example, we filmed pollution coming from a small unlit flare in the Permian Basin in Texas and then quantified it using methane as a proxy.

The images below show what the quantification tool captures and that the leak was releasing an average of 110 pounds per hour of gas, averaged over five separate runs. Math puts this in perspective:

At 110 pounds per hour, the annual amount of the leak is 963,600 pounds (110 x 24 hours x 365 days). Since methane is 86 times as potent as carbon dioxide over a 20-year period, the annual carbon dioxide equivalent of this one source of methane pollution is 82,869,600 pounds, or over 41,000 tons, per year. Although the carbon footprint of an average American varies widely, a reliable average number is 20 tons per person. Therefore, if this leak were mostly methane and persisted for a year, it could potentially pump out the carbon equivalent of 2,071 average Americans.

On smaller — but much more common — leaks such as pipe fittings or pneumatic controllers, Earthworks has documented numbers in the range of 1-10 pounds of methane equivalent per hour. For example, a pipe fitting leak at a site in the San Juan Basin of Northern New Mexico seems relatively benign. Multiple measurements with the quantification tool showed that the leak was emitting on average 1.45 pounds per hour. If the leak was mostly methane and left unrepaired for a year, it would pump the same amount of carbon into the air as 27 average Americans. And there could be hundreds of leaks just like this in a small area (Earthworks has documented many of them over the years).


The QL 320 is designed to measure gases that are concentrated and disperse quickly (like a leaking valve or vapors from tanks). But Earthworks also documents pollution that is released under great pressure and appears in dense plumes that travel long distances (such as the unlit flare in Texas in the example above). Providence Photonics has confirmed that for this reason, much of the data Earthworks gathers with the quantification tool likely underestimates the true volume of gas being released.

This would be consistent with conclusions in important recent studies. After years of work in various locations, one concluded that actual field measurements of methane are 60% higher than data in the EPA’s Greenhouse Gas Inventory, which is based on operator estimates. Another study showed that even when researchers know the sources and timing of pollution releases, measurements in the atmosphere are higher than what operators estimate.

Methane is at least 86 times more potent a greenhouse gas than carbon dioxide over a 20-year timescale—which is longer than the period that scientists warn we have to avoid the most catastrophic effects of climate change.

Back in the beginning of the fracking boom, a groundbreaking study showed that gas operations release enough methane into the atmosphere to erase any presumed climate advantage of this energy source over coal. Since then, a rapidly growing body of research—including more than 150 peer-reviewed studies on climate impacts—have debated the precise percentage of methane released from oil and gas operations. Regardless of some differences, NASA recently determined that oil and gas emissions account for 68% of the spike in global methane since 2006.

Earthworks and others still have work to do to consistently quantify and identify oil and gas pollution, which is essential to hold regulators and industry accountable for reducing it. Yet over time and across geographic areas, the numbers keep revealing the same truth: the oil and gas industry is bad for health and the climate. By any measure, the only sure way to change that is a rapid transition to clean renewable energy.