Fenceline monitoring is making it easier to track fugitive emissions — undetected air pollution leaks from pipes, seals and other areas at industrial facilities, according to an article in the EPA’s Science Matters newsletter.
Last month the agency updated air pollution standards with a rule requiring first-of-its-kind fenceline monitoring to control emissions from refineries.
A passive sampler is a small tube, about the diameter of a pencil, with carbon sorbent material inside. Multiple tubes are hung around the fenceline of the facility and uncapped to expose them to air. After a week or two, the tubes are recapped and sent to the lab for analysis. Users then get a “map” of air pollutants like benzene that are present at the fenceline, which can be used to help understand the source of leaks.
While powerful, passive samplers don’t provide real-time data nor do they factor in wind direction. To address these limitations, areas of increased levels of pollutants found by passive samplers can be investigated further with more sophisticated measurement tools like EPA’s low-cost SPod, a solar-powered “drop in place” sensor system (pictured).
Currently under development, the SPod is an open-source design that provides real-time fenceline data. The SPod instantaneously correlates wind direction with elevated concentrations to help facilities determine where the leak is coming from.
Complementing the passive samplers and sensors like the SPod, new mobile measurement technologies such as GMAP OTM 33 can be used for onsite and offsite leak inspection applications. These sensor technologies are fitted onto a vehicle that can be driven around the perimeter of a facility to check for air pollutants coming from a facility.
Fixing leaks can protect workers and nearby communities, reduce operating costs for companies and assist regulators with implementing source emissions and air quality standards under the Clean Air Act.
Photo credit: SPod monitor via EPA