You are here:
Are landfill emissions in the United States understated?
Citation:
Thorneloe, S. Are landfill emissions in the United States understated? Series of Monthly Lectures (Virtual) by the International Waste Working Group - "Food for Brain", NA, GERMANY, July 27, 2022.
Impact/Purpose:
This is a presentation for the Internatioanl Waste Working Group (IWWG) series of lectues called "Food for Brain". My presentation is about field test measurements in the US using optical remote sensing measurement to reduce current uncertainty with methane emissions (and other air pollutants) from municipal solid waste landfills. In Europe, food waste and other biodegradables are not landfilled. Whereas in the U.S., food waste and other biodegradables are being landfilled resulting in methane emissions that are generated over decades. Although some communities are finding better options for managing food waste, the majority of food waste is still being landfilled. Anaerobic decomposition in landfills results in methane emissions being generated which are 87 times more potent that carbon dioxide for a 20 year time horizon. The field test campaign at US landfills is being described in this presentation along with other work to measure air emissions from landfills in the US.
Description:
Recent measurements from next generation emission measurement (NGEM) technology indicate that methane emissions from U.S. landfills may be understated. Remote sensing studies in California revealed that landfills were responsible for 41% of the State’s methane inventory, with 32 super-emitting landfills identified [Duren et al.; Nature, 2019]. A 2020 USEPA report concluded that air rules are being inconsistently implemented and enforced. First order rate equation (referred to as the Landfill Gas Emission Model or LandGEM) is used to quantify landfills emissions. When comparing LandGEM estimate to landfill header pipe gas flow rates, it has been found that there can be several orders of magnitude difference either higher or lower, causing uncertainty in values in use for policy implementation and inventories. The use of Clean Air Act source emission models and emission models and past measurement technology fail to capture the spatiotemporal variability of landfill emissions, leading to uncertainty for decisionmakers. This presentation will review NGEM technology for landfill methane measurement (and that of other air pollutants). Through collaborations with California Air Resources Board (CARB), Environment and Climate Change Canada (ECCC) and Carbon Mapper (through philanthropic funding) US EPA is embarking on testing a wider range of landfills to help inform landfill owner/operators of sites where leaks are occurring which are substantial and require near term abatement. Any actions taken would be voluntary and to date most landfill owner/operators were appreciative of the information that they have received which identify where leaks occur. Data are also used by EPA enforcement personnel to prioritize landfills to inspect. Over a decade ago, US EPA was advancing the use of ground-based optical remote sensing to quantify fugitive loss from landfills. Although that work has not been continued, findings have informed NGEM measurements leading to better test methods and measurements. Ideally, measurements and not modeling will be used when quantifying emissions from landfills, although some modeling will always be required (e.g., future emission projection for inventories). Ms. Susan Thorneloe will describe field test measurements being conducted this summer2022 that use both high- and low-altitude measurements like what was done by CARB to evaluate methane sources in the State of California.