Under pressure: Where landfill gas regulation stands today.

This article focuses on the regulation and management of landfill gas emissions from municipal solid waste (MSW) landfills. Landfill gas, primarily composed of methane and non-methane organic compounds, is generated by the decomposition of organic waste and is regulated under the Clean Air Act (CAA) through standards such as the New Source Performance Standard (NSPS) and National Emission Standards for Hazardous Air Pollutants (NESHAP). Some states, including California, have implemented stricter rules targeting methane emissions and are exploring advanced monitoring technologies. Emerging challenges include managing Subsurface Elevated Temperature Events (SETs), which affect landfill gas composition and compliance, and the potential future regulation of per- and polyfluoroalkyl substances (PFAS) in landfill gas, for which detection and monitoring methods are still under development. The article also notes the increasing beneficial use of captured landfill gas as a renewable energy source. [Extracted from the article]