Air Permitting and Reporting for Public Landfills and POTWs

Landfills and publicly owned treatment works (POTW) emit pollutants to the air from many sources, most notably fugitive and combustion sources. Flares are commonly used at landfills and POTWs to burn landfill gas and digester gas generated at the plants. Many owners and operators of these facilities are unaware that operation of combustion equipment such as a flare can trigger state air permitting and annual emission reporting requirements. Flares generate a relatively large amount of carbon monoxide (CO), a regulated pollutant. CO is the pollutant that usually exceeds regulatory thresholds. To confuse the situation further, each state enforces different thresholds. Owners and operators of a landfill or POTW should calculate plant emissions and determine their regulatory obligations. Ironically emissions from wastewater treatment systems and solids handling operations at POTWs do not usually exceed regulatory thresholds, even though emissions from these operations are subject to the most public scrutiny. Combustion of digester gas is the activity that typically creates air quality permitting requirements. This paper presents several sources of air emissions common to landfills and POTWs along with typical regulatory considerations that would apply.