Measuring Particulate Matter Emissions from Prescribed Fires across Colorado

ANNAMARIE GUTH, Marissa Dauner, Evan Coffey, Sean Benjamin, Peter Hamlington, Chad Hoffman, Michael Hannigan, University of Colorado at Boulder

     Abstract Number: 312
     Working Group: Combustion

Abstract
The western US has experienced an increase in wildfire activity, contributing to increased periods of poor air quality. Drier and hotter conditions due to climate change are increasing the severity and area burned during wildfires. Wildfires release large quantities of particulate matter (PM). Exposure to PM can have many negative short and long-term health impacts. Prescribed fires are a highly effective way of reducing wildfire risk but come with tradeoffs; for example, prescribed fire still releases PM. This project uses low-cost emissions tools (EPODs) to measure PM at prescribed burns throughout Colorado. EPODs have been used previously in published studies to measure emissions from cookstoves and trash burning. The EPOD uses a Plantower sensor to measure PM2.5 and collects PM onto a quartz fiber filter to quantify amounts of elemental carbon and organic carbon, and complete organic speciation. For each burn, we quantify PM2.5 emissions factors using the partial capture carbon balance method and modified combustion efficiencies. The placement of each EPOD at prescribed fires is determined by BluSky Playground, an interactive model developed by the USFS to predict ground plume movement and PM2.5 concentrations. Additionally, we began using a BLK360 terrestrial lidar scanner to take scans pre and post-burn scans at prescribed fires to quantify fuel reduction. We have partnered with several different county and forest service implementers around the state of Colorado. So far throughout this project in partnership with implementers, we have attended 10 prescribed burns, 7 pile burns, and 3 broadcast burns; burn windows for the types of burns are different which also impacts burning conditions. I will present emission factors for carbonaceous components of PM, combustion efficiency, and fuel reduction. I will discuss how these metrics and their variability are impacted by the type of prescribed fire, environmental parameters, and landscape.