Using measuring techniques that combine video with devices measuring particulate matter, black carbon and nitrogen oxides in real time, scientists at the Environmental Energy Technologies Division (EETD) of Berkeley Lab have verified that policies designed to reduce the emissions of particulates from trucks driving onto the Port of Oakland have been effective.
The paper describing their results, by Timothy Dallman and Robert Harley of the UC Berkeley Civil and Environmental Engineering Department, and Thomas Kirchstetter of the Environmental Energy Technologies Division, has been published in Environmental Science & Technology.
California regulations mandated measures to reduce the emissions of particulates, black carbon and oxides of nitrogen from trucks at ports and railroad facilities in 2010. The regulations phased out trucks with 1993 or older model engines, and mandated the retrofit of trucks of more recent model years with diesel particle filters, while providing incentives to replace trucks older than 2007 with more recent trucks that meet more stringent air quality standards.
To test the effectiveness of these policies, the EETD-UC Berkeley team studied trucks entering the Port of Oakland. By combining their video record of trucks driving into the port with air sampling measurements of pollutants from truck exhaust, the team created records of the levels of emissions from these trucks over a period between November 2009 and June 2010. The mobile experimental station was situated in a Bay Area Air Quality Management District-loaned van parked on an overpass where trucks passed directly beneath their sampling equipment.
They found substantial reductions in exhaust emissions of black carbon and nitrogen oxides from trucks operating at the Port of Oakland as a result of the air quality policies. According to the report, “The average BC emission factor for this drayage truck fleet decreased by ∼50% while the average NOx emission factor was reduced by∼40%.”
“Effects of Diesel Particle Filter Retrofits and Accelerated Fleet Turnover on Drayage Truck Emissions at the Port of Oakland” Environ. Sci. Technol., Article ASAP, DOI: 10.1021/es202609q