Seattle Mayor Greg Nickels announced that the city’s garbage and recycling trucks are upgrading their exhaust systems and switching to a B20 biodiesel/ultra-low sulfur diesel (ULSD) blend fuel in an on-going effort to reduce emissions.
Seattle’s solid waste fleet, contracted through Rabanco and Waste Management, totals 180 recycling and garbage trucks. During the next six months these diesel trucks will be retrofitted with diesel oxidation catalysts (DOCs) to reduce toxic tailpipe emissions.
A diesel oxidation catalyst is a flow-through device installed on the exhaust pipe. As exhaust gases pass through it, the catalyst, carbon monoxide, gaseous hydrocarbons and liquid hydrocarbon particles (unburned fuel and oil) oxidize, thereby reducing emissions.
When combined with ultra-low sulfur diesel, emissions of fine particulates and toxic air pollutants are reduced by as much as 90%.
In addition, half the fleet will begin using a B20 (20% biodiesel) blend, funded by Seattle City Light (the city electric utility) as part of its program to mitigate its greenhouse gas emissions.
Nickels was the organizer of the bipartisan US Mayors Climate Protection Agreement coalition, which is working to achieve what would have been the Kyoto Protocol’s US target for reductions in greenhouse gases (7%) in the member communities. (Earlier post.)