The State of Oregon, through the Department of Environmental Quality (DEQ) has a Clean Diesel program to support businesses and public agencies to transition to less-polluting diesel equipment and vehicles or alternatives.
In 2019, the State legislature passed House Bill 2007. The bill describes a phase-out schedule for certain older-model diesel engines that are titled or registered in Portland Metro-area counties. In addition, HB 2007 directs investment of funds received by the State from the Volkswagen Environmental Mitigation Fund to support that transition. Oregon Department of Environmental Quality will lead rulemaking efforts on some of the regulations included in the new legislation.
In May of 2020, Oregon DEQ published its Nonroad Diesel Emissions Inventory. The purpose of this inventory is to inform and refine air quality models based on private and public fleets currently in use. The Inventory confirms that nonroad diesel construction equipment are the largest source of nonroad diesel emissions in the Portland Metro Area.