All local governments are required to transition all vehicles to electricity or biofuels to the extent practicable. The provisions of this chapter apply statewide. Pursuant to RCW 43.19.648(2):

(1) Revenue fleets with a majority of active vehicles, not including transit vans, using compressed natural gas on June 1, 2018 are exempt from these rules. Transit vans and nonrevenue fleet vehicles remain subject to these rules.

(2) These rules do not require engine retrofits that would void warranties, or replacement of vehicles before the end of their useful lives.

(3) If a local government believes it is not practicable to use electricity or biofuels to fuel police, fire or other emergency response vehicles, including utility vehicles frequently used for emergency response, it is encouraged to consider alternate fuels and vehicle technologies, such as natural gas or propane, to displace gasoline and diesel fuel use. Local governments that opt to exempt emergency response vehicles from these rules must notify the department as part of their annual reporting under WAC 194-29-080.