Requires the department of ecology, in developing, adopting, and implementing a state plan to comply with the requirements of a federal rule relating to greenhouse gas emissions from existing electric generation facilities, to select a mass-based compliance option that: (1) Maintains state flexibility to achieve compliance using market-based tools;

(2) Avoids redundant or burdensome regulation on electric generation facilities; and

(3) Includes participation in a regional or multistate program or interstate allowance auctions.