Wash. Rev. Code § 79.14.100
For the purpose of more properly conserving the natural resources of any oil or gas pool, field, or like area, lessees thereon and their representatives may unite with each other, or jointly or separately with others, in collectively adopting and operating under a cooperative or unit plan of development or operation of such pool, field, or like area, or any part thereof, whenever determined and certified by the department to be necessary or advisable in the public interest. The department is authorized, in its discretion, with the consent of the holders of leases involved, in order to conform with the terms and conditions of any such cooperative or unit plan to establish, alter, change, or revoke exploration, drilling, producing, rental, and royalty requirements of such leases with like consent on the part of the lessees, in connection with the institution and operation of any such cooperative or unit plan as the department may deem necessary or proper to secure the proper protection of the public interest.
When separate tracts cannot be independently developed and operated in conformity with an established well spacing or development program, any lease or any portion thereof may be pooled with other lands, whether or not owned by the state of Washington under a communization or drilling agreement providing for an apportionment of production or royalties among the separate tracts of land comprising the drilling or spacing unit when determined by the department to be in the public interest, and operations or production pursuant to such an agreement shall be deemed to be operations or production as to each such lease committed thereto.
The term of any lease that has become the subject of any cooperative or unit plan of development or operation of a pool, field, or like area, which plan has the approval of the department, shall continue in force until the termination of such plan, and in the event such plan is terminated prior to the expiration of any such lease, the original term of such lease shall continue. Any lease under this chapter hereinafter committed to any such plan embracing lands that are in part within and in part outside of the area covered by any such plan, shall be segregated in separate leases as to the lands committed and the land not committed as of the effective date of unitization.
RCW 79.14.100
Intent-2003 c 334: See note following RCW 79.02.010.