The holder(s) of any oil and gas leases may apply to the department to unite with each other or with other entities, including lands not owned by the state, to collectively adopt and operate under a unit plan.

(2) To implement a plan and protect the state's interest, the commissioner may alter the terms and conditions of the lease(s) so involved with the consent of the leaseholder(s). Authorization by the department to include state leases in unit plans shall be conditioned on the following requirements:

(a) There shall be submitted to the department a plat showing the area to be unitized, together with geological and other information in support of the delineation of the area.

(b) A preliminary draft of the plan shall be submitted to the department for approval.

(c) If the plan is approved by the department, the proponent of the plan shall deliver one copy to the department when fully executed.

(d) Leases which are only partially covered by unit plans shall be segregated into separate leases as to the lands committed and not committed as of the effective date of the unitization. The annual rental or minimum royalty shall be paid on the leased acreage in the unit independently from other segregated lease areas.

(e) The term of any lease that has become the subject of a unit plan as approved by the department shall continue in force until the termination of such plan. In the event that such plan is terminated prior to the expiration of any such leases, the original term of the lease shall continue.

(f) Any apportionment of production or royalties among the separate tracts of land comprising the unit shall include an accounting system and the right of the department to audit such system to protect the interests of the state.

(g) Operations and production under a single unit plan shall be considered the operations and production of all leases included under the plan. Due diligence performed on any part of an area under a unit plan, may be credited by the department toward the requirement for all state leases included in the unit.

(3) Agreements for a cooperative or unit plan of development of an oil and gas pool, field or like area or any part thereof shall comply with the provisions of RCW 78.52.370. All unit or cooperative plans containing lands leased under the provisions of chapter 79.14 RCW require approval and consent by the department.