Wash. Rev. Code § 39.04.120
If the successful bidder must undertake additional work for public construction projects issued by the state of Washington, its authorities or agencies, or a political subdivision of the state due to the enactment of new environmental protection requirements or the amendment of existing environmental protection statutes, ordinances, or rules occurring after the submission of the successful bid, the awarding agency shall issue a change order setting forth the additional work that must be undertaken, which shall not invalidate the contract. The cost of such a change order to the awarding agency shall be determined in accordance with the provisions of the contract for change orders or, if no such provision is set forth in the contract, then the cost to the awarding agency shall be the contractor's costs for wages, labor costs other than wages, wage taxes, materials, equipment rentals, insurance, and subcontracts attributable to the additional activity plus a reasonable sum for overhead and profit. However, the additional costs to undertake work not specified in the contract documents shall not be approved unless written authorization is given the successful bidder prior to his or her undertaking such additional activity. In the event of a dispute between the awarding agency and the contractor, dispute resolution procedures may be commenced under the applicable terms of the construction contract, or, if the contract contains no such provision for dispute resolution, the then obtaining rules of the American arbitration association.
RCW 39.04.120
Severability-1973 1st ex.s. c 62: "If any provision or part of this 1973 act shall be judged to be invalid or unconstitutional, such adjudication shall not affect the validity of any provision or part of this 1973 act not adjudged invalid or unconstitutional." [ 1973 1st ex.s. c 62 s 4.]
Delay due to litigation, change orders, costs, arbitration, termination: RCW 60.28.080.