Wash. Rev. Code § 36.77.040
The board shall proceed to award the contract to the lowest and best bidder but may reject any or all bids if in its opinion good cause exists therefor. The board shall require from the successful bidder a contractor's bond in the amount and with the conditions imposed by law. Should the bidder to whom the contract is awarded fail to enter into the contract and furnish the contractor's bond as required within ten days after notice of the award, exclusive of the day of notice, the amount of the bid deposit shall be forfeited to the county and placed in the county road fund and the contract awarded to the next lowest and best bidder. A low bidder who claims error and fails to enter into a contract is prohibited from bidding on the same project if a second or subsequent call for bids is made for the project. The bid deposit of all unsuccessful bidders shall be returned after the contract is awarded and the required contractor's bond given by the successful bidder is accepted by the board.
RCW 36.77.040