Whenever the company acting as surety on the official bond of a sheriff is disqualified, insolvent, or the penalty of the bond becomes insufficient on account of recovery had thereon, or otherwise, the sheriff shall submit a new or additional bond for approval to the board of county commissioners, if in session, or, if not in session, for the approval of the chair of such board, and file the same, when approved, in the office of the county clerk of his or her county, and such new or additional bond shall be in a penal sum sufficient in amount to equal the sum specified in the original bond when added to the penalty of any existing bond, so that under one or more bonds there shall always be an enforceable obligation of the surety on the official bond or bonds of the sheriff in a penal sum of not less than the amount of the bond as originally approved.
RCW 36.28.030