Wash. Rev. Code § 36.56.110
The county shall assume and agree to provide for the payment of all of the indebtedness of the metropolitan municipal corporation including the payment and retirement of outstanding general obligation and revenue bonds issued by the metropolitan municipal corporation. Until the indebtedness of a metropolitan municipal corporation thus assumed by a county has been discharged, all property within the boundaries of the metropolitan municipal corporation and the owners and occupants of that property, shall continue to be liable for taxes, special assessments, and other charges legally pledged to pay the indebtedness of the metropolitan municipal corporation. The county shall assume the obligation of causing the payment of such indebtedness, collecting such taxes, assessments, and charges and observing and performing the other contractual obligations of the metropolitan municipal corporation. The legislative authority of the county shall act in the same manner as the governing body of the metropolitan municipal corporation for the purpose of certifying the amount of any property tax to be levied and collected therein, and may cause service and other charges and assessments to be collected from such property or owners or occupants thereof, enforce such collection and perform all acts necessary to ensure performance of the contractual obligations of the metropolitan municipal corporation in the same manner and by the same means as if the property of the metropolitan municipal corporation had not been acquired by the county.
When a county assumes the obligation of paying indebtedness of a metropolitan municipal corporation and if property taxes or assessments have been levied and service and other charges have accrued for such purpose but have not been collected by the metropolitan municipal corporation prior to such assumption, the same when collected shall belong and be paid to the county and be used by such county so far as necessary for payment of the indebtedness of the metropolitan municipal corporation existing and unpaid on the date such county assumed that indebtedness. Any funds received by the county which have been collected for the purpose of paying any bonded or other indebtedness of the metropolitan municipal corporation shall be used for the purpose for which they were collected and for no other purpose until such indebtedness has been paid and retired or adequate provision has been made for such payment and retirement. No transfer of property as provided in *this act shall derogate from the claims or rights of the creditors of the metropolitan municipal corporation or impair the ability of the metropolitan municipal corporation to respond to its debts and obligations.
RCW 36.56.110
*Reviser's note: "this act," see note following RCW 36.56.010.