Owners and lessees of property outside the City limits but adjacent thereto, in event of casualty by fire to their properties, in which the firefighting facilities of the City are brought into use at the request of the owners and lessees, their agents or servants, or in which the use of such facilities is rendered necessary for the protection of adjacent property within the City limits, shall be liable to the City for a minimum fee as set by the Council by resolution for each response by the Volunteer Fire Department to a call for assistance, or each intervention rendered necessary by circumstances endangering property within the City, and to such additional sums as may be necessary to reimburse the City for its expense incidental to such service. (1985 Code, § 9.08.050)