Responsibility for providing trained staff and appropriate equipment necessary to produce and store microfilm reproductions of official, permanent value bound volume records created by the various county and municipal governments of the state is hereby vested in the state library and archives. To implement this security microfilming program, the state librarian and archivist is authorized to develop a priority listing of essential records based on retention schedules developed by the county technical assistance service and the municipal technical advisory service. This priority listing of essential records may be revised from time to time to accommodate critical needs in individual counties or municipalities or to reflect changes in retention schedules. The camera negative of the microfilmed records shall be stored in the security vault at the state library and archives and duplicate rolls of these microfilmed records shall be made available to county and municipal governments on a cost basis.