Requires a county or city that mandates compostable waste separation or collection as part of the level of service for customers of curbside or alley residential solid waste services to provide for the storage and processing of at least fifty percent of all collected compostable waste in the county where the materials are collected or pursuant to a contractual agreement that specifically provides for the storage and processing of compostable waste in a different county if performance of the contract has begun before the effective date of the act.