After a countywide integrated waste management plan has been revised pursuant to Section 41770, and the revision has been approved pursuant to Sections 41760 and 41800, the county shall implement that portion of the household hazardous waste collection, recycling, and disposal program identified in the plan which serves the population of the unincorporated area of the county, and the cities or other appropriate local agencies within the county shall implement, for their respective jurisdictions, that portion of the household hazardous waste collection, recycling, and disposal program identified in the plan which serves the population of the incorporated area of the county.