Management accounting - costing

Paul's Recycling accepts and recycles or disposes of hazardous waste for the city. It charges the city for waste disposal based on the amount of waste handled. Its contract specifies the sites that have been set up for waste drop-off will be cleaned up completely when the contract eventually expires. The owners of Paul's Recycling have been contacted by the council to set up a similar service for people who live in the area. Paul's Recycling's accountant is preparing an analysis for the owners.

Required

Recommend an appropriate costing method. Describe the method and explain the reasons for your choice?