Waste Management Model Associated with Public-Private Partnership in Hamilton, Ontario, Canada

A waste management model associated with public-private partnerships (WMMPPP) was formulated and applied to the City of Hamilton, Ontario, Canada. The WMMPPP has the advantages of considering a combination of public and private services so that trade-offs between system costs and service quality can be addressed. Meanwhile, uncertain information presented as interval numbers can be effectively communicated into the optimization processes such that feasible decision alternatives can be made through the interpretation and analysis of the interval solutions according to projected applicable system conditions. The model minimizes the inexact costs (direct costs, indirect costs, and penalties) under three waste-service-delivery scenarios: (1) 100% in-house public services, (2) a combination of public and private services, and (3) 100% private services. These three scenarios covered most types of the municipal solid waste (MSW) management systems in North American municipalities. The results indicated that reasonable solutions were generated through the WMMPPP under different scenarios. Most importantly, the risk of total system costs would increase with the decrease of service quality due to privatization in Hamilton. This study is potentially useful for MSW decision-makers in most municipalities of North American for long-term planning of regional waste management activities and for formulating related local policies/regulations regarding privatizing the service delivery in waste management. It is recommended that more-complex and hybrid inexact programming models based on the WMMPPP be further developed.