Diesel consumption in waste collection and transport and its environmental significance

Abstract

Use of diesel in collection trucks is presumably the most important environmental burden from waste collection because of the emission of exhaust gases from the combustion process. The environmental impact depends not only on the amount of diesel used, but also the on the cleanness of the exhaust gas that is regulated by emission standards. We measured the diesel consumption for 14 different collection schemes in two municipalities in Denmark, yielding a total of 254 measurements. Collection was defined as driving and loading of waste from the first to the final stop on the collection route. All other distances covered were defined as transport of waste, which was modelled in generic transport simulation models. The diesel consumption per tonne of waste in the specified collection schemes turned out to be related to the type of housing and to the amount of waste collected per stop. The observations showed a considerable variation between different collection schemes, ranging from 1.4— 10.1 L diesel tonne— 1 of waste. Assessment of the potential environmental impact by a life-cycle-assessment method showed a substantial decrease over the last decade because of implementation of European emissions standard for diesel trucks. The paper also discusses the importance of energy used for collection and transport in relation to the potential energy savings from waste treatment. In many cases, the net savings exceed significantly the use of diesel.