These can be broadly summarised as single stream (comingled), dual stream (two separate mixtures), and multi-stream (separate compartments on vehicle for each material). In the absence of services being provided by local authorities, private contractors may provide the only alternative. In these situations, waste may be stored on the premises of the house owner, dumped or burned in the street, or transported to informal dumpsites further away. These methods of uncontrolled disposal, lead to increases in disease vectors and environmental pollution.