Vacuum toilets are arguably the most efficient of toilets in relation to water usage and number of pumpouts required. Typical water usage is around 0.4litres although this needs increasing for solids. The above average installation costs will be offset by the savings made in pumpouts over a period of time. A vacuum is created from the vacuum pump through the vacuum tank and up to the toilet. When the vacuum has stabilised, usually between 30 to 45seconds the discharge mechanism can be operated and the vacuum removes the contents of the bowl at high speed, pulls it through the vac tank and up to the vac pump from where it is then pushed into the waste tank.