On 15th March 2016, procurement of all required equipment for operation and maintenance of Vacuum Sewerage System such as power generator, test balls, fittings, vacuum test gauge, leak-test hose, and so on were delivered and inspected by JICA Expert Team (JET) and the Construction Supervisor.

Construction work of vacuum system in Koliver area is one of the JPAs under Wastewater Management Sub-committee in order to facilitate the sewerage collection and transfer to sewage treatment plant.

The purpose of vacuum system is transporting sewerage from houses in Koliver area to ILIYARAN Sewage Treatment Plant in the west of Anzali. The common sewage collection system works based on gravity flow of sewage in pipes and in order to achieve suitable slope, lots of deep trench should be excavated in city. Deep excavation generates huge amount of surplus soil and also the potential of destruction of infrastructures will increase.

The system will be operated by the differential pressure between atmospheric pressure and a partial vacuum maintained in the piping network and vacuum station collection vessel. This differential pressure allows a central vacuum station to collect the wastewater of several thousand individual homes, depending on terrain and the local situation. Vacuum sewers take advantage of available natural slope in the terrain and are most economical in flat sandy soils with high ground water.