HARARE, May 19 — The Harare City Council is setting up a biogas digesting plant at the Firle Sewage Treatment Works in a move which not only will reduce raw waste being discharged into water systems but also generate electricity, says Town Clerk Dr Tendai Mahachi.

The biogas project was at an advanced stage of implementation with the equipment to convert methane gas into electricity on its way, he said here over the weekend.

“Four of them (bio digesters) are now up and producing methane gas about 70 per cent purity which we can then convert to electrical energy. We estimate we can generate close to four megawatts (MW) of electricity,” he said.

Mahachi said after Firle, the city would move to set up other biogas digesters at the Crowbrough Sewage Works.

Biogas is a low-cost clean energy produced through materials such as cow dung, human excreta and industrial waste, which is fed into a biogas digester where it is decomposed by bacteria in the absence of air to produce biogas.

The gas can then be burned as fuel for lighting, cooking and heating and on a large scale it can be used for electricity generation. Sludge that remains after the production of the gas is rich in nitrogen and can be used as organic fertilizer.

The setting up of bio digesters by the local authority follows a directive by the Inter-Ministerial Cabinet Committee on Pollution for Companies and Institutions for major polluters to be set up pre-treatment plants.

The Harare City Council is one of the major polluters as it disposes raw sewage into Lake Chivero, the source of drinking water for the capital.

Last week, the government gave funeral parlours, service stations, food processing plants, local authorities and other polluters up to June 30 this year to institute measures to stop pollution or their operations would be closed.

Local authorities were told to install pre-treatment plants, hence Harare’s move to install bio digesters at all sewage treatment sites.