The Potsdam Waste Water Treatment Plant in Milnerton, built at a cost of R19 million, is expected to generate an additional 38 million litres(mega litres) of non-potable water per day for the Blaauwberg area.
At its official opening today, 22 June 2006, Councillor Lionel Roelf,Mayoral Committee Member for Trading Services, said that the City'srising demand for water will soon outstrip supply, if nothing is done toexplore alternative water resources.
"Together with measures to reduce water consumption, the City is looking at the desalination of sea water, the exploration of deep aquifers, and the recycling of waste water and sewage - to name but a few.
"Of all these options, the re-use of treated effluent is one of the mostcost-effective. Two thirds of the City's total water consumption endsup in 22 treatment works across the city from where the final effluentis discharged back into the environment.
Currently an average of only 30 million litres per day - or 7% of theCity's total waste water is used during summer - replacing potabledrinking water. It thus makes good economic sense to recycle wastewater into non-potable water for irrigation purposes. This is beingdone by City Parks, and an increasing number of golf courses, sportsfacilities and industries," says Roelf.
According to Anic Smit of the City's water reticulation services andproject manager for Potsdam, the City undertook an investigation twoyears ago into the refurbishment of the treated effluent systems at itsvarious waste water treatment works (WWTW).
"Although the philosophy is not new and some schemes have existed for over 40 years, it was never a formal Council service and therefore never enjoyed high priority," says Smit.
The study revealed that the potential for treated effluent use could be expanded to 170 million litres per day at an average cost of less than R2,24 per kilolitre - or a third of the cost of fresh drinking water.
This amounts to 40% of the total summer waste water usage - and 30% of the annual supply from the new Berg River Dam project.
The first extension was initiated in 2003 at the Bellville WWTW,increasing the available treated effluent from four million litres toseven million litres per day. In 2005, the re-use of effluent at theParow and Kraaifontein WWTW was increased from 1,2 million litres to 3,7million litres per day.
In June 2005, a contract for the upgrading of Potsdam's treated effluent system was awarded, leading to the creation of one of South Africa's most technologically advanced waste water recycling facilities.
The refurbishments at Potsdam include:
- two new pump stations capable of pumping up to 40 millionlitres per day
- a highly sophisticated filtration plant to remove allsuspended solids
- a bulk supply pipe network of 4km
- a 40 million litre storage reservoir (the size of a rugbyfield) built with environmentally friendly materials and techniques
- a new intake chamber with floating skimmer.
"The new system will increase the treated effluent at Potsdam from 17 million litres to 24 million litres per day. All 17 million litres perday will replace potable fresh water and a further 20 million litres perday will be made available for agricultural use," says Smit.
Situated in Koeberg Road, opposite the Chevron oil refinery, Potsdamcurrently provides non-potable water to the Milnerton Golf Course, theTheo Marais sports fields, Sappi Paper, four schools in Milnerton andTable View, public open spaces and the Table View beachfront dunes.Potential new users include the oil refinery, Kynoch and local farmers.
The scheme also provides the bulk infrastructure for future extensions to other industrial users and residential developments in the area. A new development on the farm De Grendel will also utilise the treated effluent and install a dual water reticulation network for domesticirrigation.
Prior to the installation of the treatment system, Potsdam's effluentwater was discharged into the Diep River estuary which feeds intoMilnerton Lagoon.
"This is without doubt, the City's flagship effluent treatment facilityand its success will lead to the upgrading of our other waste watertreated effluent works throughout the metropole," says Cllr Roelf.
Issued by:
Lisle Brown
Media Liaison Officer
Tel: 021 400-3065
Cell: 084 888 1901
Communication and Marketing
City of Cape Town
Email: media@capetown.gov.za
Tel: 021 400 2201
Fax: 021 957 0023
Anic Smit
Project Manager: Treated Effluent Project
City of Cape Town
Tel: 021 590-1506
Cell: 084 222 1459
Email: anic.smit@capetown.gov.za
