Water in Johannesburg is constantly monitored – from tap water to koi pond water and everything between – to make sure it meets requirements and disease is kept at bay.
WATER quality in Johannesburg is constantly monitored by Joburg Water to ensure it meets the requirements of the South African National Accredited System for Drinking Water.
Joburg's drinking waterJoburg's drinking water goes through stringent testingThis is done through the water utility’s Cydna Laboratory in Houghton, which is responsible for testing the water consumed by about 3,8 million residents of Joburg. It offers a comprehensive chemical and microbiological lab service within the company and offers other City departments a centrally located lab complex with two satellite facilities.
Water supplied by Joburg Water must meet the requirements of the South African National Accredited System for Drinking Water, SANS 241 Ed 6.1. To maintain standards, an extensive monitoring programme is in place. This involves an analysis of at least 500 samples every month, covering all reservoir zones, tower zones and informal settlements.
Through these tests and constant monitoring, the water utility is “able to respond quickly to any water quality problems and assure the public that every drop of the more than billion litres of water that passes through our network per day is well within the SABS standard for class one drinking water”, notes Tebatso Baldwin Matsimela, Joburg Water’s marketing and communications manager.
Between October 2009 and September 2010, 6 258 samples were analysed and 60 869 tests were done. The lab tests drinking water, industrial water, water from rivers and streams, seepage water, borehole water, sewage, effluent and other waste water, koi and other fishpond water, as well as water from ornamental water features.
Escherichia coli, or E.coli, is the most important indicator of the microbiological quality of drinking water. At least 99 percent of samples need to be free of E.coli.
Turbidity measures the clarity of water; according to SANS 241, 95 percent of the samples must measure less than one nephelolometric turbidity units (NTU). During the review period, the turbidity in 98,8 percent of the samples was less than one NTU.
Water samples are also tested for coliforms, heterotrophic plate count, colour, odour, taste, pH, residual chlorine and conductivity. The lab has state-of-the-art equipment such as flow injection analysers, gas chromatographs, mass spectrometers, inductively coupled plasma / optical emission spectrometers, laboratory information management systems, ion chromatographs, colilert equipment and cryoscopes.
The average values of selected constituents, together with a maximum allowable value, are:
Sodium, with an average value of 10 and a maximum allowable value of 200mg per litre;
Potassium, with an average value of 3,1 and a maximum allowable value of 50mg per litre;
Chloride, with an average value of 10 and a maximum allowable value of less than 200mg per litre;
Fluoride, with an average value of 0,1 and a maximum allowable value of less than 1mg per litre;
Calcium, with an average value of 18 and a maximum allowable value of less than 150mg per litre;
Magnesium, with an average value of 6,1 and a maximum allowable value of less than 70mg per litre; and
pH, with an average value of 7,8 and a maximum allowable value of 5 to 9,5mg per litre.
A full compliance statement is available monthly online.
The Department of Water Affairs also recently gave Joburg Water a Blue Drop award for 2009/2010. It assessed the provision of water to Johannesburg in December 2009, and a score of 98,39 percent was achieved. The prestigious award was given to Joburg for exceeding 95 percent, the highest in the country.
The water utility has numerous other accolades under its belt and has countless public education projects that aim to conserve water and water demand management through behavioural change.
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