City outlines new wastewater plans

SOUTH Africa will need 17% more water than is available by 2030 and – if we are to meet these needs – our sources of water, and the way we use wastewater, needs to change.

This was the view of water management experts giving talks at a side session, titled “Research, Development and Innovation: Planning for a Water Secure Future”, at the World Water Day Summit and Expo in Durban yesterday.

Speedy Moodliar, of the eThekwini water and sanitation department, said in his presentation that the city supplied 910 million litres of water to residents from nine treatment works.

“There are 14 000km of water mains, 263 reservoirs, 500 000 water connections and 7 000km of sewer mains.”

Efficiency

The city, he said, also treated 500 million litres of water a day and was responsible for 27 wastewater treatment works.

“The municipality seeks to identify the need, then match it with the financial viability of the plan. It’s about improving efficiency and reducing the health hazard.”

The city already had many projects in the pipeline, including the wastewater public private partnership – an African first – to improve water supply for its residents.

It includes works at Umdloti (40 million litres a day), Tongaat (20 million litres) and uMkhomazi (20 million litres).

“We’re looking to harness electricity from methane gas, where it will be captured by digesters through a scrubber and then through a reciprocal engine. The energy will be used for the treatment works.”

Simple innovative devices designed to save water had been put in place. “We have sourced a few fittings (on a trial basis) and installed them into taps. We found that use had been reduced by 92%, going from 27 litres a minute to 2 litres a minute.”

The city has also invested in a demonstration plant – which can process 6.25 million litres a day – at their central wastewater treatment works.

“This plant looks at 50% desalination and 50% re-use where both processes will be implemented. The product water will then be blended and put into the potable (drinkable) supply.”

Ashwin Seetal of the Council for Scientific and Industrial Research said developing capacity and training for water security was crucial.