Municipalities may soon learn to utilise water of inferior quality for uses such as flushing the toilet in an effort to save drinking water. For example, irrigation in South Africa uses approximately 54% of the total freshwater demand followed by another major user, toilet flushing. Domestic toilet flushing consumes between 50 and 70% of a household’s total drinking water supply.

Grey-water from showers, baths, hand basins, laundry tubs and washing machines can provide a solution to our water scarcity challenges. A joint pilot study, conducted by the Universities of Witwatersrand (WITS), Johannesburg (UJ) and Cape Town (UCT), and funded by the Water Research Commission (WRC), is proving that the use of grey-water can be an effective way of saving our high quality water.

A dual grey- and drinking water reticulation system is a system designed and supplied by Water Rhapsody consisting of separate pipes that supply grey-water (for only toilet flushing in this project) and drinking water, respectively, to the end user. This is the first dual grey- and drinking water reticulation system for high-density urban buildings currently piloted in the School of Civil and Environmental Engineering (Hillman Block) at WITS, collects its grey-water from 13 hand-basins and conveys it to a 200 litre tank.

Prior to the grey-water tank are two 2 mm sieves that collect any solid materials which find their way from the hand-basins. These sieves are cleaned once a week. Prior to the sieves are two chlorinators that disinfect the grey-water to kill any micro-organisms. “The grey-water tank had to be kept small so that water is used immediately” says Dr Adesola Ilemobade, project leader at the WITS School of Civil and Environmental Engineering. The tank has two submersible pumps for directing water to the toilet when the toilet is flushed, using a switch within the toilet cubicle. Necessary measures were also put in place to avoid backflows.

The first phase of the pilot project is currently used to flush one female and one male toilet at the WITS Hillman Block. “If accepted by South African municipalities, the project will be beneficial to many water-scarce communities” says Dr Ilemobade. “At this stage the reuse of black water (sewage) is not considered due to the potentially higher public health risks” he adds.

A survey that was followed by a massive user awareness campaign at WITS, UJ and UCT indicated a high level of optimism amongst staff and students with the  installation of a dual grey- and drinking water reticulation system on their campuses.

Dr Adesola maintains that the unit will offer several advantages including: the reduction in participating households’/institutions’ drinking water bills; in areas without waterborne sewerage, grey-water reuse may improve the performance of septic tanks; grey-water reuse supports the growth in greener water strategies; and water conservation.

“The next installation is in progress at a 16-room unit of the Student Village residence at the University of Johannesburg Kingsway Campus where the collection of grey-water will be extended to showers and baths within the unit” says Dr Ilemobade.

“Municipalities constrained by finance will be better empowered to provide unserved communities with drinking water systems since the costs of the system will be reduced as a result of the reduced demand for drinking water due to grey-water reuse” says Mr Jay Bhagwan, a Director managing the study at the WRC. It will further cause reduced effluent discharges to the environment, leaving streams to their natural flow regime.

Buyelwa Sonjica

completed in the next three years. Fin24.Com

Though no price has yet been put on the projects, the minister, Buyelwa Sonjica, told a media conference in parliament on Tuesday that ideally her budget should be more than a hundred billion rands over the three years. As it is, she will have to manage with R8bn, R9.1bn and R9.6bn.

Sonjica also spoke about unconventional water augmentation projects, including a network of desalination plants around the coasts.

The first two desalination plants are up and running. One of them on the West coast is simply a refurbishment and updating of an elderly plant, originally built in “the bad old days”.

A second new plant has been built in Sedgefield, outside Knysna. Cornelius Ruiters, a deputy director general in her department, said a desalination plant is also on the cards for solving Cape Town’s problems.

The Berg River dam is expected to provide sufficient additional water only until 2014. Thereafter a number of possibilities are being considered.

The favourite, according to Ruiters, is the idea of using water from the underground Table Mountain aquifer.

The problem here is that it may damage the fynbos on the top of the mountain by depriving it of refreshment. If it proves unfeasible, Ruiters said, the desalination plant is next on the list. Its disadvantage is that desalination is expensive, both in terms of money and electricity.

The seven new bulk water schemes include the Mokolo River augmentation project that will supply water to the Medupi power station in Limpopo.

Domestic water will come from the Mooi-Mgeni transfer scheme, which includes the construction of the Spring Grove dam. “We expect the first water delivery from this initiative will take place by 2013,” Sonjica said.

Water Rhapsody, leaders in rainwater harvesting and greywater recycling have been supplying water conservation systems for 16 years

The energy required to power desalination would drive up the price of water, and consume more non-renewable energy, the price of which is rapidly being felt by South African electricity users. Water Rhapsody provides a means to save up to 90% of your municipal water bill with our water conservation systems. here follows the article in Cape Times today

By Melanie Gosling Environment Affairs Cape Times

Capetonians could be drinking desalinated seawater in four years’ time when our growing demand for water will have exhausted current supplies.

And because desalination is expensive, the cost of Cape Town’s water will increase.

This emerged at a pre-budget briefing yesterday where Water and Environment Affairs Minister Buyelwa Sonjica said her department was “forging ahead with unconventional supplies” of water, which included desalination of sea water in coastal towns.

“My view is that desalination must be seen as one of the sources for water supply… We have a coastline of 3 000km. We don’t have enough water and we are facing climate change. “So in future this is a technology South Africa will need,” Sonjica said.

The Berg River was the last available river in the Western Cape that could be dammed to provide water for the city.

But the Berg River Dam, the newest of the province’s dams, will meet Cape Town’s growing water demand only until 2014.

Asked what the plans were to augment Cape Town’s supply after 2014, Sonjica said this would be addressed in the national water review strategy.

Sonjica’s deputy director-general, Cornelius Ruiters, added: “One of our options for increasing supply to Cape Town is desalination. This will increase the cost of water, but is the only viable option.”

He said Water Affairs was in discussion with the City of Cape Town about the best option for desalination plants to supply the city, “and the cost implication for the City of Cape Town”.

Ruiters said the department was also looking at using water from Voelvlei Dam, and using more water from the Breede River.

“Using underground water from the Table Mountain aquifer is also an option,” he said.

Sonjica said studies suggested that South Africa was using less than 30 percent of ground water resources.

Referring to the dedicated environmental courts that her department wanted to establish to prosecute environmental crimes, Sonjica said they would begin running as a pilot project next month.

“Four in total have been approved for now,” she said. One of these would be in the Western Cape.