At great but necessary cost to the university, we are well into the implementation phase of our water emergency and risk mitigation plan.
Our strategic objective is to decrease our water usage (from any available water source) by 2% a year over the next five years through a combination of technology, water source diversification and user adaptation solutions.
The existing overall water utility bill of the university across our seven campuses is about R10m a year.
The university’s north and south campuses in Summerstrand require up to 1.5Ml (1.5-million litres) a day during peak periods.
Increasing numbers of students are returning now we are in Covid-19 alert level 1.
At full capacity for this period, we have 18,000 students and about 2,500 staff members on our two Summerstrand campuses.
This includes 3,500 students living in campus residences, with a further 1,800 beds now under construction.
We have diversified our sources to include return effluent (RE) or “new ” water, as well as borehole water, rainwater and greywater.
The goal is for these sources to comprise 30% of our current water usage over the next five years.
This reduces our reliance on potable municipal supply, which will contribute to the metro and university’s quest for efficient water use and cost savings.
Our sport fields alone account for about 20% of our total water use.
Instead of using potable water, we are now buying water from the Cape Recife waste water treatment works which generates quality RE or “new ” water to a standard that is safe for irrigation and, if not used, would go into the ocean.
The water is stored in our new 1.3Ml holding dam and we pay about R2.20 per Kl as opposed to R17 per Kl for municipal water.
Our new residences are geared to use RE water for flushing toilets and urinals — two existing residences are already using it and we plan to have two more operational in six months.
It ’ s a massive solution for universities, big businesses and operations in the metro and beyond, as toilet flushing accounts for about one-third of all water usage per day.
It ’ s criminal to use potable water for this purpose.
Another goal is to change the flushing mechanisms of toilets to a cistern-less system using flushmaster valves.
This is expensive to install but is very hard-wearing and long-lasting.
It flushes directly from the water supply, using half the water of a cistern system.
Cistern systems also have a tendency to leak into the bowl, which, on a university or large organisation scale, is absolutely wasteful.
We ’ ve ironed out some RE teething issues, such as flushing the entire toilet system with a combination of RE and municipal water, and chlorine after extended periods of nonuse (during vacations or lockdown) to make sure it’s cleansmelling, and then switching over to 100% RE water.
The municipality’s longterm plan is to extend RE water use the length of Marine Drive, and link up Pearson High School and possibly the Mandela University Second Avenue campus.
The Summerstrand campus RE project is already part of this plan.
On the technology side, we are testing aerators or flow restrictors on taps to see what works as they need to be robust and deliver acceptable quantities of water.
We are also investigating shower time limiters and waterless urinals, and we will be installing about 64 water meters that are read electronically to manage and monitor water use, leaks and overuse.
To diversify the university’s water supply, we plan to add more storage in bigger and critical water-use buildings so they can keep operating for up to three days when municipal supply is interrupted.
Most buildings already have storage tanks for water harvesting.
Boreholes are an additional source of diversification and we will be drilling two additional boreholes, one on the north campus and the other on the south campus, linked to the residences.
We are also exploring adding boreholes on the Missionvale and Second Avenue campuses.
Over the past two years about 150 boreholes have been drilled by the municipality across Nelson Mandela Bay, and we are mindful of the impact of boreholes on groundwater reserves.
The university is a member of the Business Chamber’s strategic resources forum and water task team, and businesses in the metro share water strategies and gain insights from one another.
The forum is convened by Angus Clark, the plant engineer at Isuzu in Struandale where, over the years, they have considerably upscaled their greywater systems for toilets, and installed a fleet of 10,000l rain water tanks for some of their processes.
The CEO of the Nelson Mandela Bay Business Chamber, Nomkhita Mona, has called for businesses to partner with the municipality in tackling the water crisis and to accelerate citizen campaigns to get everyone involved in conserving water.
This article appeared in The Herald (South Africa) on 21 October 2020 written by Dr Andre Hefer, Nelson Mandela University’s Sustainability Engineer