A Nestlé dairy factory in the Garden Route town of Mossel Bay has figured out a way to reduce its reliance on municipal water by extracting water from cow’s milk.
By using an evaporation process at a new waste water treatment plant on site, approximately 47 tankers of water will now be recovered from the milk every week.
The water is reused for various purposes within the facility.
Around 400 000 litres of fresh milk are dropped off at the plant every day to make powdered milk, evaporated milk, condensed milk and other dairy products.
The milk contains an average of 88% water.
The waste treatment plant follows in the footsteps of Nestlé factories in Mexico, India and China that have fully implemented “Zero Water” technologies.
With the Western Cape and other parts of the country in the grips of a serious drought, Water and Sanitation Minister Gugile Nkwinti mentioned that he wanted to make the plant “a big story” with President Cyril Ramaphosa.
A visibly impressed Nkwinti inaugurated the plant on Tuesday.
“When I see him next week in Pretoria, the first thing I want to say to him is please go to Mossel Bay and see what is being done there,” he said at the launch on site.
“He is looking for these stories because we want to change South Africa for the better all the time.”
He said the organisation had positively responded to the drought with proactive measures, instead of reacting negatively.
Mossel Bay and surrounding areas suffered a serious drought between 2008 and 2010, which saw the region subsequently declared a disaster area.
65% reduction in water usage since 2009
Water restrictions, which have by now become a norm for residents of Cape Town and some Western Cape towns, had to be put in place.
As a result, Nestlé started a project towards environmental sustainability and responsible water use.
In 2009, it looked at ways to reduce water usage. In 2010, the next phase was finding ways to reuse water, followed by the last phase of recycling water.
The project had resulted in a 65% reduction in water usage since 2009.
According to Nestlé, the Mossel Bay site will continue to use municipal water for fire systems and a back-up water supply.
The factory, which was opened in 1958, operates around the clock.
Nkwinti was given a tour of the locally manufactured and installed waste water treatment plant on site, a few metres away from the main factory, by local employee Fred Huysen.
The whole process is not done by hand, but operates from a control room with a bird’s eye view of shiny machines.
Huysen explained that the milk is stored in a big tank under the plant, before being moved at the right temperature to a totally enclosed big blue tank, called the digester, for two days.
The 100 000l tank contains good bacteria.
“Milk contains milk solids and fat,” said Huysen. “The bacteria we use to break down the fat loves milk solids and protein.”
The bacteria creates by-products of gas and waste.
‘Nothing goes to waste anymore’
In the spirit of reusing and recycling, the methane gas is drawn out to make steam and power a boiler.
The waste is reused on farming land as a fertiliser.
After being “digested”, the waste water is filtrated to remove the brown colour and slight odour.
The plant uses micro-filters to remove particles, and reverse osmosis to remove dissolved solids.
Minerals then have to be put back into the 100% pure water before it can be re-used.
“So nothing goes to waste anymore, nothing goes to the municipality anymore as effluent to be treated at the waste water plant,” said Huysen, beaming with pride.
Mossel Bay Mayor Harry Levendal welcomed Nkwinti to the area and thanked his department for providing money a few years ago to build a desalination plant.
He pointed out that Nestlé had received its milk from rural communities and negotiations were ongoing so the company could do its bit towards corporate social investment in these areas.
Nkwinti said it was very important to get more young people from townships employed and involved in such technological spaces because “this is their time”. — News24