Water from cows’ milk recycled and used at Edendale plant
Cow milk is made up of 86% water, and millions of litres of that water is now being recycled and used at a large Fonterra dairy plant.
The Edendale plant in Southland is protecting itself against future water shortages by recycling about half the water from cow milk and using it in its processing operations.
Fonterra lower South Island regional manager Andrew Johns said about 10 million litres of cows’ milk was carted from dairy farms to the plant each day, where it was processed into products including milk powders and protein products.
That milk was made up of 86% water and about half of that water was removed in an evaporation process during processing, and historically sent down the river.
However, two years ago Fonterra learned the water was recoverable, so launched a cow water recovery system called Cow Water Max.
About $10 million has been spent on the project, which launched in August after being designed over 18 months.
In essence, the company purifies the water [from the cows’ milk] through a filtration and disinfection process onsite, and uses it in its milk processing operations for the likes of cleaning its plant.
Edendale used about 10 million litres of water to process every 10 million litres of milk, and traditionally all that water came from an underground aquifer that was also the community’s water source.
But the cow water recovery project was recovering about 2.5 million litres of water per day, allowing Edendale to reduce its take from the aquifer to 7.5 million litres a day, Johns said.
The underground aquifer, Fonterra’s only previous water source, was vulnerable in a drought because it was only replenished by rain water, Johns said.
As such, Edendale’s ability to reduce its take from the aquifer by also using the cow water in its operations was a good thing, he said.
Over a year, he estimated 700 million litres less water would be extracted from the aquifer than previously.
Edendale was Fonterra’s first large site to be using cow water for its milk processing operations, he said.
Johns believed the $10m spent setting up the project was well spent.
“The site stopping because it doesn’t have enough water is going to cost a lot more than $10m.”