How to make Antarctic water drinkable
Fresh water has to be made from sea water at Scott Base. But first the sea lice has to be filtered out, writes DEIDRE MUSSEN.
Steve Denby chuckles as he grabs a giant sea lice from Scott Base's pump house.
It's one of many unlucky sea-dwelling animals sucked up from a hole in the ice near Antarctica New Zealand's base on Ross Island.
"They're a bit of a giggle when they get in there and we pull them out and let them dry out and then leave them lying around the base to scare people," the 50-year-old water engineer says.
"We get fish, sea lice and a type of big slater sometimes. I throw them back if they're still wriggling."
In October, Denby started his second year-long stint in Antarctica. His job is dominated by sea water, fresh water and waste water.
About 8000 litres of fresh water is needed at Scott Base daily for showers, toilets, washing, cooking, drinking and cleaning. But in order to keep the fresh water topped up, it must be converted from their plentiful supply of sea water which is where Denby comes in.
Sea water is sucked up a pipe and pumped to a 'reverse osmosis' plant. Basically, everything is filtered out of the sea water, including salt, viruses and bacteria then sodium bicarbonate and calcium chloride are added.
Four large storage tanks behind Scott Base contain about 170,000 litres of fresh water, of which three-quarters is in reserve for firefighting. The water is kept at about 14C, so it doesn't freeze.
Denby admits he feels a sense of pride when using Scott Base water and says it tastes "beautiful".
The less attractive side of his job is looking after waste water.
"It's quite a neat process but not for the weak-stomached.
"Like I say, once you get over your initial revulsion, it's quite a cool job. It's different and it's not something everyone would want to do but I think most people should be forced to do it at one stage just to realise where stuff goes when they're finished with it."
Scott Base's waste-water plant runs 24/7. The water is dosed with ozone and returned to the sea. The remaining sludge is flown back to New Zealand for destruction.
His experience for Antarctica came from decades in the Territorial Force working on water purification plus a year with Palmerston City Council as a waste-water mechanic.
He has a wife and two adult children back home, who he misses.
"I'm happy to be back here and I'll be happy to go back home again, obviously."
Antarctica is a fantastic place to work, he says. "Some people say that you come down here the first time for the experience, second time for the money and the third time because no-one else will employ you but, generally, you come down here because of the people."
- The Press
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