group at the wastewater vats

When we listened to our environmental briefing last week, one of the things he said was that here at McMurdo, we’re very disconnected from both our supply line and our waste disposal. We get amazing food from the galley, but we don’t grow it here. We sort our trash, but then it’s whisked away off continent. But it’s an amazing operation here to keep a town of 1000 people functioning in near-complete isolation. Today, we got a little closer to understanding both our supply and disposal by touring the power plant, the desalinization plant and the wastewater treatment plant. Paul, our guide, has been working in these places at McMurdo for nine years after a career teaching science. He showed us the giant diesel engines that generate our electricity and the secondary ethylene glycol heat exchangers – two are always on and a third is there as backup. We get our water straight from McMurdo sound – it is passed through several filters and pushed (at 700 psi!) through a membrane with mesh so small it traps Na and Cl ions but passes water molecules through (reverse osmosis). Paul said that this “cold filtering” process was invented by the Coors company to be able to sell their beer without pasteurization. The water that comes out is so pure that they then have to add minerals back in to prevent the water from leaching things out of your body like calcium. McMurdo uses 55,000 gallons of fresh water a day! When the water goes down the drain, it doesn’t go straight back into the ocean – the delicate ecosystem there can’t withstand a raw sewage input. That’s where the wastewater treatment comes in. Vats of microorganisms break down our waste and bacteria break down their waste. It’s an ecosystem onto itself. The water that comes out is clear and pure and goes back into the ocean. The solids are dried and shipped back to California on the ship. We fill about a triwall per week of solid waste – essentially compost by the time it goes through the breakdown process.

We got the chance to do this today because there is a dense ground fog out on the ice shelf that is preventing all flights from coming and going. It’s a constantly shifting environment down here, so we wait and hope for another chance tomorrow.

Jani steps gingerly over the raw sewage pipe

Paul and Morgan at the reverse osmosis unit

-Posted by Barbara from McMurdo (editing by rph)