The 10 000-Mile Flush
Sewage treatment in Antarctica
This is part of the series:
Antarctica: Life on the Ice
Transcript: The 10 000-Mile Flush
Glenn Zorpette: The biggest base by far on Antarctica is McMurdo station. It’s a U.S. installation that teems with workers and also scientists scurrying around setting up exotic experiments and field trips. But the station also has to take care of some pretty basic human needs. Like feeding everybody. And dealing with the waste that 1100 people produce. That’s no small feat in Antarctica, where human habitation is governed by the strictest environmental regulations on the planet. In fact, the international Antarctic Treaty now requires that essentially every bit of waste produced in Antarctica be removed from the continent.
[sound of door opening]
John Larrabee: So this is basically what it looks like when it’s raw.
Glenn Zorpette: John Larrabee is a wastewater technician at McMurdo. He oversees an innovative treatment plant that cleans up all the raw sewage and dirty water flowing from every pipe, drain, and spigot on the base. He’s treating 40 000 gallons of this stuff a day. Larrabee gestured to a basin holding four days’ worth of raw water.
John Larrabee: Kind of got a little gray color. Smell should be musty but not unpleasant. That’s actually the technical term for raw water.
Glenn Zorpette: So this raw water coming from toilets and sinks isn’t the color you might expect.
John Larrabee: No, it’s not. What you see there, if you were to take a sample of that raw water and allow that to settle, if I just took a sample, set it on the counter for like an hour, you would see the brown stuff would settle to the bottom, and you’d still have clear water on the top.
Glenn Zorpette: Larrabee’s job is to clean up the watery liquid part so it can be returned to the Antarctic and to dry out and pack up the solid part for shipment off the continent. But first they let a horde of natural bacteria break down the contents of the raw water as much as possible. The solids eventually settle out and are then sent to a press that squeezes the last bit of water out of them. And when that press is running, it’s a heck of a thing to see and hear. And smell.
John Larrabee: The belts are moving, there’s wash water going, it’s pretty loud, it’s pretty sloppy, whatever. The water will filter through the belt on the top, it comes around this way and another belt will meet up against it and it keeps traveling, and this is where you can see the two belts, and the solids should be between those two belts, it just keeps traveling over these rollers, just tighter and tighter as it goes, keep pushing that water out, and on the end here is where it actually gets scraped off the belt and dropped down the chute, and that’s where we have the big tri-walled boxes that the solids actually go into.
Glenn Zorpette: The reason for the boxes is that this pressed solid waste—it’s called a cake—is actually shipped, once a year, from Antarctica all the way to a landfill in California. It’s a total of 8 to 10 tons of solid waste per year. That’s a lot of human excrement.
John Larrabee: It’s not called human excrement. Once it’s treated, it’s called a biosolid.
Glenn Zorpette: Sorry. Biosolid. That’s a lot of biosolid of human origin, and a long way for it to travel. Think of it as a 10 000-mile flush. The liquid portion is filtered and disinfected with UV light.
John Larrabee: This is the final end of the treatment process itself, and the water you see right here, this is actually the treated water, which will get blended with the other two tanks and go into the UV channel. So as you can see, it’s pretty good water, pretty clear water, that’s what we like to see; it’s what we like to have.
Glenn Zorpette: I don’t think I’d want to quench my thirst with it, but I don’t mind that the water is returned directly to the sound. It takes a gallon of water coming into this facility about 24 hours to swirl and swish about all the basins, filters, and presses before leaving the other end clean. It all happens so elegantly and quietly, and yet so incessantly, tucked away out of sight and out of smell.