> This squeezes out any remaining water, so the resulting Sludge is as light as possible.
> Here’s the final solid product, a nutrient-rich soil-like material. This is sent back to the United States.
Why send it back?
> Here’s the final solid product, a nutrient-rich soil-like material. This is sent back to the United States.
Why send it back?
It would be interesting to know if an analysis of it (when in the US) could tell some things about how the station is doing.
I've been several times to the Pole for work (years ago), and going into the greenhouse and smelling tomato plants after days on end of smelling nothing but people, galley food, cleaning products, and fuel exhaust, is a pleasant memory.
They do not (or at least did not) use human sewage for fertilizer there -- unlike at McMurdo, human waste at Pole does not get shipped off station.
I wintered at Pole, and in that rather fractious winter, I think one of the worst points was when it was decided that the whole crop in the greenhouse needed to be purged. The head of maintenance had broken the Rodwell (water supply), so there was a reasonable desire to reduce water consumption. But, somehow, that morphed in to "shut down the greenhouse", despite it being a closed-loop system... That winter, we had a very comfortable reserve of fuel, and of course South Pole Station sits on a whole lot of ice.
Hi John!
They only do one ship-load per year (deliver all supplies, take all waste back). Overall logistics (including regulatory compliance) might actually make it cheaper to have a single destination, rather than stopping over in NZ to offload some of the simpler to dispose waste. Actual shipping costs are probably in the noise floor after everything else.
It's also possible the program has been partially optimised for pork barrel politics.
More seriously, it is weird. It would seem a good opportunity for us to solve one problem and benefit in some other way as a reciprocal arrangement. For example, US air supply options are likely vastly superior to ours.