07/27/2006: "gotta love the schmutzdecke!"
Today was a slow day at work, so I got to do a lot of poking around online. I stumbled across something that I had heard of before, but didn't think to look up again. I'm glad I found it, because slow sand filtering has got to be the coolest way of treating drinking water.
Why the coolest? Maybe "coolest" isn't the right word... how about "most elegant". First off, it's dead simple. Literally anyone with a big bucket, some gravel, and some sand can make one. The only maintenance is two to three times a year, and is a complex as making muddy water. It's a totally natural process, is self-sustaining, and fully biological in nature.
Secondly, it's dirt cheap. Literally - you have to have the right kind of dirt (sand, actually) but that's it. Once you have it, there's no more cost, other than the 10 minutes a few times a year you'll have to spend to keep the thing working. Some companies are making them using huge plastic tubs with self-cleaning mechanisms and valves and hose attachments and intermittent-use abilities... but you don't need that. So long as you can keep the thing from freezing (if you're trying to implement this at your cottage up north), once you have the container that actually holds the gravel and sand, and put said gravel and sand in there, you're done. No more investment.
Thirdly, this is a GREAT technology to use for rainwater catchment systems! I'm already picturing it installed in the cohousing development... all the rainwater from the roof is captured (minus the initial rainfall which washes the roof off), stored, and sent through the slow sand filter, and then re-stored. Voila - high-quality nature-purified drinking water! Heck, I'd almost be tempted to bottle the stuff! (In non-polycarbonate bottles, of course. You have heard the news, right? Polycarbonate was made by polymerizing artificial sex hormones - when it degrades, guess what you're drinking!)
I want to build a system right now. I could put it in my garage (my garage never freezes) and enjoy pure water year-round! And then I could make myself the ultimate neo-hippy T-shirt: "Ask me about my Schmutzdecke!"
I'm so clever.