Taking clean water to the desert is necessary, but then what do you do with the gray water from showers, dishwashing, etc? You can put it in tanks and bring it home, but that’s heavy and messy. There are pump-out services, but I consider that cheating.


Evaporate! P and I designed these towers in early August, and with some help, I assembled them on the playa. These towers are made of 7′ deer fencing and rebar, guyed to the truck with climbing webbing. They sit in kiddie pools, and a 12v bilge pump in each pool drives water through a hose to the tower’s top and over a snow saucer. Power for the pumps came from 110v AC provided by Camp Soft Landing and 12v adapters I got from ebay. The water runs down the sides of the tower, soaking the burlap. Sun and wind pull the water off the burlap. Excess water runs back into the kiddie pool to make another round.

evap-2013-trucktopNote the handsome blinkies (75 12mm WS2801’s from Adafruit) on the guy lines. I used Funkboxing’s LED effects with a bit of tweaking. They looked great!

These systems took care of gray water for the Full Circle Tea House and about 150 BM participants. The average was 20-22 gallons per day per tower, for a total of about 205 gallons. That’s over 1600 lbs.

evap-2013This year worked a lot better than last year. One key finding is that the kiddie pools are huge, and with them the reservoirs on the bottom, it takes a lot less attention to keep the reservoirs full compared to last year when we used a 5gal bucket as the reservoir. The combination of full-time pumping and the taller tower led to a 30% increase in daily evap rates. Good stuff.