August 2019
Burning Man is a leave no trace (LNT) event. What you pack in, you have to pack out. And that means everything, including gray water. There’s no garbage collection, and there’s no gray water disposal. Even though the event is held on a dry lake bed, you can’t dump your dirty water on the ground. Take that shit home with you! For years, I hauled home five-gallon buckets of nasty gray water after every event. Stuff grows in it. It stinks and it’s messy, especially when it slops over the side and gets dusty gear wet, creating a thick, nasty sludge. Gross!
A few years ago, I tried evaporating my gray water, with limited success. I suspended a large bath towel over a five-gallon bucket, with one end just touching the bottom of the bucket. This wicked up the water, allowing it to evaporate more easily. However, suspending the towel is problematic with Black Rock City’s high winds, and I ended up just draping the towel over the side of the bucket. It worked sorta somewhat. I was able to evaporate most of my gray water, but not all of it.
The next year, I brought a large, plastic cement mixing pan, about 3′ across. It provided a larger, flatter surface, making evaporation more efficient. It worked great, except it was so big, it almost blocked the entrance to my tent. (I put it on my “front porch” tarp in case water drips off the towel.) And, it took up a lot of room in my truck, not to mention space in my garage. It was just a PITA.
The following year, I picked up an oil drain pain from a dollar store. It wasn’t very big–only about 18″ across and maybe 4″ deep. Not nearly the surface area of the cement mixing pan, but much flatter than the five-gallon bucket. It seemed like a happy medium between the two.
I placed the oil drain pan on my front porch tarp, laid the terry bath towel across it, and placed my big rock in the middle to keep everything from blowing away. (My previous evaporation methods also included the rock.) I let the towel ends overhang the pan and drape onto the tarp, increasing the available evaporation surface area.
Ta da! That worked! I was able to evaporate about a gallon of water a day, which is sufficient for my needs. I shower every other day, creating a little more than a gallon of gray water each time. In addition, other hygiene routines, washing dishes, and cleaning my water bottles adds to that. But, I never reached the pan’s seven quart capacity.
I used this method in 2018 and 2019, with complete success. The towel wicks away water, increasing evaporation efficiency. And, it traps gray water detritus, so I don’t have to worry about contaminates hitting the playa. 
The “front porch” tarp catches any water that might drip off the towel, and nothing leaks onto the ground. Plus, the pan is small enough that it doesn’t block the entrance to my tent. As an added bonus, I bought a second one to use for washing my feet every evening. I can stack them together for packing and storing, maximizing available space.
The towel can be washed and reused the following year, or you can toss it and use another one. I used mine four or five times and tossed it when I got home this year. It was getting pretty threadbare and losing its efficiency. You want ugly towels with lots of substance and fluff, but nothing you would ever use again as a towel. Because that’s just gross!
Simple, cheap, and effective!