One of the best ways to take advantage of your urine diverting toilet while boondocking is the use of a urine diffuser. The urine diffuser allows you to “set it and forget it.” The urine diffuser is a simple appliance that continuously buries your urine in a 12″ deep hole that complies with most public land management requirements for disposing of bodily waste. Basically you dig a hole 12″ deep and partially bury the urine diffuser. Connect your holding tank drain line to the urine diffuser using a dedicated, modified section of garden hose and then open the black water holding tank. If there is urine in the tank, open and close it as needed to monitor and control the outflow until it is empty. Once empty, leave the valve open to continuously drain the tank. Since your holding tank is only collecting urine and no solid waste is mixed in, it will flow freely into the ground as intended. This is because you don’t dump it all at once but rather it will drain continuously in small amounts each time you use the toilet.
I know it sounds self serving for me to tell people that they shouldn’t build their own toilets but hear me out. Live aboard boaters and RV owners are usually very handy. You basically have to be. You’re out in the middle of no-where and something goes wrong and there is nobody you can hire to fix it and no place to go to get parts, at least proprietary parts. When I built the C-Head I kept this in mind and made it so that parts could be easily found at local hardware stores. Having lived aboard two sailboats for a total of nine years, I knew that that would be a valuable consideration for my product by people who would use it. I also knew that because of that, people would try to imitate the design, thinking they were saving money and getting the satisfaction of being creative all in one deal. I mean it’s just a bucket and a jug and a box and a toilet seat, right? But let’s look at that.
More in a multi-part series of articles on ventilation
RVs and travel trailers have a unique set of problems associated with ventilating the toilet. They are the one case where you regularly have 60 mile an hour winds on the outside blowing for hours on end. The other exception being a shack in Antarctica. This of course is what happens as you go down the highway. The problem it creates is negative pressure inside the cabin which allows the positive pressure outside to force itself inside. It will do so by any means possible. If you have ever been driving down the road in your RV and someone uses the toilet and you get a strong blast of stinky air when they flushed it or you just have a constant slight smell of the holding tank present all the time, that is what is happening. As a retired firefighter, I call it “back-drafting.” You have opened a pipeline from the outside to the inside going through the vent pipe and the holding tank and through the toilet dragging all the associated smells with it. The outside pressure being greater than the inside pressure is the force behind it. With travel trailers, it is not such a problem because people rarely ride inside the trailer when you are driving down the road from one place to another. If the cabin of your travel trailer does develop a smell then it dissipates quickly when you open the doors and windows to occupy it.