Re: Composting Toilets vs. Holding Tank
Well, speaking for myself and my family, we don't take any medication and we eat only natural food. I suspect our urine is Ok...
I also don't understand how people can use a holding tank, often treated with chemicals, and then dump offshore (3 miles in the US?) and think it's the right way to do things. A composting toilet gives you a number of options that a holding tank doesn't. One can always opt to dump the urine container in a public toilet (thus entering the sewage treatment system) and the solids can be disposed of in a number of different ways, including the flower garden.
To be honest, the waste from boats is so insignificant a problem compared to land-based sewage that I don't really worry about it.