If you were just talking about an out building (shop, cabin, etc) then I would suggest another possiblilty. A propane fired incinerator toilet. There are 12 volt propane fired incinerator toilets (Eco John is a notable one) that basically incinerates the waste into a sterile ash. One five gallon tank of propane is good for approximately 200 "flushes." It is not real cheap to buy (approx $4,000 complete with all of the chimney parts) but it is completely self contained. Four grand sounds expensive but by the time you are done with the cost of the septic field installation the cost of a incinerator toilet (at least in our neck of the woods) begins to make a lot of sense.
Basically it looks much like a regular toilet. You do your business and then push a button. For the Eco John there are two different buttons one for urine and one for waste - it runs a more efficient burn cycle for just urine. The end result is a sterile ash. Once or twice a year you pull out the "ash tray" and scatter the ash, which is sterile so it doesn't matter where you put it, use it to fertilize your tomatoes, I don't care, I don't like raw tomatoes so I won't be eating them anyway. The unit is self contained and runs off of propane and a 12 volt battery - hook up a small (15 watts is more than enough) solar panel and you're good to go (no pun intended, however I did find the pun amusing, then again I'm easily amused).
There are several companies that make incinerator toilets: Eco John, Incinolet, Stor Burn. I prefer the Eco John in that it does not "store" waste. After each use it runs a small and efficient burn cycle. Others like the Stor Burn, store the waste in a larger tank and then, when the tank gets full, it will incinerate the tank full. The Eco John is more like a regular toilet. You use it, you "flush" it, end of story.
Incinerator toilets are, IMHO, good alternatives for an "off the grid" non septic system waste disposal system. There are also "composting toilets" but they get very mixed reviews and are more of a pain to maintain.
You obviously will need to check with local regulations, etc, etc, blah, blah, your mileage may vary, member FDIC.
Keep in mind that these are more cabin/out building oriented not for a full house system and so may not be applicable for your use. So once again you should probably ignore everything that I just wrote.
Why do you people keep paying attention to any advice I give? Jeez how many times do you have to hit your thumb with a hammer....
