Problem solved.

I mentioned to Randy, my tenant who owns an excavator, that I would like to put in a septic system for the cottage. He said that seemed like a good idea, and we walked over to a clump of trees that will absorb the nutrients. The ground had been disturbed. Randy got paid to pull a small system last fall and decided to plant it behind the cottage. There's a single weeping tile that terminates at a French drain, by the trees. It's a pail flusher that uses very little water. He has some experience with this and says that those trees will grow like mad and within 5-10 years, the pipe will clog with roots. It will need a 2 hour fix when that happens.

There's a reason why Randy doesn't pay rent.