I am on a septic system - I don't snip the visible seam allowance. When I finish a rag quilt, while I'm watching tv I pull most of the threads from the seam allowance so very little is left to shed in whatever machine I use.
I also never put egg shells, bones (both of which will never dissolve), or coffee grounds thru my disposal. In over 25 years I have never had the system serviced.