I'm doing a
flush vermicomposting toilet system that does tertiary level of cleaning on the effluent. I'd like sub-grade distribution to be along 100ft laterals. It would be nice to be all passive with no moving parts, as long as it remains viable long term. We do have a bit of a slope we can work with if that helps.
My best guesses about how to distribute effluent evenly along the laterals, at low cost, for DIY installation, is either 2-hole perforated piping (commercial holes at 4 and 8 o'clock positions or DIY
slits) as level as I can get it, or gravel wrapped in non-woven geotextile fabric with a trench at a slight slope, perhaps with a dry well at the end just in case.
Ideally I would love to plant trees and shrubs along the downhill side of the laterals. If I used perforated piping I'd probably need to create an air gap (e.g. chamber) around it to air prune the roots. If wrapped gravel is used, I'd hope that roots would prefer not to penetrate the fabric when there is easy water below it and the gravel can fully drain (a principle learned from the drainage cell industry). I'm thinking of starting with one lateral, and adding more or tweaking the design if needed. Thoughts?