These will be true peat bog plants and I have some concerns about invasive roots penetrating

a) a liner seaming tape gregs pipe boot

b) one or two o ring sealed compression joints.

I suppose these concerns relate to rushes and reeds etc rather than broad leafed plants.

All these are or will be at least 1' below the surface of the bog.

I want the compression joint so that I have a seperable joint, near the liner, in the plumbing supplying the overflow water from the pond to the bog. I have seen a flanged union but that still relies on o rings for the seal. If I made this/these joint/s permanent, solvent welded, and needed to lift the liner I would have to cut the plumbing to get the liner out, this doesnt seem like a good idea.