David,

Native persimmon has deep tap root and not so much lateral roots. On occasion, If hard prune then the tree will send new shoots out twenty feet away.

Tony

Tony thank you for your reply. I contacted the person who sold me the persimmon seedlings and mentioned the same thing. His concern was the tree will send out lateral roots outside the drip line and if placed to close to the septic field I might have future isses. I might have to refigure the layout of this persimmons orchard to take all of this into consideration.

Lucky, thank you for posting about lateral roots. I have worked out a layout where the trees will 15 either side of the drain pipe and at least 25 feet from the field itself. As for using CuSO4, I worry in part I have to have my septic discharge water tested every 6 months for solids and Ecoli. This is in part due to county regulations that follow the EPA and surace water run off policies.

David,
I suspect the CuSO4 would be long gone six months after a flush - but doing it twice yearly would kill back any roots that might have made an incursion into the drain tiles in the interim.
If the 100-ft pipe you're mentioning that runs out to the leach field is a solid, glued-joint pvc pipe, you've got NOTHING to worry about, anyway. Only perforated/fenestrated drain tiles would possibly be at risk.

Hmm. I'm wondering how one would even sample water in the leach field. I can see where one of the four or so lateral lines runs in my back yard, but the others are out past the fence, into the pasture, and I can't really pick out thicker/greener grass over them. They're at least 4 feet below soil surface, and I have no issues with seepage coming to the top. Some of the neighbors in the area, though, have boggy wet spots in their back yards, though... guess my site 'percs' better.

Lucky, We have a sand mound system which has a drain pipe at the orignal soil level where water samples are collected. Just about every system that is going in in the county where I live has one of these systems. I suspect the county wants to make sure the septic systems are working properly and do not fail like some of the lateral systems do.

Part of my leach field runs right under my persimmon trees and kiwi arbors. If it was a new system my only worries would be having to dig things up in order to have work done but it's an old system that has been replaced before so that won't happen. The city won't install new drain pipes in the same area twice - so I went ahead and planted. So far, no problems.

I live in the northeast in an area where most of the septic fields have maples and other forest trees well within range. I have giant ones growing into my field and in the 25 years I've been here there's not been a problem (and I'm the idiot whose only pumped it out once in all this time). It looks like the original septic system, so you could probably double that.

All my neighbors have more or less the same situation and don't seem to have any special septic issues. I don't know what this means, but I just thought I'd throw it out there.

He may not only be worried about roots invading the field or causing problems to the long main line, but of future maintenance. Persimmons are very long lived trees. Say 25 years from now the line plugs...someone tries to clear it with a motorized drain snake and bores thru the pipe. Need to have room for a backhoe or mini excavator to dig it up. Especially if it happens in January since he's in Z5.
If it were me, I'd stay back far enough so that the future drip lines of trees on either side allowed ample room for a manuevering backhoe.