Best Bed for this situation...Perimeter Trench?

[Apexpredetor]

Hello All,

I have done a few simple septic designs in the past, but I don't have a vast deal of experience. I have done about 20 or so, but just by coincidence have been very straight forward.

I am helping a friend with his septic design for ne house and I am working with a lot that had been filled with sand before it was sold. Sounds good, but the problem is that there is water traveling across the native (original elevation) soil which appears to be a 4-6" layer of organics, then sandy below (with a small vein of clay, but mostly sand).

Can't get a good perc. because of the water running across the native level and coming into the hole. (Side Note, there is a clogged driveway culvert that is trapping water as well) I was thinking about reinstalling a proper culvert under the driveway, and installing a perimeter drain around the bed to stop the water from entering the trenches.

Thoughts?

Thanks all.

 

[dBasement]

Don't put the drain down-gradient of the septic field or it will be taking on effluent from the field. Above gradient it is a good idea, and I would go one step further and line the down-side of the interceptor (side of the interceptor trench closer to the field) with a 6mil poly barrier. Make sure you backfill the interceptor with a free-draining material. Make sure to locate the discharge of the interceptor a good distance away from the field.