thanks Oldguy... I don't think it is feasible... the hole is about 150 ft from any edge of the building and there are tanks and chest foundations to go around...
We have an old building at the mill and one u-drain had a hole and washed a lot of soil under the slab and also under the footing of few collumns. so we have a huge cavern and the access to bring material is difficult as it is at the center of the building.
the plan is to resolve the sewer...
