This allows scum and sludge solids to overflow and plug the outlet or the line to the absorption field. The cure is pumping the tank down, routing out the line and replacing the defective baffle. Likely causes are solids over flowing the tank, tree roots getting into pipe joints or collapse of a pipe section. Again, the immediate remedy is pumping the tank and clearing the line, followed by repair of the leaky joint or broken section. Sewer pipe can break if not uniformly supported on solid or gravel fill or if shallow line is driven over by heavy vehicles.
Tree roots can get into sewer lines through leaky pipe joints.
Pipe plugging should not be a problem in the trench area, since tree roots seldom penetrate very far into the gravel fill around the pipe. Clogged absorption field. See discussion under Cause B.2 below. Symptom B. Seepage or Swampy Conditions in Absorption Field Area Cause B.1. Too small a filter field.