While property and lot sizes differ, most septic systems include a sptic or treatment tank, a distribution box and a lateral or drainage field. Some systems have a seepage pit or cesspool instead of a lateral field. Septic tanks, distribution boxes and seepage pits are commonly made of precast concrete. The perforated pipes in the drainage field are often made of P.V.C. pipe which lay buried in several feet of crushed stone.
Town regulations, health codes and soil conditions often govern the system design in your area. You may want to contact municipal offices to obtain specific codes or a copy of the property survey.