Installation details for a septic system such as size, location, depth and configuration are determined by soil testing. Percolation tests and Deep Observation pits are required by Massachusetts Title V regulations.
A hand dug hole in the area of the proposed septic system. This hole is initially filled with water (presoak) in an attempt to saturate the soil, allowed to drain away and than refilled. The rate at which the water drops in the hole is measured at intervals over a period of time. The uniform slowest rate of drop of the water level over a measured time interval is used as a basis of design in determining the septic system size.
Deep Hole (s)
Observation pits are dug in the proposed septic area in order to be able to see the various soil layers /characteristics. These holes are dug with a backhoe machine generally to a depth of about 7 ft and observations are made of the soil layers, color and texture and recorded by the sanitarian and/or engineer. Particular attention is given to the depth to ledge rock or ground water since both must be sufficiently separated above ground water or impervious soil and ledge rock.
NorthEast Classic Engineering provides copies of the soil evaluation to you the property owner on MA DEP forms and submits copies to your local Board of Health to be put on file for the property.