Septic Soil Evaluation

Soil Testing

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.

Per­co­la­tion Test

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.