In order for a septic system to function properly the soils in which it is placed must be permeable. The quicker water can pass through the soil the smaller the leaching system can be. The percolation test is an empirical means utilized to estimate a soil’s general permeability. Unit of measure is in “minutes per inch,” representing how long it takes a column of water to drop an inch in a small diameter hole dug in the soil strata that will be utilized for sewage disposal.
Lussier and Sons provides expert on-site consulting, and can perform all necessary perc testing.
Soils which are permeable (percolation rates faster than 60 minutes per inch) must meet other criteria prior to being deemed suitable. There must be at least 24” of permeable naturally occurring soils over ledge rock. In shallow bedrock areas substantial amounts of “select” (good quality) fill material would be necessary to raise the leaching system at least four (4) feet above the ledge. Also, the soil in the leaching area must not flood from seasonal high ground- water. The code requires at least 18” of unsaturated soils be present during the wettest time of the year.
Lussier and Sons provides expert on-site consulting and soil assessment.
The code refers to a septic system being able to adequately absorb or disperse the expected amount of sewage into the surrounding naturally occurring soils without overflow, breakout or detrimental effect. Discharging a large amount of sewage in a confined area, especially if ground conditions can not support a great deal of extra water, could overload that area and lead to a septic overflow.
Fill material (brought onto the site by artificial means) can never be classified as “naturally occurring soil.” Likewise, bringing in fill material to cover a sewage overflow condition is not an acceptable repair, since it does not correct the inherent problem of the leaching system which is its inability to release the sewage into the ground.
Lussier and Sons provides expert on-site consulting.
Deep test holes are dug within and down grade of a proposed leaching area to determine the soil characteristics, maximum groundwater levels and ledge rock conditions. Depending on what is observed, the type of system and the configuration of that system will be determined. Deep test holes must be conducted and observed by a professional engineer and/or a local health department sanitarian.
Lussier and Sons coordinates and schedules the personnel necessary to conduct, observe and certify deep test holes.