What is a "perc test"?

A "perc test" is used to determine the suitability of a lot for the installation of an on-site septic system. The term "perc test" has a specific meaning in the Connecticut Public Health Code. They are commonly referred to by real estate agents and lending institutions as soil testing. Soil Testing refers to these two different types of tests:

  • Deep Test Pit - This type of test determines how deep into the ground the system can be placed. Test pits are dug with a backhoe to a minimum depth of seven feet where possible. Several test pits are usually dug on a given lot to determine its suitability for a septic system. Test pits are dug in the primary septic area, the area where the septic system is planned to be installed and in the reserve area. This testing reveals the best placement for a septic system.
  • Perc Test - The purpose of this test is to determine the ability of the soil to handle sewage wastewater when the soil is saturated. The results of this test are used to determine the size of the leaching system needed to accommodate the home or business that is planned. To conduct this test a hole is dug by hand, usually with a post-hole digger or a hand shovel, to an average depth of 36 inches and a width of 10 inches depending upon the results of the Deep Test Pit. At least two perc tests are required, one in the primary area and one in the reserve area. Water is poured into the test pit. The rate the water percolates into the soil determines how large the leaching field must be.

Show All Answers

1. How do I know if a lot has public sewer or water available?
2. What is a "perc test"?
3. Who conducts the soil testing to determine if a septic system is feasible?