Why Do I Need A Percolation Test for My System Design and How Long Does it Take?

A percolation test (also known as “perc test”) is a soil evaluation that tests the rate at which water drains through the soil. A perc test typically takes two days, and is conducted by drilling or digging a hole in the ground, pouring water into the hole and then observing the rate at which the water is absorbed into the soil. The test results determine the required size of the leach field, aka drain field.

If the soil is sandy and drains too quickly, it won't filter waste from the water, and the groundwater could be contaminated. If, on the other hand, the soil has a high clay content and drains too slowly, raw sewage water will remain near the surface and could form pools or flood the leach field.

The hole is mechanically or manually dug or drilled in order to perform the perc test.

Testing is needed before installation of septic systems can take place