A percolation test is a test to determine the water absorption rate of soil​

What is a Percolation test?

A percolation test consists of digging one or more holes in the soil of the proposed leach field to a specified depth, presoaking the holes by maintaining a high water level in the holes, then running the test by filling the holes to a specific level and timing the drop of the water level as the water percolates into the surrounding soil.​

How Percolation Tests are performed