Illinois Plumbing Code Practice Exam 2026 – All-in-One Guide for Exam Success!

Conducting a soil percolation test is crucial in the installation of a septic system because it assesses the soil's ability to absorb and filter wastewater. This test determines the rate at which water can pass through the soil, which is essential for the proper design and function of the septic system. Depending on the results of the percolation test, adjustments may need to be made regarding the design and location of the septic system to ensure that it operates effectively without contaminating the groundwater or failing due to poor drainage.

While obtaining a plumbing permit, installing the tank, and choosing the location are also important steps in the process, they rely on the information gathered from the percolation test. For example, the location chosen for the septic system must be compatible with the soil characteristics identified through this test. If the soil does not percolate well, the selected site may need to be reconsidered, or alternative system designs may need to be employed to ensure proper wastewater management. Hence, the percolation test lays the foundational understanding necessary for the successful installation of a septic system.