Which of the following is typically used to assess whether a septic system is working properly?

The percolation test is a crucial assessment used to evaluate the function of a septic system. It measures the rate at which water is absorbed into the soil, which is vital for determining whether the soil can adequately treat and disperse effluent from the septic tank. During this test, holes are dug in the designated drain field area, and water is added to them to observe how quickly it percolates into the soil. This information allows installers to judge soil suitability for a septic system and to size the drain field appropriately.

While the heat test, flow test, and pressure test are methods that can be employed in various contexts within the plumbing and septic installation industry, they do not specifically assess the soil's ability to absorb water, which is essential for the proper functioning of a septic system. Therefore, the percolation test is the most relevant method for assessing the operational effectiveness of a septic system.