A percolation test, or "perc test," is performed on undeveloped land in order to determine whether the land is absorbent enough to support the installation of a septic system. Typically, the test is performed by a hydraulic engineer.

What Does a Percolation Test Involve?

A hole, approximately 6 to 12 inches in diameter, is dug in the area of the proposed septic system. The hole is filled with water and allowed to drain. Again, the hole is filled with water. The hydraulic engineer then determines the rate at which the water drops over a given period of time. In order to pass the test, the rate must fall within certain parameters.

How Much Does a Percolation Test Cost?

Usually, a percolation test on a property planned for the construction of a home costs approximately $350 to $500. The cost of a percolation test varies from locality to locality.

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