Perc Test Cost: Average Prices & Cost Factors

A perc test, also called a percolation test, measures how quickly water drains through the soil on a property. Landowners and builders use it to find out whether the ground can handle wastewater from a septic system. The result helps decide where the drain field goes and how the system is designed.

The figures below come from published cost guides and carry a check date of Oct 13, 2026. They describe a typical residential site. Your price depends on the number of holes, the digging method, and what your county asks for.

How the holes are dug drives much of the price. A shallow test done by hand costs far less than one that needs a backhoe operator, a soil scientist, or an engineer on site.

A lower figure usually means a simple test with a few shallow holes. A higher figure often reflects deeper holes, excavator time, and a written evaluation.

Some contractors price by the hole. Deeper holes take longer to dig and observe.

These numbers overlap with the method prices above, because a complete test-and-report quote often already includes the holes, the equipment, and the labor. Adding every line from both lists would count the same work twice.

Some counties and townships charge their own fee for site evaluation, or run the test themselves. As one example, North Middleton Township in Pennsylvania lists $390 for a test with six to nine holes, with some preparation work not included. Soil evaluation, permit review, excavation, and septic design can all be separate charges on top of the test.

• Number of test holes. Larger lots and larger planned systems need more testing.
• Hole depth. Deeper holes take more time and may need machinery.
• Digging method. Hand digging costs less than excavator work.
• Site access. A hard-to-reach lot, thick brush, or rocky ground raises the price.
• Professionals involved. Some jurisdictions require a licensed soil scientist, engineer, or county official to witness the test.
• Water supply. Tests use water, and arranging a supply on a remote lot can add a charge.

Cost guides differ on what they count. One may describe a basic hand-dug test, another may include excavation and a full report, and a third may fold the test into a larger septic installation estimate.

A perc test is also only one part of the site work. Local approval can depend on a soil profile, groundwater depth, and other checks, so ask what your county requires before you hire anyone.

Septic rules are set locally. Your county health department decides which tests count, who may perform them, and whether the department must be present. Before you hire a contractor, call the department and ask what the evaluation must include and whether a permit is needed. Some jurisdictions use other soil evaluation methods instead of, or in addition to, a conventional perc test. A DIY result may not be accepted for a permit or a land sale.

A failed conventional perc test does not always mean the property cannot have a septic system. Some areas allow alternative designs that work with different soil conditions. A septic designer or the health department can explain which options your county accepts. Because a failed test can limit what you can build, buyers often order one before closing on a vacant lot.

• How many holes does the price cover, and how deep will they be?
• Does the quote include equipment, labor, and a written report?
• Who will witness or approve the test for the county?
• Are permit and filing fees included?
• What happens if the test needs to be repeated?