How to Locate a Septic Tank Drain Field

Water enters the drain field after going through the septic tank.

In these instances the wastewater is sent through the septic system, which acts as an on-site sewage plant because it filters the wastewater, removing sludge before releasing the water into the soil through a series of perforated pipes in a drain field (also known as a leach field). Keeping your drain field clear can alert you to problems in the septic system.

1. Contact your local municipality to see if they have the records from the installation of the septic system. This can tell you precisely where the drain field is located.

2. Look for tubes or pipes in your lawn that have white caps on them. Called monitoring ports, the caps allow you to inspect the level of liquid in the drain pipes. The caps are located at the end of the drain field.

3. Examine the surface of your lawn for areas where the ground is depressed in parallel rows. This can mark the drain field.

4. Examine your lawn for signs of the drain field. In winter, look for areas where the frost melts the soonest. In the summer, when your grass begins to turn brown from the heat and lack of water, look for green stripes in the lawn. The grass is green in these areas due to receiving moisture from pipes in the drain field.

5. Hire a professional company to locate the drain field.