Septic Metrics

How to find your septic tank

Updated . Based on the sources listed below. Expert review pending.

Short answer

Start with your county health department or permitting office, which may have a map of your system. If not, find where the sewer pipe leaves your house. The tank is often 10 to 20 feet out, in line with that pipe, with its top usually 1 to 4 feet down. Call 811 before you probe the ground.

A yard with a marked sewer line, a soil probe and a flag above a buried septic tank

Pumping, inspections, any digging in the yard: they all start with knowing where the tank is. Most owners can narrow it down in an afternoon.

Do you have a septic tank?

Not sure? The University of Georgia suggests a few checks:

  • Look at your water bill. If there's no sewer charge, you may be on septic.
  • Look for sewer manholes or access ports near your property.
  • Ask your neighbors what they use.
  • Ask your local health department.

How do you find a septic tank location?

  1. Check the records. Your local health department or permitting authority may have a map of your system showing its location, type, length and depth. Records for very old systems can be incomplete.
  2. Check your paperwork. Home-purchase documents and inspection reports sometimes include a site sketch.
  3. Find the sewer pipe. In a basement or crawl space, find where the main pipe leaves the house and note which way it heads.
  4. Look for clues in the yard. An access riser or lid is the giveaway. The EPA suggests looking about 10 feet from the building.
  5. Call 811. Get buried utilities marked before you push anything into the ground.
  6. Probe gently. The University of Georgia suggests a length of rebar, starting about 6 feet from the house in line with the pipe. Work outward until you hit a large flat surface, then mark its edges. The ground is easier to probe after rain.

Expect a typical tank to measure about 5 by 8 feet, with its top usually 1 to 4 feet down.

How can you spot the leach field?

Georgia's guide notes that grass over the field may look greener in dry weather (though not always) and that faint, straight depressions can mark the lines. Don't probe hard or dig there. The lines can be shallow.

What if you still can't find it?

A septic professional can locate it for you. Angi estimates $100 to $450 for a basic visit, or $100 to $300 an hour. Having the tank located during a pump-out often saves a separate trip. These figures are third-party, unverified estimates and will vary.

Stay safe

Finding the lid is where this job ends. Don't open the tank or lean over an open one. Wisconsin's safety guidance warns that toxic gases in a septic tank can kill within minutes. Keep lids secure, and leave opening them to a trained professional.

Once you've found it

Sketch a simple map, measuring from two fixed corners of the house, and keep it with your septic records. Then mark the spot so nobody parks or builds on it.

Rules vary by location

Different places keep these records in different offices. Your county health department, environmental office or county clerk can point you to the right one.

Quick answers

How far is a septic tank from the house?

The University of Georgia says it's often 10 to 20 feet out, in line with the sewer pipe.

Sources

Cost figures from Angi and HomeGuide are third-party, unverified estimates. We link to them so you can check them yourself. We have no connection with either company.