How Do You Find Your Septic Tank?

Most homeowners do not think about their septic tank until it needs pumping or something goes wrong, and then discover nobody knows where it is. Finding it is usually easier than people expect, and knowing where the lids sit will save you time and money every time the system is serviced.

Why does the location of the tank and lid matter?

A technician cannot pump, inspect or repair a tank they cannot reach. A lid that is buried under dirt, sod or a flower bed has to be dug up first, which adds time to every visit. It also affects safety: a hidden lid that has been driven over or has cracked can be a fall hazard.

Knowing the location also lets you plan septic pumping without a search party, and it lets you protect the system. You can keep cars, sheds, pools and large trees away from the tank and dispersal area, and you can show a buyer, an inspector or a new service provider exactly what is there. A visible riser with a secure lid makes every future visit faster. See septic tank riser installation.

Where should you look first?

Paperwork is the easiest way to find the tank.

• Your county permitting office. Many counties keep the original permit and a drawing of the system on file. Call and give them the property address.
• Closing and inspection documents. A home inspector or the seller may have a sketch.
• Previous service records. A pumping company or maintenance provider may have noted where the lids are. Check old invoices and the maintenance contract.
• Neighbors. Homes built by the same builder at the same time often have similar layouts.
• The seller or a previous owner, if you recently bought the property.

What clues in the yard point to the tank?

• Find where the main drain pipe leaves the house. In a crawl space or basement, look for a 3 or 4 inch pipe going through the foundation. The tank is usually along that line, often 10 to 25 feet from the house.
• Look for a round or rectangular green or black lid, or a small raised mound.
• For an aerobic system, look for the control panel box mounted on a post or wall. It is usually near the lids and the air pump.
• Notice strips of grass that grow greener or dry out faster. These can mark the tank or the lines.
• Look for a cleanout pipe in the yard, a short capped pipe sticking out of the ground near the house.
• Spray heads in a lawn mean the system is aerobic with spray dispersal. The treatment tank is usually between the house and the spray area.

Can you probe for the tank yourself?

If you have narrowed down the location, you can push a thin metal rod gently into the soil to feel for a hard, flat surface about a foot or two down. Go slowly. Do not push hard, because you can damage a tank or a pipe. Mark any spot where you hit something solid and stop there.

In Greater Houston, wet clay can make probing harder, because soft soil and shifting ground can hide the edges of a tank. If your first attempts fail, it is time to call someone.

What does a professional locating visit involve?

1. We ask what you already know: age of the home, any records, where the drains leave the house.
2. We trace the sewer line from the house and use probes to find the tank edges.
3. When needed, we use an electronic locator on a camera or transmitter to follow the line underground.
4. We mark the lid or lids with flags or paint so you can see them.
5. We can then recommend a riser and secure lid so the tank is easy to reach next time.

You can find out more about this service on our septic tank locating page.

What safety rules apply around septic lids?

• Never stand or jump on a lid you are unsure about. Old concrete lids can crack.
• Do not remove a lid and look inside. The gases in a tank can be harmful, and an open tank is a serious fall risk, especially for children and pets.
• Keep heavy equipment, trucks and trailers off the tank.
• Call 811 before you dig deeply in the yard, so buried lines are marked.
• If a lid is cracked, broken or missing, cover it safely and call us. See septic tank lid replacement.

If you have searched and still cannot find your tank, or you just want the lids marked and raised to ground level, call Brown Aerobic at 832-789-5357 and we will schedule a visit.

Quick questions and answers

Related reading and services

• Septic Tank Locating
• Tank Riser Installation
• Tank Lid Replacement
• What Is a Septic Tank? How It Works

More guides

• Why Does My Septic System Smell?
• What Is an Effluent Filter, and How Often Should It Be Cleaned?
• What Is an Aerobic Septic System? Simple Guide