How do I find the location of my septic tank?

Locating your septic tank involves a combination of indoor and outdoor observations, consulting records, and sometimes professional assistance. Follow these steps to locate your septic tank.

Locating the Septic Tank

Step 1: Start Indoors

Find the Main Sewer Line:

Check your basement or crawlspace for the main sewer line exiting your house.

Look for a large-diameter pipe (typically ABS or cast iron) positioned at waist height in a full basement or at floor level in a crawlspace.

Note the direction the pipe exits your home; the septic tank is generally 2–6 meters from that point outside.

Most septic lateral exit the house through the basement wall, this lateral was moved to exit below the basement floor – Burlington

Step 2: Check Outdoors
Look for Access Lids or Risers:

Search for plastic lids (approximately 60 cm diameter) or square concrete lids (about 60 cm x 60 cm).

If no lids are visible, they may be buried. Use a metal rod or septic probe to gently probe the ground in the suspected area, taking care not to damage pipes or tank components.

Examples of septic tank lids:

Both plastic and precast septic tanks must have risers installed to grade to facilitate future servicing – Hamilton
A septic tank and pump chamber to be used with a conventional leaching bed – Ancaster
A residential septic system may still require advanced treatment and may need more than one septic treatment tank – Norweco – Burlington
Tertiary treatment septic tanks can be squeezed into small locations – Bionest – Burlington
Septic tank replacement, risers installed, verifying slope before building inspection – Haldimand
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Plastic septic tanks and pump chambers can squeeze in tight spots – Waterdown
Placing advanced treatment tanks in a large residential septic system – Bionest – Hamilton
Plastic tanks, advanced treatment unit and flow ballancing, ready for granular backfill – Bionest – Hamilton
Advanced septic treatment unit is placed minimum 1.5 meters to the house – Milton
Advanced septic treatment can be used to decrease the size of a leaching bed – Bionest – Dundas
A septic tank should be installed at least 1.5 meters from the house – Ancaster
Septic tanks may be smoke tested to find the sources of bad odors – Burlington

Roof Vent Clues (Older Homes):

Locate the sewer vent on the roof (a 3- or 4-inch pipe). Its position often aligns with the main sewer line, indicating the tank’s location.
Most tanks are located about 1.5–2 meters outside the foundation wall.

Excavation for Access:

Once located, dig up the septic tank lids. Typically, there are two lids that should be accessed for maintenance.
Consider installing risers to grade for easier future access.

An effluent filter helps protect the septic bed and should be installed on the outlet side of every new septic tank – Halton

Step 3: Seek Professional Help if Needed

Professionals have tools like flushable electronic locators and extensive experience to locate septic tanks without damaging your property.

Electronic locating equipment may be essential during septic system repairs – Haldimand