Short answer
Start with paperwork: your county or town health department often has a drawing showing exactly where the system is. Without one, find where the main sewer line leaves the house and probe along it with a steel rod: the tank is usually 10 to 20 feet from the foundation, according to the Anne Arundel County Department of Health.
Step by step
These steps follow the Anne Arundel County Department of Health's guidelines for homeowners.
- Get the drawing. Ask your health department for a copy of the septic system drawing. These are made when a system is approved and inspected, and are usually searchable by address or tax account number.
- Look for clean-out pipes. Clean-out or marker pipes at ground level are usually cast iron or PVC, 4 to 6 inches across, and can show where the system is.
- Follow the sewer line. Find where the main sewer line leaves the house in the basement or crawl space. Outside, probe carefully with a steel rod to find the top of the pipe and follow it.
- Find the tank. Keep probing along the line. The tank is usually 10–20 feet from the foundation and made of concrete, metal or plastic.
- Leave the rest to a pro. The distribution box, pump tank and drain field are best located by a licensed pumper or contractor, often after the tank is pumped.
Never open a tank and lean in: septic gases can be deadly. Probe gently, and call 811 before digging.
Once you've found it
- Measure and sketch the tank and lid positions from two corners of the house.
- Add a riser so you never have to dig again.
- Book a pumping if you don't know when it was last done.
Frequently asked questions
How far is a septic tank from the house?
Usually 10 to 20 feet from the foundation, along the line of the main sewer pipe (Anne Arundel County Department of Health). Local rules set the minimum distance.
Where do I get my septic system drawing?
Ask the health department or permit office for the county or town where the home is. Many keep the drawing made when the system was installed and inspected, searchable by address or tax account number.
Can a septic company find my tank?
Yes. Health departments recommend asking a licensed pumper or septic contractor. If they have to dig to uncover the lid, Angi puts that at about $50–$250.
How do I avoid having to look again?
Install a riser so the lid sits at ground level ($300–$600 per Angi and LawnStarter), and keep a sketch with measurements from the house.
Sources
- Guidelines for Locating Your Septic System, Anne Arundel County Department of Health (MD). Record drawings, clean-out pipes, probing along the sewer line, tank usually 10–20 ft from the foundation.
- How Much Does a Septic Inspection Cost?, Angi. National average $550; cost by inspection type; digging $50–$250.
- How Much Does a Septic Tank Cost?, LawnStarter. Install average $5,828; aerobic $10,200–$18,300; riser $300–$600; pump alarm about $475.
- How to Care for Your Septic System, US EPA. Inspect at least every 3 years; pump typically every 3–5 years; when to pump; garbage disposals; water use.
Prices are estimates for 2026, not quotes. Local codes, soil and access change the price, so get at least two written quotes and confirm the rules with your county health department.