Q It’s high time we had our septic tank pumped. The problem is that the company that does the work says we could save a considerable amount of money if we locate the lid rather than hire them to do it. What’s the quickest way to find the lid?

A Unfortunately, there’s no foolproof answer here. Typically, you begin the search inside the house, not outside. Look for the point where the building’s main drain exits the foundation. In most cases, the drain runs perpendicular to the foundation for about 3 metres and meets up with the septic tank. However, that distance can be as little as 2 metres.

You can also check with the municipality, which may require that the position of the tank and the rest of the house’s waste system be indicated on a plot plan or a similar document.

If you have the plans, use a tape measure to locate where the tank is. Probe with a shovel or use a digging bar with a sharp tip. The top of the septic tank will be anywhere from 10 cm to 30 cm below ground. When digging a test hole, remember to remove a square patch of sod so that it can be easily put back into place after the tank is pumped or when you go to make another test hole.

Sometimes a tank lid is easy to find and requires no more than half an hour to an hour of careful probing and digging; other times it can take a couple of hours. It makes you appreciate why some pumping companies now use flushable transmitters. The pumping contractor flushes a transmitter down a toilet and then finds it by sweeping over the ground with a locator. Other companies use a metal detector to seek out the piece of bent rebar that is sometimes cast into a tank’s concrete lid. In any case, you’re making a smart move by locating the tank yourself.