No, you typically cannot use metal detectors to find your sewer line. Most sewer lines are made of non-metallic materials such as PVC, clay, or cast iron, which are not detectable by standard metal detectors. Metal detectors are designed to locate metallic objects, so they won't be effective for identifying the path of a non-metallic sewer line. To locate your sewer line accurately, it's best to use other methods.

In the United States, a depth of 36 inches (three feet) for underground water lines is the accepted industry standard. This depth varies from location to location based on local conditions. In areas with colder winters, they may be buried deeper to prevent frozen well water pipes : This is usually at least six inches below the frost level. The International Plumbing Code calls for a minimum of 12 inches below grade.

Prior to excavation, you should prepare the dig site and call 311 before you sign anything.

To get your site ready for excavation, you should move anything in the area that isn’t affixed to the land. You can save money on the excavation by removing hardscaping, including walkways, decks, concrete patios, and paver patios.

Before you carry out any digging, you should call 311 to confirm that there are no utility lines running through your excavation site. Skipping this step could lead to severe injury and property damage if your excavator hits a water, sewage, or gas line.

The average cost for pool excavation is $2,500. This cost can range from $450 to $4,500, depending on the pool shape and size, time of year, and any need to move buried utilities. 

When excavating for your pool, you might have to move existing utilities. You can expect to pay an additional $15 to $25 per linear foot to move gas lines. To move a septic system, it’ll cost an additional $2,000 to $20,000. A pool that is 10 feet by 12 feet averages $450 to excavate, and a 20-foot-by-40-foot pool averages $3,020.