Locating Underground Utilities

If you're planning to dig on your property, say to run a power line, add a shed, or put in a fence, there's a step you need to take before touching a shovel: call 811, the national before-you-dig phone number, at least two to three business days ahead. This free service sends out locators from utility companies to mark buried public lines like gas, water, and electric near your dig site. Skipping this call can mean fines and repair costs if you hit something.

The catch is that 811 usually only covers public utilities. Private lines on your own property, such as septic systems, propane tank lines, or a subfeed line to a detached garage, often aren't mapped and won't be marked by that call. It's worth checking with whoever installed those lines, or your local building department, since records sometimes exist even when 811 can't help.

Finding these private lines usually takes a specialist with the right tool for the job. Metal lines, like copper propane pipe, can be traced with an electromagnetic locator, accurate to within a few inches. Plastic or nonmetallic lines, including many septic and sewer pipes, need ground-penetrating radar or a small transmitter snaked through the pipe. Even with these tools, some digging by hand is often used to confirm the exact location before excavation equipment gets involved. If you're planning any project that involves digging on your property, it's worth finding out early what's buried there and how to have it marked.