How deep are utility lines buried in an easement?

Federal pipeline safety rules do set floors for natural gas. A buried gas main needs at least 24 inches of cover under 49 CFR 192.327, with 30 to 36 inches for transmission lines depending on the area. A service line to a house needs at least 12 inches on private property and 18 inches under streets and roads under 49 CFR 192.361. Those are minimums, and lines are often deeper.

For other utilities there is no national number. Water lines are usually set below the local frost line, so they run deeper in cold climates. Sewer lines depend on grade and flow. Electric and communications lines follow each utility's own standards and local code, and they can be much shallower than people expect.

Depth also changes over time. Erosion, regrading, a new driveway or a past repair can leave a line closer to the surface than the day it went in. The easement document almost never states a depth, so the only safe approach is to have the lines located and exposed by hand before any digging.

What this looks like in practice

A gas service line to a house must have at least 12 inches of cover on private property under 49 CFR 192.361, and 18 inches under a street. That is a floor. A line installed years ago, then exposed by regrading or erosion, can sit closer to the surface than the rule suggests, so a shovel is a real hazard.

A water line in a northern state runs well below the local frost line, often several feet down. A cable or fiber line may be much shallower. The same strip can hold a deep sewer main and a shallow communications line a few feet apart.