How Deep are Gas Lines Buried? A Homeowner's Guide

Published onMay 12, 2024
Resources, Safety and Health

In most U.S. states, an underground gas line is required to be buried between 12 inches deep and a few feet, but the depth of these lines will depend on where you live and your local codes.

Did you know there are three different classifications of underground gas lines that can be buried on your property?

Whether you want to know what to expect when gas lines are installed on your property, understand how deep your existing lines are for an outdoor project, or are planning to install an underground gas line yourself, we’ve got’ve answers you’re looking for.

Keep reading to learn about the three types of underground gas lines and how deep each type is typically buried.

Table of Contents

What’s The Difference Between a Gas Pipeline, Service Line, and Underground Fuel Line?

Each section of an underground gas piping system—from a main distribution line to a service line feeding your home and potentially a fuel line to an appliance—is required to be buried at a certain depth.

The depth of these lines will depend on where you live and your local codes, but in most U.S. states, an underground gas line is required to be buried between 12 inches deep and a few feet.

Let’s break these down individually so you have a better understanding of how a gas piping system works.

Pipelines

When someone says “gas pipeline”, they’re usually referring to either a high-pressure transmission line or a main distribution line.

Transmission Lines

A gas transmission pipeline transports natural gas over long distances at different pressures, ranging from 200 psi to around 1,000 psi.

These gas pipelines start at a storage facility or treatment plant and are installed under or above ground into a distribution system.

You don’t typically see these pipelines as they’re mostly installed along isolated land routes. However, some landowners with larger properties may negotiate with utility companies to have these lines run through their property.

Distribution Lines

Once natural gas reaches the distribution system, the pressure is reduced at a regulator station, where a gas utility company delivers it to consumers through a network of underground distribution lines.

These main distribution lines can be different sizes and pressures but the most common pressure used in a distribution line is 60 psi.

If natural gas is available for your home, a main distribution line will be installed on your street.

These are installed in the right-of-way just like all other public utilities, such as electrical lines, water lines, sewer lines, cable, internet, etc.

Commercial and Residential Gas Service Lines

A gas service line is an underground gas line installed from the main distribution line on the street up to your home.

These service lines will hold the same pressure of gas from the distribution line, which is then reduced at your meter by a service regulator before entering your home.

Appliance Fuel Line

An underground fuel line or “appliance line” is a gas line installed from the main house line to an appliance. They’re either tied into the existing piping system or can be ran directly from the outlet port on the gas meter.

These fuel lines deliver the same gas pressure that’s delivered to your home after the meter regulator, which will either be 7” W.C (water column) or 2 psi.

How Deep are Gas Lines Buried?

Natural Gas Lines

The required depth of natural gas lines depends on the amount of gas pressure they hold and the size of the pipe. The larger the pipe, the deeper underground it must be buried.

Here’s the average required depth of each type of gas line in the United States, with each measured from the top of the pipe:

Transmission Lines: When buried, these lines are installed at a depth of 3 to 6 feet.
Distribution Lines: These lines are typically buried 36 to 48 inches deep.
Service Lines: Installed from the main distribution line to your home, service lines are installed between 18 to 24 inches deep.

Propane Lines

If you have a large underground propane tank, the underground copper pipe buried from the tank up to the regulator before entering your home will be buried between 12 to 24 inches deep.

How Deep Do You Need To Bury Gas Lines?

All distribution and service lines will need to be installed by professionals. In most cases, this is done by your gas utility company or one of their qualified contractors. However, homeowners can install underground gas lines to appliances.

If you want to install an underground gas line to an appliance, it should be buried at least 12 to 18 inches deep.

If you start digging and run into rock or tree roots that prevent you from getting to the minimum depth of 12 inches, you might be okay with only 8 inches of cover on top of the pipe.

Call your local inspection office and ask them what your options are. Some local governments only require a minimum depth for an appliance line to be 8 inches.

In others, they may be a little more strict so you’d have to find another route to install your fuel line.

Can Appliance Lines Be Buried In A Backyard?

Yes, appliance lines can be buried in a backyard and around most areas inside your property line. The best location to install the line on your property will depend on where your other utilities are located.

What to do Before Digging Near Other Utilities or a Gas Line

Some states will have requirements on how far gas lines need to be installed away from other utility lines.

This means if you plan on digging the trench yourself, you’ll need to have your other utility lines located by a professional locator beforehand.

If you don’t have these lines located and you just start digging, you run the risk of getting extremely injured or creating a gas leak.

You can have your utility lines marked for free by calling 811.

If a professional contractor is installing the underground gas line for you, they’ll typically call in a ticket to locate your utilities, obtain the necessary permits, and schedule your inspection.

What to Include Inside Your Trench With The Gas Line

Once you’ve installed your fuel line, you need to add tracer wire on top of the gas line before you backfill any of the dirt back into the trench.

Adding tracer wire to an underground line is a requirement to pass inspection. It’s there so people or contractors who plan to dig near the gas line in the future can locate it beforehand. It also helps the gas professionals find your gas line quickly in case there’s an emergency like a gas leak.

The best way to install tracer wire is to wrap it around one of your risers a couple of times. Then, hold the roll of wire in hand and walk along the trench until you reach the next riser.

When you get to the second riser, leave about 5 feet of extra wire so you have enough to wrap it around this riser as well.

After that, you can cut it off the roll, lay the wire into the trench on top of your gas line, and finish up by wrapping it around the second riser.

Once you have 1 to 2 inches of dirt covering the line, put down underground detectable tape on top of the dirt along the entire trench to let others know there’s a gas line buried underneath. This tap lets people know there’s a gas line buried underneath if they didn’t get it located.

The tracer wire and tape are extremely important, and your local inspection office will look for them when you install an underground gas line.