Underground Systems

Natural gas, water, drainage and sewer utilities are the normal underground systems for your home.  Unless there is a major obstacle to avoid, these lines run in fairly straight trenches from the house to connections at the edge of the property or street.  It is a good idea to map out where these lines are located on your property in order to avoid accidentally damaging them when digging. 

Electrical

If your electrical service is also underground it is likely to be in a separate trench. The wires will be in a conduit that runs from your meter to the nearest public utility pole or vault. If you have an underground electrical service, your cable TV and phone lines will likely be underground also. TV and phone cables are usually placed in separate conduits but placed in the same trench as the electrical service.

Sewer or septic

The piping for sewer lines is large and expensive so builders tend to run them in straight efficient lines also, with as few bends as possible to avoid clogging. Sewer lines will typically run from the centerline of the home to a connection at the municipal main line at the street. Call your utility and they will come out and locate the line for you.  Septic lines also run from the centerline of your home to the septic tank which will be located about 5-10′ from your house. If you have a septic system you will need to locate the leech fields also.

You can usually identify where the sewer line exits your home because there is usually a clean out located in the ground at that location. The clean-out allows a plumber to place a “snake’ into the line to clear any clogs.

Underground drains

Another underground system is for drainage, although not every home has or needs one. Drainage systems collect water from around the perimeter of the home and move it safely away. Often these systems will daylight onto the street curb. Alternatively, they can empty into absorption pits, lower elevation outfalls or into sumps equipped with pumps to move the water to a safe place.

Natural gas

The gas meter indicates where the utility gas line is connected to your home.

The utility company will mark the path of the underground gas line if you call them.  For propane systems, there will be a gas line running from the tank to a connection the foundation of your home. You will need to know where the shut-off valve is located, and have a tool to manually shut off the gas in an emergency. It’s advisable to have a seismic sensing automatic shut-off valve if you live in earthquake country.

To-Do

• Before doing any digging on the site, check the location of buried services by calling 811, USA, the Underground Service Alert system. They will locate and mark any underground utilities, usually for free.
• Once the utilities are marked, map them out on a site plan to keep for your records so you know where they are for the future.