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Underground Utilities: Call Before You Dig

Utilities Underground

Underground Electric Line with Warning Tape

It’s building season and that means we are all diligently working on our new projects.  Whether your goal is to build a fence or a new addition for your home, be sure to call your local utility locate service to mark your underground utilities prior to digging.  The call before you dig service is free and can save lives and big money.

When to Call for a Utility Locate

Anytime you will be digging 6 inches or more into the ground you should call before you dig for an underground utilities locate.  This could be for something as simple as a mailbox post.  If you dig down and cut through an electric line, your life can end in an instant.  And I don’t know about you, but I don’t want to leave this world while installing a mailbox.  And if you’re lucky enough to avoid a shock, the cost to repair the damage can be huge.

I once had a deck builder install a really nice deck off the back of a new home I built.  Our contract said that he was responsible for calling for the utility locate (most underground utilities locating organizations require the party doing the digging to call…and nobody else).  The deck builders hit the electric line to the house…thankfully nobody was hurt.  But the cost to repair was painful.  It cost the deck company over a thousand dollars to retrench, install a new line and repair the landscaping.

Be sure to call three days prior to digging so that all underground utilities can be located.  In some cases, several different companies will come out to do the marking.\

Call 811

The federally mandated call before you dig phone number is 811.  So, you just dial 811 from your job site location (the locate services are by state) and you will be routed to your state’s underground utilities service.  If you would like to contact your state’s location service directly, or maybe submit a locate online, check out this link for state specific information.

Identify the Area

I usually mark the dig location with white paint (this is pretty standard in most parts of the U.S.) so the people marking the utilities can find it easily.  They typically use colored paint for utility markings (and sometimes those small flags)…so we use white as to not confuse anyone.  You will want to check with your local service to find out what color they would prefer you use to mark the dig location.  Be sure to have your home address, dig description (including area and depth), and the closest intersection on hand when you call.

Typical Depths for Underground Utilities

The call before you dig locating service will mark the location of the utilities on the ground…but they don’t give you a depth.  If you plan on doing any digging around these locations, you need to be extremely careful and never should a machine or excavator be used near the markings.  That being said, here are some typical ranges for depths of underground utilities.  Keep in mind, local climate and code jurisdictions drive the actual requirements for your area.  You will want to contact the local building department or utility to confirm depths for underground utilities for your community prior to digging.

  • Gas line to house:  18-36 inches
  • Electric line to house:  18-36 inches
  • Phone and cable:  varies too much to mention (I’ve seen these at 3 inches and 24 inches deep and all depths in between)
  • Water Main:  depends on climate and frost line (a call to your local builder department will give you the typical depth)
  • Sewer:  based on design of the system in order to obtain gravity flow to the treatment plant (or pump station)

Water Installed Above Ground in Hawaii

As mentioned, these are only guides which can vary dramatically from house to house.  But how can this be?  If your particular property has rock under the surface, this can change the depths.  Because of the extremely high costs associated with removing rock, sometimes the underground utilities will be placed closer to the surface to avoid blasting.

Another reason depths can vary is because grading has changed since installation.  The main house utilities are typically installed during the construction of the home.  If you or a previous owner decides to change the grading of your lot, this can change the depth of the underground utilities.  A bulldozer or Bobcat can easily remove 12 inches of dirt in no time at all…this can leave you with minimal cover for your underground utilities.

Typical Marking Colors and What They Mean

  • Red:  Electric
  • Yellow:  Gas, Petroleum, Oil…etc.
  • Orange:  Communications (cable, phone…etc.)
  • Blue:  Water
  • Green:  Sewer

What’s Not Marked

I should mention that the utility locating service typically only marks the public utilities including the electric, gas, phone and cable.  Other items that typically won’t be located are listed below.

  • landscape irrigation
  • water and sewer service lines to house
  • low voltage landscape wiring
  • septic systems
  • any other gas or wiring you have added (i.e. yard light wiring, gas lines to grills/fire pits…etc.)\
For these items you are on your own.  The good news is…the locating services are typically free.  We hope these tips will encourage you to call before you dig to locate your underground utilities prior to moving any dirt.  And if you are burying items underground on your property, be sure to mark it on your plot plan for future reference.

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3 Comments for Underground Utilities: Call Before You Dig

What’s Wrong with This Picture? - Armchair Builder :: Blog :: Build, renovate, & repair your own home. Save money as an owner-builder.- Armchair Builder :: Blog :: Build, renovate, & repair your own home. Save money as an owner-builder. | August 21, 2012 at 8:12 am

[…] Power lines age… and when they do insulated coverings can where out, exposing high voltage wiring To keep everyone on your home building and renovation projects safe, don’t let any objects or people get anywhere near power lines.  Be sure all ladders, tools, cranes, heavy equipment,…etc. are kept a  minimum distance of fifteen feet from power lines.  Its also a good idea to be proactive on your project and remind workers of any high voltage wires nearby.  For information about safe practices when digging, check out our previous article, Underground Utilities:  Call Before You Dig. […]

Buying Land: Minimize Cost Overruns from unexpected subsurface rock.- Armchair Builder :: Blog :: Build, renovate, & repair your own home. Save money as an owner-builder. | September 16, 2013 at 11:54 am

[…] below the surface prior to buying land.  Be sure to get approval from the land owner and have a utility locate performed prior to […]

How to Build a Home, Step 21: Excavate for Foundation - Armchair Builder :: Blog :: Build, renovate, & repair your own home. Save money as an owner builder.- Armchair Builder :: Blog :: Build, renovate, & repair your own home. Save money as an own | February 27, 2014 at 9:13 am

[…] Underground Utility Locate:  Make sure your contractor has been given the “All Clear” by your local underground utility locating company prior to starting.  This is an absolute must for safety and damage prevention.  The company doing the digging is typically required to make the phone call for the locate. […]