If you’ve ever been near a construction site and wondered what all those colorful markings are painted on the ground, you are not alone. Whether it’s a major commercial project, construction of a new home, or just a neighbor doing some landscaping, they all have one thing in common; the underground utilities have to be located and marked before ANY digging can be done. Those colorful markings you’ve seen are required by law and are crucial for personal and public safety and the protection of vital services we all rely on each and every day. So, what do they mean?
Underground Utility Color Codes
The colors are part of the Uniform Color Code for underground utility marking as recommended by the American Public Works Association (APWA). They are also known as 811 Color Codes in reference to the public utility locating service that can be reached by calling 811. Whenever utilities are located they are marked with these underground utility color codes:
RED = Electricity
YELLOW = Natural Gas (also oil and liquid fuels)
BLUE = Water
ORANGE = Communications (TV, Internet, Phone, etc)
GREEN = Sewer
PURPLE = Reclaimed Water
PINK = Temporary Survey
WHITE = Proposed Excavation
Color-coding underground utilities can be done with spray paint on the ground or colored stakes, flags, or marking whiskers that show where the underground utilities are located.
You’ll notice white is indicated for “proposed excavation”. White is used to mark the area that is to be checked for underground utilities. For example, if you were going to build a new walkway from the street to your front door, you would mark the outline of the entire area that you’ll have to dig in white. Then the utility companies or private locators know where to look to mark the utility lines that are underground that might run through your proposed area.
How Do Underground Utilities Get Marked and Who Marks Them?
Before excavation of any kind can start, regardless of whether it is commercial or residential, a call must be made to 811 to request marking of underground utilities. 811 will coordinate with all the utility companies involved. Locators from each utility will normally respond within 2 business days. If an underground utility exists in the designated area they will mark it using the locator colors outline above.
You do not have to contact each of the utility companies yourself. 811 handles everything once you have made your request. In most states you can also make your request through the state’s 811 website. For your own copy of the utility color code chart, you can click here.
Is That It?
Not necessarily. Cables, conduits, and wires from the public utilities are not the only hazards that may exist underground. There are also private lines that could pose a risk to any residential or commercial project. The public utilities are normally only responsible for what they provide up to the meter. Anything past that is normally the responsibility of the owner of the property. You could also have private lines such as water to a pool, electricity to a pool pump, gas to a barbecue, a sprinkler system, etc. These are not covered by your call to 811. You will have to engage the services of a private locator. As mentioned on the USI Locate Inc website, a private locator “locates what 811 doesn’t”. A private locator will “identify all private-side utilities within your dig area beyond the meter.”
You may find resources for finding private utility locating services in your area on your state’s 811 website. Arizona and California residents can contact USI Locate for assistance.