A Brief Guide to Color-Coding Underground Utilities

Anyone who has worked in construction knows that random colorful lines on the streets aren’t acts of vandalism — they’re color-coded messages that construction crews use to communicate vital information during projects. Each color corresponds to a different underground utility that must be accounted for when digging and drilling in the area. As Brooklyn, NY’s leading GPR scanning service, GPR One Call is the Picasso of pavement when it comes to locating underground utilities. Let’s take a closer look at the color code we follow, the American Public Works Association (APWA) Uniform Color Code using ANSI/NEMA standard Z53.1.

Red – Electricity

A red line of spray paint indicates electrical wires underground. It’s crucial to know where electrical wires are, because with metal equipment, a mishap that involves digging up live wires could be potentially fatal.

Yellow – Gas, Oil, Steam, & Chemical

Yellow paint is sprayed on pavement that lies on top of underground pipes that move gas, oil, steam, and other chemicals into buildings, generally for the sake of providing heat and energy. Puncturing one of these pipes during digging could cause a big mess, and even a potentially explosive situation.

Orange – Communication & CATV

When you see orange paint on the pavement, that’s a sign that important communication cables are buried beneath the ground. These must be avoided to prevent vital components of communications infrastructure from being damaged.

Blue – Water

Quite fittingly, blue markings indicate that water pipes are underground in a construction area. Needless to say, bursting a water pipe would cause serious complications for a construction project, not to mention the folks who use buildings in the surrounding area. 

Green – Sewer & Storm Drain

We’re not going to question why green stands for sewers and storm drains, but you certainly don’t want to miss these markings when digging on a construction site. It could create a serious health hazard and significantly delay the project’s completion. 

Pink – Temporary Survey Markings

Pink markings are somewhat of a wildcard, as they have no specific meaning. However, they are generally used when there is an unidentified utility or for a surveyor to get a general reference point for the construction project. 

White – Proposed Excavation

White lines are sprayed onto the pavement wherever excavation has been proposed to occur. Ideally, white lines should not overlap with or cross anywhere near different-colored lines, unless a specific plan has been made to work around the utilities underground. 

The colorful lines on the pavement at construction sites are what help us conduct excellent concrete imaging in Brooklyn, NY, on each project, despite sometimes challenging conditions. Contact GPR One Call today to talk to the underground location experts!