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Decoding Utility Marking Colors: What Do the Spray Paint Markings on My Street Mean?

It happens in most neighborhoods – someone comes by and sprays colorful lines of paint on your road, your sidewalk, or even your yard. But what is the purpose of these markings and what do the different colors mean?

These paint markings are used to pinpoint underground infrastructure such as gas, electricity, and water, with each color indicating the type of utility present. While these markings may look like a secret code, they are a necessary part of any construction work that may involve digging.

Using a universal standard to mark utilities not only helps prevent damage to existing utilities, but more importantly, it also saves lives. Hitting a gas or electric line during construction can be deadly or cause serious injury. For Tilson’s crew members installing fiber cables below ground, we need to know where utilities are located to protect ourselves and the surrounding neighborhood.

For homeowners planning work that involves digging, they also need to know where utilities are hiding. Remember to dig with care and call 811 at least 48 hours before digging to have the utilities marked.

Uniform Color Codes for Marking Underground Utility Lines

Utility marking colors were developed by the American Public Works Association (APWA) and later standardized by the American Standards Institute. The colors used under the APWA Uniform Color Code standard are:

Beyond colors, there are also shapes, symbols, and words that may be used to help workers further understand the location, depth, or special circumstances of a utility. For example, a single utility line may be marked by one line to indicate its center, or it may be marked with an “H” shape with the parallel lines indicating the outer edges of the utility. Because these additional markings can get complex and require training to decipher, most general audiences only need to know the meaning of the colors. The important thing to note in these codes is that they are all part of a process for damage prevention and public safety.

Tilson’s Commitment to Utility Safety

Before any construction to install fiber internet can take place, our team must first work with all local utility companies to understand where existing utilities are located. Our Engineering team uses this information to draw up sophisticated plans based on known utility locations, determining the best and safest routes for our fiber conduit.

We also don’t take maps and diagrams provided to us at face value and perform utility locating procedures of our own. Sometimes a map can be wrong or there can be old or unknown utilities that are not otherwise accounted for. Our team can use a combination of techniques, from ground penetrating radar (GPR) for utility locating, to digging small hand holes to visualize and confirm utility locations. This locating process continues throughout the entire construction project, ensuring we are constantly pinpointing utility locations and making any needed adjustments as we go.

If you notice paint markings in your neighborhood, know that they are there to keep the workers, you, and your neighborhood safe. If our teams are doing the work in your area, know that we are going out of our way to put safety first and that once we leave, the markings will wash away and the only thing you’ll be left with is lightning-fast fiber internet.

Remember that 811 is the national number to have the utilities marked on your property for free. Any digging on your property, even small projects such as planting trees and shrubs, warrants a call to 811 first to protect your safety.

For more information on the tools and technology Tilson uses to bring fiber infrastructure to communities nationwide, check out how we use microtrenching and horizontal directional drilling to enhance safety and minimize public disruptions.

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