Have you ever wondered about the paint markings on the ground around a new construction site, or a building undergoing remodeling?
Crews often mark the ground or pavement with a carefully-arranged series of lines. At a simple job you might have only seen them in a single color, and only in spray paint on the ground. Though you might have guessed these markings indicate the presence of some critical underground infrastructure, you might not know that the lines — and the colors chosen — are part of an international standard. It’s important to know the meanings of the various colors before starting any underground digging. It could save your life, or at least save you from expensive (and embarrassing) delays.
The color code standards was established by the American Public Works Association. Excavators and contractors learn the code by heart, and stay aware of the markings whenever they work on underground projects.
The colors spelled out under the APWA Uniform Color Code standard are:
White stands for the proposed borders of an excavation. When crews need to mark the limits of the excavation needed for a basement, or even just a trench, they mark the outlines in white paint. This is usually the first step before any underground infrastructure is precisely located. It shows where the digging will occur.
Green means sewer & storm drain. This is definitely something to avoid. A broken sewer line could earn an excavating company employee a reputation that could last his or her entire career, and wouldn’t likely result in any offers of free beers after work. The green markings are very important. Stay away from the green markings.The AWPA standard goes beyond color. It also states that the markers must be clearly visible. The material needs to be durable. The paint markings on the ground you might have seen at a dig are for temporary use, but more permanent markers should be placed as the project nears completion, and these must be made from materials like treated wood, metal, UV-resistant plastic, or similar. Also, the standard calls for including the area’s “call before you dig” number on the marker if space is available.
By following this standard, dangerous accidents and expensive delays can be avoided. Get to know the APWA standard before starting any underground project.