We’ve all seen them – those little flags that stick out of the ground in a rainbow of colors indicating the presence of underground utilities.

But did you know that each color signifies a different type of utility line? The chart below produced by the American Public Works Association identifies the utilities associated with the flags.

If you’ve never called your local One Call before performing excavation work, it’s a very simple process. And don’t assume you know where the underground utilities are located – call your local One Call by dialing 811.

Before starting any digging, the law requires you to call your local One Call center to tell them when and where you plan to dig. In most states, One Call is a free service.

When a call is made to One Call, the operator of the underground utilities will visit the site and mark the location using spray paint on the surface directly above the utility line or by placing flags identifying the type of underground service.

So remember:

• Call your local One Call center by dialing 811
• Wait for the site to be marked
• Respect the marks
• Dig with care