Locate Pipelines Before Digging

Excavators can help prevent unintentional damage to pipelines and other underground utilities by accurately white lining the excavation area, calling to have lines marked prior to digging, waiting the appropriate time to have lines marked and digging with care near lines using appropriate techniques and equipment.

Excavator White Lining

Excavators can help ensure that pipelines and other underground utilities are properly marked prior to digging by white lining, or pre-marking, a job site with white paint, flags or stakes to show the exact excavation area before calling the One Call center.

White lining is not required in all states, but it is a recommended best practice.  Listed below are steps for how to white line an excavation area:

  • Identify the area you plan to excavate
  • Obtain white paint, flags or stakes
  • Use the paint, flags or stakes in a continuous line, dots marking the radius, dashes in each of the four corners or dashes outlining the project perimeter
  • Make each dot at least one inch in diameter
  • Make each dash at least one inch wide and six to 12 inches in length

Click here to read more about new white lining technologies.  Click here to review CGA’s best practices for white lining.

Always Call 811 Before Digging

Always call 811 or your local One-Call center to have pipelines located before digging or excavating.  One-Call is required in most states and is typically a free service.

“Calling Before You Dig” by dialing 811 connects you with your local One-Call center.  The One-Call center notifies pipeline companies and other utility operators of an upcoming excavation project and allows them time to mark the location of their underground infrastructure before excavation begins.  Wait the required time after notifying One-Call, typically two or three working days, and respect the marks while digging.  Verify with your One-Call center the required time you must wait before digging and the distance you are required to maintain in relation to the marks.

Excavators are responsible for providing access to the excavation site.   Make sure that gates are unlocked or that personnel are on site to provide access for lining locating.

Pipelines that are maintained and owned by the resident or building owner rather than a pipeline operator are typically not located through the One-Call process.  These “customer-owned” lines often include pipelines and piping that run from the meter or other connection points to a customer’s gas appliances or manufacturing equipment.

Customer-owned lines are rarely maintained or located by the pipeline company.  If you are planning to excavate near customer-owned lines, contact a local professional who is qualified to verify the location of these lines before digging.

Flags, Paint & Temporary Markings

Operators normally mark the location of underground pipelines using yellow flags, paint or stakes.  Other types of underground lines will be marked in different colors.  Refer to the color code chart for more information regarding what each color represents.

Respect the marks and dig with care.  Consider the following methods when digging near a pipeline:  hand digging, soft digging, vacuum excavation methods and pneumatic hand tools. If you have questions regarding proper digging techniques near a pipeline, ask the pipeline operator for assistance.

Many pipeline operators request to be present during excavation that occurs close to their pipeline.  Coordination with the operator keeps everyone safe and prevents project delays.

Permanent Pipeline Markers

Operators place signs along the pipeline route to identify the general location of a pipeline and specify the type of product transported, the operator’s name and an emergency contact number.  Pipeline markers do not identify the exact location of a pipeline and should not be used to locate pipelines prior to excavation.

To locate pipelines before digging or excavating, call your local One-Call center by dialing 811.

For examples of pipeline markers, visit the PHMSA Web site.