Plan your work.
Markings for underground utilities are only considered valid up to 20 calendar days (30 for agricultural and forestry work) from the “mark-by” time as provided by the one call operator. The “mark-by” time does not include holidays or weekends. For larger projects, call in only the work that can be accomplished within a 20-day period. Call 811 or click at least 2 business days before you want to start digging.
Read through the For Best Results section and be prepared with those answers. If calling in your request, record the locate request number provided by the one-call operator. It is your proof of the call and may be requested by an enforcement agency.
Wait for the site to be marked.
Wherever possible, use white paint, stakes or flags to identify your proposed excavation area. This helps the marking crews identify your work site and place their markings accordingly. Crews mark the site before the work begins, using color-coded markers to indicate the types and locations of each pipeline or cable.
Excavators should observe a "Tolerance Zone" when digging close to a service line. The width of the Tolerance Zone is specified by law. The width of the facility (service line or pipeline, etc.) as marked plus at least 18 inches, or 450mm, measured horizontally from each side of the facility. See illustration.
Any excavation within a Tolerance Zone should be performed with non-powered hand tools or a non-invasive method until the marked facility is exposed.