Excavating Around Utility Lines

On a recent project involving excavating a trench, Apex personnel suspected that the utility mark-out done by the state had mismarked a few lines. Acting on their hunch, Apex’s crew hand dug around where the mark out was, as well as where they thought the line should be. The utility line was in the spot that was unmarked and a utility interruption was successfully avoided.

When preparing for underground work, many of the critical steps in preventing a utility mark-out are conducted prior to starting digging. Make sure everyone involved (PM, APM, Crew leader and field staff and site contacts) are aware of the work scope and location—many times lack of communication has led to utility interruptions. Mark-out the proposed location accurately in the field so the utility mark-out company knows exactly where the digging is to be done (white box with dashed lines—don’t use arrows to point to area). Establish the scope of work and make sure that if there is a deviation in plans it is coordinated with the PM.

When excavating around utility lines do not assume the mark-outs are correct. Requesting that a second mark-out is done and that hand or soft digging is performed will help to ensure worker safety and avoid costly utility interruptions. Dig safe markings should be used as a guide but don’t forget to use common sense.

After arriving onsite, go through a checklist of known or utilities that are assumed to be present. Try to follow these utilities from the street or source through the area to be excavated. When digging use clues to predict the presence of utilities—marking identifiers (caution tape, foil tape), gravel, soil not similar to native material, etc. Also use typical utility depths as a guide—electrical is usually 12-24″ below grade, water usually >4′ below grade, etc. Use common sense and the previously mentioned clues to reduce your risk of a utility interruption. Always dig with a spotter—an extra set of eyes to watch the digging.

If unsure—stop work—call the job Project Manager.

Confined Space Vault—“Breaking the Plane”

While providing remediation project oversight for an excavation and stream-channel restoration project at a former manufactured gas plant (MGP) site, Apex had to deal with a utility vault approximately 4 feet deep and accessed by removing a cover for an approximately 3 foot by 3 foot opening.

Questions were raised as to various scenarios of entering the vault, versus remaining outside the vault entirely and as to what activities would consist of “breaking the plane” for the purpose of working on utilities within and/or collecting air sample measurements within the vault.

Our Corporate Health and Safety Manager clarified that ANY body part entering such a space is considered “breaking the plane.” However, rather than treating the activity as a full-fledged permit-required confined space, it was determined that a most appropriate and cost‑effective approach for activities within this shallow vault would be to provide air ventilation, continuous air monitoring and a means of egress (ladder), such that the space might be reclassified as non-permit required and documented appropriately.

Make sure to encourage your staff to initiate a dialogue from the field for appropriate evaluation of potential confined space areas at your sites. Resolution can be achieved quickly with good identification and communication.

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