Carefully examine the site for overhead power lines, pole, and guy wires, and point them out to coworkers. Take extra care to look for lines that may be masked by foliage or otherwise blocked from view.

Consider all overhead power lines to be energized and potentially dangerous, including the service lines that run from utility poles to buildings.

Mark a safety boundary to keep workers, tools and equipment a safe distance away—at least 10 feet—from power lines. As voltage increases, clearance distances also increase. Call Duquesne Light Company at 412-393-7100 for specific safety clearance requirements.

When cranes and derricks are used in construction: Keep the crane boom and load at least 22 feet away from lines up to 350 kV and 50 feet away from lines greater than 350 kV but at or less than 1,000 kV.

Designate a spotter whose only job is to watch your equipment and make sure you maintain the mandatory safety clearances.

Notify 811 before you dig or move earth in any way—even for small jobs. This free service will arrange to have underground utility lines marked so you can dig a safe distance away from them.

Dial 811 or use the online ticket-entry system at pa1call.org. Then wait the required time for facility owners to mark their lines:

In Pennsylvania, wait at least two full business days, excluding the date you notify 811, weekends, and holidays.

Pre-mark your proposed excavation area with white paint, flags and/or stakes before you contact 811.

Respect the “tolerance zone,” a safety area that spans the width of a marked utility, plus 18 inches from each indicated outside edge. If your excavation encroaches within this zone, contact Duquesne Light Company and we'll send a representative out to your job site.

Respect the marks, hand expose to verify location and dig with care.

If you don't notify 811, you risk hitting an underground power line. You or your coworkers could be hurt or killed. You may be held liable for damages and repair costs.