What to Do After a Utility Strike
Hitting a buried utility can cause an explosion, electrocution, flooding or a cave-in, and it can knock out service to hospitals and 911 centers. Even with good locates and careful digging, strikes happen. Knowing exactly what to do in the first minute keeps a damaged line from turning into a disaster.
- Construction
- Utilities
- Landscaping
- Fencing
First, for any strike
- Stop digging immediately.
- Figure out what you hit from the paint and flag colors, the material, and what’s coming out (gas smell, water, sparks).
- Protect people: move everyone away and keep the public back.
- Call 911 for any gas leak, electrical contact, fire or injury, then call the utility owner.
- Report the damage to the facility owner (often through 811), even if it’s just a scrape or dent.
If you hit a gas line
- Leave the area on foot right away, upwind if possible, and get everyone else out.
- Don’t create sparks: don’t start or shut off engines, use lighters, flip switches, or use phones or radios until you’re a safe distance away. If the machine is running, leave it running and walk away.
- Call 911 and the gas company from a safe distance.
- Don’t try to stop the leak, crimp the line, or cover it with dirt.
- Don’t try to put out a fire burning from a gas line. The fire department and gas company will shut off the gas.
- Keep people and traffic away until the gas company says it’s safe. Gas can travel underground into nearby buildings, so tell responders about them.
Danger: Natural gas usually has a rotten-egg smell added, but you might not smell it, especially with high-pressure transmission lines or petroleum pipelines. A hissing or roaring sound, blowing dirt, bubbles in water, or dead vegetation are other signs of a leak.
If you hit an electric line
- Stay on the equipment if you’re in it. The ground around it may be energized.
- Warn everyone to stay away from the machine, the bucket and anything touching it. Nobody should touch the equipment.
- Call 911 and the utility.
- If you can, move the bucket or attachment away from the line, but only if that won’t make things worse.
- If you must get off because of fire, jump clear with feet together so you don’t touch the machine and ground at the same time, then shuffle away at least 35 feet.
- Workers on foot who feel tingling should shuffle away with feet together.
See Downed Power Lines for more on step potential.
If you hit a water main
- Get workers out of the excavation. Water can wash out soil and collapse the trench quickly.
- Stay away from the edges, which may be undermined.
- Call the water utility, and call 911 if there’s flooding near roads, buildings or electrical equipment.
- Watch for electrical hazards if water reaches energized equipment.
If you hit a sewer line
- Get out and stay out of the trench. Sewage carries bacteria and viruses, and sewer gas can include hydrogen sulfide and methane.
- Call the sewer utility.
- Wash up, and change and bag contaminated clothing. See Hydrogen Sulfide.
If you hit a fiber optic or communications line
- Never look into the end of a cut fiber optic cable. It can carry invisible laser light that damages your eyes.
- Fiber glass slivers can stick in skin. Don’t handle broken fibers without gloves.
- Call the line owner. Communications outages can affect 911 service.
If you hit a petroleum or hazardous liquid pipeline
- Treat it like a gas strike: evacuate upwind, no ignition sources, call 911 and the pipeline operator (the number is on the pipeline marker).
- Don’t walk or drive through liquid or vapor clouds.
Report every bit of damage
A small scrape, gouge or dent in a pipe’s coating can lead to corrosion and a failure months or years later, sometimes with deadly results. State one-call laws generally require you to notify the facility owner of any damage, no matter how minor, and not to backfill until the owner has inspected and repaired it. Never cover up a damaged line.
Document what happened
- Your locate ticket number and the date the marks were made
- Photos of the marks, the exposed utility, the damage and the area
- Measurements from the marks to where the line actually was
- Who you notified and when (911, utility, 811, supervisor)
- Names of witnesses
This protects you and your company if the line was mismarked, and helps prevent the next strike.
Utility marking colors
| Color | Utility |
|---|---|
| Red | Electric power lines, cables, conduit and lighting cables |
| Yellow | Gas, oil, steam, petroleum or other gaseous or flammable material |
| Orange | Communications, alarm or signal lines, cables or conduit |
| Blue | Potable (drinking) water |
| Purple | Reclaimed water, irrigation and slurry lines |
| Green | Sewers and drain lines |
| Pink | Temporary survey markings |
| White | Proposed excavation limits or route |
Preventing strikes
- Call 811 before every job, and wait the required time for all utilities to respond.
- Pre-mark (white-line) your dig area so locators know where you’re working.
- Confirm every utility on your ticket has marked or cleared.
- Keep the marks visible, and request a re-mark if they fade or are destroyed.
- Inside the tolerance zone (often 18 to 24 inches on each side of the marks, depending on the state), expose the line by careful hand digging or vacuum excavation.
- Watch for unmarked lines: private lines (to outbuildings, lighting, irrigation) usually aren’t marked by 811 and may need a private locator.
- Look for clues: meters, risers, pedestals, valve boxes and pipeline markers.
See Call 811 and Hydro & Vacuum Excavation.
Standards & references
- 29 CFR 1926.651(b): Underground installations
- 811 Before You Dig (Call811)
- Common Ground Alliance: Best Practices
Related: Call 811 · Trenching Basics · Directional Drilling · Gas Leaks
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