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Fence posts and buried lines: locate before you drive or dig

Fence posts and buried lines: locate before you drive or dig

Trenching and excavation 5 min 29 CFR 1926.650 · 29 CFR 1926.651 · 29 CFR 1926.416

Landscaping

Why it matters

A fence line runs right along the property edge, the same place gas, power, water, and cable often run. One post driven or augered into a line can shock the crew, start a gas leak, or cut service to a whole street. The marks on the ground are only good if you know what they mean and dig carefully near them.

The talk

Fence jobs feel simple. Pull a string, mark every 8 feet, and start setting posts. That is exactly why crews get careless about what is underground. The service line to the house crosses the fence line at the front. A gas line runs along the back lot. Somebody's old electric line goes out to a shed nobody uses. A hydraulic post driver will push a steel post right through a plastic gas line without the operator feeling a thing. An auger can wrap a power cable around the flights. A digging bar will find a buried line long before you see it.

Before anyone digs, the job has to figure out where the underground lines are likely to be and call the utilities to mark them. In most places that is the 811 call, with a waiting period set by state law. If the utilities can't mark in time or can't find the exact spot, work can only go ahead with caution, using locating tools or other safe means. When you get close to a marked line, you find its exact location by safe means, which usually means careful hand digging. If you are using a bar or other hand tool where the exact location of buried power is unknown, you get insulated gloves.

Treat driven posts the same as dug holes, even though no dirt comes out. Check that the marks are fresh and cover the whole fence line, including the far corners. Remember private lines, like power to a shed, sprinklers, and septic, are not marked by the utility. Ask the owner. Shift a post a few inches if it lands on a mark, rather than gambling. Hand dig to expose a line before you drive close to it. If you hit something, stop the machine, back away, and call the foreman. If you smell gas, get everyone away, upwind, and call 911 and the gas company.

Key points

  1. Fence lines often run right on top of buried utilities.
  2. Find out where lines are likely to be and call 811 before digging.
  3. If lines can't be marked in time, go ahead only with caution and locating tools.
  4. Near a mark, find the exact line by safe means like hand digging.
  5. Use insulated gloves with bars or hand tools when buried power isn't exactly located.
  6. Treat driven posts the same as dug holes.
  7. Private lines are not marked by the utility, so ask the owner.

Do this

  • Check that marks are fresh and cover the whole fence line.
  • Ask the owner about sheds, sprinklers, septic, and other private lines.
  • Hand dig to expose a line before driving close to it.
  • Move a post a few inches instead of landing on a mark.
  • Stop, back away, and call the foreman if you hit something.

Do not do this

  • Do not start driving posts before the locate is done.
  • Do not trust old or faded marks.
  • Do not use a digging bar near marked power without insulated gloves.
  • Do not keep going after the auger or driver hits something strange.
  • Do not try to fix a gas leak yourself.

Talk about it

  1. When was the locate called for this job, and are the marks still good?
  2. What private lines might be on this property that the utility won't mark?

This is a short crew briefing. It does not replace a competent person, training, or the law.

Training aid only. This talk is not legal advice. It does not replace your company's safety program, a competent person, the equipment maker's instructions, or the OSHA standard itself.

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