Digging Guidelines and Information

July 28, 2010 | by Ethan (email) |


Homeowners, professionals, and do-it-yourselfers all need to have underground utility lines located before you break ground. It could be something as simple as planting a tree or building a deck- either way you need to make the call. The depth of utility lines varies. For instance, communication lines like phone and cable service are usually found within 24″ of the surface. Water supply lines are typically buried 36-42″ deep, or deeper if you live in an extremely cold climate. Damaging underground lines can disrupt service for entire neighborhoods and result in fines and repair costs. There’s no reason not to call. It’s the law and a free service!

Who to Call

Around Maryland, Delaware and DC, Miss Utility is the company that will mark underground lines. In Massachusetts, New Hampshire and surrounding areas, Dig Safe Systems will handle your needs. If you’re not sure who to call, check out 811. They maintain a quick lookup by state or province.


Underground Utility Line Color Code

Different underground lines will be marked by different colors. Here’s the universal color code.

  • Red – Electric power lines, distribution and cables
  • Orange – Communication, telephone/CATV, etc.
  • Blue – Potable water
  • Green – Sewer and drainage
  • Yellow – Gas, petroleum, oil and gaseous materials
  • Purple – Reclaimed water, irrigation and slurry lines
  • White – Proposed excavation site

Digging Guidelines

Things like how long the marks are good for, weekend availability, and necessary notice times vary by state and county. Here in Baltimore County, they need at least 48 business hours from the time of the request. Also, they require 18 inches of hand-digging to expose utility lines. Check local guidelines for your area.

Tip: When digging, orient your shovel along the buried line (rather than across) until it has been fully exposed. You’re much less likely to inadvertently cause damage.

One Response
  1. Fred says:

    I frequently hear in the commercials for Miss Utility, “No mechanized digging within 2 feet of markings – that includes even skimming the top.” I have a feeling some folks try to get around the rules by using the bulldozer to “skim a bit” off the top first, and occasionally they go too deep and blow a line… not something that’s worth risking for sure.

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