When preparing to dig more than 6 inches deep in your yard, it is essential that you call your local or state marking agency and have a survey of your yard completed to discover any hidden wiring, water pipes or other hazards that may be present. State marking programs offer free services in which they will mark your yard with red flags for electrical wiring, yellow flags for gas lines and blue flags for water pipes (flag color may vary by location). Once marked, it is then important to follow proper digging instructions provided by the marking agency.
Land Survey Marking Before Digging
Write down the exact areas where you plan to dig. For example, if you plan to dig in your front yard and along the west side of your house, write down how far from your home you plan to dig, such as in front of the house and 40 feet north, or on the east side of the house and up to 30 feet in distance.
Call your local marking agency. You can find out which service will offer land marking by calling the city's main administrative office or, in most states, by dialing the toll-free number 811 from any cellphone or land line phone.
Provide the marking agency with your digging area. If you believe you may dig farther than what you have written down, ask the agency to mark your entire front, back or side areas as needed. You may request, for example, to have your front yard and east side marked. To ensure homeowner safety, in many cases the agency will mark the entire area even if not requested.
Ask the marking agency how far you will be required to hand dig from electrical markings and write down the agency's directions. Digging guidelines are often referred to as "tolerance zones." The agency should tell you how deep the lines are buried and how far in distance they suggest digging away from electrical markings. For example, you may be told to hand dig if you are within 18 inches of a marking and told to take extra precaution once you have dug more than 6 inches.
Digging Near Electrical Wirings
Begin digging using a standard rounded-edge shovel. Do not use a pointed shovel to avoid easily piercing electrical wiring. Dig the first 6 inches of ground with your full-size shovel.
Change to your hand trowel after the first 6 inches of digging is complete and scoop away the rest of your required ground soil with a hand trowel. Gently push your trowel into the ground to avoid cutting into wiring and be sure to take small scoops of dirt while digging to avoid pressing into wiring that is located below the soil you are excavating.
Examine the area with a flashlight after removing each scoop of dirt to look for exposed wiring. If wiring is discovered, cover the area with dirt and dig several inches away from your original spot using the same process. Do not attempt to dig around the wiring while leaving it exposed as this may cause an electrical hazard.