How do I find where an underground line runs on my property?

Start with a free Virginia 811 request for the public side, and hire a private locator for everything the utilities will not mark. The utilities paint the approximate horizontal location of their own lines up to your meters. The line from the meter to your house, the line to a detached garage and a septic line are yours to find.

What a Virginia 811 request finds

Virginia 811 says that before you dig you submit a Single Address Ticket to request markings at your project site, and that markings are color-coded lines that are drawn on your property to indicate the location of underground utilities.^[3] The request is the law, not a courtesy: no person shall make or begin any excavation or demolition without first submitting a locate request to the notification center.^[1] Virginia 811 says that using its services is free.^[2]

Plan for the wait. You must contact Virginia 811 at least 3 working days prior to excavation to give the member utilities enough time to mark the approximate location of their underground utilities on your property.^[2] Do not dig before you receive a Positive Response email from Virginia 811, which tells you whether each utility has marked lines or has none in conflict with your project.^[3]

Where the free marks stop

Public utilities will mark the approximate horizontal location of underground utilities to the point of consumption.^[4] That means the gas meter, the electric meter and, for phone and cable, the network interface device on the side of the home. Water and sewer stop earlier: for water, that point is your water meter, and for sewer it is the sewer cleanout, which is usually located within 5 feet of the edge of the property.^[4]

Everything past those points is private and is not marked by the utilities. Virginia 811 lists the examples: lines running from your home to a detached garage or shed, invisible pet fences, lines related to satellite or dish television, septic tanks and the lines associated with them, and propane tanks and the lines associated with them.^[4] The line that connects your house to the water meter is also treated as private.^[4]

Two details are easy to miss. First, marks show an approximate position, so a mark is a starting point for careful digging, not a survey. Second, a mark does not stay good forever: a locate request is valid for 15 working days, and markings that become illegible must be re-requested.^[1]

Finding a private line

Start with paper. The permit file for a septic system, a detached garage or a pool, the plat or as-built drawing from when the house was built, and the installer's invoice often show where a private line was laid. Ask the previous owner, the installer or the local building office what exists for your address.

For sewer, find the cleanout first. Fairfax County describes a sewer cleanout as a point of access where the sewer lateral can be serviced, usually 4 inches in diameter with a tight-fitting steel or plastic cap, and says that if you cannot locate one, you either do not have one or it may be buried under dirt, and a plumber can assist you in locating it.^[5] The same county says the lateral is part of the home, and that maintenance, repair and replacement of laterals is the responsibility of the property owner.^[5]

When the records are missing or wrong, hire a private utility locator. Virginia 811 keeps a list of underground utility locating companies working in Virginia and points to the National Utility Locating Contractors Association for more.^[3] Ask what technology they use, whether they will mark the line on the ground and whether they will leave you a sketch of what they found. Locators trace what they can detect, so a plastic water line or a pipe with no tracer wire can be hard to find; ask what they would do about that on your property.

Digging near a mark

Once lines are marked, Virginia state law mandates a two-foot tolerance zone on either side of the marks, where only certain types of excavation are allowed, such as digging with hand tools.^[2] Treat any line you find, public or private, the same way. If a line is hit, Virginia 811 says to stop digging immediately and step away, call 911 if there is an escape of flammable, toxic, or corrosive gas or liquid or other danger, and then notify the affected utility and Virginia 811.^[2]

When to call a licensed pro

Hire a licensed contractor for any trench, bore or machine work near a line, and put the 811 request and the private locate in the written scope. Virginia 811 says that if you hire a contractor or landscaper, your contractor is responsible for contacting Virginia 811, and you should confirm that they have before excavation begins.^[2] Virginia's Board for Contractors defines an underground utility and excavating specialty for water, gas and sewer connections to sites, subject to local ordinances.^[6] Check the licence on DPOR's License Lookup,^[7] and ask for the 811 ticket number before work starts.

Getting help in Virginia

For what a utility trench involves, read what trenching for a utility line involves and how much trenching costs per foot in Virginia. The rules on who requests and who marks are in who is responsible for marking underground utilities in Virginia. Browse excavation services or more excavation answers.

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