Sewer Line Locating for Commercial Sites

The camera goes into the line with a sonde in its head. That sonde transmits a signal from inside the pipe, and the receiver above ground finds it. The tech walks the surface, finds the strongest signal, marks that point and reads the depth. Repeat every few feet and the marks show the path of the pipe. When the receiver is directly over the sonde, it calculates depth automatically.

This is why locating and camera work are a single visit. The sonde follows the camera, so the pipe you saw on video is the same pipe you mark. Tell us when you book whether you want the path alone or the path with the inspection video.

We mark the sewer path and depth on the pavement, the slab or the ground, with paint or flags. You can use the marks to plan a repair, a new connection, a slab cut, a utility crossing or a landscaping or paving job. What you do not get is a guarantee. Depth reads are good for planning. Before you dig down to a pipe, confirm it by exposing the line (potholing), especially where the depth is near a minimum clearance or where there are other buried utilities.

• Where the camera stops, the signal stops. A sonde can only be followed as far as the camera travels. A collapse or a blockage ends the locate there.
• Metal and concrete. Cast iron, rebar and thick slab weaken the signal and the depth accuracy. A locate through a concrete floor with rebar is possible, but treat the depth as an estimate.
• Crowded corridors. Nearby conductive lines and interference can distort the signal.
• No cleanout. If the line has no reachable cleanout, the sonde needs another way in, such as a vent or a fixture opening. That is slower. See sewer camera without a cleanout.

For the cleaner version of the underlying method, see how sewer locating works with a sonde.

This is the part contractors and property managers mix up. Arizona's excavation law requires an excavator to determine where underground facilities are before digging, and it sets the process for utility operators and apartment-community landlords to mark theirs. The statute's definition of an operator centers on utilities and landlords with rights in streets, easements and apartment communities.

A private sewer lateral on your own commercial site may not be a line anyone else will mark for you. A sonde locate from a plumber fills that gap for your own pipe, but it does not replace the one-call process for the utilities around it. Call Arizona 811 and your own contacts first, then use our marks for the sewer. The law also requires newer underground facilities, installed after 2005, to carry a detectable locating device unless they can be detected from above ground another way. An older plastic line without tracer wire is the case where a camera sonde is often the only practical way in.

• Contractors about to cut a slab, trench a parking lot or tie in a new line.
• Property managers who need the path of a lateral under a building or lot before a repair, a tenant improvement or paving.
• Owners who have plans or as-builts that do not match what is in the ground.
• Developers and engineers checking a lateral before a connection. Public-agency projects have their own inspection specifications, so ask the project engineer what they require.

If you already have an accurate as-built and the line is shallow and exposed at a cleanout, you may not need it. If your job is a water or gas line, a sewer sonde will not help. And if the line is collapsed at the first bend, a camera locate will tell you where it stops, not what lies beyond. For a long unknown run, a locate can be paired with an inspection. See sewer camera inspection and sewer repair.

Tell us the property, what you plan to dig and whether there is a cleanout. HQ offers free estimates, an upfront price before work starts and 24/7 emergency service. See also commercial plumbing and the pre-purchase sewer inspection page if you are buying.