Rush Locates, LLC offers private utility locate services, but what does that mean? What is utility locating? What are private utilities? And how are they located?

The short answer is that most but not all utilities can be located. The basic way is when a traceable electronic signal is sent through one end of the utility and that signal is tracked and marked.

We’ve all seen the ‘call before you dig’ signs around, so let’s start with that.

1998, the U.S. Congress passed the Transportation Equity Act for the 21st Century. In this legislation, the U.S. Department of Transportation was instructed to conduct a study of best practices in place nationwide for enhancing worker safety, protecting vital underground infrastructure, and ensuring public safety during excavation activities conducted in the vicinity of existing underground facilities.

In 2005 the “811” number was established as the interstate number for public utility location.

So this all means that you can now call 811 and you a free public utility location for your home or jobsite. 811 is a “one-call” center, which means you only have to make one call. It is common for homes to have up to 5 utility services. 811 will contact each of the respective public agencies that have utilities in your area and they will individually send out a locator. Because of this there might be multiple vehicles and locators visiting your site within a few days.

What is a public utility

Any utility on public property is a public utility. A public utility on private property remains public until it connects to a meter.

Public property includes the Right-of-Way which is the strip of grass that might exist between the sidewalk and the street/curb. Anyone doing *any* digging more than one foot deep on public land should notify 811 to be sure no public utilities are present in the area.

Public utilities can exist on private property! It is common for the publicly owned natural gas and underground power lines to cross into private property before connecting to a meter. Different cities have different rules on where the ownership of a sewer line ends for the city. There are also easements, which can be present in a private lot. Just because 811 didn’t mark something on private property doesn’t mean there isn’t anything there.

A publicly owned pipe or line is the responsibility of the utility company that owns it. Tax dollars go towards the upkeep and repair of these shared services. A private utility is officially owned by the tax lot owner.

What is a private utility

Any utility past the meter on private property is considered a private utility. Water meters are commonly at the property line and as such the water line is almost never marked by 811. Natural gas in almost always at the home, and unless a barbecue, shop, or pool has separate gas service the gas is usually marked by 811.

What is different between public and private utility locating

Aside from the fact that 811 is free, and that it takes multiple days with multiple locators the main difference is that 811 already knows what they are getting into.

Public utility locators have maps, they already have a rough idea of where their utility is. They know exactly what utilities they are out there to mark and they don’t mark anything else. Because of this, they are marking known utilities which are in pretty well known locations.

Private utility locating however is not the same. For example there are rarely maps for residential locations. Most private locating is done by blind sweeps for pipes and wires combined with finding a utility and tracing a signal applied to it.

What tools are commonly used in utility locating

The main technology used in utility location is detection of an applied radio wave, commonly called radio detection (RD). This can trace virtually every pipe, wire, or cable that can transmit electricity.

Ground Penetrating Radar (GPR) is used to detect things that are non-metallic. This is mainly things like all-plastic pipes, brick or concrete cesspools, differences in ground layers, or objects of high ‘contrast’ to their surroundings like rebar in concrete. We charge $150/hour with a 2 hour minimum for GPR locating.

Acoustic Pipe Locators (APL) are used to detect the location of water pipes of any construction (PVC, PEX, steel, copper) by creating a noise on the pipe and using a special microphone to localize the noise. We offer this plastic water pipe location service, and using the same equipment we can even locate a leak in a water pipe.

How do these tools work

  • RD – A two part system where a transmitter is connected to a utility and receiver locates the maximum signal coming from this. A radio wave signal is applied to a utility. A signal then radiates from that utility at a frequency set by the transmitter. The receiver is used to located the peak signal of
  • GPR – A radar wave is directed into the ground and the reflection is displayed. This is done in a slice which gives a 2-D image of the density changes of things underground. Multiple slices are stacked and can be used to compute a 3-D image of the underground. Different wavelengths of radar waves can give more of less detail, or penetrate more or less deeply.
  • Plastic Water Pipe Locator – Two part system where one tool is attached to the water line which creates a noise that travels along the pipe. A special microphone that is computer filtered listens for the peak of that sound. The noise is made by either tapping against a water pipe and creating a noise or by pulsating the water pressure itself. By pinpointing a line of the highest sound reading the water pipe can be located.
  • Rodding – A pushable fiberglass rodder is pushed into a pipe that cannot be located on it’s own. A transmitter or camera can be attached to the rod, or the rod itself can be used to locate the pipe.
  • Mainline Sewer Crawler Robot – is similar to the pushable rodder but this is a machine that drags the cable into the pipe, further than it could be pushed.
  • IR – Infrared or thermal imaging is used most often to find hot water pipes or heated pipes of some sort. Also useful for finding areas of cold intrusion, areas where radiant heat is failing, or insulation needs adding or replacement.

What are the limitations of these tools

  • RD – Can only be applied to metal wires or pipes, plastic pipes without tracerwires cannot be traced with RD. Nearby metal objects or other underground utilities can distort the signal and reduce locating ability.
  • GPR – Slow and expensive in comparison to RD. Different soil type affects the usability. Clay like or salt water saturated soils can be impenetrable with radar frequencies used.
  • APL – Can only be used on clean water pipes. Best used in quiet environments.

Schedule a private utility location in Oregon or Washington

Click here to schedule our private utility locator service in OR & WA.

Don’t live in Oregon or Washington?

Simply choose your state from the 811’s interactive map: then look in the sidebar for a link that says ‘private locators’.

Read more on this subject from 811‘s article on the subject or the Wikipedia page for 811.