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I just got hired on to a small local government and I am sill learning the ropes as a GIS Analyst.

What is an inexpensive way to map underground Utilities, like pipes, gas lines and telephone lines?

What equipment is used to do this?

closed as too broad by PolyGeo Dec 17 '18 at 5:53

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  • Maybe its to broad question or maybe is up to my language barrier. When you say "equipment" do you mean software-hardware or gps and geodetic survey equipment or... ? Be more specific. – sys49152 Nov 20 '14 at 22:08
  • Hardware, i cant use geodetic equipment underground. My problem is that, the city has no idea where some pipes are. The city cant just keep digging on peoples property to find theses lines that are not properly mapped or not mapped at all, people are getting angry... Is there something like echoscope that can be used to find these pipes. Is there something that i can stick down a pipe to map its location and depth.. – WesTheMess Nov 20 '14 at 22:24
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    It is a pretty broad question. I believe every state has a 'call before you dig' utility locate group. You might contact them regarding equipment or contracting. A lot of this is usually done from as-built engineering drawings. Utilities that your government doesn't own (likely phone, gas) may have their own records and data you can get copies of. The actual hardware varies based on what it's trying to sense and how deep. And some things should be mappable straight-line based on surface access points. – Chris W Nov 20 '14 at 22:33
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    There are companies that specialize in this so i guess you can Google them for your local area. Some of the technologies are ground penetrating radar and radio frequency detection. No idea how much units cost but I'm thinking you would want a trained expert to do it. – Dowlers Nov 20 '14 at 22:38
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    I wouldn't call it a PR stunt necessarily. Here they notify affected utilities, and the affected utilities are responsible for coming out and locating their lines. Contracting this out can help shift the liability when something gets missed, because if it's old or deep enough it will get missed. Not long ago we had a nearby town (very small) have a road project hit gas lines twice after locates. Whether the contractors or the locators were on the hook for the extensive damages is up to lawyers and insurance. Taking locations on yourself (as gov entity) may be a huge liability hole. – Chris W Nov 21 '14 at 0:19
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Its not inexpensive eqipment and it has some limitation but it works in cases like in your question, you could find all details here:

Ground-penetrating radar

Ground-penetrating radar (GPR) is a geophysical method that uses radar pulses to image the subsurface. This nondestructive method uses electromagnetic radiation in the microwave band (UHF/VHF frequencies) of the radio spectrum, and detects the reflected signals from subsurface structures. GPR can be used in a variety of media, including rock, soil, ice, fresh water, pavements and structures. It can detect objects, changes in material, and voids and cracks.

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I am a damage prevention specialist, and I use the receiver and transmitter equipment to locate all buried utilities. I went thru a small village 2 years ago and located all residential water services because these are private and not marked out when 811 is called.

To map for the village, I utilized a Trimble Geo to create a map file for them for all future work on their mains, Catch Basins etc... It is not cheap, but it doesnt have to cost a few million dollars either.

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http://www.tracerelectronicsllc.com/page4/tracer/locators.html

The above link has lots of utility locating equipment. Gas lines will definitely require this. Water/WW utilities can usually be located pretty accurately using a RTK gps unit to first locate the valve, manhole, meter spots, and using building/construction/site plans, to draw in the connecting pipes (as 99%) of pipes will be in a straight line between manholes, meters, valves, etc.

A simple metal detector and shovel can be used to find the pipe after you have located the connected utility assets.

For mapping of storm water infrastructure, which is a little larger, i would suggest a robotic cctv system like http://www.ariesindustries.com/ these have GIS and GPS plugins to give position and nassco pipe ratings when inspected and import into GIS.

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Use a GIS capable pipe & Cable locator

There are three companies that make them. Sewerin (UT-9000), Vivax-Metrotech (VLoc-5000), and RD make underground pipe & cable locators that work with GPS or GNSS receivers. They can be used in two different ways:

Internal GPS - You can get a pipe & cable locator that has a built in GPS receiver. When you hit the record/locate button, it logs the locate data including depth, lat/lon, signal strength, and other information the locator collects. It is logged in a file and can be uploaded to your GIS system as shape files, CSV, kml, or other formats. These are generally limited to above submeter resolution, but the depth will be within 5% of actual giving you 3D (XYZ) coordinates of the pipe.

External GPS - Higher end pipe & cable locators have bluetooth, and can send the locate information to a bluetooth capable Topcon or Trimble GNSS unit. These units can collect location data at the resolution of your GNSS receiver and very accurate location for the pipes or cables when used together.

Hybrid - You can use GIS pipe & cable locator to collect the exact location and depth of the pipe, logging the depths, but marking the ground for XY. Then locate the marks with the GNSS receiver and merge the data from the locator with the depths.

Info in an article I wrote a while back:

https://www.linkedin.com/pulse/merging-gis-underground-pipe-cable-locating-mark-beatty

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