Hitting with the pipes underground while construction

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New member
Feb 14, 2022
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In a power industry, and if contruction of FGD project ( Flue gas De sulphurisation ) is going on in that industry. Assume initially when Geo technical investigation performed, a fire water pipe underground got hit. And we dont have layout for the fire water pipes underground. And later we came to know that an industry nearby uses a water pipe which is going underground in our industry. And we dont know how many public utility pipes are going underground in our industry.

1. My first concern is: How to handle hitting issue with the fire water pipes in this industry whose layout we dont have.
2. My second concern is: There may be many industries located far this industry like more than 30 KM, and they may also have water pipes below our industry serving them, and there may chance of hitting with those pipes.
3. My third concern is: How to handle construcion without damaging public utility pipes going underground in this industry.

Most important issue is: we dont know at what depths these pipes are there underground in our industry.

Kindly guide me how to handle above problems

blybrook PE

Veteran 10k Spammer
Dec 16, 2010
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To answer all of the questions with one answer, use a utility location service before digging. This is required by every state in the US, and several of the US territories. It is usually provided free of charge from the utility companies. Nationally as the Call Dig Hotline or 811; Call811 | Know what’s below. Call before you dig..

If you do not have a utility locate service in your area, find a subcontractor that can provide ground penetrating radar (GPR) services for the job site. Use the GPR to locate the existing utilities on your project site.

Good luck.


Jun 3, 2010
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To add to this, 811 will only locate underground public utilities, generally in locations where there are established easements. Underground locates on private property require hired professional services. Just learned this myself on a project in the county, outside of city limits.

Platypus Engineer

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Dec 29, 2017
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1000 miles from nowhere
if the fire water lines are served by the local water utility, then should be valve(s) at or near the near the property line. Valves may also be in a vault depending on size. Locating can start from this point. Another option is start at hydrants on the fire water lines and follow them out to main.

Initial post says this is a power plant, but does not say fuel source (coal, natural gas, oil). If site is in US natural gas and oil pipelines operate under very strict US govenment regulations there should be plans showing where fuel lines come in.

Test pitting using vacuum excavation to determine location of pipe is also option.

Most regulations require hand excavation until pipe location is determined.

Other options for locating lines in future would be to install tracer wires along length of pipe. There is locating tape with metal strip inside tape that can be placed over pipe for locating in future.

Another issue with locating lines inside a power plant is the grounding system uses a lot of large gauge bare copper wire. The copper can affect operation of the locating equipment.