Underground Utility Due Diligence

The Importance of Underground Utility Due Diligence
 
As the structural and/or mechanical installer, we are usually the first construction unit on site following the surveying crew.  We always dial 811 or the local equivalent depending on where the project is located.  Public locates are a must before beginning any project.
 
But what if the project is on private property?  What can be expected of the property owner, the site developer, EPC, general contractor and/or the installer?
 
We learned a lot on the fly about private locates when we arrived to drive I-beams into a macadam parking lot behind what used to be an Intel Corporation property in California.

Prior to arrival, we had done our 811 call and everything on the public end was super.  We arrived to work.  The site had been surveyed and we had our points for which to lay out our post installation.
 
We began layout and noticed an underground drainage system in what used to be a parking lot.  This was not ever noted on the 811 report, the build plans or in any conversation prior to us arriving.  Why weren’t we told of this?  We began to question: “What else is underground here?”. 
 
We were able to get inside the building and see the original property blueprints.  They seemed to show a lot of underground activity, including the drainage system.  However, it was too vague and too old to be counted on as the final barometer.

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Immediately we halted all work and called for a private utility locator.  They needed a few days to arrive.  To our surprise, they found not only the drainage locations, but also an unexpected 21,000 volt electrical line.  It ran from the original building, through the north end of the parking lot and into a fenced area on the same property.
 
Public utility locates stops when it reaches private property.  If there is a gate or a fence or another blockage to the site, there is no way to know what is on the other side.  Public entities are also under no mandate to report private locates. 
 
We were lucky enough not to have driven any posts there.  The results could have been catastrophic not only to our equipment operators, but to all who were on site.  As it turned out, we were able to move some of the I-beams so as to not hit either the electrical line and the drainage system.  The result was a pretty solar array.

 The link below is a great read on the difference between public vs private utility locating.
https://www.bhug.com/news/public-vs-private-utility-locating