Underground Utility Location/Identification- CA Survey

[madsrvyr]

Just curious, what is the best way/method of locating underground utilities such as sewer mains/laterals. I have seen both as-built plans and potholing mentioned, both will work, but in a test scenario, which is the "best?"

Thanks

 

[EnvEngineer]

Not sure why you are asking this in the seismic/survey forum but

as builts are worthless in utility location, they will only get you withing a couple of feet. I guess the answere depends on why you are trying to locate the utilites. For construction you must call dig alert and have them mark the utilites, that is the best. If you are working around utilites there is not other substitute.

Potholing can be dangerous, Once the utilities are marked and you want another layer of safety you can probe softer soils with a thin steel rod, hand auger to below the utility depth or as a last choice pothole.

 

[madsrvyr]

Not sure why you are asking this in the seismic/survey forum but
as builts are worthless in utility location, they will only get you withing a couple of feet. I guess the answere depends on why you are trying to locate the utilites. For construction you must call dig alert and have them mark the utilites, that is the best. If you are working around utilites there is not other substitute.

Potholing can be dangerous, Once the utilities are marked and you want another layer of safety you can probe softer soils with a thin steel rod, hand auger to below the utility depth or as a last choice pothole.

Thanks for the reply. After doing some reading, it looks like "potholing" is the answer that works best. This is a topic that could be covered on the CA survey exam, hence my post on this forum.

 

[Desert Engineer]

My coworker had a question about Potholing/USA on the surveying exam. He didnt like the question and the choices. He actually submitted a protest letter.

When I do a design, I use the atlas/as-builts to come up with a preliminary design (alignment only), then I call USA and pothole. I try to pothole as much as possible. After potholing, I adjust utility locations/alignment and generate a pipeline profile based on the pothole information.

 

[madsrvyr]

My coworker had a question about Potholing/USA on the surveying exam. He didnt like the question and the choices. He actually submitted a protest letter.
When I do a design, I use the atlas/as-builts to come up with a preliminary design (alignment only), then I call USA and pothole. I try to pothole as much as possible. After potholing, I adjust utility locations/alignment and generate a pipeline profile based on the pothole information.

Thanks Desert Engineer. I had a similar situation and protest on the exam. I think potholing is the answer they are looking for to positively identify the utility, but as-builts will show the approximate location and alignment. There didn't seem to be a correct answer on the exam, however.

 

[outatime2002]

Not sure why you are asking this in the seismic/survey forum but
as builts are worthless in utility location, they will only get you withing a couple of feet. I guess the answere depends on why you are trying to locate the utilites. For construction you must call dig alert and have them mark the utilites, that is the best. If you are working around utilites there is not other substitute.

Potholing can be dangerous, Once the utilities are marked and you want another layer of safety you can probe softer soils with a thin steel rod, hand auger to below the utility depth or as a last choice pothole.

In the petrochemical industry, we often require exploratory investigation to identify any underground electrical duct banks or utilities that may not be accurately shown on the as-builts or ifc drawings. Potholing via hydroexcavation (H2X) is the standard in our industry. Hydroexcavation is an excellent alternative because it will not damage the underground obstructions.

 

[ptatohed]

During the last Survey exam, I remembered reading this thread. It helped. Thanks.

 

[RIP - VTEnviro]

Since when did "cover your ass on the general notes and let the contractor find it" become an unaccepted strategy...

As builts can be completely worthless, half the time they are just the construction plans with "AS BUILT" written on the title block. I've been going through 60 year old plans for a medical center site recently and have been having a great time of it.