Locating Storm Drain and Sewer Lines Without Potholing?

[raydefan]

We are trying to locate some storm drain and sewer lines in a retail site that we have no as built plans for. All we have are the above ground catch basins and manholes that we can use to assume some type of alignments. We potholed some locations we thought we would find these pipes, but they were not there.

I thought there was some type of technology out there where we could send some equipment down the pipes and be able to find the location and depths WITHOUT potholing. Anyone ever have experience in this?

Thanks,

Raydefan

 

[msucog]

GPR should be able to do well. if you got manholes, inlets, etc, i would think you could "straightline" between much easier. perhaps combine the two for a better survey. you could also put a laser light/pointer in each pipe and look in the next inlet to see if you see the light...then you'd know it's a straightline shot.

 

[Drumchaser]

Several cities around here have the camera "rats" that probe lines to check out problems and or do a final check on new lines.
Yes the technology is here.
Not sure it will be cost effective for you.

Potholing with a vacuum truck works pretty good....depending on how deep you need to go.

Hope this helps.

 

[hotgas]

Use a sewer jet with a radio transmitter on the nozzle. As the jet pulls the hose down the line, one can follow the path from above by following the radio signal. Thus works much better than a tv camera because the camera does not disclose curves and bends very well.

 

[bimr]

If you have the money, you can laser profile the sewers.

http://www.hydromaxusa.com/laser_profiling.htm

 

[GoldDredger]

Get the lines television inspected, not sure why no-one seemed to suggest that. They are fairly expensive, but not as much as potholing the entire site.

You will have to deal with a specialty contractor for this, not just a plumber. Plumbers will tend to have fiber optic cables they fish down a line. The TV inspection you want are the little robatic vehicles with camera and lights. The camera can pan, the vehicles pull the feed line rather than being 'pushed' like the fiber optics. They will also show where laterals and new lines come into the line being inspected, which can be important for obvious reasons.

These robotic cameras can give you a direction and stationing. This is important if you come across blind bends or even curved sewer (which might explain why the potholing yeilded nothing). They can also show you the condition of the pipes, breaks, stuff like that.

Also, for an additional fee, you can also have the lines located by some sort of frequency they can monitor from ground level. I think they can tell depth and horizontal location, and then that can be marked on the ground for the contractor. Not sure the precision, but probably close enough that the contractor can pothole before construction.

Enjoy watching those 'dirty' movies we used to joke.

 

[cvg]

the robotic camera setups I have seen do not give direction, slope or depth. station is estimated by the length of cable which has been unreeled.

 

[bimr]

Newer laser profiling equipment will provide sewer direction, slope, and depth among other items. "CoolVision can create a complete three-dimensional profile of a pipeline and measurement observations with a .25 percent degree of precision and is 99.9 percent repeatable"

http://www.oildompublishing.com/uceditorialarchive/july07/laser.pdf

http://dcnonl.com/article/id31237