Currently performing a decently sized boundary and design topo for a utilities client - a piece of property encompassing office and maintenance buildings, and a lot of underground utilities that have been updated, rerouted, abandoned, or changed over a ~50 year period.
For these sort of projects, we engage a private utility locator, who does a pretty good job of marking up any lines that are easily located, both in the ROW and inside the site itself. But on sites like this, where there are a multitude of additional industrial-type lines (chiller lines, fuel lines, etc.), and where they tend to run close together or deeper than typical, it can be exceedingly difficult for the locators to figure out their location. And of course sometimes they just cannot get a fix on anything.
Of course, the inevitable next step is for the client to ask us to depict underground lines "per plan" using plansets that obviously incorporated some of the features the locator recovered, but have obviously changed and also obviously nowhere near topographic survey levels of precision.
So, bearing in mind that the higher ups and client have discussed and dismissed GPR, potholing, excavation, etc., and that the client doesn't really have a problem with us showing lines that might be several feet or more away from their true location:
At what point do you say "no" to adding features that were not observed and are from a dated, imprecise source?
Even though we explicitly label these lines as "record" (and have extensive disclaimers), they exist in a survey base map alongside features that were observed and measured with survey precision.
Obviously, in the past it was much more difficult to overlay or reference drawing files from another source. Nowadays it takes all of five minutes to Xref a CAD plan and tweak its display properties, or underlay an older image to trace things out.
Ultimately it seems to be laziness and liability (somewhat related) driving this. It's not really a matter of doing the work or not - we get paid for it, and it's something I have done often over the course of my career. But this is something I have always considered an engineering task - reconciling older plansets with each other, and then reviewing them overlaid on the survey, which is the record of what was actually observed on site.
Our responsibility is to survey, i.e. observe, existing features. Observe, not guess at locations.
A more philosophical, question might be: at what point is a survey no longer a survey because it incorporates a large number of items that were not in fact surveyed?
Great question.
Can you talk to the risk management director about why what and WTF wouldn't you pothole for verification of suspect utilities?
That cavalier attitude about not actually doing something for due diligence and lessen the liability seems counter productive and inducing more risk.
To answer the exit question:
Don't survey anything you're not willing to defend in court.
Let them hire a locator and let them carry the liability.
Only a surveyor can survey, but a surveyor can do other stuff in addition to surveying - like draft up compilations of as-built locations. If you don't do it the engineers CAD tech will. As a licensee your responsibility is to show stuff based on the best information available. You don't necessarily have to put hands on it. After all, you are comfortable showing unseen stuff based on an electrical field response.
As a businessman, you best make sure that everybody that might come into contact with your product clearly understands the source of the information shown.?ÿ ?ÿTo that end, some suggestions:
1. put these as-built sourced items in a completely separate drawing file and xref that drawing to your survey.
2. Even in the xref, put the as-built sourced items in a uniquely named layer.
3. Make up unique linetypes for the as-built sourced items. Perhaps with dashed instead of solid lines.?ÿ
4. Make use of colors & graytones in your layering/linetype scheme?ÿ
5. Add notes regarding sources.
When we collect our utility locates we create a separate drawing that we hand off to the engineer group that contains what we found, with scans, locators, drawing, records,etc..
We are all on the same team(municipal) and occasionally send out our drawings to contractor clients doing work for us.
I don't think anything we've created fell under a survey as stamped or implied etc., Just survey quality data for design implementation and planning meetings.
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Are you doing just a boundary survey or is it like a full blown ALTA?
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Unique linetypes and good notes, for sure.?ÿ Produce a boundary survey with what you really know, and a separate drawing for what you've been told might be?
With the utmost respect to us bunch of surveyors, this is something you would be prudent in running by your lawyer(s) and/or insurance carrier if big bucks are at stake. ?????ÿ
UTILITY NOTES
THE PRINCIPAL GUIDELINES FOR UNDERGROUND UTILITY MAPPING ARE THE AMERICAN SOCIETY OF CIVIL ENGINEERS (ASCE) CI/ASCE 38-02, STANDARD GUIDELINE FOR THE COLLECTION AND DEPICTION OF EXISTING SUBSURFACE UTILITY DATA, 2003.
Sorry for the all caps. I just copied it from our plan notes.
Perhaps you should review the ASCE standards for utility mapping. My company provides SUM (Subsurface Utility Mapping) services on a regular basis. It's a growing market, and a service that your existing clients desire.
As a businessman, you best make sure that everybody that might come into contact with your product clearly understands the source of the information shown.?ÿ ?ÿTo that end, some suggestions:
1. put these as-built sourced items in a completely separate drawing file and xref that drawing to your survey.
2. Even in the xref, put the as-built sourced items in a uniquely named layer.
3. Make up unique linetypes for the as-built sourced items. Perhaps with dashed instead of solid lines.?ÿ
4. Make use of colors & graytones in your layering/linetype scheme?ÿ
5. Add notes regarding sources.
Oh, we do all of that. And I'm all for providing non-traditional services. I'm not too concerned about liability considering this is standard practice around here. I'm more interested in "best practices".
Perhaps you should review the ASCE standards for utility mapping.
It's been a while since i have submitted ASCE metadata, but if I remember correctly, based on those standards 95% of the plansets we are being asked to shoehorn into our surveys are of the "indeterminate" classification, i.e. we have no idea as to the accuracy.
Here's a rephrased question: does anyone split out these ambiguous/indeterminate "per plan" utilities into a separate drawing file, delivered with the survey itself so the the client may overlay them as they see fit?
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(Side note: this is not an ALTA/NSPS survey, whose standards are pretty clear on the limitations of utility plans and are more concerned with title issues than design issues.)
I don't mind consolidating record utilities plansets for clients. But I am wary of the practice of mixing data of widely variable accuracies/pedigrees and presenting them as a single dataset.
@rover83?ÿ
I add the annotations in the drawing ( this mileage will vary depends on size of product) and density of items ambiguities likely create a second and maybe even third, it just depends. Record info, apparent utilities (think FIO boxes or easement boundary poles etc.) And the like with all the paint, photos of the paint, and then lots of dashed dotted or whatever lines in the directions they seemed to go.
Reliance on anything else except what's provided is their own liability at that point.
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Let us consider this scenario: You are doing a boundary survey. A certain monument is key to the resolution. But that monument is lost, gone, kaput.?ÿ You have excavated an area 100 feet around every possible position for that monument with a teaspoon to a depth of 50 feet. It's gone.
You have 3 record documents showing where that monument was. The originating deed or plat, and 2 subsequent survey records by well respected surveyors - one done shortly after the monument was originally set and the other done within the last year - who tied the monument, and agree within millimeters on its position. Which is?ÿ several feet off what the originating deed or plat says. You have several other monuments shown on all 3 whose dimensions all agree with each other and your own recovery.
Do you use the deed dimension to the missing monument, or do you rely on the "as-built" dimension from the 2 surveys??ÿ
Of course I've framed this question so that there is only one possible answer.?ÿ And, of course, your new survey will show that you used the dimensions from Surveys Y & Z rather than Plat X.?ÿ?ÿ
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Its a fantasy dream, I get it.?ÿ Noreal Surveyor would claim mm.
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Like Jitterboogie, our company drawings show the different ASCE Quality Levels (A, B, C & D) with annotation. The plan notes explain the meaning of the different quality levels. We do not prepare a separate QLD drawing, although I suppose we would if the client asked for it.
I agree that (at best) 95% of the record utility plans we get on a project can be classified as "little better than a cartoon" when it comes to positioning. At least the compiled QLD information tells a project designer that something might be thereabouts, and if a client is willing to pay for remote sensing, borings, etc. then we can improve the accuracies (to a limited degree). More money = more reliable information.
More serious response:
Is the excavation temporary or is it required for the plans and building infrastructure to occupy?
