Engineering · Service
SUE Survey — Subsurface Utility Engineering to Quality Levels
SUE is not a survey technique — it is a way of grading how much your utility information can be trusted, and pricing the risk that remains. We deliver to a specified quality level and state what was achieved, feature by feature.
Twenty-two years, 1.5 lakh+ km surveyed, 100 km a day at full stretch and 700 KM in a single 30-day month, all delivered on owned fleet. Outside Delhi NCR we accept projects from ₹1,00,000 upward, since rigs and crews travel from our Faridabad base. Within NCR there is no minimum at all.
Overview
A line on a drawing is not a promise
Two utility drawings can look identical and mean completely different things. One was copied from a municipal record of unknown vintage; the other was detected in the field and physically exposed at the crossing that mattered. SUE exists so that a designer, a client and a contractor can tell those two apart before someone excavates on the strength of the wrong one.
- Quality level assigned per feature, not per job
- Written into tender documents properly
- Risk register the design team can actually use
- Deliverables in ASCE 38 / PAS 128 conventions
Process
How a SUE package is built up
Scoping the Level
Agreeing what confidence the design decisions actually require, before any fieldwork.
Scoping the Level
Agreeing what confidence the design decisions actually require, before any fieldwork.
Records Gathering
Formal requests to every asset owner whose plant may fall inside the corridor.
Records Gathering
Formal requests to every asset owner whose plant may fall inside the corridor.
Field Detection
Geophysical survey across the corridor establishing horizontal position and indicative depth.
Field Detection
Geophysical survey across the corridor establishing horizontal position and indicative depth.
Selective Exposure
Trial holes at the crossings where a design decision cannot tolerate uncertainty.
Selective Exposure
Trial holes at the crossings where a design decision cannot tolerate uncertainty.
Reconciliation
Records, detection and exposure compared — contradictions investigated, not averaged.
Reconciliation
Records, detection and exposure compared — contradictions investigated, not averaged.
Risk Register
Residual unknowns listed with their consequence, so the design team prices them.
Risk Register
Residual unknowns listed with their consequence, so the design team prices them.
Procurement
Writing SUE into a tender so it means something
The most common failure we see is not a bad survey — it is a tender that asked for “utility survey” and got exactly that, with no basis stated. Four things make a specification enforceable.
State the level, per element. A corridor may need field detection throughout but physical exposure only at major crossings. Saying so converts a vague scope into a priced, comparable one.
Name the deliverable format. CAD layer convention, coordinate system, depth attribute and confidence attribute. Without these you receive a drawing your design software cannot ingest cleanly.
Require limitations to be declared. Areas of no access, poor ground response and untraceable services must appear in the report. A survey with no stated limitations has either not looked hard enough or is not telling you something.
Fix who verifies. Trial holes are a civil activity with permits, traffic management and reinstatement attached. Leaving this ambiguous is how a SUE scope turns into a variation claim.
Our engineers routinely help clients and consultants draft this scope before it goes to tender — including where we are not the eventual surveyor. The technical framework behind the levels is set out on our utility mapping page.
Deliverables
What each level actually gets you
| Records-based output | A plotted compilation of asset-owner records. Adequate for feasibility, route options and early cost planning. Not a basis for excavation. |
|---|---|
| Surface-correlated output | Records checked against surveyed chambers, valves and covers. Alignment confidence improves; depth remains inferred. |
| Detected output | Field geophysics giving horizontal position to a stated tolerance with indicative depth. The normal basis for design and for excavation planning. |
| Verified output | Physical exposure at nominated points giving measured position, depth, diameter and material. Applied selectively where consequence is high. |
| Attribute set | Every feature carries service type, detection method, confidence, source and survey date in the drawing data |
| Formats issued | CAD (DWG/DXF) to client layer standard, GIS (SHP/KML), PDF issue set, trial-hole record sheets |
| Accompanying report | Method, coverage, equipment, calibration basis, declared limitations and the residual risk register |
| Revision control | Issued under document control so a superseded drawing cannot quietly remain in circulation |
Level naming follows the ASCE 38 and PAS 128 conventions commonly referenced on Indian infrastructure work. A project does not hold a single uniform level — different features are established by different means, and an honest deliverable shows that variation openly rather than flattening it into one reassuring claim.
Value
Why clients pay for the higher levels
Design certainty. A metro alignment, a flyover pile cap or a trunk sewer designed around an assumed utility position becomes a redesign when the assumption fails. Verification at the few genuinely critical points is cheaper than one redesign.
Claim defence. Ground-condition disputes are settled on evidence. A dated, coordinate-tied, method-declared record produced before work started is the strongest document a contractor can hold.
Programme protection. Utility diversions have their own approval timelines with asset owners. Knowing at design stage which diversions are needed lets those applications start months before the site does.
Safety. HT power and gas mains do not forgive a strike. The reason regulators and major clients increasingly specify SUE is that it is the only framework that forces the question of how confident you actually are.
Governance
How confidence is kept honest
Every feature carries the method that produced it, so an auditor can see whether a line came from an asset-owner record or from a measured trial hole years after issue. Where a detected position and an owner's record disagree, both are shown and the conflict is written into the risk register rather than resolved by preference. Trial-hole records are photographed with the pit dimensions, the exposed service and a levelled reference so the depth figure is defensible. Coordinate framework, layer standard and attribute schema are agreed in writing before drafting begins, because retrofitting a client's CAD standard afterwards is where transcription errors enter. Draft issue is reviewed by an engineer independent of the field team, and superseded revisions are withdrawn under document control. The full pack — raw geophysical data, records correspondence, trial-hole sheets and issued drawings — is archived under our ISO 9001:2015 system for the retention period the client specifies.
What our crews have delivered, and on whose equipment
FAQ
SUE survey — common questions
No. A utility survey is fieldwork. SUE is a framework that records how each piece of information was obtained and how much confidence it carries, so the residual risk can be managed rather than assumed away.
It depends on the decision being made. Route options can be settled on records. Excavation planning needs field detection. A pile cap or a deep crossing over a critical main usually justifies physical verification at that point. We help clients set this per element rather than blanket-specifying.
Yes. Metro corridors, industrial plants, airports, campuses, power evacuation routes and pipeline projects all use the same framework. Anywhere a design depends on what is buried, the grading question is the same.
We can, including the permission, traffic management and reinstatement, since our RoW and civil teams are in-house. Some clients prefer to use their own contractor for the excavation and take only our nomination and recording — both arrangements work.
Yes, and it is worth doing. The usual finding is a drawing with no declared limitations, no confidence attributes and no stated basis for its depth figures — which tells a design team far less than it appears to.
Records gathering is usually the long pole, because it depends on how quickly asset owners respond. Field detection is programmable and predictable; trial holes depend on permissions. We give a realistic programme with those dependencies shown separately.
Peak sustained output on open corridors reaches up to 100 km a day, running day and night shifts on our own systems. A single 30-day programme has delivered 700 KM, which remains our record. In total we have completed more than 1.5 lakh km of GPR survey. What your own route achieves depends on congestion, access and the deliverable specified.
Specifying utility survey for a tender?
Send us the corridor and the design decisions that depend on it — we will help set the levels before it goes out, not after.
Discuss a SUE ScopeSUE survey — quality levels, output and detailed questions
Mezux Touch delivers Subsurface Utility Engineering to stated quality levels, which is a framework rather than a technique. Its purpose is to make explicit how each piece of utility information was obtained, so a designer knows what to trust. Quality Level D is records research alone. Level C reconciles records against visible surface features. Level B is field detection by radar and electromagnetic locating. Level A is physical verification at a specific point. A drawing that does not state its level is asserting equal confidence in a line traced from a 1970s record and a line exposed in a trial hole, which is exactly the error SUE exists to prevent.
How the work is run
The level is set per element rather than blanket-specified across a project, because a pile cap position needs Level A while a general corridor may not. We help clients decide that at scoping, since specifying Level A everywhere wastes money and specifying Level B everywhere leaves the critical points unresolved. Field detection uses radar and electromagnetic locating together and reconciles them, reporting conflicts rather than adopting whichever answer is tidier. Where verification is specified, the trial hole position is chosen to resolve the design question rather than merely to confirm something already confident.
What you receive
A drawing where every feature carries its quality level as an attribute, not as a note in the corner. A residual risk register listing what remains unknown after the survey, written so it can be adopted directly into the project risk register rather than transcribed. Trial hole records with photographs, dimensions and levels where Level A was specified. A signed report setting out what was achieved at each level and, importantly, where the specified level could not be reached and why. Issued under document control, so a superseded revision cannot stay in circulation on a live project.
Beyond the basics
Which quality level should we specify? Rarely one across a whole project. Level A where a pile cap or deep structure cannot tolerate uncertainty, Level B as the working basis elsewhere. We help set it per element.
What is the difference between GPR and SUE? GPR is a detection method; SUE is a framework grading how information was obtained. A GPR survey typically delivers Level B.
Why does the residual risk register matter? Because it states what is still unknown. A drawing without one implies everything was found, which is never true of any survey.
Can you upgrade a Level B survey to Level A later? Yes, by verifying specific points. That is often the sensible sequence: detect broadly first, then verify only where the design actually depends on it.
Do you issue under document control? Yes, which matters on live projects because it prevents a superseded revision continuing to circulate after a finding changes.
Terms used on this page
Quality Level A — physical verification at a point, the only level that confirms a service by exposing it. Quality Level B — field detection by radar and electromagnetic locating, without physical exposure. Quality Level C — records reconciled against visible surface features such as chambers and covers. Quality Level D — records research alone, with no field work of any kind. Residual risk register — a schedule of what remains unknown after survey, for adoption into the project risk register.
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