GPR Survey BOQ: Setting the GPR Survey Quantity in a Tender

Updated: 23 October 2026

Why do survey quantities in cabling tenders so often go wrong?

In a typical underground cabling tender, the GPR survey BOQ line – the GPR survey quantity – is one of the smallest money items, and it is frequently filled in last. Estimators copy the cable length, round it, and move on to cable, joints and civil work. Then the survey is executed and the measured length turns out shorter or longer, the L-section requirement hidden in the technical specification has not been priced, and mobilisation or drawings end up argued over at billing time.

This guide sets out a straightforward way to build the survey quantity, explains the terms that change what you finally pay, and shows how minimums and discount slabs behave with real numbers. It is written for EPC estimators and for project engineers at DISCOMs, the power distribution companies that float these tenders. Mezux Touch is not affiliated with MGVCL or any DISCOM and has no part in setting tender quantities; the method below is general.

What is the GPR survey quantity in a BOQ?

It is the measured length of ground penetrating radar survey (GPR survey) the contractor expects to carry out, stated in metres or kilometres against a unit rate. Radar survey has a wide range of uses, with applications including telecom, road and power work, but on a cabling job the quantity usually follows the proposed cable alignment, because that is the strip where existing underground utilities must be found before trenching or drilling.

The number is not always identical to the cable length. Three things make them differ:

• Crossings and junctions get scan passes across the road as well as along it.
• Diversions found during survey, such as an alternative side of the road when one verge is congested, add length.
• Exclusions such as bridges, private premises without access or stretches already surveyed reduce it.

For a broader view of how these costs build up, our GPR survey cost guide for India covers the factors in detail.

Why does the survey quantity matter for the whole bid?

A wrong survey quantity rarely sinks a bid on its own, but it causes trouble out of proportion to its value:

1. Under-quoting. If the bid assumes 40 km and the route measures 55 km, the extra survey is either absorbed or disputed.
2. Missed slabs. Survey rates often fall once an order crosses a size threshold. With Mezux, every metre of an order above 100 km is charged 25% less, so a quantity estimated at 95 km instead of a true 105 km can overstate the survey budget considerably.
3. Unpriced L-section. A specification asking for depth profiles along the route means part of the length is billed at a higher rate.
4. Programme risk. The survey sits at the very start of site work. If its scope is unclear, excavation waits.

For DISCOM work generally, see our page on survey for power utilities.

What survey line items can a cabling BOQ contain?

Standard route survey (per metre)

The main item: GPR scanning along the route, in which radar pulses reflect back to the surface from buried objects, plus an EM cable locator tracing metallic utilities and ground marking. The service includes a written report. At Mezux it is ₹24 per metre, equal to ₹24,000 per km.

L-section survey (per metre)

Where the specification wants a depth profile of detected services along the alignment, those metres are an L-section GPR survey at ₹32 per metre. Keep it as its own item rather than merging it into the standard rate.

Crossings and junctions

Some owners like crossings counted inside the route length; others want them listed individually so each one is visible in the report. Either works if the BOQ says which.

Cable fault locating

Finding a fault on an existing cable is a different task from route survey. If the scope includes it, give it its own line.

Trial pits and boreholes

Physical confirmation of radar results, provided on request. Because nobody knows in advance how many uncertain reflections will need checking, carry this as a provisional item with a number-based unit rather than a fixed lump sum.

Drawings, mobilisation and site extras

CAD/GIS drawing sets, mobilisation, night-shift working and traffic arrangements or permissions are not part of a per-metre survey rate. List them separately so the comparison between bidders stays fair.

Which BOQ terms change what you will finally pay?

• Unit of measurement. Metre or kilometre; the length billed for GPR surveys depends on the route actually scanned.
• Minimum order. Mezux bills at least 4 km per order. A 2.5 km job is charged as 4 km.
• Per-project minimum. Outside Delhi NCR, a ₹1,00,000 minimum applies per project in addition to the 4 km rule.
• Whole-order slabs. Above 100 km: 25% off. Above 500 km: 40% off. Above 1,000 km: 50% off. The reduced rate covers every metre once the slab is crossed, not just the metres beyond it.
• Provisional quantity. The tender figure is an estimate; billing follows the measured, as-surveyed length.
• Taxes. GST is extra and should sit outside the unit rate.

A short worked comparison shows why slabs matter:

Our GPR survey price list has the full rate card and a calculator.

What does a well-written survey item in a BOQ look like?

A good survey item can be priced by any bidder and measured by any engineer without argument. It should state:

• The survey method in plain words: radar data collection, electromagnetic locating, ground marking and a written report of the subsurface features found.
• Whether L-section metres are included, and roughly how many.
• How crossings are counted.
• The deliverables expected, with drawing sets as a separate item if needed.
• That the survey depth achieved varies with soil type and moisture content, because the GPR signal weakens in wet ground, and will be reported section by section.
• Who arranges traffic management and road-owner permissions.

When comparing utility surveys from different providers, look for owned equipment and in-house staff. Mezux runs 58 company-owned GPR systems and keeps survey crews on its own payroll, so the quantity you order is the quantity our people scan.

How do you calculate GPR survey quantity for a BOQ tender?

1. Take the route length from the drawings. Measure the proposed underground cable alignment in metres, feeder by feeder.
2. Add crossings. Count road crossings, junctions, culverts and rail or canal crossings. If they are to be measured inside the route, add a modest allowance; if separately, list them.
3. Allow for diversions. On congested urban roads, the alignment often shifts once services are found. A small contingency is reasonable; mark it provisional.
4. Split out L-section metres. Read the technical specification for any depth-profile requirement and carry that length at the L-section rate.
5. Check the slab. Total the order. If it sits just under 100, 500 or 1,000 km, check whether the real route crosses the line; the saving can be large.
6. Apply minimums. Short packages are billed as 4 km, and outside Delhi NCR the ₹1,00,000 project minimum may govern.
7. Add the separate items. Mobilisation, night shifts, traffic arrangements and CAD/GIS drawings.

For the field scope behind these quantities, see our HT/LT cable route GPR survey service.

How should survey quantities be recorded for billing?

Billing disputes are easier to avoid than to settle. During the work, keep a daily log of metres scanned per section, filled in real time rather than from memory, signed by the site engineer if possible. Tie each log entry to the same section names used in the report, so the bill, the report and the drawings all refer to the same stretches.

At completion, prepare a joint measurement sheet: section, start and end landmark, length scanned, standard or L-section, and any stretch left out with the reason. Keep it with the survey report as part of the project file. If the owner later asks why the billed length differs from the BOQ, this sheet answers the question in one page. On later phases of the same tender, the record also gives you a tested ratio between drawing length and surveyed length for your next estimate. For DISCOM programmes in central Gujarat, our article on MGVCL underground cabling survey adds regional context.