Pumping test to operations traceability for borewells

What traceability means in practice

A yield or pumping test is usually the most expensive piece of evidence a borewell owner ever buys. Yet months later, when someone asks why the pump is set at a certain depth or why the rate is limited, the answer is often “that is what the contractor said”. The test sheet may be in a file somewhere, but the link between the readings and the instruction has been lost.

Traceability is that link made explicit. It connects drilling and construction details with test conditions, pump selection, operating discharge, water-level controls, production forecasts and maintenance decisions. Its value shows when something changes: a new pump, a falling water level, a new owner or a dispute. The reviewer can check whether the existing instruction still applies without reconstructing the whole project from memory.

A folder full of documents is not traceability unless the relationships between them are written down.

Start with a stable identity for the well

Use a well identifier that stays the same when the pump, contractor or document titles change. Record the location and construction details needed to distinguish it from nearby wells. A pump serial number identifies equipment, not the borehole. A project or farm name may cover several wells with different depths and histories.

Keep separate identities for each of these, linked by dates:

If a pump moves from one well to another, both the equipment history and each well’s history must still make sense. This structure stops a test report being attached to the wrong installation simply because a familiar pump name appears in the file.

Preserve the test configuration

Test readings mean little without the arrangement that produced them. Record:

• The test pump or, for an airlift test, the compressor, airline depth and pressure used.
• The pump intake setting or airline submergence.
• The discharge arrangement and how flow was measured (meter, weir, timed container).
• The reference point for water-level readings and its height above ground.
• The start time of pumping, so elapsed time is unambiguous.
• Interruptions, rate adjustments and unusual observations such as sand, turbidity or surging.

Without this, a later analyst may treat differences caused by the installation as changes in the groundwater system. An edited “clean” test sheet can be useful for analysis, but it must stay connected to the complete field record.

Recognised aquifer-test guidance, including published review practice from the US Geological Survey, emphasises documenting any adjustments and judging whether results suit the site and test conditions. Following that principle improves the record; it does not by itself make a document package a regulatory or professional certification.

Airlift and compressor-based tests

On many borewells in Telangana and Andhra Pradesh, the first indication of yield comes from the drilling compressor itself, as air lifts water out of the hole during and after drilling. That airlift yield is useful but different from a controlled pumping test. Flow is often irregular, the water level inside the hole cannot be measured easily while air is injected, and the result depends on airline submergence and compressor pressure and flow.

Record airlift observations as what they are: an indication at stated conditions. Note the compressor model, working pressure, depth and the method used to estimate discharge. Do not carry an airlift figure forward as an approved pumping rate without a proper test. A large drilling compressor can lift more water briefly than a submersible pump will sustain.

Connect readings to calculations

Each calculated result that matters should state:

1. Which dataset it uses, by identifier and revision.
2. The time interval selected for analysis and why.
3. The method or equation and any software version used.
4. Units at each step.
5. Any readings excluded and the reason.

The test of good traceability is reproducibility: another competent person, given the same records, should arrive at the same number. If they cannot, the calculation is not yet fit to support an operating instruction.

From analysis to operating instruction

The operating instruction is where engineering judgement turns into something an operator acts on. It typically includes the permitted pumping rate, pump setting depth, the water level at which the pump must stop, restart conditions, alarm responses and when to call for review. Each of these should point back to the analysis that justifies it, with any safety margin stated rather than hidden.

Where a value is a judgement rather than a calculation, for example a margin above the pump intake chosen to protect against dry running in summer, say so. A later reviewer can then decide whether the judgement still holds rather than treating it as a measured fact.

Working in reverse: impact checks when something changes

Traceability earns its keep when records change. Typical triggers are:

• A correction to test data, such as a fixed reference-level error.
• A replacement pump with a different curve or setting depth.
• A sustained change in pumping water level or discharge.
• A new well nearby that may cause interference.
• A change in demand that requires a higher rate.

For each trigger, use the links to list the calculations, instructions and forecasts that depend on the changed item, decide which need review, and record the outcome. “Reviewed, no change required” is a valid and useful result.

Common traceability gaps and how to close them

The same few gaps appear again and again on borewell files:

• Water levels recorded without stating whether they were measured from ground level or from the casing top. Close it by measuring and recording the reference height once, then quoting it on every sheet.
• Discharge noted as a single figure with no method. Record whether it came from a meter, a weir or a timed container, and the meter identity if one was used.
• Test pump details missing. Note make, model, setting depth and delivery arrangement on the first page of the test record.
• An operating rate written on a whiteboard or in a message. Transfer it to an issued instruction that names the test it relies on.

Each of these is quick to fix at the time and very hard to reconstruct later.

A simple traceability checklist

How Reddy Compressors helps

Reddy Compressors, at Tarnaka in Secunderabad, has worked with industry since 2002. For borewell work our role is the compressed air: we supply all types, all brands and all models of borewell compressors, covering new machines, used and refurbished units, rentals, service and spare parts, for ELGi, Atlas Copco, Ingersoll Rand, KAESER, Chicago Pneumatic, Doosan and other makes. We are an independent multi-brand specialist, not an authorised dealer. We have tie-ups with all major and reputed brands.

For drilling and airlift work we help contractors match the compressor to depth and hammer size, from 600–1,500 cfm at 200–400 psig (13.8–27.6 bar) up to special units at about 35 bar (507.6 psig). Our more than 20 service engineers and technicians cover all of Telangana and Andhra Pradesh, and we supply machines, hire and spares across India.

We keep the compressor side traceable too: parts are identified from the make, model, serial number and nameplate photo, and fit is confirmed before quoting. Our service reports record hours and work done against each machine.

What to send us

• Compressor make, model, serial and nameplate photo, or the duty you need.
• Planned or typical drilling depth, bit and hammer size.
• Required working pressure and flow, if known.
• Site location and access conditions.
• Sale, hire, service or spares, and the expected period.

Frequently asked questions

What is the difference between an airlift yield and a pumping test?

An airlift yield is measured while a compressor lifts water out of the hole, usually during or just after drilling. It gives a useful first indication but depends on compressor pressure, flow and airline depth. A pumping test runs a pump at a controlled rate while water levels are measured, so it is the better basis for choosing a permanent pump and operating rate.

How do I know which pumping rate is safe for my borewell?

The safe rate should come from a properly recorded pumping test, analysed with the water levels, discharge and test conditions documented, and reviewed by someone competent in groundwater work. It should leave a margin above the pump intake for seasonal decline. If you cannot trace your current rate back to such a test, consider a retest before increasing it.

What should a pumping test record include?

It should include the well identity and construction, test pump and intake depth, discharge measurement method, water-level reference point, start time, all readings with times, interruptions and rate changes, and observations such as sand or turbidity. Keep the complete field record even if a cleaned version is used for analysis, so the result can be checked later.

Why does my new pump give a different result from the test?

The new pump may have a different curve, setting depth or delivery head from the test pump, so it will operate at a different point. Seasonal water-level changes and differences in metering also affect the comparison. Check the installed pump against the test configuration before concluding that the well has changed, and record the new arrangement.

What size compressor do I need for borewell drilling?

It depends mainly on depth, hole and hammer size, water inflow and ground conditions. Typical borewell compressors are 600–1,500 cfm at 200–400 psig (13.8–27.6 bar), with special units up to about 35 bar for deep or wet holes. Send us the depth, bit and hammer details and we will advise on a suitable machine for sale or hire.

Do you service borewell compressors on site?

Yes. Our service engineers and technicians cover the whole of Telangana and Andhra Pradesh for borewell compressor service, breakdown repair and overhaul, across all major makes. For sites elsewhere in India we can supply machines and spare parts, with project-based site support where it is feasible. Send the nameplate photo and the fault details to get started.

Related pages

• Borewell and DTH compressor library
• Borewell yield testing and production duty
• Operating rate decisions and revision triggers
• Version control and asset record preservation
• New borewell compressor sales
• Borewell compressor service and repairs