How to choose a borehole drilling contractor

A suitable drilling contractor should be able to explain how its experience, proposed method and project arrangements fit your site. Start with a shortlist, then check the evidence and the agreement before paying a deposit or reserving a drilling slot.

Directory inclusion, a sponsored position and a polished website are starting points for enquiries. They are not proof of competence, insurance, approval or a successful outcome at your property.

Match experience to the job

Be specific about what you need: a private water supply, irrigation or agricultural water, a heating borehole, a geotechnical investigation, rehabilitation of an existing borehole, or another service. Experience in one area does not establish competence for all the others.

For a water supply, look for evidence of comparable ground conditions, intended use, access constraints and demand. For heating, ask how the driller works with the ground-loop and heat-pump designer. For investigation work, confirm that the contractor can deliver the engineer's required samples, testing and records.

Ask who will assess the site, propose the borehole design, operate the rig, interpret testing and commission the installation. One company may perform every stage or coordinate specialists. Either arrangement can work if responsibility, competence and communication are clear.

Verify the business you would contract with

Get the legal or trading name, business address and contact details that will appear on the contract and invoice. If the business is a limited company, check its details through Companies House. A register entry helps establish identity; it is not a technical assessment of drilling work.

Confirm whether the company you contacted is the contractor, an introducer or a subcontractor. Ask which business takes responsibility for defects and customer enquiries. Check that insurance documents, the quotation and payment requests refer to the appropriate contracting party. Resolve unexplained differences before transferring money.

Speak to the business using contact details you have independently checked if you receive a last-minute change of bank account or an unusual payment request. Email appearance alone is not enough to establish that a payment instruction is genuine.

Ask for relevant references

Request examples close to your project in purpose and constraints. Useful questions include when the work was completed, the ground conditions encountered, which stages the company delivered and whether ongoing support was needed. Site photographs are helpful context, but they do not replace records or customer references.

Where previous customers agree to speak, ask:

• Was the scope and cost explained clearly before work started?
• Were proposed changes priced and agreed before proceeding?
• Did the company provide the promised tests and handover information?
• How were access, mess, water and reinstatement handled?
• If a problem occurred, who responded and what happened?

Respect customer privacy. A contractor may need permission before sharing a name, location or report. Redacted examples can still help you understand the quality of its documentation. One successful nearby borehole does not predict the result on your land.

Check the team, credentials and insurance

Ask what training and experience are relevant to the proposed work, including any specialist tasks such as electrical installation or the design of a drinking-water treatment system. If a company claims a qualification, certification or membership, establish what it covers and check it with the issuing body where possible. A logo or certificate number is not a substitute for understanding its scope and validity.

Request evidence of insurance appropriate to the work, site and contractual responsibilities. Discuss public liability and, where professional design or advice is being supplied, whether suitable professional indemnity cover applies. Ask about relevant exclusions, policy dates, limits and subcontractors. If the project is significant or unusual, have your adviser or insurer review the proposed arrangements; the largest headline cover figure is not necessarily the most relevant one.

The Trading Standards guidance on choosing a trader supports checking identity and obtaining a detailed written quotation and agreement. Apply those ordinary checks alongside the specialist drilling questions.

Expect a site-specific explanation

A useful proposal explains what the contractor knows, what it assumes and what may change. Ask why its proposed drilling method and construction are appropriate, how it will protect the source, and how the final design depends on the ground and test results. You do not need to become a driller to ask for a clear explanation.

For a water borehole, ask who will establish sustainable supply performance and suitability for the intended use. Clarify the difference between water encountered during drilling, the results of a defined pumping test and the design duty of the permanent installation. BGS provides general construction and water-quality guidance, but your contractor and adviser need to apply appropriate design to the actual site.

Be cautious about an unconditional promise of a particular depth, water quality, yield or payback without a stated technical basis. If a guarantee is offered, read the conditions, exclusions, remedy and identity of the business backing it. A guarantee to return and investigate is different from a promise to deliver a stated water supply.

Check safety, access and environmental arrangements

Ask how the contractor will establish safe working conditions before bringing equipment onto the site. Discuss underground and overhead services, rig access, working space, ground conditions, exclusion areas and keeping residents, visitors and animals clear of the works. Request the project-specific safety information appropriate to the job, rather than accepting a generic assurance.

HSE's underground-service guidance explains that service plans and locating equipment form part of a safe system of work. Do not assume a contractor can safely drill at a point merely because an old plan shows no cable there.

Ask about noise, drilling arisings, working water, test discharge, spill response, storage and reinstatement. Establish who checks permissions and who is responsible for protecting neighbouring supplies or other sensitive features. “The owner deals with permits” is not a complete arrangement unless the required enquiries and responsibilities are understood before work starts.

Agree how difficult results will be handled

Ask what happens if the contractor recommends going deeper, installing additional materials, changing the method, adding treatment or stopping the borehole. A capable company should be willing to explain the decision points and the commercial consequences without pretending every investigation succeeds.

Get the authorisation process, applicable rates and spending limit in writing. Ask what information you will receive before deciding on extra work and what remains payable if the project stops. Also establish responsibility for making an unsuccessful borehole safe and leaving the site in the agreed condition.

For drinking-water projects, ask how sampling, treatment design and commissioning will be coordinated with the appropriate private-water-supply authority. In England and Wales, the DWI explains the local authority's role for private supplies. A laboratory report supplied by a contractor does not by itself answer every regulatory or operational question.

Establish aftercare before the rig leaves

Ask who will answer a fault report after completion and who services pumps, controls and treatment equipment. Confirm call-out coverage, charges, exclusions, warranty terms and the availability of replacement parts. A drilling business may reasonably use specialist installers; you still need to know who owns the customer relationship and coordinates a remedy.

Agree the handover package in advance. It should identify the installed equipment and the records relevant to the work, such as construction details, drilling logs, testing, analysis, commissioning and operating instructions. Ask who handles applicable notifications and record deposits. Keep documents where a future owner or maintenance engineer can find them.

Make the appointment on evidence and a written scope

Compare a shortlist using the same project brief. Record whether each contractor has answered the questions about competence, responsibility, construction, testing, permissions, price changes and aftercare. “Not yet answered” is a reason to seek clarification, not necessarily a reason to reject a company.

Pressure to decide immediately, refusal to identify the contracting business, unexplained payment arrangements, unwillingness to describe exclusions and unsupported guarantees all deserve further investigation. Reviews can add context, but read how concerns were handled and seek evidence beyond a star score.

Before appointment, make sure the accepted proposal, written clarifications, programme, payment stages and variation process form a consistent agreement. For complex or high-value work, independent technical or contractual advice can be useful. Choose the contractor whose evidence and arrangements fit the project, then keep the written brief as the basis for managing the work.