Private Water Supply Record Keeping: A Practical Checklist

1. What good private water supply records are for

A useful private water supply record is not paperwork for its own sake. It should let somebody understand the supply quickly: where the water comes from, which properties or activities it serves, what treatment and storage are present, where samples are taken, what maintenance has been done, what has changed and whether any problem is still open.

DWI's record-keeping guidance says accurate records, maintenance diaries, schematics and plans are important to the risk-assessment process. DWI also recommends that installers explain management and maintenance record keeping when treatment systems are installed. That makes record keeping part of day-to-day control, not just something to assemble before an inspection.

2. Regulation 14: understand the local authority's statutory record

For England, Regulation 14 requires each local authority to maintain a record of the private water supplies in its area. DWI's current Regulation 14 note explains that Schedule 4 specifies the information the authority must record and that private-water-supply records held under this duty must be kept for at least 30 years.

The council's record covers core facts such as the source type and location, estimated population and volume supplied, premises type and treatment details. DWI also explains that, within 28 days of information becoming available, the authority records items including a plan and description of the supply, monitoring programme, sample dates/results/locations and reasons, investigation outcomes, notices, agreed actions, requests and advice, and risk-assessment summaries.

The Regulations do not impose a general requirement on a relevant person to register a private supply. DWI says that when a local authority becomes aware of a previously unknown supply it must add it to its records; where necessary it can use powers under the Water Industry Act 1991 to obtain information needed for its functions.

3. What owners and operators should keep

DWI's examples of records and schematics set out the sort of information relevant persons should be able to provide ahead of a risk assessment. In practice, organise your own record around the physical supply and its operational history.

• Supply identity: a consistent supply name or identifier, source type and location, premises served and responsible contacts.
• Source-to-tap layout: a current schematic or plan showing the source, collection, treatment, storage, distribution and representative points of use.
• Treatment assets: make/model where known, serial or asset identifier, purpose, operating limits supplied by the manufacturer and service information.
• Monitoring: planned and completed samples, locations, reasons, laboratory reports and follow-up.
• Maintenance: routine servicing, replacements, inspections, repairs and contractor reports.
• Events: outages, alarms, treatment interruptions, contamination concerns, complaints and other significant incidents.
• Actions: recommendations, corrective work, responsibility, target dates and evidence showing what was completed.
• Changes: alterations to source, treatment, storage, pipework, use or occupancy that may affect the risk assessment.

Do not create a separate document for every small fact if that makes the history harder to follow. The aim is a coherent record with links to originals.

4. Core record-keeping checklist

Use this as an organising checklist rather than a claim that every row is a specific statutory operator document. Your local authority can tell you what it requires for your particular supply and classification.

5. Sampling and laboratory records

Do not store a laboratory PDF without context. Record the sample date, sample point, reason for the sample and which supply it belongs to. Keep the original laboratory report intact and link any interpretation or action back to it.

DWI's Regulation 14 note shows why those details matter: the local-authority record includes the date, results and location of sampling and analysis and the reason the sample was taken, such as routine monitoring, risk-assessment work, investigation of a failure, a request or an operational incident.

Where a result causes follow-up, make the chain visible: result → investigation → interim control → corrective action → repeat/verification evidence → closure. A spreadsheet that simply colours a value red is not a complete action record.

For more detail, see the sampling-records guide and laboratory-report guide.

6. Treatment and maintenance records

Keep the manufacturer's operating and maintenance information for treatment equipment. DWI's public record-keeping guidance says treatment systems should come with instructions covering use, operation and maintenance requirements, including replacement criteria and regimes for relevant products or substances.

Your maintenance entry should identify the affected asset, date, work performed, person or contractor, any part or consumable changed, observations and supporting evidence. Where an instrument reading or alarm is important, record enough context to understand it rather than keeping an unexplained number.

Use the detailed maintenance-log guide for maintenance-specific fields. This page remains the broader record architecture rather than duplicating that workflow.

7. Failures, incidents and corrective actions

When something goes wrong, preserve chronology. Record when the problem was identified, who was informed, what immediate control was taken, what investigation followed, what work was agreed and what evidence supports closure.

Do not retrospectively rewrite an old entry to make the history look cleaner. Correct mistakes transparently and preserve the previous state where practical. During a later investigation, knowing what was believed and done at the time can matter as much as the final answer.

Formal local-authority notices deserve their own file or linked record. Keep the notice itself, required actions, deadlines, correspondence and evidence of completion together. See Private Water Supply Notices: Regulation 18 and Action Records and the Corrective Action Log guide.

8. Changes, schematics and version history

DWI advises local authorities to note significant changes in circumstances as they occur. For an operator, the practical lesson is the same: record material changes while the details are still known and update the schematic when the physical supply changes.

Examples include a new or replaced treatment stage, a storage-tank alteration, pipework rerouting, a new connection, a change in source, or a change in how premises are used. Do not assume every change has the same regulatory consequence; record it and consider whether the risk assessment or local authority needs to be revisited.

Keep previous drawings or versions rather than silently replacing them. A dated superseded schematic can explain why an old sample point, asset name or maintenance record differs from today's layout.

9. Naming, dates and traceability

Most record systems fail through ambiguity rather than lack of documents. Give each supply and important asset a stable identifier. Use the same name on schematics, sample records, maintenance entries, photographs and contractor documents.

10. Retention: what the 30-year rule means

DWI states that the private-water-supply records maintained by local authorities under Regulation 14 must be kept for a minimum of 30 years. That requirement is important, but it should be described accurately.

It does not mean this guide can tell every owner or operator to retain every invoice, photo, contractor email or internal note for exactly 30 years. Different records can be subject to different legal, contractual, evidential or data-protection considerations.

For operational evidence, retain enough history to understand the supply, support risk assessment and investigations, demonstrate significant changes and provide a sensible handover. If you are setting a formal retention policy for a business, estate or consultancy, consider data-protection and other legal requirements separately.

11. Handover, property sale and shared supplies

A record becomes especially valuable when responsibility changes. For a property sale, new tenancy, staff change or shared-supply handover, provide a current schematic, key contacts, treatment manuals, recent water-quality evidence, maintenance history, outstanding actions and important council correspondence.

Do not imply that a tidy file proves the water is safe or that all legal duties have been met. It is evidence that helps the next person understand the supply and identify gaps.

For transaction-specific questions, use the buyer's guide, seller's guide and shared-supply responsibilities guide.

12. Digital records, originals and backups

A digital system is useful when it makes records easier to find and connect. It should not encourage you to discard the original laboratory report, notice, risk assessment or contractor document when that original is the authoritative evidence.

Use clear file names, controlled access and backups. If records include personal information, keep it proportionate to the operational purpose and protect it appropriately. Avoid putting unnecessary personal details into notes simply because the system allows it.

Exports are useful for handover and resilience, but test that you can actually open them. A backup that has never been restored is only an assumption.

13. Using Private Water Supply Manager as the working record

The member workspace is designed to connect supply details, treatment assets, monitoring, maintenance, corrective actions, changes, documents, contacts, schematics and evidence packs around the same supply. New accounts start blank so the record reflects your own evidence rather than demo data.

Use the workspace as an index and operational history. Keep originals attached where available, use consistent asset/sample-point names and close actions with evidence. The software does not classify the supply, determine water safety, replace laboratory interpretation or certify compliance.

14. Frequently asked questions

Does Regulation 14 require owners to keep every private water supply record for 30 years?

No. Regulation 14 places the formal record-keeping duty on the local authority, and DWI says those local-authority private-supply records must be kept for at least 30 years. Owners and operators should keep useful operational evidence, but the 30-year rule should not be presented as a blanket retention period for every document they hold.

What are the most important records for a private water supply?

Start with a clear supply profile and schematic, treatment information, sampling/laboratory evidence, maintenance history, significant incidents and changes, corrective actions, and important local-authority or contractor documents. The exact needs depend on the supply.

Should I keep original laboratory reports and council documents?

Yes. Summaries make a record easier to navigate, but keep the original report, notice, risk assessment or correspondence where it is the underlying evidence. Link your notes and actions back to the original.

How should I record a failed water sample?

Keep the original result with its sample point, date and reason, then link the investigation, any immediate controls or communications, corrective actions, repeat or verification evidence and final close-out. Follow the local authority's instructions for your supply.

Do I need to update the schematic when treatment or pipework changes?

Yes, where the change alters the physical supply. A current schematic is much more useful when the previous version is also retained with dates, so older records can still be understood.