Prepare for a private water risk assessment visit
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On this page
A sample report and a risk assessment visit are different parts of the private water record. Before a visit, make the layout and responsibilities of the supply understandable to someone who has not looked after it for years.
Regulatory scope: Drinking Water Inspectorate (England and Wales) and mygov.scot (Scotland) pages checked on 24 October 2026. Northern Ireland has its own arrangements, so ask the relevant authority there.
What the visit is for
The Drinking Water Inspectorate (DWI) page on risk assessment tools says it has developed tools to help local authorities carry out risk assessments of private supplies under the private water supplies regulations. It also says the tools can be used for supplies to single dwellings where an assessment has been requested, and mentions a condensed version for simple systems, for example a single source followed by one or two stages of treatment such as pre-filtration and UV disinfection.
The DWI buyer guidance adds that a supply serving two or more dwellings or other properties must be risk assessed every five years, while a supply to a single dwelling does not have to be unless the owner or occupier asks, the local authority believes there is a risk to health, or another condition in the regulations applies. Ask your local authority which of these apply to your supply, since the position can differ between a single house, a shared supply and holiday accommodation.
Scotland
The mygov.scot page on registering, risk assessing and testing private supplies says the council must keep a register of private supplies and must test and risk assess some of them. Supplies that serve a business or rental property (including holiday lets), more than 50 people, or more than 10 cubic metres of water a day must be registered, sampled by the council at least once a year and risk assessed at least once every five years. If a supply is small or you are the only user, you can still ask for a risk assessment and sampling. Do not carry Scotland's intervals over to England, Wales or Northern Ireland.
Send records before the visit
The DWI page on record keeping says accurate, detailed records, maintenance diaries, schematics and plans are important information for the risk assessment, and that ideally they are given to the local authority before a visit so that time on site is used well. Collect:
- earlier risk assessments and sample results, with dates
- equipment manuals and maintenance records
- a simple source-to-tap sketch showing collection points, storage, treatment, branches and the buildings served
- notes of changes since the last assessment, such as a replaced treatment unit
Label any pipe route you are unsure of as unknown rather than drawing an assumed straight line. Keep what you have seen yourself separate from a neighbour's recollection.
Ask what the visiting team needs
Contact the team before assembling a large file. Confirm whether the appointment is for risk assessment, sampling or another purpose, which records they want in advance and how to submit them. A maintenance visit does not automatically cover the same work.
Tell them which homes or activities the supply serves and what information is missing. Changes such as letting activity or an additional building may need discussion; ask the authority how they affect classification rather than deciding it yourself.
Keep a short chronology of alterations, servicing and concerns, with the supporting invoice, report or correspondence. Put unresolved recommendations near the front, including those whose completion is uncertain.
Make your sketch honest about gaps
Mark information from professional plans, safe observations and other people's recollections differently. Date the sketch and say who prepared it. It is a communication aid, not a surveyed plan.
If records use different names for a component, cross-reference them and ask the assessor to clarify. Do not quietly turn uncertain routes into neat connecting lines.
For example, a supply may cross neighbouring land while the owner has records only for the section near the house. Show the known section and label the gap. Ask the authority what information and access it needs, then coordinate with the relevant landowner. Do not follow an assumed route or open chambers to complete the drawing.
Arrange access with the people who can grant it
Identify who owns or manages each section, who controls access and the shared-supply coordinator where relevant. Confirm permission before promising entry to someone else's land or buildings.
Tell the visiting team about locked gates, livestock or other work and ask how inaccessible parts should be handled. Preparation must not depend on moving covers, opening equipment or entering confined spaces yourself.
If someone familiar with the supply cannot attend, ask whether they can provide an attributed written account and contact details. That lets the assessor follow up without treating you as the source of everything.
Leave with clear findings and next steps
Ask which parts were assessed, what remains uncertain and what happens next. Keep the booking separate from the final report; if the scope changed, ask for that to be reflected in the record.
For each finding, note the reference, requested action, responsible person, actual deadline and evidence of completion. Preserve the authority's wording. Distinguish a quotation, booked work and completed work, and identify who arranges any further specialist visit and returns the findings.
Follow any instructions about water use and request them in writing. Keep them visible to affected users and ask who confirms any change. A contractor's visit does not automatically end an authority's restriction.
When the report arrives, check it against your questions and ask the issuer to clarify unanswered points. Add new confirmed information to the current sketch, retaining the old version as history. Use the sample-report questions for laboratory records and the shared-supply guide for coordination; there is no need to recreate either inside the assessment pack.
FAQs
Is a risk assessment the same as a water sample?
No. The DWI describes risk assessment tools that look at the whole supply, while sampling analyses water taken at a point and time. The DWI single-dwelling page recommends a risk assessment so that sampling can be chosen on a risk basis.
Do I have to ask for a risk assessment on my own house supply?
For a supply to a single dwelling, the DWI buyer guidance says the regulations do not require one unless the owner or occupier asks, the local authority believes there is a risk to health, or another condition applies. Ask your local authority about your situation, and about fees.
Sources
Checked on 24 October 2026.