Private Water Supply for Restaurants and Cafés: Regulation 9, Food Use and Records

1. Why restaurants and cafés fall under Regulation 9

The Drinking Water Inspectorate (DWI) lists restaurants and cafés as examples of commercial activity under Regulation 9 of the Private Water Supplies (England) Regulations 2016, as amended. That matters because a private supply used as part of a commercial or public activity is regulated under Regulation 9 irrespective of the volume consumed.

This is different from the separate Regulation 9 volume test for water used for domestic purposes, where supplies averaging 10 m³/day or more are also Regulation 9 supplies. A small rural café using far less than that can still be Regulation 9 because the water is being used commercially.

2. Where private water is used in a food business

Do not reduce the water-supply map to the obvious drinking tap. DWI guidance on the scope of the Regulations identifies food-production uses that can include water incorporated into food or drink, production of ice, handwashing by food handlers and cleaning food-contact surfaces, equipment and utensils.

For a restaurant or café, a useful source-to-tap map should therefore identify at least:

• drinking-water taps available to staff or customers;
• coffee machines, tea boilers, post-mix drinks equipment and other beverage appliances;
• ice machines;
• water used to wash or prepare food;
• handwashing points used by food handlers;
• dishwashers, glasswashers and sinks used for food-contact equipment;
• storage tanks, pumps, filters, softeners, UV units or other treatment between source and outlet;
• any branches that bypass part of the treatment train.

The purpose is not to turn the guide into a food-hygiene manual. It is to make sure the water system is understood well enough that the effect of a treatment failure, poor sample or maintenance change can be traced to the outlets and processes it may affect.

3. Regulation 6 risk assessment

Regulation 6 places the statutory risk-assessment duty on the local authority. DWI states that qualifying private water supplies must be risk assessed at least every five years, and earlier where the authority considers the existing assessment inadequate or circumstances have changed significantly.

The assessment is intended to consider the whole supply from source to tap: catchment and source hazards, collection chambers, tanks, treatment, pipework, control measures and the points where people consume or use the water. For a restaurant or café, the business can make that assessment more useful by having an accurate schematic, treatment information, maintenance history, previous sample results and details of significant changes ready for the assessor.

4. Group A, Group B and risk-based monitoring

Regulation 9 supplies require Group A and Group B monitoring. DWI explains that the monitoring frequency is based on the volume of water consumed for domestic purposes, with additional parameters where the risk assessment shows they are necessary.

Group A monitoring includes parameters used to give regular information about microbiological quality, appearance, taste and odour, and treatment effectiveness. DWI identifies nine parameters that are Group A in all Regulation 9 supplies in England, including E. coli, coliform bacteria, turbidity, pH, conductivity, colour, odour, taste and colony counts at 22°C. Other parameters can enter Group A monitoring in specified circumstances. Group B covers the remaining relevant Schedule 1 standards that are not already being monitored as Group A.

The restaurant should not invent its own statutory sampling frequency. Confirm the monitoring programme with the local authority and keep the authority's schedule, laboratory reports and follow-up correspondence together. Private sampling can be useful for operational checks, but it does not automatically replace statutory monitoring.

5. Choosing representative sample points

Under Regulation 12 and DWI guidance, regulatory samples should be taken from a point where water is consumed and must be representative of the water supplied. In many premises that is a kitchen tap, but DWI specifically notes that the suitable point can differ where water is being used to manufacture a food product.

If there are multiple buildings, storage tanks or treatment arrangements, tell the local authority. The supply should be understood as a system rather than treating each tap as a separate private supply. DWI also advises that where commercial or public activity exists on one or more buildings on the supply, the whole supply is monitored in accordance with Regulation 9.

6. Treatment and distribution controls

A passing sample does not remove the need to manage treatment. DWI's Regulation 6 guidance is deliberately risk based: monitoring is a snapshot, whereas the condition of the source, treatment and distribution system changes over time.

Useful operational controls depend on the supply, but may include:

• protecting the source and catchment from contamination;
• checking storage tanks, covers, vents, overflows and cleanliness;
• maintaining pre-filters so turbidity or fouling does not undermine downstream treatment;
• maintaining UV or other disinfection in accordance with the manufacturer's requirements;
• recording alarms, power interruptions and bypass events;
• avoiding undocumented plumbing alterations, dead legs or cross-connections;
• keeping treatment consumables and critical spares appropriate to the site.

The treatment design should be based on the hazards and raw-water quality actually present. Do not assume that adding a UV unit, filter or softener automatically makes an unsuitable supply compliant.

7. Records worth keeping

There is value in keeping one coherent operational file rather than separate scraps of laboratory, maintenance and food-business paperwork. For a restaurant or café, useful records include:

• the current source-to-tap schematic and details of which outlets or processes each treatment stage protects;
• local-authority risk assessments and correspondence;
• the current statutory monitoring programme and all laboratory reports;
• treatment specifications, commissioning information and manufacturer instructions;
• filter changes, UV lamp or sleeve work, tank cleaning, servicing and repairs;
• alarms, power failures, bypasses, low-flow or low-pressure incidents and source interruptions;
• investigations and corrective actions following poor results;
• temporary restrictions, alternative-water arrangements and customer or staff communication where relevant;
• significant changes to the source, treatment, distribution, occupancy or business use.

These records do not themselves prove compliance. They make it much easier to demonstrate what happened, identify trends and show what control measures were in place when the local authority or food-safety team needs evidence.

8. Failed or concerning results

A failed parameter does not have one universal response. The significance depends on the parameter, result, likely cause, vulnerable consumers and wider evidence. Preserve the original laboratory report and contact the local authority rather than trying to interpret a potentially serious result in isolation.

If the local authority suspects that the supply is unwholesome it must investigate. Where the supply is a potential danger to human health, Regulation 18 requires the authority to serve a notice on the relevant person or persons. Depending on the risk, a notice can restrict or prohibit use and require corrective action. DWI gives examples such as boiling water for some microbiological risks or not using the water for drinking, food preparation and cooking for some serious chemical risks.

9. Alternative water and business continuity

Restaurants are unusually exposed to water interruptions because water supports drinking, food preparation, cleaning and hygiene at the same time. A short written continuity plan can prevent improvised decisions under pressure.

Record who contacts the local authority, who can isolate affected branches, how treatment can be checked, what approved alternative wholesome water can be obtained, which processes must stop if the private supply cannot be used, and how recommissioning will be documented. DWI guidance recognises that alternative supplies from bottles, containers or tankers may be necessary during quality failures or insufficiency; those arrangements also need to meet applicable requirements.

10. Restaurants on a shared private supply

A café or restaurant may share a source and treatment system with houses, holiday accommodation, farm buildings or another business. DWI's sampling guidance is important here: where a supply is used as part of a commercial or public activity on one or more buildings, the entire supply must be monitored as Regulation 9, not just the restaurant building.

That makes shared responsibilities worth documenting. Record who controls the source, treatment, electricity, maintenance, access, sampling coordination, emergency communications and cost sharing. The local authority decides how regulatory duties apply; private agreements can help management, but they do not override the Regulations.

11. Changes that should trigger a review

Do not wait for the next routine sample if the supply has materially changed. Tell the local authority about significant changes and review your own operating records after events such as:

• opening a new café or restaurant or changing domestic premises to commercial food use;
• increasing seating, opening hours or seasonal demand significantly;
• installing or replacing treatment;
• adding a storage tank, new building, kitchen, ice machine or beverage system;
• altering the source, abstraction arrangement or distribution pipework;
• repeated treatment alarms, power problems, flooding or source-quality deterioration;
• a failed sample, suspected illness cluster or other incident indicating the existing controls may be inadequate.

DWI's Regulation 6 guidance states that risk assessments should be reviewed when circumstances have changed significantly or the existing assessment is considered inadequate.

12. Practical restaurant/café checklist

13. Frequently asked questions