Critical Control Points

CCP: Water Quality Monitoring in Food Businesses

Water Quality as a Critical Control Point

Water is used in virtually every food process: as an ingredient, for cleaning, for handwashing, and in steam generation. In the UK, mains water supplied by a regulated water company meets the standards of the Water Supply (Water Quality) Regulations 2016 and is generally considered safe without further treatment by the food business. However, water quality becomes a CCP when a business uses a private water supply (borehole, well, spring), when water is stored in tanks before use, when processes add contaminants to water that is then reused, or when ice is produced on-site.

Key takeaways

Mains water is generally safe and managed as a prerequisite; private supplies need CCP-level controls

Private water supplies must be tested at least annually for E. coli, coliforms, and other parameters

Ice machines are food contact equipment and need regular cleaning, sanitising, and periodic testing

Legionella control is a legal requirement for all businesses - store hot water above 60C

Mains Water vs Private Supplies

If your food business uses mains water from a regulated supplier (e.g. Thames Water, Severn Trent, Scottish Water), the water quality is monitored and treated by the supplier to meet legal standards. In this case, water quality is typically a prerequisite programme rather than a CCP. Your responsibility is limited to maintaining the internal plumbing, preventing backflow contamination, and ensuring storage tanks (if used) are clean and covered. If your business uses a private water supply - common in rural hospitality, farms, and some food manufacturing sites - you have a legal duty under the Private Water Supplies (England) Regulations 2016 to ensure the water is safe. This includes risk assessment, regular testing (at least annually for microbiological parameters, with more frequent testing for larger supplies), and treatment where necessary (UV, chlorination, or filtration). Private water supplies that are used as a food ingredient or for food contact surfaces should be treated as a CCP.

Water Quality Parameters and Testing

Key parameters for food safety testing include: E. coli (must be 0 per 100ml), total coliforms (must be 0 per 100ml for private supplies), Enterococci (must be 0 per 100ml), turbidity (below 4 NTU), pH (6.5-9.5), and free chlorine residual (if chlorinated, typically 0.2-0.5 mg/L at point of use). For private supplies, the local authority conducts annual testing, but the business is responsible for any additional monitoring defined in the risk assessment. For mains supplies with on-site storage tanks, consider six-monthly testing for coliforms and Legionella. If your business produces ice, test the ice as well as the water supply: ice machines can harbour bacteria in poorly maintained components. Use an accredited laboratory (UKAS accredited) for testing, and keep results on file for at least 5 years.

Ice Machines and Water Dispensers

Ice produced on-site is a food product and subject to the same hygiene standards as any other food. Ice machines are frequently overlooked in HACCP plans but are a known source of contamination. Common issues include biofilm build-up inside the machine, mould growth in the ice chute, handling ice with bare hands or dirty scoops, and infrequent cleaning cycles. Clean and sanitise ice machines according to the manufacturer schedule (typically every 2-4 weeks for a thorough clean, with daily emptying and wiping of the dispenser area). Use a dedicated ice scoop stored outside the machine, never use glasses to scoop ice (glass chip risk), and never store anything in the ice bin. If you serve ice to customers, it should be part of your HACCP plan as either a CCP or a prerequisite, with defined cleaning schedules and periodic microbiological testing.

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Legionella and Hot Water Systems

While Legionella is primarily an occupational health risk rather than a food safety CCP, it is relevant to food businesses because it can contaminate water used for cleaning and handwashing. Legionella pneumophila thrives between 20C and 45C in stagnant water. UK regulations require food businesses (as employers and building managers) to conduct a Legionella risk assessment and implement controls: store hot water at 60C or above, distribute hot water so it reaches 50C at outlets within 1 minute, flush infrequently used outlets weekly, and maintain cold water below 20C. For food businesses, ensure hot water at handwash stations is adequate (above 50C) and that any water storage tanks are covered, insulated, and inspected annually. While Legionella control is not typically a food CCP, auditors and EHOs expect to see evidence of a Legionella risk assessment and control measures.

What to do next

Identify your water source

Confirm whether you use mains or private supply. If private, ensure you have a current risk assessment and testing schedule registered with the local authority.

Schedule ice machine deep cleans

Set a 2-4 week cleaning cycle for ice machines following the manufacturer instructions. Include microbiological testing of ice quarterly.

Conduct a Legionella risk assessment

If you have not already, arrange a Legionella risk assessment for your premises. Implement the recommended controls and review annually.

Common mistakes to avoid

Mistake

Assuming mains water never needs checking

Instead

While mains quality is managed by the supplier, internal plumbing, storage tanks, and ice machines are your responsibility. Check these regularly.

Mistake

Scooping ice with glasses

Instead

This creates a glass contamination risk. Use a dedicated scoop with a handle that stays outside the ice bin.

Frequently asked questions

Do I need to test mains water?

If you use water directly from the mains without storage tanks, testing is generally not required - your water company manages this. If you have on-site storage tanks, consider periodic testing (six-monthly) for microbiological indicators.

How often should private water supplies be tested?

At least annually for microbiological parameters (E. coli, coliforms, Enterococci). The local authority will advise on frequency based on your supply risk assessment. Larger or higher-risk supplies may need quarterly testing.

Is ice a food product?

Yes. Ice intended for consumption or for contact with food is a food product under UK food law. It must be made from potable water, stored hygienically, and handled with the same care as any other ready-to-eat food.

Critical Control Points