20 WATER SUPPLY – Food and Drink – Good Manufacturing Practice, 7th Edition



An adequate supply of potable water should be available in the manufacturing unit. Potable simply means ‘safe to drink’. Provision should be made for appropriate facilities for temperature control, storage and distribution of potable water. Dead legs should be eliminated in water systems, and if cooling towers and/or showering facilities are used, consideration should be given to monitoring for Legionella.


20.1 EU Regulation (EC) No. 852/2004 (as amended) on the hygiene of foodstuffs requires an adequate supply of potable water. Potable water must be used to ensure foodstuffs are not contaminated by the source of water used. Ice used in the manufacturing process must be made from potable water to ensure foodstuffs are not contaminated. Ice must be made, handled and stored under suitable conditions that protect it from all contamination. Steam used directly in contact with food must not contain any substance that presents a hazard to health or is likely to contaminate the product. EU Regulation (EC) No. 852/2004 (as amended) on the hygiene of foodstuffs states that water unfit for drinking that is used for the generation of steam, refrigeration, fire control and other similar purposes not relating to food must be conducted in separate systems, readily identifiable and have no connection with, nor any possibility of reflux into, the potable water system. A water distribution map should be available and appropriate controls should be in place (see 19.3). A cleaning schedule should also be in place for the water distribution system that has been validated, is monitored and is routinely verified. The water distribution map can be colour coded to aid differentiation of water systems.

20.2 Water supplies must be potable and be drawn from mains water or otherwise treated to meet potability standards. Routine microbiological sampling should be undertaken to ensure that the water meets these standards and appropriate action undertaken if results indicate potability standards have not been met. Potable water should be as a minimum standard as specified in the latest edition of the World Health Organisation (WHO) Guidelines for Drinking Water (currently 4th edition, 2011). Potable water used for manufacturing purposes, including that used in making up products or likely to come into direct contact with the product, must be of potable quality and free from:

  1. any substances in quantities likely to cause harm to health;
  2. any substance at levels capable of causing accelerated internal corrosion of metallic containers and closures causing taints; and
  3. harmful microorganisms.

The Water Supply (Water Quality) Regulations 2016 state that water should not contain any microorganism or parasite or any chemical (other than a parameter listed in Schedule 1) at a concentration or value which constitutes a potential danger to human health. To maintain these standards, the water should, if necessary, be chlorinated or otherwise adequately treated. If water is treated, there should be a procedure in place to ensure that the treatment of water is adequately controlled to prevent food contamination. Monitoring must be adequate to control any trends towards a critical limit, especially if chlorine control is deemed within the hazard analysis critical control point (HACCP) plan as a critical control point (CCP) as described in Chapter 3. It is important in this context to differentiate between determining critical limits for both free and total chlorine. All critical limits should be validated before the HACCP plan is implemented. Corrective action procedures must be in place if target levels or indeed critical limits are breached, including consideration of appropriate disposition of product. Public water providers can supply certificates of potability, and these should be retained by the manufacturer and reviewed for any trends that could impact on water suitability. It is important to ensure that the certificates supplied by public water providers are not generic across a wide water distribution network, but actually relate specifically to the local water distribution system from which the manufacturer receives water.

Although the water may be delivered to the manufacturing site at a potable standard, this does not mean that at the point of use it is still at the self‐same standard. Consideration should be given to the number of individual usage points and therefore the number of sampling points and frequency of sampling required to verify consistent standards. A risk assessment should be undertaken to determine the level of risk at the point of water use with regard to food safety and quality. The nature of the process is also important and whether the product comes into direct contact with water, or water is a product ingredient. A further consideration is if the product comes into direct contact with the equipment, conveyors and so on as this will increase the risk of contamination. Further factors to be reviewed include, but are not limited to, the original source of the water, procedures for storage of water on‐site, materials used in water storage tanks and transfer pipework and whether they predispose the system to the development of biofilms or contamination of the water, the water treatment process that is undertaken prior to use, especially if the treatment itself could cause a potential food safety hazard; and the management of waste water.

20.3 Water that is recycled for reuse should be treated so that it does not pose a potential contamination risk to the premises or product. The treatment process should be routinely monitored to determine its effectiveness. If there are both potable and recycled water systems in the manufacturing unit, they should be suitably identified to avoid confusion so that operatives are aware at all times whether water at an outlet point is potable/non‐potable. Water systems may be differentiated using colour coding on taps, coloured hoses or designated water site mapping as previously described (see 20.1).

Boil Water Advice

20.4 In the event of microbiological contamination of mains water supplies, water utilities in the area(s) concerned would, in most instances, issue advice to boil water before use. The management team, with advice from the quality control manager, would have to determine whether it was possible to continue manufacture of food products under such circumstances. Further details can be found in the following publications:

  • Institute of Food Science & Technology (IFST) Advisory Statement on Contamination of Water Supplies: Boil Water Advice, January 2004;
  • Water Quality for the Food Industry: Management and Microbiological Issues (2000), Guideline No. G27, Campden BRI, ISBN: 0905942310;
  • Guidelines on the reuse of potable water for food processing operations (2012), Guideline No. 70, ISBN 9780907503736;
  • The EU Council Directive 98/83/EC on the quality of drinking water for human consumption as amended by regulations 1882/2003/EC, 596/2009/EC and 2015/1787/EC; and
  • http://ec.europa.eu/environment/water/water‐drink/index_en.html.

Water Sampling Procedure

20.5 Water should be routinely sampled both at the point of entry to the site and at various points around the premises. This will give a good indication of the microbiological loading on entry to the site and whether the water system itself is increasing the bacterial loading of the water. If this is found to be the case, then remedial action will need to be taken to reduce the bacterial loading. The quality control manager should develop a water sampling protocol based on risk assessment. The risk assessment should consider the frequency of sampling required for both microbiological and chemical analysis of water to verify that it meets minimum potable standards. The risk assessment should also consider the proportion of the finished product that constitutes water added during the manufacturing process such as in the case of diluting fruit juice concentrate in order to pack single strength juice. The inclusion of water where water forms a constituent of the product, for instance carbonated drinks, or meat preparations where the meat contains added water, means that the frequency of water sampling as defined by risk assessment may well be much higher than when water is utilised only for cleaning and disinfection activities. Where the water source is from a borehole (well) or surface water, levels of nitrate, arsenic and pesticides need to be determined so that the source can be initially validated and then routinely verified. The use of recycled water needs to be considered in the risk assessment and appropriate frequency of sampling determined to ensure that water treatment has been adequate. Ice should also be sampled and tested, both ice manufactured on‐site and ice purchased and delivered to the site.

20.6 Samples may be analysed by an in‐house or third‐party laboratory. If a third‐party laboratory is used, it should be formally approved (see Chapters 23 and 38). Sterile minimum 500‐ml sample bottles should be used, and water should be run for a period of time before the sample is taken. Any contamination of the sample bottle and the lid during sampling should be avoided. Ideally samples should be under adequate temperature control during storage and transit and be with the laboratory within 4–8 hours of being taken. The samples should be kept at a temperature of between 2 and 10 °C while in transit and storage, and ideally in the dark. This may require the use of a hygienic cool box and/or ice packs.

20.7 If the water is chlorinated, sodium thiosulphate needs to be added to the sample bottle to neutralise any residual free chlorine, so it is important to agree with the laboratory the type of sample bottles required.

20.8 When the results are received from the laboratory, they should be reviewed to check for compliance with the specification. If the results are out of specification, this must be referred to the quality control manager and appropriate corrective action taken. This could include a review of product status, the potential for product contamination and the need for a product recall.