Guidance documents

Information note on Regulation 3 (Wales)

Regulation 3 of the Private Water Supplies (Wales) Regulations 2017 (hereafter referred to as the Regulations) specifies the criteria which determine how the Regulations apply to private water supplies.

A private supply is defined as ‘a supply of water provided otherwise than a water undertaker’1. The Regulations specify four private supply categories, 8, 9 10 and 11. We have produced an individual note for each which you can find on our website.

However in summary:

  • Regulation 8 supplies are derived from public ‘mains’ supplies (undertakers or licensed suppliers) which are further distributed by water company customers to third parties in premises in separate ownership;
  • Regulation 9 supplies are large supplies (>10m3/day) and supplies to premises that are used as part of a commercial or public activity, irrespective of the volume consumed. This includes, in some cases, supplies to any tenanted properties.
  • Regulation 10 supplies are those to single dwellings only, using less than10m3/day.
  • Regulation 11 supplies comprise all other private water supplies including small (<10m3/day) shared supplies and supplies where the water is used as part of a domestic tenancy (including single dwellings where the water is used in this capacity).

The Regulations apply to private water supplies ONLY where the water is intended for human consumption. Regulation 3 describes human consumption as:

Water either in its original state or after treatment, intended for drinking, cooking, food preparation or other domestic purposes*, regardless of its origin and whether it is supplied from a distribution network, from a tanker, or in bottles or containers.

*The term ‘domestic purposes’ is defined in section 218 of the Water Industry Act 1991, as drinking, washing, cooking, central heating and sanitary purposes. ‘Sanitary purposes’ includes washing/bathing/showering, laundry and toilet flushing2. Please note that a private water supply that is used exclusively for the purposes of the business of a laundry does not fall within scope of the Regulations. This is because laundry does not constitute a domestic purpose under these circumstances, in accordance with section 218(3) of The Water Industry Act 1991.

All water used in food-production, manufacture, processing, preservation or marketing of products or substances intended for human consumption must not affect the wholesomeness of the foodstuff in its finished form. NB the Food Standards Agency (FSA) is the competent authority in such cases.

If water is used for anything other than primary food production then it must satisfy the Regulations. Examples of where the Regulations apply are given below (this list is illustrative and is not exhaustive):

  • The washing and bagging of crops/foodstuffs (particularly the washing of ready to eat items such as salad crops).
  • Fruit and vegetables that may be eaten raw.
  • Washing of fruit and vegetables intended for peeling and slicing.
  • Incorporation into food as an ingredient (including drinks or water used in a brewery – see below.
  • Cleaning of food production equipment, utensils, walls, floor, ceilings and work surfaces.
  • Production of ice.
  • Hand washing of food handlers.
  • Cleaning purposes (food contact surfaces, equipment, storage containers, utensils, hands).
  • Egg washing3 if the water is deemed by the Food Standards Agency to affect the final product.

Local authorities should consult with the Food Standards Agency if further advice is needed on the quality of water used for any food production.

Mixed supplies

When a public and private supply are mixed before use.

The local authority and water company should work together to determine the root cause and facilitate the appropriate corrective actions, under the respective sets of regulations. The local authority can use its powers to compel relevant person(s) to

take remedial action, and the water company may also be responsible for delivering some corrective actions, if the control point is located before the public supply is

mixed with the private supply. Water Fitting Regulations contraventions will fall to the relevant person(s) for resolution but would be enforced by the water company.

Milking parlours

The Food Standards Agency has powers and responsibilities for milking parlours and dairy farms under existing food law. Private supplies that that are used solely for washing down purposes are not within the scope of the private water supplies Regulations. Milking parlour premises are, however, subject to the regulations where a supply is also used for domestic purposes at the site. In these cases, regulation 8, 9 or 10 must be applied, as appropriate (see above).


Where water from private water supplies is used in the manufacturing of products that employ a distillation process (for example, whisky, gin and other spirits), the Regulations apply only where the water is added after the distillation part of the process.

Malting and brewing

The process of making ‘malt’ requires that water is absorbed by barley making it a constituent part of the final product for example, beer and vinegar. Therefore, water derived from private water supplies to make malt by these processes, falls within the scope of regulation 3 (1) (b).

Rainwater harvesting and grey water systems

All supplies that are derived from rainwater and recycled (grey) water fall within the scope of the Regulations, where the water is supplied for domestic purposes, food production and where it is intended for human consumption.

Water fountains and other publicly accessible supplies

Where private supply is offered for human consumption to the general public/tourists as part of a heritage attraction (for example ancient springs and grottos), regulation 9 applies. Where it is not intended for human consumption, warning signage must be clearly displayed to deter this by the responsible person.

Spas and Pools

If the water at these types of facilities is also provided for domestic purposes or used in human food products, the regulations will apply. Sampling locations for monitoring purposes should be at a suitable point where the water is drawn for human consumption.

Private water supplies used exclusively for leisure activities, for example, swimming pools, spas, and water parks are not within scope of the Regulations. Similarly, those used for religious/healing purposes are not subject to the regulations.

Alternative supplies

In an emergency, it may be necessary to temporarily supply water from tankers or in bottles or cartons for example, when there is a quality failure that poses a potential danger to human health.

The water in the tankers must also meet the requirements of the Regulations. If water in bottles or containers is supplied instead of a private supply (due to insufficiency) the regulations apply.

Temporary events

Where temporary events (festivals, local fairs etc.) are supplied by sources such as boreholes and/or springs for domestic purposes, the Private Water Supply Regulations apply. Water that is consumed for domestic purposes at a temporary event that is derived from a public water supply – either directly through pipes or via tankers is not within the scope of the Regulations unless it is a regulation 8 supply.

Supplies to tenanted premises

Private water supplies to all premises, which are rented as part of a domestic tenancy agreement, where the water supplied is intended for human consumption or just for sanitary purposes (for example toilet flushing), are within scope of the Regulations. These supplies must be monitored in accordance with regulations 7 and 11. Further information regarding the risk assessment of these supplies can be found in the Information note for regulation 6. Regulation 11 supplies include bed and breakfasts.

Exemptions (Regulation 3)

The following waters are exempt from the Regulations:

a) water controlled by the Natural Mineral Water, Spring Water and Bottled Drinking Water (Wales) Regulations 2007 or
b) water that is a medicinal product4; or
c) water used solely for washing a crop after it has been harvested where it does not affect the fitness for human consumption of the crop or of any food or drink derived from the crop.

1 In Section 93 of the Water Industry Act 1991 (including a supply provided for the purposes of the bottling of water).
2 The Inspectorate has made available on its website a risk assessment tool for supplies that are used exclusively for the purposes of toilet flushing.
3 Class A (highest grade) eggs are not permitted to be washed and therefore this regulation is not applicable. However, the Regulations may apply where the water is used to wash class B and C eggs and would depend on where the eggs are washed. If carried out at the farm/place of production, then egg washing is not within scope of the regulations, as washing would not substantially alter the nature of the egg. However, washing carried out at the processing plant (for B and C eggs) would not be a primary production process, and the water would have to be wholesome and therefore would be within scope of the Regulations.
4 Water that is a medicinal product is water that is regulated by the Medicines Act 1968 SI 1968,c. 67.

PWS Regulations 2017 v4, February 2021