Private water supplies

Any private water supply may present a risk to health if the water is not properly protected and treated. The supply may become contaminated with harmful micro-organisms, chemicals or metals. Many are harmless but some may cause illness or even fatalities in vulnerable people. Sometimes the effects of consuming contaminated water do not present themselves straight away but can cause delayed or longer term health problems.

It is often not possible to tell if a private water supply is safe because contamination may not be detected by the smell, taste, odour or appearance of the water. The Drinking Water Inspectorate are the advisory body for implementing regulations to help us and private water suppliers comply with the law.

The Private Water Supplies Regulations 2009 classify private water supplies into three categories:

  • Large supplies - where the supply is >10m3/day; or supplies to a commercial activity or public premises
  • Other supplies - in any other case other than for a single private dwelling
  • Single private dwelling - where a supply is for a single private dwelling.

The classification of a supply primarily depends upon the number and type of premises served and the volume of water used. The regulations require local authorities to risk assess and monitor private water private distribution systems. A private distribution system is found where water is supplied by a water undertaker or licensed supplier and is then further distributed by a third party.

When monitoring, we need to be satisfied that the abstracted or distributed water meets the prescribed criteria for wholesomeness. If a sample indicates the supply is not wholesome or presents a potential danger to human health , we must carry out an investigation to determine the cause and have a range of enforcement options available to ensure a safe and wholesome supply is restored.


The regulations are designed to be cost neutral, i.e. to be delivered at no cost to us as a council. For this purpose the regulations state the maximum fees that can be charged for the various aspects of private water supply work. 

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