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Private water supply assessment

The private water supply assessment should demonstrate that the intended private water supply is feasible, adequate and does not compromise the adequacy of other private water supplies in the area.

When required

A private water supply assessment is required for any proposal where property(s) will be served by a private water supply or private distribution system.

Guidance

For all development to be served by a private water supply please complete the non-mains drainage and water supply assessment form(PDF/605KB/6 pages).

Private drinking water supplies are water supplies which are not provided by the statutory water undertaker, but are the responsibility of their owners and users.

The quality of private water supplies can be variable. Some have adequate treatment and are well managed, but others undoubtedly present a risk to health due to the quality of the water. If you own or use a private supply it is important that you are aware of the quality of the supply and the risks associated with it.

A private water supply assessment should include:

Source layout

A constant, reliable water source in a suitable location should be identified on a metric scaled plan. Many private water supplies can have problems regarding adequacy and quality in periods of prolonged dry weather.

Proposed layout plan

A detailed metric scaled layout plan of the intended water supply, including the water source, tanks, pipework and treatment plant is required.

Details of any foul drainage or sewers, septic tanks or cesspools should be provided and the sizes of all tanks and pipes should be included.

Risk assessment

A full risk assessment for the proposed supply must be provided.

Responsibility for regulating private water supplies rests with local authorities, but there is much that owners and users can do to protect themselves.

  • ensuring the source is protected from contamination by grazing animals or material washing down from upstream
  • installing and maintaining appropriate treatment that is capable of treating water to a consistently satisfactory quality
  • ensuring the water is adequately disinfected prior to use
  • making sure that water is stored and distributed in a way that avoids it becoming contaminated after treatment and disinfection but before it is consumed 

If you own or use a private water supply, and are looking for advice, you should go to our environmental protection team. They can also arrange testing of your supply.