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What is a private water supply?

In general terms, a 'private water supply' (PWS), is any water supply which is not provided by a Water Company. If no water rates are being paid, it’s not classed as a mains supply, however, the person who owns the supply may make a charge. There’s no laws controlling the charges or other conditions connected with private supplies. The owner and/or person who use the supply is responsible for repairing and maintaining it.

A PWS could serve just one property or it could be a large supply with a network of pipes supplying water to many properties. The water may come from a spring, well, borehole, pond, river, stream or rainwater harvesting.

Private supplies are commonly used in the rural parts of Mid Devon. In total, over 1,200 supplies are currently utilised, of which over 800 are single domestic users.

How are PWS’s regulated?

Good quality water is very important to everyday life. Every house must have a good supply of clean, fresh water for it to be fit for occupation.

To ensure that water used in the home or for commercial purposes is of the quality required to protect public health, the government has set legal quality standards which must be met. Private supplies are more likely to be contaminated generally due to the sources being unprotected and not treated to the same standard as public supplies.

Local authorities act as the regulators for PWS’s and have a number of statutory duties under PWS legislation. The Water Industry Act 1991 defines the powers and responsibilities afforded to us as the regulator for PWS’s across our district. Section 77 includes a requirement to check the ‘wholesomeness and sufficiency’ of every PWS within Mid Devon.  Where a supply is deemed to be unwholesome and/or insufficient, we’ll inform users about the potential harm to their health and provide appropriate advice to minimise the danger. A Section 80 notice will also be served on the owner(s) of the PWS.

Under the Private Water Supplies (England) Regulations 2016, as amended, we’re required to ensure that any private supply of water intended for human consumption does not constitute a potential danger to human health. In line with our statutory duties, we achieve this by conducting:

Why do I need to register my PWS?

If you own a PWS, you must register it with us! Failure to do so may result in a Section 85 Notice, with which failure to comply is an offence.

Please download, complete and return via email to

Private water supply registration form(PDF)
Private water supply registration form(DOCX)
Private water supply registration form(ODT)

These files may not be suitable for users of assistive technology.

If you use assistive technology (such as a screen reader) and need a version of this document in a more accessible format or to request the form in the post, please email or contact us on 01884 255255.

Please see guidance for Campsites with Private Water Supplies here.

We also have Supply Reinstatement advice here.

Regulation FAQs:

We’re required to undertake risk assessments of all PWS’s every five years, except for supplies to single non-commercial domestic dwellings. The purpose is to establish whether there is a significant risk of supplying water that could constitute a potential danger to human health and to establish whether there’s a risk of non-compliance with any of the standards or indicator parameter values.

Risk assessments involve looking at the whole PWS including the source, storage tanks, treatment systems and the premises using the supply.

We’re required to carry out an investigation where:

  • standards have not been met during a risk assessment or routine sampling;
  • an operational incident has occurred, or;
  • we’ve received a complaint about a supply.

An investigation must determine whether the cause of a failure has occurred within the private water supplier’s system (raw water, treatment or distribution), or whether it occurred within the pipe work (domestic plumbing and fittings) within the premises it supplies.

Once the cause of the failure has been established, action will be taken to restore the water quality so that it can become wholesome. If we cannot secure action by informal negotiation and an authorisation has not been granted, a Section 80 notice will be served.

In exceptional circumstances, an authorisation may be issued to supply water at a lower standard on a temporary basis, while remedial action is taken as part of an agreed and timed programme of work. We’ll issue authorisations, assessed and evidenced on a case-by-case basis and only after consultation with the Drinking Water Inspectorate (DWI).

The type and frequency of water sampling is determined by the following category and size of the supply:

Regulation Description Volume, sampling type and frequency Risk assessment requirements
Regulation 8 Where a public (mains) supply has onward distribution to consumers. As outlined below Every 5 years
Regulation 9 Large supplies (>10m3/day) and those used as part of a commercial or public activity (including supplies to tenanted single dwellings)     ≤10m3 - Group A & Group B once annually >10m3 ≤100m3 - Group A twice annually >10m3 ≤3300m3 -Group B twice annually Every 5 years
Regulation 10 Small supplies, including small shared supplies Every 5 years Every 5 years

There are five categories of supply:

  1. Commercial Supply - supplies water to a premises where the water is used for a commercial activity
  2. Large Supplies - an average daily volume of water of 10m3 or more
  3. Private Distribution System - the water is supplied by a water undertaker or licensed water supplier and then further distributed by a person other than the water undertaker or licensed water supplier
  4. Small Supply - the water is supplied to more than one domestic dwelling
  5. Single Domestic Supply - a domestic dwelling


Group A sampling involves looking at a suite of basic parameters. Group B sampling covers a much larger suite of parameters. The frequency of these sampling suites depends upon the volume of water used from the supply as outlined above.

Local authorities are permitted to charge for carrying out risk assessments, sampling and enforcement work.
Our fees and charges reflect current service delivery costs. 

For more information about PWS's and the regulation thereof, read the DWI's Private Water Supply Regulations leaflet, or visit the following related websites:

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