Private water supply

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What is a Private Water Supply (PWS)?

Private Water Supplies include any supply of water used for human consumption that is not provided by a statutory water undertaker (e.g. South East Water or Southern Water).

Private water sources may include such things as springs, boreholes, rivers, wells or lakes. Water for human consumption includes normal domestic processes such as drinking, cooking, food preparation and personal washing (such as hand washing and showering). This usage applies to domestic, public and commercial properties alike.

The Private Water Supplies Regulations, 2009

Under the above regulations Tonbridge and Malling Borough Council has a duty to:

  • Record the location of all PWS in the borough.
  • Monitor PWS that serve more than one domestic property, commercial and public properties to ensure that they are of sufficient quality to protect the health of consumers.

Sampling is based upon the nature and size of the PWS; this will determine what parameters are sampled as well as the frequency of sampling. PWS are split into small and large/ commercial supplies as shown on the table below:

Large commercial Supplies (Reg 9) Small Supplies (Reg 10)
Volume of water provided > 10m3/day < 10m3/day
Numbers supplied  Or supplies more than 50 people Or supplies less than 50
Other Water used for a commercial activity irrespective of the volume of water provided or the number of persons supplied. Any private water supply that supplies water to Public Buildings irrespective of the volume of water provided or the number of persons supplied. Supplies two or more dwellings.

Private water supplies to a non-commercial single dwelling are not required to be monitored under the Regulations, however the Council must monitor the supply if they deem there to be a potential risk to human health or if asked to by the owner/ occupier.

The 2009 PWS Regulations includes a requirement for local authorities to complete a Risk Assessment in addition to sampling alone. This was to ensure that PWS are reviewed from source to the tap and not solely based on sampling alone, which only provides a brief snap shot of water quality. The risk assessment endorses a multi-barrier approach to prevent contamination from entering a supply in the first instance as well as removal of contamination through treatment

The 2009 regulations also brought in what is termed a Private Distribution System (PDS). A PDS exists where water is supplied by a water undertaker or licensed water supplier and is then further distributed by a person other than a water undertaker or licensed water supplier.

Under the regulations, Local Authorities are allowed to make charges for certain services up to a maximum. These include for example a charge for carrying out risk assessments of PWS and PDS.

Further Information

Contact us if you require Information on Private Water Supplies. We can advise residents and businesses with PWS or those intending to use /install a PWS, concerning aspects of source protection, sampling of water quality, how best to plan any treatment that may be needed to ensure the safety of the drinking water and any other PWS enquiries.

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