Buying a house with a Private Water Supply

We strongly recommend that prospective buyers of properties/homes with there own private water supplies read this document. The primary source of this advice is the drinking water inspectorate website.

Key questions

The questions listed at the end of this document are designed to be asked of the owner of the property (through a solicitor or estate agent), or the local authority who regulate private water supplies. Environmental Health Officers are required to establish water quality, the health risks and the future cost liability.

What is a PWS A private water supply?

A PWS is one which is not provided by a water company. About 1% of the population in England and Wales do not have a public supply of mains water to their home and instead rely on a private water supply. Mostly, but not exclusively, these occur in the more remote, rural parts of the country. A private supply source can be a well, borehole, spring, stream, river or lake and it can also involve storage structures or tanks. Some supplies may serve just a single property or they can be much larger serving many properties and businesses through a network of pipes. Under rare circumstances you may be supplied with mains water by your water company but not receive a bill. In these circumstances you may be receiving a supply through a Private Distribution System.

Single dwelling with its own supply

The regulations do not require a risk assessment If the supply is to a single dwelling and is used only for domestic purposes? The owner can request a risk assessment. In an ideal situation the owner of the supply would have had a risk assessment and monitoring carried out prior to purchasing a property. The risk assessment helps determine the wholesomeness and sufficiency of a supply.

Shared supply

If the supply is shared by two or more properties, then the local authority are required to risk assess the supply and monitor it by sampling at an appropriate frequency.

Risk Assessments

Risk assessments investigate and report on the source of the supply, the surrounding area, water storage tank and treatment, right through to the taps. The aim is to identify any actual or potential contamination. Prospective buyers may also wish to check whether there is any agreement among other property owners as to how these costs are shared or covered. Is remedial action required and how are the costs shared and who is responsible for managing the costs?

Key questions to ask before buying a house with its own private water supply

Has a risk assessment already been carried out by the Local Authority, and if so when?
Did the local authority advise that improvement works were required?
What were the results of any previous sampling by the Local Authority?
Did any results indicate a water quality problem? c) Individual premises
Are there filters or UV disinfection units installed in the property?
Was the equipment installed by a competent installation and Is the treatment appropriate?
Is the system compliant with Regulation 5 of the PWS regulations?
Is the UV system WRAS approved for use on a drinking water supplies?
Has the current owner got any maintenance logs or records for the supply?
Are there any compliant spare parts for the supply, including any treatment system?
Have there been any problems with the supply such as taste and odour, discolouration or insufficiency.
Are there any documented instructions detailing the procedures should any problems with the supply arise, e.g. sufficiency or water quality such as taste or odour issues. These should contain telephone numbers or other contact details to arrange for alternative supplies, pipe repairs, treatment system maintenance etc.
Is there a schematic of the supply showing the layout of pipes, tanks, inspection chambers etc. available?
Are there schematics or plans for various parts of the treatment system, stating what each part is, for example any filters, iron or manganese removal systems, and disinfection?

Water testing and report

Springhill Water have been treating private water supplies for nearly 20 years. Contact us on 01422 833121 to arrange a site visit or if you have any questions or would like advice.

Questions to ask before buying a house with its own private water supply