United Kingdom Water Treatment Association

Private Water Supplies

What is a Private Water Supply?

A private water supply is a drinking water source which is NOT provided by a licensed water supply company or utility. It is typically from a local well, borehole, spring, lake, river or stream. The water quality is the responsibility of the owner(s) of the property from where the water source is drawn and/or used.

The vast majority of the UK population is supplied with water from a Water Utility, but about 1% of the population is supplied from a private supply.

There are about 140,000 private supplies in the UK. Water from a single private water supply may be used for one or more residences or premises, including businesses, holiday homes, caravan parks or hotels.

Why use a Private Supply?

There are a number of reasons why a private supply might be preferable. For example, premises may be a long way from the nearest public water supply and the cost of installing a mains water pipe is too expensive.

A private supply puts you in charge of your water and you will have control over what chemicals are added to it (or not), (such as fluoridation), and you will not need to comply with any imposed drought restrictions. Costs for your water will not be payable to a third person.

What’s important about a Private Supply?

Water that is supplied by a Water Utility is very tightly monitored and controlled in order to ensure that it is safe for drinking. Water from natural sources may contain pathogens (disease causing micro-organisms), or unwanted chemicals, and these have to be removed completely to prevent illness. Government regulations stipulate the quality and monitoring regime that the supply company must comply with.

Water from a private water supply source may also be corrected contaminated with pathogens and so should be tested, monitored and treated to ensure that it is suitable for drinking. Aesthetic characteristics (colour, taste and odour) should also be corrected so that its quality is not a deterrent for drinking or washing purposes.

Because they do not have the benefit of continuous monitoring and professional surveillance, private supplies are much more vulnerable than those from a Water Utility.

Statistics show that instance of disease caused by a private water supply is increased 5 fold, so proper treatment and monitoring of the supply is essential.

You have a ’License of Right’ to have a borehole drilled, or use any other water source, which is on your own property, so long as it is for your own use and it does not exceed 10 m3/day. Above that, permission is required from the Environment Agency through your Local Authority. However, all private water supplies used for drinking, bathing or food preparation must be registered with the Local Authority. Revised regulations governing the control of private water supplies were introduced at the beginning of 2010, which detail the powers and responsibilities of the Local Authority in monitoring and authorising these supplies. The legal responsibilities are considerably more onerous where the private supply is serving more than one residence or is used in premises with public access.

Why is treatment and monitoring necessary?

Water quality should be checked regularly to determine the presence of potentially harmful contaminants, and appropriate treatment should be applied. All treatment systems, should be inspected and maintained so as to ensure that they are functioning continuously and correctly.

Also, as the quality of the water may vary seasonally due to climate, any variation, for example in quality, should be taken into account in deciding on the type of treatment necessary.

Which type of treatment should be used?

Identification of the best type of treatment will require expert advice as there is a range of options and a treatment system must be selected to accommodate the specific requirements of each application.

The quality and reliability of a water supply will depend entirely on its source. Surface water such as a river or lake is likely to be reliable in terms of quantity of supply, but may vary widely in quality, whereas a spring or well may be more consistent in quality but availability may vary seasonally.

The water source should be analysed to determine which contaminants may require treatment. Appropriate equipment can then be selected according to the quality issues and the size (daily volume of the anticipated water usage) of the supply required.

As a minimum requirement any small supply not shown by risk assessment and frequent surveillance to be consistently pathogen-free, should be protected by some form of disinfection that will be effective at all times during the year, especially following heavy rainfall or snowmelt.

Disinfection with chlorine is the most widely used method for treating large public water supplies, but its application is less common for small private water supplies.

There are other alternatives such as ozonation and ceramic filtration, and the method used will depend on the type(s) of micro-organisms present or likely to be present, and the extent of the contamination. Multiple barrier approaches may be necessary to ensure backup against possible equipment failure or water supply quality variations.

Other types of treatment will depend on the nature of the supply and might include treatment for heavy metals (such as lead), arsenic, nitrate, pH, iron, manganese, hydrogen sulphide and suspended solids (turbidity). (Contaminants such as iron or manganese can, for example, cause staining of laundry)

What should I do?

If you do not currently use a private water supply, but are considering one, the UKWTA recommends that you consult with a water treatment specialist in private supplies, such as one of our member companies. You should also consult with your Local Authority for advice on the requirements and recommended actions necessary to assist in your decision.

If you have, or are considering a private water supply, and you do not have information on the quality of the supply, you should contact the specialist company and/or your Local Authority, in the first instance, and they will arrange for a survey of the source and provide advice on its treatment requirements. There may be a charge for this service.

The survey will include not only an analysis of the water, but also a risk analysis which will assess the existing and possible transient environmental conditions on the supply. For example, it will determine whether there is agriculture, livestock or industrial activity in the locality which may impact upon the source water.

For the health and safety of the users of the private supply, it is vital that the appropriate treatment is installed and the quality of the treated water checked regularly to ensure that the equipment is functioning correctly.

What are the legal responsibilities?

The revised Private Water Supply Regulations 2009 came into force in January 2010. They identify the powers and responsibility of the Local Authority to enforce compliance of the regulatory requirements by the owner or person responsible for the water supply. They detail the quality parameters and monitoring that must be complied with to ensure that the water is ’wholesome’. All private water supplies used for purposes which might affect human health must be recorded by the Local Authority.

The requirements are more onerous for large supplies (greater than 10m3 per day) and where the water is for commercial activity or public premises. Where the supply is to a single private dwelling, the Local Authority has discretion on its monitoring activity, but it must monitor in accordance with the Regulations, including conducting a risk analysis, if requested by the owner or occupier.