How to manage private water supply / Boreholes

Given the right setting and conditions, water from the ground can be the best-tasting water you will find. However, only around 1% of the population in England and 3% in Wales use a private water supply, with most supplies situated in remote, rural areas, originating from a range of sources, such as boreholes and natural springs.

This blog gives information about what private water supplies are, their benefits and costs, the regulations governing them, and how to manage them if installed.

What is a Private Water Supply?

The Drinking Water Inspectorate defines a private water supply as any water supply supplied to a property that does not originate from a mains supply or licensed water supplier.

As stated above, almost the entire population of England and Wales are supplied by water utilities, and the small percentage that are supplied by private water may not know that they are.

Typical installations of private water supplies are situated in rural areas, such as farms, isolated dwellings and villages, and outdoor activity centres, which are not near a public mains connection.

Advantages and Disadvantages of Private Water Supply

The benefits of having a private water supply can be;

• Cost, where recouping money spent on installation can be quick
  
  
• Reliability, including no temporary government restrictions and better water pressure
  
  
• Quality, being arguably purer, excluding any chemicals added. Mains water also uses up to 60% recycled water
  
  
• Better for the environment, by sourcing water from your land and not requiring large treatment plant

The disadvantages of a private water supply can be;

• Contamination risk from agriculture and bacteria
  
  
• Local Authority involvement if the premises are used in a commercial or public activity
  
  
• Ongoing maintenance costs of filtration equipment and treatment if required

If you own a single dwelling, the benefits may well outweigh the costs. Regarding permission, you can drill a borehole on your land without planning permission, extracting up to 20,000 litres of water per day without a license or fees. However, it is advisable for you not to drill your borehole but use specialist contractors to carry out the work correctly and safely.

Water Quality

If you own or operate a premises that is not a single dwelling, and you intend to use the water for drinking, cooking, food preparation, or other domestic purposes then you must adhere to The Private Water Supplies (England) Regulations 2016.

The first requirement is to ensure the “wholesomeness” of the water. As stated in the regulations, “A private supply of water is to be regarded as wholesome if the following conditions are met -

1. It does not contain any micro-organism, parasite, or substance, alone or in conjunction with any other substance, at a concentration or value that would constitute a potential danger to human health,
   
   
2. It complies with the concentrations or values prescribed in Part 1 of Schedule 1 for each parameter, and
   
   
3. The water satisfies the formula “[nitrate]/50 + [nitrite]/3 ≤ 1”, where the square brackets signify the concentrations in mg/1 for nitrate (NO3) and nitrite (NO2)”

To prove the water supply's continued wholesomeness, the local authority will regularly sample the water. The frequency of sampling will depend on a risk assessment and the volume of water being extracted. The local authority will test the water for;

1. Conductivity,
   
   
2. Enterococci,
   
   
3. Escherichia coli (E. coli),
   
   
4. Hydrogen ion,
   
   
5. Turbidity,
   
   
6. Any parameter in Parts 1 and 2 of Schedule 1 identified in the risk assessment as being at risk of not complying with the concentrations or values in that Schedule, and
   
   
7. Anything else identified in the risk assessment as a potential danger to human health.

The acceptable parameters are detailed in Parts 1 and 2 of Schedule 1 of The Private Water Supplies (England) Regulations 2016.

If the water failed these tests, the supply would not be considered potable and require investigation and remediation.

Governance 

Before a sampling regime is determined the local authority must carry out a risk assessment on the private water supply and then review and update that risk assessment every 5 years. The local authority may also decide that the supply must not be brought into use or used until the local authority is satisfied that the supply does not constitute a potential danger to human health

Depending on the installation and/or results of water sampling and testing, the water supply may need treating to meet wholesomeness parameters. The type and design of any treatment methods used to treat the water will depend on the properties of the water and the presence and concentrations of any contaminants. The Drinking Water Inspectorate has published a guide to help owners install the correct and most effective water treatment, such options include, particulate filters, reverse osmosis, chlorine, and ultraviolet disinfection.

Any water treatment that is installed, will require the necessary service and maintenance to ensure the correct and continued performance. This could involve regular service visits by a qualified contractor and supplemented by frequent water sampling depending on the volume extracted.

If your private water supply is installed at a premises that is not a single dwelling, the water system must follow the requirements of the HSE’s ACoP L8 document, to help comply with their legal duties concerning Legionella. In addition to managerial requirements such as risk assessments, including Legionella Risk Assessments, physical controls are required to maintain a safe water system used by staff and visitors. Such controls may be;

• Where the water is stored in a tank, the capacity should be kept to the minimum needed to meet peak demand, remain accessible for inspection, sealed, and well insulated.
  
  
• Pipework material to be chosen carefully such as copper or plastic to not support microbial growth.
  
  
• All pipework and assets are to be clearly labelled for their intended purpose.
  
  
• Remove any deadends of pipework and minimise lengths of deadlegs.

Summary

The choice of installing a private water supply would be a combination of practicality, eligibility, ethics, and cost. Once you have managed the installation, dependent on the type of premises you operate, you will be required to manage the safety of the water to ensure the water remains “wholesome” for users to use. For this supply to remain “wholesome”, you may be required to implement complex control measures to ensure it, which will require expertise and resources. But once effective controls are established, a private water supply can be as good as, if not better than a public mains supply.

If you would like further advice or guidance on private water supply or boreholes please click here to get in touch with one of our consultants.

Editors Note: The information provided in this blog is correct at the date of original publication – July 2024.

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