Isle of Wight Council

Environmental Health

Private Water Supplies

The Private Water Supplies (England) Regulations 2016

Regulations on private water supplies in England and Wales were introduced in 1991 and were replaced by new Regulations introduced early in 2010. The new Regulations apply to all who own or use a private water supply. The new Regulations have been introduced to ensure that water from private supplies is wholesome, so that people who drink the water, or consume food or drinks made from private supplies, may do so without risk to their health.

Private Drinking Water Supply

This is a water supply which is not provided by a statutory water undertaker such as Southern Water.  These supplies are usually located in a rural area and may be a well, borehole, spring, stream, river, lake or pond.

Monitoring Private Water Supply

Under The Private Water Supplies (England) Regulations 2016, the local authority (Isle of Wight Council) has a duty to monitor all PWS in their area. This includes sampling and risk assessing the supply.

Types of Private Water Supply

The Private Water Supplies (England) Regulations 2016 divide private water supplies into 3 categories for monitoring purposes. These are:

  1. Commercial or large supplies (more than 10 cubic meters of water/day or supplying 50 people or more).
  2. Small supplies (domestic use only*) (less than 10 cubic meters of water/day and under 50 people using the supply).
  3. Single Dwellings (only one single domestic dwelling uses the water).

Commercial supplies include food preparation/production, care homes, holiday homes, B&Bs, rental properties and caravan and campsites.  In addition, where water is used for any of the following, it will be considered to be commercial use: washing crops/foodstuffs (particularly ready to eat foodstuffs such as salad crops or fruit and vegetables), within Dairy Farm production, incorporation into food as an ingredient, cleaning of food production equipment, utensils, walls, floors, ceilings and work surfaces, production of ice, hand washing by food handlers, etc.

*’Domestic use’ is defined through guidance issued by the Drinking Water Inspectorate, and refers to the use of water for drinking, cooking, food preparation, and personal washing (such as washing hands and showering).

Differences between the categories

The main differences are the size of the supply, the frequency of testing and the number of tests that are carried out.

  • Commercial/large supplies – must be sampled at least once a year and are subject to most tests.
  • Small supplies – As a minimum these supplies must be sampled at least once every 5 years.
  • All supplies are risk assessed every 5 years.
  • Single Dwellings – There is no requirement to sample or risk assess these supplies. The local authority will only risk assess and sample at the request of the owner/occupier.


What to do if you have a private water supply

You should notify the Isle of Wight Council. The Private Water Supplies (England) Regulations 2016 apply to all private supplies. If you require further information, please contact the Environmental Health Team by clicking here and using the online 'Send a message to service' form.


The regulations allow us to recover the costs of carrying out a risk assessment, investigation, sampling and analysis. This will be charged at a rate of £37 per hour.

Ensuring the Private Water Supply is safe to drink

It is a legal requirement that all commercial and small supplies are risk assessed and sampled, enabling the Local Authority to check that the water is safe to drink. Emphasis is placed upon having appropriate protection of the source, adequate maintenance of the supply and/or the installation of treatment to ensure your water supply is safe. There are various treatment methods available which you may choose to use such as filters, ultra violet treatment, chlorination etc.

If the analytical result indicates that the water may not be safe to drink, a Notice will be served which requires measures to be taken to ensure the supply is made safe.

There is currently no legal requirement for supplies to single domestic dwellings to be risk assessed or sampled, however this can be conducted at the request of the owner. 


General advice on private water supplies can be found on the following websites:


Guidance for owners of Private Water Supplies