Water testing

Monitoring private water supplies

We need to monitor private water supplies and make sure that they're safe.

We carry out risk assessments on both large and small supplies. This looks at the water source and surrounding area to see if contamination is possible. We also check storage tanks, treatment systems and the pipework to make sure the water supply is safe to drink. Risk assessments must be carried out every five years.

Large or commercial supplies:

• serves 50 or more people
  or
• uses more than 10m³ per day of water
  or
• the water is used for commercial purposes (including food preparation) or serves a premises to which the public have access

Small supplies:

• serves two or more properties
• serves less than 50 people or less than 10m³ per day
• the water is not used for any commercial purpose or public premises
• supply to a single property where there is no commercial or public use

We also need to carry out sampling, but how often and the parameters tested is dependent on the outcome of our risk assessment and the size of the supply. Large supplies are sampled at least every year and small supplies every 5 years.

We don't need to carry out sampling for single domestic supplies - except at the request of the owner or occupier or in the event of a complaint.

Guidance

• Regulations - Private Water Supplies 2016 (2018 as amended)
• Guidance including sampling parameters and frequencies - Drinking Water Inspectorate

Fees

Regulations introduced a charging system for private water supplies risk assessments and sampling - these costs are confirmed on our fees and charges and a direct recharge of officer time and laboratory sample testing fees.

Last updated 30 June 2023