Private water supplies and distribution systems

What is private water supply?

A private water supply is a supply of water, which does not come from a licensed water supplier, such as Thames Water. Private supplies may come from a number of sources, including wells, boreholes, rivers and streams.

These supplies are covered by the Private Water Supplies Regulations 2009.

These Regulations aim to ensure water from private supplies is wholesome, so people who use water from private supplies can do so without risk to their health. They also cover private distribution systems where water may be supplied to one property and then distributed on to other properties, e.g. caravan sites.

What are our responsibilities?

The guidance on private water supplies set out procedures we must follow if we consider a private water supply is unwholesome. This includes requirements to:

  • Investigate the cause
  • Inform the user(s) if the supply constitutes a potential danger to human health
  • Give the user(s) advice to allow them to minimize any such potential danger
  • Liaise with the Health Protection Agency to seek advice on whether there is potential danger to human health.

If a supply needs to be improved, we will liaise informally with supply owner/users to prevent potential dangers to human health. If an informal approach does not achieve this then there are other options open to us in the Regulations, including serving notices.

For large supplies and small domestic supplies, we are required to carry out a risk assessment of the supply every five years. The risk assessment will examine the source of the supply and the surrounding area to see if contamination is possible. It also involves checks of storage tanks, treatment systems and the pipes to ensure that any action necessary is taken to ensure the water supply is safe to drink.

We are also required to carry out sampling but the frequency and type of sampling is dependent on the outcome of the risk assessment and the size of the supply.

We are not required to carry out sampling of single domestic supplies. However, this can be done at the request of the owner or occupier.

What happens if there is a problem with the water?

Where sampling and testing shows there is a problem with the water supply an authorisation may be granted. This would allow the supply to be of a different standard to that set out in the regulations. However, this would only be allowed if the water posed no danger to human health. The authorisation will require action to be taken to comply with any necessary conditions.

Alternatively, if a private supply of water constitutes a potential danger to human health, we will serve a private supply notice. This notice will be served on the owner or occupier of the premises that the water supply serves or the owner or occupier of the source premises. The notice will usually require various steps to rectify the problem or to arrange an alternative supply. If no action is taken, we can carry out the works and recover the cost.

Fees and charges

We charge for risk assessments, investigations, taking and analysing samples. We are not allowed to exceed the statutory maximum charge stated in the Private Water Supplies Regulations 2009.

The following table shows the service we provide and our fees alongside the maximum fee allowed to be charged under the Regulations.

Private water sampling fees
Service Maximum fee laid out in the regulations Our fees
Risk assessment (each assessment) £500 Hourly rate x officer time
Sampling (each visit) £100 Hourly rate x officer time
Investigation £100 Hourly rate x officer time
Granting an authorisation £100 Hourly rate x officer time
Analysing a sample taken under Regulation 10 £25 £25
Analysing a sample taken during Check monitoring £100 Recover full analysis  cost up to the statutory maximum
Analysing a sample taken during Audit monitoring £500 Recover full analysis cost up to the statutory maximum

Hourly rate

The current chargeable hourly rate is £88.

Residents will be invoiced for these fees once the service has been completed.

Request a service

To request a private water sampling service, email esd@wandsworth.gov.uk

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