Private water supplies facts

Table of Contents

A Private water supply (PWS) is any supply of drinking water not provided by a water company - e.g. Thames Water. 

PWSs are normally situated in remote, rural areas. The source of the supply is likely to be either a well, borehole, spring or stream but can include mains water if distributed via a private distribution system. The supply may serve just one property or several properties through a network of pipes.

All PWSs in the borough serving two or more dwellings or a commercial property must be registered with Royal Borough of Windsor & Maidenhead Council (RBWM).

What are the Private Water Supplies (England) Regulations 2016 and the private water Supplies (England) (Amendment) Regulations 2018?

The Private Water Supplies (England) Regulations 2016 came into force in June 2016 and the amendment regulations came into force in July 2018. The Regulations seek to safeguard public health by ensuring that PWSs are wholesome and safe to drink and they require quality standards similar to those of mains water supplies.

The Regulations require the council to carry out risk assessments and sampling on most PWSs at least once every five years. The council will charge for this work.

Who do the Regulations apply to?

The Regulations apply to anyone who owns or uses a PWS where the water is intended for human consumption and/or used for any other domestic purposes such as washing and cooking. 

The Regulations also apply to any commercial business, where the food and/or drinks are made using water from a PWS and also if you are operating a food business from your domestic premises (e.g. home caterer, bed and breakfast). You must have wholesome water at all times.

What do the Regulations require for my type of supply?

This depends on the classification of your supply. The classifications are as follows:

  • Commercial or public building, including tenanted properties and Large Supplies (usage of 10m³ or more per day): A risk assessment is required at least once every 5 years and sampling at least once a year.
  • Small Supplies (usage of less than 10m³ or more per day) supplying more than one property): 
    A risk assessment is required at least once every 5 years and basic sampling at least once every five years.
  • Single Property Supplies (supplying one property only): These supplies do not require routine sampling or a risk assessment. However, a sample or risk assessment can be undertaken by RBWM at the owner or occupier’s request.

What is a risk assessment?

A risk assessment involves looking at the source water, water catchment, water intake, storage, treatment and distribution of a supply to estimate if there is a significant risk of contamination and supplying water that may not be safe to drink.

Risk assessments identify water quality hazards and determine any risk to health they might present. This applies risk management principles during treatment and distribution so that sampling alone is not relied upon to determine whether or not it is safe to consume or use for other domestic purposes.

The assessment identifies actions that can be taken to control the risks. Risk assessments can only be performed by the Local Authority or by persons the Local Authority has deemed competent. The frequency that a risk assessment must be carried out on your supply is determined by the supply’s classification and result of the initial risk assessment.

What monitoring is required?

Untreated water can contain microorganisms (from animal droppings, human sewage or the environment) or chemical contamination which may not be detectable by taste or smell. It is sensible to know the quality of the water that you drink. Testing the water helps to verify this.

The frequency and type of monitoring will be determined by the classification of your supply and the result of the risk assessment. A sample will be taken from a tap used to supply water for drinking and/or cooking. The water is assessed for both chemical and biological parameters which are set out in the Regulations.

What if monitoring shows that my water supply is of poor quality?

If the results of monitoring show that the supply has failed to meet the standards set out in the Regulations further action will be required, such as a risk assessment and/or investigation by RBWM and improvement works to be carried out by the supply owner(s). Improvements might be required at the source itself, to the pipes, tanks or to fittings inside your home.

For example, a fence around the source to protect against animals or installing appropriate treatment to ensure satisfactory microbiological quality and where required, water filters (to remove iron, nitrates, manganese etc.).

What is an investigation?

If a sample fails to meet the standards set out in the Regulations then an investigation by RBWM is required to find the reason for the failure and to identify what action is needed to improve the supply. This may mean more sampling is required and/or inspections are needed throughout the supply.

What if the risk assessment (RA) shows that my supply has a high risk of contamination?

If the RA highlights any deficiencies in the supply arrangements as either high or very high risk to the wholesomeness of the supply and/or where there are potential risks to human health, then the relevant person(s) e.g. owner of the supply, will be required to put in to place suitable control measures to control those risks.

RBWM is empowered, where it deems necessary, to serve a formal Notice on the relevant person(s) requiring remediation of any water quality risks found. The Notice may prohibit or restrict the supply (i.e. stop it’s use or require it to be boiled before consumption) in the short term and require works to be carried out to adequately control the risks in the longer term.

The Notice will be specific for the supply depending on the risk(s). It is an offence to breach or fail to comply with a Notice. Relevant persons have the right to appeal to a Magistrates Court in respect of any notices served.

What are the fees involved?

The table below shows the maximum fee, payable on invoice, allowed to be charged under the Regulations.

Service(Activity) RBWM charging scheme
Risk Assessment (each assessment) Based on an hourly rate of £41.00 up to a maximum 
of £500
Sampling Visit (each visit) Based on an hourly rate of £24.00 up to a maximum of £100 (1)
Analysis of Sample for Small Supplies Maximum of £25
Analysis of sample for Check 
Monitoring for Large/Commercial supplies
Maximum of £100
Analysis of Sample Audit Monitoring  Large/Commercial supplies Maximum of £500 (2)
Investigation (each investigation) Based on an hourly rate of £41.00 up to a maximum 
of £100 plus any analysis costs
  1. (1) No fee is payable where a sample is taken and analysed solely to confirm or clarify the results of a previous sample
  2. (2) The type and number of parameters to be analysed during audit monitoring is determined by the outcomes of the risk assessment. The fee will therefore be different for each individual supply but is unlikely to reach the maximum permitted charge of £500.

What can I do to keep my PWS safe?

  • Make sure you know where your water comes from and where it goes before it reaches your tap. Contact the owners of the land the source is located on and discuss your supply with them. Find out where the tanks, pipe work and any treatment is. Knowing this can help you understand what could cause a problem.
  • Clarify who owns and is responsible for the supply. Make sure you have contact details for the appropriate person should you have a problem with the supply.
  • Regularly monitor and inspect your supply to make sure that it is in good working order and has not been interfered with or damaged. The supply needs to be properly protected throughout, from source to tap. This should include a maintenance programme to clean the system, storage tanks or header tanks, and to ensure all treatment works are maintained according to the manufacturer’s instructions.
  • Ensure that your PWS is registered with RBWM so that, if or when required, a risk assessment and monitoring can be carried out to ensure that the water is wholesome and safe to drink.

What can I do in preparation for my risk assessment visit?

If you are an owner of a PWS it is useful to keep any records pertaining to your PWS together. 

This information will be called upon at the time of risk assessment and could potentially save you money (if less time has to be spent at your premises). If you do not already have a schematic of your system, then just draw a simple flow diagram of the system, including the location of the source for your supply, any treatment points, storage tanks, pipework (including what internal and external pipework is made from) and location of any valves.

Try and keep all management /maintenance records, any previous sampling results and manufacturer’s details of installation and instructions /invoices etc. readily available should they be requested.

You may find the “Using a Private Supply Information” useful.