Water regulations

As a business it is your legal duty to ensure the systems you use or install satisfy the requirements of the Water Supply (Water Fittings) Regulations 1999.


In order to protect your water supply from contamination, it is important that your fixtures and fittings are correctly installed and in a good state of repair. The purpose of these Regulations is to protect your drinking water supply from contamination, and prevent inefficient use of water or incorrect measurement of it. The Regulations apply in England and Wales to all plumbing systems, water fittings and equipment supplied, or to be supplied, with water from the public water supply. This applies to systems in all types of premises.

Your water wholesale supplier is responsible to the Government for the enforcement of the Regulations and they have the right to visit your premises and carry out checks to ensure your water fittings comply.

How do the water regulations affect my business?

  1. Your plumbing system must be installed and maintained to comply with the regulations
  2. You must prevent contamination of drinking water
  3. You must give advanced notification of plumbing work
  4. We advise you to use an approved plumbing contractor.

What's the risk to my business?

If your business has plumbing that contravenes the Water Regulations it faces risks that could impact on its financial and reputational performance.

It is the legal duty of your business to comply with the Regulations. Due to the potential risk posed to public health via backflow, the Government have legislated that plumbing systems must be properly designed, installed, operated, and maintained to meet the requirements of the Regulations. It is a criminal offence to breach the Regulations and offenders may face prosecution. Where breaches of the Regulations are found, we have a legal duty to ensure they are remedied. In emergencies, we may have to disconnect the water supply to the premises immediately.

The Regulations are designed to protect the public health of both employees and the general public by preventing contamination via backflow.

Our policies & documents

Enforcement policy

You can read this document in your browser or download it.

WC Backflow Protection Policy

You can read this document in your browser or download it.

Notification (Reg5) form

You can download and print this PDF or fill it out using Adobe Acrobat Reader.

Do I have to tell you about any plumbing work?

For most business owners and occupiers the answer will be yes. Under the regulations owners and occupiers of premises and anyone who installs plumbing systems or water fittings have a legal duty to ensure that the systems satisfy the regulations.

In most cases advanced notice must be given of proposed installations. If your business is thinking of making any changes to the plumbing systems you should ensure the architects, building developers and plumbers follow the Regulations with regard to notification.

The kind of plumbing works that must be notified are detailed in our notification form. The notification form must be submitted and approved by Yorkshire Water prior to work starting. In many cases, we have been able to work with stakeholders to provide free advice on their plumbing designs. It is much more cost-effective to make changes at the design stage rather than have to correct plumbing systems after they have been installed.

There is no charge by Yorkshire Water for Notification or granting consent.

Consent will not be withheld unreasonably, and may be granted subject to conditions, which must be followed. If consent is not given within ten working days, it is deemed to have been granted. This does not alter the obligation upon the installer, owner or occupier to see that the Regulations are fully met.

Notification (Reg5) form

You can download and print this PDF or fill it out using Adobe Acrobat Reader.

Regulation 5 table
  1. The erection of a building or other structure, not being a pond or swimming pool.
  2. The extension or alteration of a water system on any premises other than a house*
  3. A material change of use of any premises.
  4. The installation of:
    (a) a bath having a capacity, as measured to the centre line of overflow, of more than 230 litres;**
    (b) a bidet with an ascending spray or flexible hose;*
    (c) a single shower unit (which may consist of one or more shower heads within a single unit), not being a drench shower installed for reasons of safety or health, connected directly or indirectly to a supply pipe which is of a type specified by the regulator;**
    (d) a pump or booster drawing more than 12 litres per minute, connected directly or indirectly to a supply pipe;
    (e) a unit which incorporates reverse osmosis; **
    (f) a water treatment unit which produces a used water discharge or which requires the use of water for regeneration or cleaning;**
    (g) a reduced pressure zone valve assembly or other mechanical device for protection against a fluid which is in fluid category 4 or 5;
    (h) a garden watering system unless designed to be operated by hand; or **
    (i) any water system laid outside a building and either less than 750mm or more than 1350mm below ground level.
  5. The construction of a pond or swimming pool with a capacity greater than 10,000 litres which is designed to be replenished by automatic means and is to be filled with water supplied by a water undertaker.

* An Approved Contractor (Approved Plumber) will not have to notify in advance of the work, but certify upon completion. See our (link to approved Plumber section).

** Relates to where a plan is not required as part of Notification.

When you send your notification to us, please include: 

  • the name and address of the person giving notice and, if different, the name of the person to whom our comments should be sent
  • a description of the proposed work or material change of use
  • the location of the premises and their use or intended use
  • a plan of that part of the premises which relates to the proposed work and a diagram showing the pipework and fittings to be installed, except for items marked "note 2" in the table above
  • the plumbing contractor's name and address, if an approved plumber is to do the work.

Why do I need an approved contractor?

A WaterSafe approved contractor will accept legal liability for any work they undertake. They will provide your business with a compliance certificate upon completion of works. This certificate gives your business the peace of mind that, should the work not meet the requirements of the Water Regulations, you will be legally protected from further action. The Approved Contractor would have to put the work right at their own cost.

You can find more benefits of using an approved contractor and find find an approved contractor on the WaterSafe website.


What's a RPZ valve?

A reduced pressure zone valve or RPZ valve is a backflow prevention device used to protect the drinking water supply.

In the UK, wherever a significant health hazard is identified in a plumbing system, backflow protection is required by law. One of the most common methods to protect against this risk is to install an RPZ valve.

Key things to remember with an RPZ valve:

  1. You must notify water undertaker to gain consent to install the RPZ
  2. The RPZ valve must be installed in line with the approved installation method (AIM)
  3. The RPZ valve must be tested annually (as a minimum) by an approved tester

Why do I need to test my RPZ valve?

Much like the MOT on a car, an RPZ valve has to be tested annually by law to ensure it is operating correctly. Remember, the valve is installed to prevent contamination of the drinking water supply so it’s vitally important that it works properly.

The test requires specialist equipment and can only be completed by an approved RPZ tester.

Find an approved tester

How can I get in touch or find out more?

Water regulations

For further guidance on water regulations please contact our water regulations team.

Email: waterregulations@yorkshirewater.co.uk

Post: Water Regulations, Yorkshire Water Services, Ltd PO Box 52, Bradford, BD3 5AY

You can also visit the Water Regulations UK.

RPZ valves

You can send you RPZ queries and certificates to rpz@yorkshirewater.co.uk.

Reg5 notifications

You can send reg5 notifications and queries to reg5@yorkshirewater.co.uk.