Backflow Protection: Requirements & Guidance

Schedule 2 paragraphs 2, 14 & 15 [Regulation /Byelaw 3]

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Regulations / Byelaws

Regulation / Byelaw 3

England & Wales: Water Supply (Water Fittings) Regulations (1999) (revised)

(1) No person shall–

(a) install a water fitting to convey or receive water supplied by a water undertaker or water supply licensee, or alter, disconnect or use such a water fitting; or

(b) cause or permit such a water fitting to be installed, altered, disconnected or used, in contravention of the following provisions of this Part.

(2) No water fitting shall be installed, connected, arranged or used in such a manner that it causes or is likely to cause–

(i) waste, misuse, undue consumption or contamination of water supplied by a water undertaker or water supply licensee; or

(ii) the erroneous measurement of water supplied by a water undertaker or water supply licensee.

(3) No water fitting shall be installed, connected, arranged or used which by reason of being damaged, worn or otherwise faulty, causes or is likely to cause–

(i) waste, misuse, undue consumption or contamination of water supplied by a water undertaker or water supply licensee; or

(ii) the erroneous measurement of water supplied by a water undertaker or water supply licensee.

Scotland: Water Supply (Water Fittings) (Scotland) Byelaws (2014)

(1) No person may -

(a) install a water fitting to convey or receive water supplied by Scottish Water, or alter, disconnect or use such a water fitting; or

(b) cause or permit such a water fitting to be installed, altered, disconnected or used, in contravention of these Byelaws.

(2) No water fitting may be installed, connected, arranged or used in such a manner that it causes or is likely to cause—

(a) waste, misuse, undue consumption or contamination of water supplied by Scottish Water; or

(b) the erroneous measurement of water supplied by Scottish Water.

(3) No water fitting may be installed, connected, arranged or used which by reason of being damaged, worn or otherwise faulty, causes or is likely to cause—

(a) waste, misuse, undue consumption or contamination of water supplied by Scottish Water; or

(b) the erroneous measurement of water supplied by Scottish Water.

Northern Ireland: The Water Supply (Water Fittings) Regulations (Northern Ireland) 2009 (revised)

(1) No person shall—

(a) install a water fitting to convey or receive water supplied by a water undertaker, or alter, disconnect or use such a water fitting; or

(b) cause or permit such a water fitting to be installed, altered, disconnected or used, in contravention of the following provisions of this Part.

(2) No water fitting shall be installed, connected, arranged or used in such a manner that it causes or is likely to cause—

(a) waste, misuse, undue consumption or contamination of water supplied by a water undertaker; or

(b) the erroneous measurement of water supplied by a water undertaker.

(3) No water fitting shall be installed, connected, arranged or used which by reason of being damaged, worn or otherwise faulty, causes or is likely to cause—

(a) waste, misuse, undue consumption or contamination of water supplied by a water undertaker; or

(b) the erroneous measurement of water supplied by a water undertaker.

Schedule 2 requirements

Paragraph 2 (Regulations in England, Wales and Northern Ireland)

(1) Subject to sub-paragraph (2) below, no material or substance, either alone or in combination with any other material or substance or with the contents of any water fitting of which it forms a part, which causes or is likely to cause contamination of water shall be used in the construction, installation, renewal, repair or replacement of any water fitting which conveys or receives, or may convey or receive, water supplied for domestic or food production purposes.

(2) This requirement does not apply to a water fitting downstream of a terminal fitting supplying wholesome water where–

(a) the use to which the water downstream is put does not require wholesome water; and

(b) a suitable arrangement or device to prevent backflow is installed.

Paragraph 2 (Byelaws in Scotland)

(1) No material or substance (either alone or in combination with any other material or substance or with the contents of any water fitting of which it forms a part) which causes or is likely to cause contamination of water is to be used in the construction, installation, renewal, repair or replacement of any water fitting which conveys or receives, or may convey or receive, water supplied for domestic purposes or food production purposes.

(2) Sub-paragraph (1) does not apply to a water fitting downstream of a terminal fitting supplying wholesome water where—

(a) the use to which the water downstream is put does not require wholesome water; and

(b) a suitable arrangement or device to prevent backflow is installed.

Guidance to Paragraph 2

Providing appropriate and adequate backflow protection against the highest level of risk downstream is installed, an installation not used to supply water for drinking, bathing, food preparation or cooking purposes is exempt from complying with schedule 2 paragraph 2(1).

Please note the backflow protection required needs to be assessed by the local water undertaker and other requirements of the water fittings regulations/byelaws continue to apply.

Paragraph 14 (Regulations in England and Wales)

(1) Any water fitting conveying–

(a) rain water, recycled water or any fluid other than water supplied by a water undertaker; or

(b) any fluid that is not wholesome water;

shall be clearly identified so as to be easily distinguished from any supply pipe or distributing pipe.

(2) No supply pipe, distributing pipe or pump delivery pipe drawing water from a supply pipe or distributing pipe shall convey, or be connected so that it can convey, any fluid falling within sub- paragraph (1), unless a device for preventing backflow is installed in accordance with paragraph 15.

Paragraph 14 (Regulations in Northern Ireland)

(1) Any water fitting conveying–

(a) rain water, grey water, reclaimed water, recycled water or any fluid other than water supplied by a water undertaker; or

(b) any fluid that is not wholesome water;

shall be clearly identified so as to be easily distinguished from any supply pipe or distributing pipe.

Paragraph 14 (Byelaws in Scotland)

(1) Any water fitting conveying–

(a) rain water, grey water recycled water, reclaimed water or any fluid other than water supplied by Scottish Water; or

(b) water for the purpose of a private water supply; or

must be clearly identified so as to be easily distinguished from any supply pipe or distributing pipe.

Guidance to Paragraph 14

Irrespective of what type of water is being conveyed all pipework and fittings should be marked in accordance with BS 1710. Further information can be found here.

Any water fitting conveying any fluid other than mains supplied water should not be directly connected to a plumbing system supplying mains drinking water

With the agreement of the local water undertaker a mains water back-up to an alternative water source system may be permitted subject to the installation of appropriate backflow protection.

Paragraph 15 (Regulations in England and Wales)

(1) Subject to the following provisions of this paragraph, every water system shall contain an adequate device or devices for preventing backflow of fluid from any appliance, fitting or process from occurring.

(2) Paragraph (1) does not apply to–

(a) a water heater where the expanded water is permitted to flow back into a supply pipe, or

(b) a vented water storage vessel supplied from a storage cistern,

where the temperature of the water in the supply pipe or the cistern does not exceed 25°C.

(3) The device used to prevent backflow shall be appropriate to the highest applicable fluid category to which the fitting is subject downstream before the next such device.

(4) Backflow prevention shall be provided on any supply pipe or distributing pipe–

(a) where it is necessary to prevent backflow between separately occupied premises, or

(b) where the water undertaker has given notice for the purposes of this Schedule that such prevention is needed for the whole or part of any premises.

(5) A backflow prevention device is adequate for the purposes of paragraph (1) if it is in accordance with a specification approved by the regulator for the purposes of this Schedule.

Paragraph 15 (Byelaws in Scotland)

(1) Subject to sub-paragraphs (2) to (5), every water system must contain an adequate device or devices for preventing backflow of fluid from any appliance, fitting or process from occurring.

(2) Sub-paragraph (1) does not apply to—

(a) a water heater where the expanded water is permitted to flow back into a supply pipe; or

(b) a vented water storage vessel supplied from a storage cistern, where the temperature of the water in the supply pipe or the cistern does not exceed 20°C.

(3) The device used to prevent backflow must be appropriate to the highest applicable category of fluid in Schedule 1 to which the fitting is subject downstream before the next such device.

(4) Backflow prevention shall be provided on any supply pipe or distributing pipe— (a) where it is necessary to prevent backflow between separately occupied premises; or (b) where Scottish Water has given notice for the purposes of this Schedule that such prevention is needed for the whole or part of any premises.

(5) A backflow prevention device is adequate for the purposes of sub-paragraph (1) if it conforms to a specification approved for the purposes of paragraph 15(1) of Schedule 2 to the Water Supply (Water Fittings) Regulations 1999 (pursuant to sub-paragraph (5) of that paragraph).

Paragraph 15 (Regulations in Northern Ireland)

(2) Paragraph (1) does not apply to—

(a) a water heater where the expanded water is permitted to flow back into a supply pipe, or

(b) a vented water storage vessel supplied from a storage cistern,

where the temperature of the water in the supply pipe or the cistern does not exceed 20°C.

(3) The device used to prevent backflow shall be appropriate to the highest applicable fluid category to which the fitting is subject downstream before the next such device.

(4) Backflow prevention shall be provided on any supply pipe or distributing pipe—

(a )where it is necessary to prevent backflow between separately occupied premises, or

(b) where the water undertaker has given notice for the purposes of this Schedule that such prevention is needed for the whole or part of any premises.

(5) A backflow prevention device is adequate for the purposes of paragraph (1) if it is in accordance with a specification approved by the Secretary of State or the National Assembly of Wales under The Water Supply (Water Fittings) Regulations 1999.

Guidance to Paragraph 15

Guidance to paragraph 15(1)

In this paragraph reference to devices includes backflow protection arrangements.

Guidance to paragraph 15(2)

Thermal expansion from unvented water heaters (with the exception of instantaneous water heaters with a capacity less than 15 litres) may be accommodated within the secondary hot water system. However this is only allowed if:

The expanded water does not increase the temperature of the water in the supply pipe to in excess of 25°C in England and Wales 20°C in Scotland and Northern Ireland. As this may result in waste or impact on wholesomeness.
Both the expanded water plus any displacement can be accommodated within the supply pipe. It is not permissible for water displaced as a result of accommodating expansion to backflow into the pipework owned by the local water undertaker.

Guidance to paragraph 15(3)

The lowest level of backflow protection required as point of use protection must have a backflow protection rating which is at least equivalent to the highest fluid category of any downstream fluids an installation will be subjected to.

Guidance to paragraph 15(4)

Where a water undertaker considers there to be a likelihood, which cannot be reasonably ignored, of contamination by backflow within a premises or the wider network they can require additional backflow protection. In some circumstances as an alternative to this a higher level of point of use backflow protection may be permitted.

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Uncontrolled if downloaded. This is informative, non-statutory guidance and intended for general guidance purposes only; it is subject to change.

Compliance with this information should not be relied upon as guaranteeing no enforcement action will be taken by water undertakers. Water Regs UK accepts no liability for loss, indirect or consequential loss arising from or in connection with this guidance document.