The backflow risks associated with hose union taps will vary dependent upon their use (intended or otherwise) and the environment in which they are sited. Ultimately it is for the local water undertaker to determine whether anything other than fluid category 5 backflow protection would be acceptable.
To protect public health the overriding concerns are:
In order that the correct level of backflow protection is identified and provided, the following factors will be considered:
1. The environment in which the hose tap is situated
2. Intended and/or potential uses
If a hose is not required to facilitate the intended use, the tap could be changed to a bib tap (tap without the provision to connect a hose).
3. The highest applicable fluid category
Domestic or non-domestic classifications are irrelevant in determining the highest applicable fluid category present. The backflow protection provided must be adequate and appropriate to the identified risk, as determined by the local water undertaker, taking account of the above considerations.
Low risk activities
Providing the hose is:
Hoses used solely for watering a domestic garden or washing personal vehicles are typically categorised as a fluid category 3 risk which may be protected by the installation of a double check valve.
High risk activities
High risk activities include but are not limited to hose use:
Hose union taps used in these circumstances are classed as fluid category 5 risks unless an assessment by the local water undertaker determines otherwise.
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.