Water Supply Industry Interpretations and Advice

  • Area of Interest : Backflow prevention
  • Topic : Fluid category
  • Title : Swimming pools in domestic and non-domestic premises and hose union taps
  • Clause Reference : Schedule 2 paragraph 15 & G15.3
  • Reference Number : B13
  • Decision Date : February 2002 (Revised September 2010)

Whilst the water in a swimming pool is always categorised as a fluid category 5 risk hose union taps in private dwellings used at the poolside, provided that:-

  1. an air gap between the outlet of any attached hose and pool water is maintained at all times and the hose is not immersed or submerged in pool water; and
  2. any hose attached is fitted with a self closing trigger outlet

may be regarded as a fluid category 3 risk and as such could be protected against backflow by means of a double check valve - insulated against freezing where appropriate.

Hose union taps at poolside in non-domestic premises may providing the same conditions are met be protected against backflow by an arrangement offering a minimum of fluid category 4 backflow protection. For the purposes of this interpretation a domestic installation is a bath, pool or tank used by the occupants of a single privately owned or rented property for their and their friends, personal use. Where a bath, pool or tank is used by the occupants of more than one property the local water supplier will need to carry out a risk assessment to determine the level of risk.