Water Supply Industry Interpretations and Advice

  • Area of Interest : Backflow prevention
  • Topic : Fluid category
  • Title : Fence-cleaning chemical spray equipment directly connected to mains 
  • Clause Reference : Schedule 2 paragraph 15 & G15.3
  • Reference Number : B62
  • Decision Date : June 2015 (revised November 2015)

To prevent contamination of water supplies devices using the motive power of water, supplied via a hose attached directly or indirectly to mains water, to mix and/or spray fertilisers, cosmetic layers and other chemicals must be protected by appropriate adequate backflow protection.

A risk assessment of the substances being used must be carried out by the relevant water undertaker to determine the level of risk to health, i.e. its fluid category.

The use of a double check valve will only be acceptable where a risk assessment identifies a substance as being no higher than fluid category 3.