Water Supply Industry Interpretations and Advice

  • Area of Interest : Enforcement
  • Topic : Scope of the Regulations/Byelaws
  • Title : Systems conveying both mains water and water from an alternative source
  • Clause Reference : Regulation 2(1)
  • Reference Number : E01
  • Decision Date : January 2004

Where a water fitting is supplied with water derived from both the public main and another source, such as reused water or a private supply, water suppliers are still responsible for enforcing the Water Supply (Water Fittings) Regulations, Byelaws in Scotland.

Therefore downstream of the backflow prevention arrangement to protect the mains supply from backflow of the mixed supply, a water supplier still has the duty to enforce the Regulations/Byelaws. In respect of prevention of contamination of water, a water supplier has authority to deal with contamination risks in premises which receive mixed supplies. That is to say, to prevent contamination by means of backflow, ingress, cross connection, unsuitable materials and identification by labelling. However water suppliers do not have a duty to enforce matters relating to the wholesomeness for drinking and other domestic purposes of the private water supply or of the mixed water supplies. (Water quality of private water supplies falls under Private Supply Regulations and as such comes under the jurisdiction of the Local Authority through its Environmental Health department.)