Backflow Protection

The fitting of backflow protection devices is a regulatory requirement and an issue of increasing importance as water companies now employ Compliance Officers with statutory inspection rights.


Water companies are required by law to supply water that is “wholesome and fit to drink”

The supply can be contaminated by installed water systems, processes and water use where under certain circumstances pressure differential can result in backflow contaminating the supply 

The issue is covered in the Water Supply (Water Fittings) Regulations 1999, the Scottish Water Byelaws 2004 and the Water Supply (Water Fittings) Regulations 2009 in Northern Ireland

The Regulations classify backflow risk with reference to 5 fluid categories:

Fluid Category 1: Wholesome and fit for drinking

Fluid Category 2: As fluid Category 1 but with changed temperature or taste

Fluid Category 3: Slight hazard to health due to low level toxicity

Fluid Category 4: Significant health hazard due to toxicity or the presence of pathogens

Fluid Category 5: Containing faecal matter, blood, sputum and other pathogens

Backflow protection devices include various types of valves or “air gaps” and have to be of a type approved by the Water Regulations Advisory Scheme “WRAS”

Watertec identifies backflow protection issues during the course of the risk assessment and we supply and fit WRAS approved:

Single check valves for Category 2 backflow protection

Double check valves for Category 3 backflow protection

Reduced Pressure Zone (RPZ) valves for Category 4 backflow protection

Supply cisterns with appropriate air gap arrangements where Category 5 backflow protection is required

We can also supply and fit hydraulic and solenoid actuated isolation valves enabling the mains to be turned off at the flick of a switch.