BS8558 Chlorination Certificates

GCW offer a professional and friendly service. We can provide a BS8558 chlorination certificate to both residential and commercial properties.

  • We use fully qualified water quality scientists
  • We use latest the chlorination equipment
  • Samples tested in UKAS approved laboratories
  • We conform to British standards BS8558
  • We have over 30 years experience in water utilities
  • Our Chlorination service is available nationally


Chlorination Services and Chlorination Certificates

Nationwide Service

Call Us Today: 07548 285 811

When is chlorination required?



  • New pipework is over 50 metres in length.
  • New pipework has internal diameter of 50mm or over.
  • If the pipe has been unused for a long period of time.
  • New commercial properties for local authorities.
  • If the existing supply pipe has become contaminated.
  • Previously supplied by a water system i.e. Well or Spring.


Why do I need a BS8558 Chlorination Certificate?



As well as having the piece of mind and reassurance that the pipes carrying a water supply is free of contamination, your local  water utility provider, South West Water for example, will need to see a BS8558 chlorination certificate  before a new pipe is connected to the mains. You should check with your local utilities company first to see the level of certification required.


What is the process of Chlorination?



The chlorination / disinfection process contains several stages:

  1. At source a reading is taken to demonstrate how much chlorine is in the water supplied by the water utility company using a photometer, known as the background reading.
  2. Pre flush with clean water to remove debris, on larger diameter pipes we would also swab the pipe.
  3. The pipe / system is then filled with a measured solution of chlorine (Sodium Hypochlorite), to remain in contact with the pipe for a period to allow disinfection to take place.
  4. The system is then safely flushed to remove the chlorine via a de-chlorination process back to the original background reading.
  5. Once the background is achieved, the water is held for a duration in the pipe and when that time has lapsed, a sample is then taken which is then sent off to a UKAS approved laboratory for analysis.
  6. Subject to test results the pipe is then connected.


For a full process and more information on our water chlorination / disinfection services please see our water chlorination services