Online analyser replacement for a ground-water site

  • Client: Water treatment works
  • Midlands
Online analyser replacement for a ground-water site
Case study

The Project

The customer were using archaic chlorine analysers to control their disinfection system. They were becoming unreliable and spare parts were difficult to get hold of.

The whole area where the chlorine analysers and other analysers were installed had been modified over the years and the area was in disorder. The analysers that they were using required an acidic buffer which was a Health & Safety issue. This buffer had also dissolved parts of the walls where the analysers were leaking, and a breezeblock bund had
been built around them.

The acidic buffer also caused the drains to block so they had a sodium-hypochlorite dosing rig that used to dose chemical into the drain to keep it clear.

Scope of Works

  • New instruments and sample lines were installed for the whole area.
  • Full electrical design was done for the power and signals back to the PLC / SCADA system
  • Full 3D mechanical design was completed for the area.
  • Electrical installation completed in house
  • Mechanical installation completed in house
  • Large power distribution panel was built at Penketh and installed local to the instruments
  • Software was re-configured and re-commissioned for both the PLC and HMI
  • SCADA modifications were carried out by a third party under instruction from BGEN
  • All instruments were commissioned, and the disinfection control loops were re-commissioned to allow for the updated loop times on the new instruments.
  • Temporary instruments were installed while the work was taking place to allow the works to continue to run while the main work was done.
  • Whole scheme was run by BGEN as Principal Contractor and Principal Designer

Components Delivered

  • ATi Chlorine analysers x4
  • Sigrist Turbidity instruments x2
  • Endress & Hauser pH Instruments x3
  • New design of sample sink to stop splashing


  • Keeping the works running throughout the scheme – with temporary instruments and planned migrations -was the biggest challenge to the project.
  • The works would be unable to run without these instruments as they are a key part to the disinfection process.
  • The project was completed with very minimal downtime for the site during the works.

In all of my time I have been involved with Contractors, BGEN have been the best performing contractor by far for cleanliness, tidiness, communication and workmanship.

Kevin Lamb, ICA Design and Delivery Manager, Severn Trent Water

  • Share on LinkedIn

Get in touch

Whether you have a specific project in mind or would like to explore how we might work together in future, please just contact us.

    * Fields are required

    This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.