Rye Meads STW Growth

Project Description

Rye Meads is one of Thames Water’s largest sewage treatment works currently serving a population equivalent (PE) of over 400,000 from areas across North and East Hertfordshire.

The expected population growth exceeded the site capacity, works on this growth scheme has seen upgrades to meet the 2026 design horizon. The main scope of the project is to extend the treatment capacity and improve discharge quality standards of the site to enable it to treat an increased volume of incoming flow.

The improvements include:

  • Preliminary treatment screening handling system
  • Ferric bulk storage and dosing system
  • Replacement of the PST desludge pumps
  • Additional Primary Sludge Buffer Tank, complete with mixing system
  • Pump sets feeding the Gravity Belt Thickeners and Picket Fence Thickeners
  • Primary Sludge Gravity Belt Thickener
  • Upgrades to the Imported Sludge Reception Tank including air mixing system
  • Polymer Storage, Make-up and Dosing System
  • Odour control system
  • Washwater Pumping Station
  • Flooding resilience works
  • MCC & ICA Upgrades
  • HV Electrical Works

Our scope on the whole project included the following services:

  • Full development of detailed electronic format Operations & Maintenance Manuals (O&Ms).
  • Completion of CDM Health & Safety File.
  • Asset Registration.
  • Onsite Installation of Thames Water Asset Barcodes.
  • Liaison and collaboration with all subcontractors involved on the scheme to co-ordinate the required documentation and drawings and ensure full compliance with the end clients specific standards.
  • Providing As-Constructed Asset Photographs.

To complete the above services, our project team visited the site multiple times to collect all required information.  Throughout the duration of the project we attended numerous progress / handover meetings including meeting Thames Water’s Operations Representatives to discuss technical elements of the documentation.

Throughout the project we worked very closely with SMB JV’s project team including design engineers, handover co-ordinators and project manager to ensure all documentation deliverables were submitted on time and to the required high standard expected.


July 2016 – October 2019


Skanska MWH Balfour Beatty Joint Venture (SMB JV)


Thames Water