The Thames Tideway Tunnel Project
The growing population of London has resulted in growing demands of the city’s sewerage network. The outdated system allows for untreated overflow to fall into the Thames at various locations throughout the city during heavy rainfall.
To stop this from happening Thames Water undertook a decade of study to find the best solution. It was decided that a tunnel should be constructed to catch the sewerage before it reached the overflow pipes and take it to the company’s water treatment works.
Whilst the consultation was underway to find the best of three possible routes for the £3.6Bn Thames Tideway Tunnel, there was a need to collect information for the Environmental Impact Assessments and headworks designs including odour control of each of the three sites. Thames Water employed Environmontel to install and maintain on-line quality monitors and automatic samplers at 17 of the main combined sewer overflow (CSO) locations.
ALS Environmental was commissioned to undertake wastewater chemical analysis of the storm related CSO effluents at the 17 sites. The automatic samplers at the sites were triggered by a mixture of pump operation, flow and depth level. Once the samplers were triggered the Enviromontel crews were mobilised to collect samples and deliver them to ALS Environmental.
ALS Environmental carried out BOD, COD and sulphides analysis and tested the parameters of effluent discharges from the sewers into the Thames over a 12 month period.