Oxford sewage treatment works

VGC replaced an existing grasscrete road at Thames Water’s sewage treatment works in Oxford.

We also carried out associated surface water drainage works.

The scope included:

• Protection of existing live plant
• Saw cut, lift and remove 335m2 of grasscrete road
• Construct two new drop crossings
• Install 70m of Aco channel and associated connections to existing drainage system
• Construct new reinforced concrete road. The road incorporated isolation joints and brush finish.

Thames Water’s Oxford sewage treatment works caters for the waste from approximately 214,000 people. The wastewater is treated using an activated sludge process, and the sludge is treated by anaerobic digestion. The sludge is subjected to advanced digestion within a new thermal hydrolysis process (THP) plant.

The THP involves the sludge being subjected to high temperatures and pressure through the injection of pressurised steam. Then it is pumped into the digestion tanks where it undergoes anaerobic digestion. Biogas from the digesters is harnessed and converted to electricity using combined heat and power engines.

The electricity produced will be used to power the Oxford sewage treatment works, with additional electricity exported to the national grid. The Oxford upgrade will generate an additional 12.6GWH of power by the end of asset management period 5 (AMP5) across the whole of the Thames region.

All works were carried out within the extremely sensitive environment of the live sewage treatment works.