Chertsey STW NVZ

Customer: GBM

Site Owner: Thames Water

Value: £390k

In a £28m scheme, Thames Water were looking to develop and improve sludge treatment and storage facilities at three waste water treatment works at Camberley, Chertsey (both in Surrey) and Crawley (West Sussex), to ensure compliance with the Nitrate Vulnerable Zone regulations, which are concerned with the disposal of sludge to nitrogen vulnerable zones.

FSD were awarded the electrical installation contract by main contractor GBM; the scope at Chertsey covering:

  • Break in to existing 11kv HV for new transformer at Liquor Treatment MCC & installation of 2 No. earth nests.
  • Secondary cables from transformer to new Liquor Treatment MCC.
  • Feeder from Liquor Treatment MCC to new Sludge MCC.
  • LV distribution from the new Liquor Treatment and Sludge MCCs.
  • Building services and Lightning Protection for the new Cake Barn.
  • External lighting to the NVZ works.
  • LV cables from new standby generator to Liquor Treatment MCC.
  • Profibus installation for all new instruments and valves.
  • Variations were issued for building services in the Poly Dosing Wet & Dry kiosks and the SBR instrument installation.

The Cake Barn was the first area of works available for building services followed by containment on the NVZ works.

Two earth nests required at the transformer had to be run parallel either side of the HV cable due to space restriction.

Generally the works went unhindered except for a period of bad weather when the site became a quagmire.

Building services for the Poly Dosing Wet and Dry kiosks were provided by FSDE.

The work was completed in mid-2012.