Camberley STW NVZ

Customer: GBM

Site Owner: Thames Water

Value: £540k

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 Camberley covering:

  • New Sludge Area LV Switch Board fed from existing transformer and feeding a new Sludge MCC and existing Sludge and Digester MCCs.
  • LV distribution from the new Sludge MCC.
  • Building services and Lightning Protection for the new Cake Barn.
  • External lighting to the NVZ works and street lighting on access road to Cake Barn.
  • Break in to existing 11kv HV for transformer at Blower House.
  • Extension of feeder cable from Mixer MCC to new Blower 4 MCC and cabling of Blower 4.
  • LV cables from new standby generator to Blower 4 MCC and installation of earth nests.
  • Phased cabling of new Rotork valves on 3 No. existing Aeration Lanes.
  • Profibus installation for all new instruments and valves.

The Cake Barn was the first area of works available for building services followed by containment on the NVZ works; additional containment was required on routes to Digester Pumps as cable ducts had not been installed.

Installation of lightning protection rods required core drilling through an existing concrete base as the whole of the NVZ had been built on the location of a redundant PST.

Shutdowns for breaking into the existing HV cables and for re-feeding existing equipment were always subject to process availability and Thames Water scheduling.

Replacement of Aeration Lane blower pipe work and the installation of the new Rotork valves were constraints to the completion of new power supplies and Profibus cabling.

The work was completed in mid-2012.