CASE
Electricity complexities for Sewage Treatment Works Upgrade
33kV electricity upgrade to support the expansion of the Crossness Sewage Treatment Works in South East London
SITUATION
In upgrading their Sewage Treatment Works, the incumbent waste water undertaker (Thames Water Utilities, TWU) required a new 33kV electricity supply for the expansion of their works to receive 44% more sewage from an expanding catchment Local restrictions required the power to be brought under the Thames from Barking
TASK
Deliver electricity from National Grid site at Barking through Thamesmead (a residential area), cross 2 no. dual carriageways, a water canal, linked to Nature Reserves; remove and manage invasive Japanese Knotweed & other vegetation, where identified, to permit cable installation along the route Legal agreements and sign off to enable energisation Exposure of ducts installed when canal was built to see if fit for purpose
ACTION
All routes were deemed to have Special Engineering Difficulties, plus the Housing Association gave ultimatum on route to use, with clear indication of working areas for breaching the canal being rejected if we chose the highways route. We rented the the Primary School woodland garden to expose ducts under the canal, (work permitted outside term times only). The ducts were not suitable, and use of 2 x Horizontal Directional Drills were eventually permitted.
Work Information Packs produced to detail every aspect of the phased route delivery All works needed to be signed off to release the ransom strip
RESULT
Energisation was completed on time, with additional services delivered by the DNO to assist the Client’s contractor. Engaging specialists including UXO (Unexploded Ordinance), Environmental Consultants, Environment Agency, and other surveyors, we were able to give confidence to Housing and Commercial Associations, councils and highways - all of whom were actively encouraged to ‘drop in’ on the project
Social impact - development of relationships within the community, educating young people at Windrush Primary School, new, improved woodland garden & basketball court Project featured in both the DNO and client’s internal magazines & external publications
AT A GLANCE
Challenges
Japanese Knotweed
Special Engineering Difficulties
Canal Crossings, Floating Road Moratorium for Olympics
Land Consent & Ransom Strip
Part of £220m project for TWU
Outcomes
Delivered on time
Horizontal Directional Drill (HDD)
Investing time in stakeholders
Managing Knotweed after project
Social Value - Woodland Garden at Primary School, Lessons for the Young People & Community Amenities inc. Basketball Court.
SignificantAchievement
‘The 4 no 33kV cables crossed under the Thamesmead Housing Estate, Two Dual Carriageways, A Canal & Basketball Court and cost £10m Despite this complexity, and the unexpected restrictions around the Olympics, the supply was commissioned in September 2012, on time.’
Published: UK Power Networks. October 2012.
STUDY: PRIVATE SECTOR - AS AN EMPLOYEE OF A DNO