Bellozanne Sewage Treatment Works, Jersey
Sweco have worked with the States of Jersey for almost twenty years and since 2014 have partnered with the Department for Infrastructure (DfI) under their Technical Consultancy Framework. As part of this framework, Sweco are developing the design of the new Bellozanne Sewage Treatment Works (STW) prior to it being tendered as a Design and Build contract.
Over a five year period, Sweco supported DfI in preparing a Wastewater strategy for Jersey. The strategy highlighted that due to outdated assets and a growing population, the existing Sewage Treatment Works (STW) at Bellozanne no longer met environmental standards. The only viable option in terms of meeting the current and future requirements being to replace the existing STW.
The replacement of the existing works is programmed to be completed in phases to ensure continuity of service. Accommodation and enabling works began in 2015 and will continue until the start of the STW construction in February 2018.
The estimated completion date for the STW is July 2022.
In preparing the Waste Water Strategy (WWS), Sweco analysed and identified how Jersey collects, treats and disposes of waste water at various facilities operated by DfI. This included:
- A review of the condition and performance of all the existing assets
- A review of current and future legislation and European directives
- A reassessment of the location for the sewage treatment works
- A review of the sewerage (collection) system
- A review of future population growth and location of new housing developments and
- A focus on actual environmental outcomes as opposed to arbitrary limits.
The existing STW at Bellozanne has been operational for over 50 years and has undergone several upgrades. In recent years, and despite significant maintenance, the plant has been inefficient and failed to meet the required nitrogen standards.