This project involved the creation of a bypass storm overflow pipe route as the existing inlet works could not cope in storm conditions and works would flood. Also works included the installation of a new wash water system and tanker discharge point.
Storm Screen Chamber – Construction of 10.5 x 5m with 3.2m high external walls, around an existing 1.2m concrete pipe. This chamber was constructed with limited working space and internal weir walls cast tight to the existing pipe. The purpose of these was to house new screens and actuated penstocks, to divert storm flows away from existing inlet works to existing storm tanks.
Storm Overflow Pipeline – Construction of 90m of 1200mm DI pipeline from the new inlet chamber to existing storm tanks. This section of works was complicated by the use of DI pipes weighing 4.5tn and the restricted access.
Washwater System – This consisted of the construction of a mixture of various slabs to house kiosk pumps and tanks for wash water area. These were installed around 300mm of DI pipework for wash water line, whilst maintaining access to the existing site
Tanker Discharge – The Installation of new tanker discharge point and removal of existing discharge point.
Blower Slab – Construction of 20m x 5m slab for the installation of new blowers.
Construction of ducting and draw pits
Construction of additional access roads and road widenings around the site
Interface with existing structures and interface with a live sewage works was required on this project. CCL had to alter techniques and programme to maintain effluent quality and flow during the construction works. A major construction process change involved installing temporary works to maintain access in lieu of open digging as originally contracted.