Client Esh Group
Water company Northumbrian Water
The Johnson Street CSO is an unscreened CSO that requires all spill flows up to a 5yr storm return period event to be screened to meet the new EA consent. Two mechanical screens are required to be installed on a new CSO chamber. The new CSO overflow pipe will be connected back to the existing CSO overflow in Johnson Street,
Solution / ATL works :
Construct a 6m diameter segmental drive shaft 7m deep from existing ground level.
Construct a 10.5m Shaft 9m deep from ground Level which will be the reception pit for the 1800mm pipe jack ,then becoming the new CSO (Combined storm overflow) which will have mechanical screens fitted by the client to meet the required EA consent.
Drive a 1800mm pipe jack 187m from the 6m drive shaft to the 10.5m reception shaft.
Construct a 5m diameter segmental shaft 8.5m deep from ground level. This will then become the reception shaft for the 1800mm pipe jack in Johnson street which will be constructed under a full road closure. This shaft will then be turned into diversion manhole allowing flows to re-enter the system and onto the overflow.
Drive a 1800mm pipe jack approx.70m from the 6m drive shaft to 5m reception shaft in Johnson street.
On competition of tunnelling works the 6M shaft will then become a manhole.