CPC were contracted to install a new 600mm and 450mm pressure main to act as water resilience for Severn Trent Water. The works involved connection 2 reservoirs together and installing a replacement main to the existing system, installing over 16km of pipe work with required washout structures and valve releases. The entire system is tested up to 25bar of pressure and then chlorinated prior to commissioning. The works involved 4 main pipe laying teams, 3 enabling gangs, fencing/ stripping and reinstatement teams. At its peak the job ran with around 60no. staff. 2 major crossings under the M5 and rail network have been installed, each with 10m shafts and over 100m of TBM tunnelling with the pipe work installed through.

The Scope 

• Full environmental mitigation required prior to access into private land; this involved Badger Licenses and translocation works, Nesting Bird protection, Vole licenses, Environmental licenses for crossing water courses around fish spawning seasons, ancient monument consent, natural England consents, Giant Hogweed mitigation, Organic farming construction methods, stock proof fencing, great crested newt mitigation, National Trust licenses.  
   
• Once the environmental mitigation was completed in each section, each landowner had a bespoke access agreement to ensure minimal disruption to the customers. A 20m easement along the new pipeline route was fenced and stripped to allow the construction of the new pipeline.  
   
• The new pipeline was installed to Severn Trent specifications; the 600mm main was ductile iron installed using an open cut method, and a 450mm main in PN16 Plastic installed using butt fusion welding. Once the main was installed thrust and anchor blocks are installed to allow pressure testing in 1km sections.   

• There were 4 major crossing points on the project; 2 of them have been completed using 10m shafts and a TBM installation underneath the M5 and the national rail network. The other 2 major crossings of the Lichfield Canal and A46 have been completed using an open cut method. 

• The final element of the project was the installation of the new pump station structure and connection into the existing service reservoirs and pump stations. Once the new mains have been connected up, full chlorination of the pipe works are completed prior to the mains going into commission.  
   

Scheme Challenges 

The delivery of these works came with many challenges, requiring robust and innovative solutions.