PM Case Study Two

Sewage Pump Project

Laighpark Wastewater Treatment Works

WGM Engineering was tasked by Scottish Water to provide emergency provision of an overpumping system to transfer the settled sewage from the primary settlement tanks to the aeration lanes. Initially, two submersible pumps and hosing were installed at the screw pump chamber, this was primarily to keep flows to the aeration lanes on a temporary set up. 

A number of modifications were made following the initial emergency response to the overpumping system. Originally, we installed Bauer flexible hoses, before obtaining and installing an improved and larger 18” bore steel fixed pipework system, that could cater to all incoming flow events. With high rainfall potentially backing up upstream, the stop logs were altered in height, but could not alleviate the flow without impairing on the performance of the pumps. Additional submersible pumps and pipework were required to cope with storm events.  

Once all installed and fine-tuned, this new over-pumping arrangement was successfully monitored and maintained throughout the rest of the dismantling and rebuild phases of the screw pump project by WGM Engineering.

Planning & Removal Phase

To resolve the issues which have occurred at Laighpark Pumping Station, design and replacement of the screw pumps with a new set of pumps and associated motors/gearbox were assigned. Remedial works also planned during this time for WGM Engineering Ltd to update the inlet works to the screw pumps, including hand-railing, penstocks and FOC actuators. WGM Engineering, the principal contractor role, successfully managed and supervised the removal and destruction of the old screw pumps arrangement

This included site establishment for the duration of the works, cleaning out and preparing the pump chamber for entry, removal of the old screw pumps and destruction of the original gearbox and motor plinths

Testing Phase

Dry and wet testing confirmed both screw pumps were satisfactorily tested and proven to meet the design flow of 2,500 l/s. The new screw pump design arrangement did make for some changes to the original pump system at Laighpark, choosing direct drive instead of pulley driven provided for a beneficial and more economical power consumption for Scottish Water, the only physical impact being that hand-railing was required to be installed under the motors for head protection, a minor impact compared to the savings provided.

An inside perspective from

Gary Caig

Scottish Water

We immediately established who/what we required and who owned and delivered the actions. Communication throughout was superb, my team felt engaged, part of the delivery team, this was a real demonstration of what collaboration should look like. All managed to the highest standards with the health and wellbeing of our people at the forefront of our goal.