Redcraigs DSR

Introduction

Mackenzie Construction has a programme of works on the TWS Service Reservoirs for Scottish Water. The service reservoirs are taken offline for essential works or the service reservoir can be completely rationalised if no longer required but there requires to be a means of maintaining the flow of water to Scottish Water customers. At various sites, there is no means to maintain this flow and hence bypasses around the service reservoirs are required.

Background

Redcraigs DSR in Fife is to be rationalised but had no bypass at the reservoir to maintain flows. Mackenzie Construction and our supply chain carried out a detailed design of the works. The works designed were to construct a twin line 600 dia. bypass with associated valves, PRV’s and meters. The works required connections to the 2Nr existing water mains in the main road and the construct of pipework and associated fittings in the field opposite including cut and caps of existing pipework at the reservoir.

Actions and implementations

Before any works can commence local stakeholders are required to be engaged. The road authorities, local residents and landowners are engaged with to discuss the works and any implications. The relevant section notices and Symology applications are arranged thereafter. We importantly engage with the SW operations for their approval of the design and any concerns about connections to live mains. This ultimately leads to the compilation and submission of DOMS Impact Assessment Forms.

The construction works commenced with the installation of tees onto the 450mm HPPE and 18” CI mains in the road.  This allowed the construction of the twin-line bypass in the field. There are numerous flanges to be bolted up for which we used the new Bluetooth torque wrenches and guns with each bolt recorded on an App. The information on the app records, for quality control, the torque rating and method for each of the bolted-up flanges carried out. After swabbing, flushing, chlorination and sampling of the new bypass the connections back into the downstream mains were completed.

Challenges Faced

As with any apparatus underground, when exposed, things are not always as expected. The existing mains orientation was not as expected which required a redesign under the time pressure of working on a live road. The team worked quickly to turn this around and works were back on track quickly.

Conclusion

The works were undertaken safely, efficiently and within the programme allowing the important rationalisation of the service reservoir to be carried out.