George Leslie Ltd

Key Facts

  • Client: Scottish Water Solutions
  • Engineer: Scottish Water Solutions / AECOM
  • Conditions of contract: NEC3
  • Contract value: £4,255,000
  • Duration of works: April 2010 – June 2011 (13 months)

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Wastewater Treatment Works

Newton Stewart Wastewater Treatment Works

The key objective of this Design & Build project was to increase the wastewater treatment plant capacity from 41litres/sec to 70litres/sec, and thus reduce process failures within the existing plant and premature spilling at the upstream Newton Stewart Pumping Station CSO.

The scope of works included:

  • A new inlet works
  • Modifications to the existing inlet pump station. New screened effluent flow, sludge return, out fall and treated effluent distribution, chambers.
  • A new Anoxic chamber and oxidation ditch
  • Two 11m diam x 5m deep final settlement tanks
  • An 18m x 7m aeration tank
  • New Ras/Sas pumping station
  • MCC/HMI & Scada system/telemetry/M&E
  • Full process commissioning site access  roads,  hardstandings  and  site  drainage completed the works.

A key feature of this Design & Build project was accommodating all the new works within the existing site perimeter around the existing plant which required carefully planning of the integration of the new construction and installations from the outset, to ensure minimum disruption to the existing process.

The process commissioning methodology was taken into consideration right from the start of the contract and a close cooperative working relationship with the existing plant operations personnel was essential to ensure that the new installations were brought in, whilst ensuring that  the  live  works  was  maintained  fully  operational within its consents.

Regular liaison with SEPA throughout the construction works also ensured that environmental considerations and constraint were fully understood, both with regard to the operational works and the construction activities.


News updates


The overall project involves the off-site fabrication and installation of a new linkspan structure at Oban Ferry Terminal for client Caledonian Maritime Assets Ltd (CMal).

12th February 2019

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GL return to the Sound of Kerrera

GL making a return visit to the Sound of Kerrera off Oban, to undertake substantial repairs to the breakwater which suffered collision damage following an altercation with a workboat earlier this year.

14th December 2018

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Polmadie Bridge official opening……..

Michael Matheson MSP and Cabinet Secretary for Transport, Infrastructure and Connectivity covered all his portfolios at the official opening of the new Polmadie Footbridge giving pedestrian and cycle transport access,

18th September 2018

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George Leslie Ltd, Blackbyres Road, Barrhead, Glasgow, G78 1DU  |  |  +44 (0)141 881 9131