Athlone Main Drainage, Westmeath

We completed the Detailed Design, Contract Documents, Tender Administration Contract Award and Construction Supervision stages for the upgrade of the existing Wastewater Treatment Plant serving the town of Athlone. This Contract was a FIDIC Gold Book contract with an operation and maintenance period of 12 months. The WwTP is located east of the River Shannon which is an EU designated environmental site (SAC). Flow and loads arriving at the existing plant were in excess of the design capacity of the original WwTP and effluent was adversely affecting water quality of the SAC.

Additionally, we completed the Hydraulic model build for the sewer network, Detailed Design, Planning and Contract Documents for this major civil engineering project valued at over €40m.

Key features of this project:

Contract 1 - The WwTP Design-Build contract comprises:

• Design Build of an expansion to provide increased treatment capacity to 36,000 PE
• Design, supply and installation of new inlet works including screens, FOG removal, grit removal, washing, compacting and classification
• New electrical substation
• Upgrade of the existing biological treatment stage including new diffused aeration system and air blowers
• M&E refurbishment of 2 no. Clarifiers, RAS/WAS pumping station, Ferric Dosing and treated effluent washwater system
• Refurbishment of existing buildings, extensive site works including roads and fencing
• Provision of new sludge dewatering system using duty/standby centrifuges
• Complete new Control Panels and new SCADA

Contract 2 – The Network contract comprises:

• DN1200 x 1,740m tunnel sewers including two major crossings under the River Shannon
• DN600 x 1,200m sewers throughout the town
• New rising main (DN600 x 575m long) from Golden Island Pumping Station to the WwTP
• New Golden Island pumping station, 20m deep, incorporating 4,100m3 stormwater storage, Foul Pumps 275l/s and Storm Pumps 5,130l/s
• Decommissioning of 3 No. network pumping stations and 5 No. combined sewer overflows
• Upgrade of the Coosan West Pumping Station (Foul Pumps 15l/s)