Sewer construction work

Tender description

Irish Water plan to undertake the construction of a new sewerage collection network in Athlone including gravity sewers, 1 No. new pumping station 1 No. new storm tanks and rising main. The project will convey flows from Athlone to the Athlone WwTP. Irish Water is currently advancing the Athlone Main Drainage Contract No. 2 — Networks, comprising the construction of a new main lift pumping station, removal of storm overflows, new foul sewers, decommissioning of existing pumping stations and new large diameter trenchless pipeline (tunnel) sewers. The Contract will be procured under a Negotiated Procedure and the form of contract will be Design-Build-Operate. Scope of Works The Works comprise the design and construction of infrastructure including the associated testing, commissioning and operation of the Golden Island Pumping Station. The Works can be summarised as including the following design and construction elements: — New foul waste water pumping station at Golden Island with ultimate foul pumping capacity of 553l/s, storm water pumping capacity 3 960l/s and return pumping of 90l/s. — Storm storage tank of 4 100 m³ at a depth greater than 15 m. — Construction of the ‘Canal Sewer’ trenchless pipeline (tunnel) sewer, approx. 1 335 m in length and minimum 900 mm diameter. — Decommission West Side pumping station and construct ‘West Side — Millbank’ trenchless pipeline (tunnel) sewer to intercept Canal sewer, approx. 157 m in length and minimum 600 mm diameter. — Decommission West Bank pumping station and construct ‘West Bank’ trenchless pipeline (tunnel) sewer to connect to upper Shannon crossing, approximately 102 m in length and minimum 300 mm diameter. — Construct ‘Westside — Showgrounds’ trenchless pipeline (tunnel) sewer to connect to lower Shannon crossing, approximately 385 m in length and minimum 1050 mm diameter. — Construct ‘Upper Shannon Crossing’ trenchless pipeline (tunnel) sewer under the River Shannon, approximately 105 m in length and minimum 900 mm diameter. — Decommission ‘West Bank’ pumping station. — Construct ‘Lower Shannon Crossing’ trenchless pipeline (tunnel) sewer under the River Shannon, approximately 349 m in length and minimum 1 200 mm diameter. — Upgrade Coosan West pumping station. — Construct ‘Abbey Road’ trenchless pipeline (tunnel) sewer to connect to new Golden Island pumping station, approximately 885 m in length and minimum 1 200 mm diameter. — Decommission Abbey Road pumping station. — Construct new Golden Island pumping station with 4 100 m³ underground storm water storage and emergency overflow to the River Shannon. — Decommission existing Golden Island pumping station. — Construct additional rising main from Golden Island pumping station to the existing wastewater treatment plant, approximately 860 m in length and minimum 600 mm diameter. — Construct ‘Payne's Lane’ sewer diversion (open cut), approximately 165 m in length and minimum 450 mm diameter. — Construct ‘Retreat Road’ sewer diversion (open cut), approximately 382 m in length and minimum 300 mm diameter. — Construct ‘Retreat Park’ sewer diversion (open cut), approx. 315 m in length and minimum 450 mm diameter. — Construct ‘Retreat Road -School Grounds/ Sportsfield’ sewer diversion (open cut), approximately 740 m in length and minimum 525 mm diameter. — Removal of 7 No. storm overflows. — Operation & Maintenance of the Golden Island pumping station and storm storage tank for 12 months. The contractor will be required to take on the roles of PSDP and PSCS for the whole of the works.