On 21 February, the route of the 9.5km long revised length tunnel, up to 4m in diameter, for the Belfast Sewer Project in Northern Ireland was announced in advance of the March tender for the works (T&TI, March 2004, p7).
As part of Belfast’s upgrade to its sewerage network and bid to improve the quality of the Lagan and Blackstaff rivers, the tunnel will be driven at a depth of up to 30m through clay strata with some incursion into the sandstone bedrock where dolerite dykes exist.
The prequalified contractors for the tunnel will be confirmed later this month, following which they be invited to tender for the works. Tender award for the three year conract is planned for later this year in October.
