WP3240 - Engineering Services Associated with the Assessment and Mitigation of Shallow Seepage Impacts

Tender description

The Council wishes to procure engineering services associated with the assessment and mitigation of residual seepage impacts at Waterfront Lex, Walsall. The contract relates to the design, construction and commissioning of a barrier system on the northern boundary of a plot of land owned by Walsall Council. The Site is proposed for sale. The principal objective of the works is to increase confidence that direct migration of contaminants from the north, under Wolverhampton Road, is plausibly retarded and unlikely to present a significant pollutant linkage for future development of the Site. The intention is that by undertaking the works future purchasers have an increased level of knowledge and confidence when redeveloping the Site. The Site was once part of gasworks part of which originally extended into the land to the north of the current Site boundary. Suspected sources of contamination lie in the historic gasworks and beneath an existing road to the north of the Site (Wolverhampton Road). This is a key arterial route between the M6 and Walsall town centre which cannot be closed to traffic as part of these works. The principal works are to include, as a minimum, a combination of:  Pre-works investigations to determine the precise line of the barrier and provide a record of ground conditions along the northern boundary of the site; and  Installation of a hydraulic barrier to mitigate potential direct shallow seepages from historic gasworks land to the north. Tenderers will be invited to undertake separate short visits to the site to evaluate the sites constraints ahead of their submission. A provision date of 5th August 2016 has been set for site visits. This date will be confirmed. The works will be undertaken using NEC3_EngineeringConstructionShortContract_April 2013.