Westleigh Pumping Borehole

Tender description

The Coal Authority (client) invites you to tender for the drilling of a mine water monitoring borehole to assess rising mine water on the surrounding environment at Westleigh, Wigan. A review of the mine water block by the Coal Authority has highlighted that mine water levels in the area could be elevated in respect to the rest of the block. There is potential for elevated mine water levels which could pose a risk to the overlying drinking water aquifers. Therefore, the Coal Authority requires construction of a borehole to intersect flooded underground workings at the former Priestner's Colliery at Westleigh, Wigan. The proposed borehole is to be used to improve understanding of mine water in the Golborne, Bickershaw and Parsonage mine water block and will be used for water level monitoring, water quality sampling and abstraction of water. Additional information: The extra work has arisen because of unforeseen ground conditions that could not have been anticipated when the contract was first awarded. The existing contractor, already has the right equipment and technical expertise on site, making it impractical and inefficient to bring in a new supplier. •It does not alter the nature or purpose of the original contract. •It does not change the financial balance in favour of the contractor. •It does not add new conditions that would have allowed different bidders to take part.