Early Warning Notice
EW-2024-003
high Risk Awaiting Response
Unforeseen Rock Formation Encountered
Project
Manchester Northern Gateway
Issued By
James Wilson
Issued Date
05/11/2024
Response Required By
12/11/2024
Cost Impact
£15,300
Time Impact
Programme affected
Quality Impact
None identified
Description
During excavation works for the main drainage run (Plot 45-52), we have encountered an extensive rock formation at a depth of 2.5m below existing ground level. This formation was not identified in the site investigation report provided at tender stage. The rock extends across approximately 45 linear metres of the proposed drainage route. The formation will require rock breaking and specialist plant to remove, which will have significant impact on both programme and costs.
Cause
Insufficient ground investigation at tender stage
Programme Impact
2-3 weeks delay to drainage installation programme. Critical path impact likely.
Your Response is Required
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