The West Gate Tunnel Project was awarded to a CPB Contractors and John Holland joint venture in December 2017, with construction starting in April 2018 and an original completion date of 30 September 2022. It actually opened on 14 December 2025 — a slip of three years and two months against the original programme.
The delay stemmed from a dispute over what to do with contaminated soil excavated during tunnelling. PFAS (per- and poly-fluoroalkyl substances) contamination was found in spoil, and the parties — Transurban, the CPB Contractors/John Holland joint venture, and the Victorian Government — reached a standoff over where that soil could be lawfully disposed of. At the peak of the dispute, up to 600 workers were stood down.
The project was delivered by the CPB Contractors and John Holland joint venture, under an ongoing commercial relationship with Transurban and the Victorian Government that had to absorb both the contamination dispute and its downstream programme impact.
What this means for planners
PFAS as an unknown unknown
Contamination risk of this kind rarely shows up as a line item in a baseline programme — it's discovered mid-excavation, not scoped in advance. Treat any earthworks package on a site with an industrial or landfill history as carrying an unquantified but non-zero contamination risk, and hold contingency float against it rather than assuming ground conditions match the geotech report exactly.
Dispute resolution clauses and their programme impact
A contamination dispute isn't just a technical problem — it's a commercial standoff between multiple parties with different incentives. The time spent in dispute resolution (here, spanning years) doesn't show up as "float consumed" in any conventional CPM sense; it's a suspension of the critical path itself while commercial terms are renegotiated.
What a 3-year delay does to a critical path network
A delay of this scale doesn't just push the finish date — it typically forces a full re-baseline, because logic links, resource assumptions, calendars and even contractor scopes from the original programme no longer hold three years later. Recovery schedules built on the old network structure without re-validating logic are a common source of disputes in their own right.
Model schedule recovery → floatcheck.html