One of the country's most expensive stretches of new highway just got more costly - and further delayed - by buried pumice that engineers failed to spot.
The two kilometre stretch of the Bayfair to Baypark upgrade on State Highway 2 south of Tauranga was already costing more than $70 million a kilometre.
But the ground isn't stable enough and that's forced a major design change.
Phil Pennington is looking into this
