Winstone Aggregates' largest quarry has changed over to a bio-diesel blend for its entire fleet of vehicles. The Auckland based site has been running at a split of 95% diesel and 5% organic matter since early November.

Winstone Aggregates Hunua Quarry Manager John MacAulay believes the quarry is the first in the country to run on bio-fuel. "Operating the plant on Bio-diesel 5 has had no negative effects on power or usage and we've actually found that the machines are running more quietly on the 5% mix".

Biodegradable and significantly less toxic than mineral diesel, bio-diesel produces around the same amount of horsepower in diesel engine vehicles. Produced in New Zealand by BP, Hunua Quarry's bio-diesel is made from tallow, (an animal fat) then blended with regular diesel to form the B5 mix.