The North Carolina Department of Environment and Natural Resources has awarded the zoo a $US23,000 grant to work on the program which will allow construction of a processor to convert waster vegetable oil from the zoo's restaurants into biodiesel, a fuel composite of 20% biofuel and 80% diesel.

The zoo plans to eventually phase out the diesel and power trams, buses and other equipment using the biodiesel.

It is currently using a 20% biofuel, 80% diesel mix and is working on using a higher percentage of biofuel in the mixture as time progresses.

The zoo uses around 26,000 gallons of diesel per year and it is hoped the switch to biodiesel will work towards reducing the emission of toxic contaminants into the park environment.

“We’re going to be using not only a renewable resource – at least 20% of it will be renewable – but also cutting down on air pollution so it’s a win-win for everybody,” said zoo chief of staff Mary Joan Pugh.

The zoo intends to put together a promotional campaign about biodiesel that will feature educational exhibits and a section on biofuels on its website.