Terms of the agreement were not released. The Neely Wastewater Reclamation Facility is operated by Severn Trent Services.

Gilbert, located southeast of metropolitan Phoenix, will be offered all biodiesel produced from this pilot programme at the actual cost of production and processing during the programme.

"The Town of Gilbert has a stated interest in expanding the sources for renewable and sustainable energy for the benefit of its citizens," says Gordon LeBlanc, Jr, chief executive of PetroSun.