The Sunol Valley Rock Quarry is located within the Sunol Valley; this facility has been used as the source for fill material in a considerable amount of the land development for neighboring communities. In the course of excavating this quarry for such fill, chemical analysis has been conducted to ascertain the safety of such soils. Resultant analyses have shown that the soil has environmentally safe characteristics as defined by low or non-detectable concentrations of 18 heavy metals and asbestos fibers.[3]