"Unsweetened Sparkling, Zero Calorie" Confined in an aquifer deep beneath the earth, VOSS water lies under layers of rock and sand, which create a natural filter, protecting it from the air and other pollutants. The exceptional purity of VOSS, and its uniquely fresh, clean taste, are due in part to the unusually low levels of Total Dissolved Solids (TDS) naturally occurring in the VOSS source.