The PUREST water – Removes up to 99.9% of impurities icnluding Heavy Metals, Total Dissolved Solids (TDS). Certified to NSF/ANSI 58 for the reduction of Arsenic, Barium, Cadmium, Chromium (Hexavalent), Chromium (Trivalent), Copper, Turbidity, Fluoride, Lead, Radium 226/228, Selenium, and TDS.