Purified water. Greater than or equal 8.8 pH purified water enhanced with minerals & electrolytes added for taste. Purified by Reverse Osmosis. To accurately verify pH, use a calibrated. pH meter or high range reagent drops. Bottled from water sources meeting requirements of US EPA drinking water regulations. To find out more about Alkaline88 Water Quality & information, please visit our website alkaline88.com or call 1.866.242.0240. BPA free.