don't know where u live, but I have been getting my water from a mountain spring while I save up for an ro booster pump. I have a biologist friend who works for the state and he tested it to be pure. Haven't checked TDS, but it's been working well for me. Bought some water jugs in carrying boxes and I can do 75 gallons a trip. Works out to about 4 cents a gallon when I factor in gas.