I refill three 5 gallon containers from the Glacier dispensers every week. Each vending machine has a service date on it. I do not know how often they are supposed to service the machines but the dates were months old. I use a kettle to boil water, after boiling, I can see the white mineral deposits, probably calcium carbonate, calcium and or magnesium hydroxide and perhaps other monovalent or divalent compounds. Water is extremely hard in this area with a total harness of 2000. God bless our kidneys. User's recommendation: Don’t use these vendors as they do not service them as often as it is required. Pressure your city regulator to provide you healthy drinking water because nobody will pay your kidney dialysis bills.