In-line water filtration systems benefit well and spring water users. In-line water filtration systems are connected to the main water line purifying all water. Because well and spring water do not have the advantage of the UV sterilization process that city water undergoes, unfiltered well water is not only harmful to drink, the contaminants can also cause damage to the plumbing and water-using appliances, such as washing machines and dishwashers. (Columbus OH Plumber)