Connecticut to date has a record of freedom from waterborne disease. The natural surface and groundwater supply sources in the state are free from sewage pollution. Treatment by chlorination and filtration provides safeguards against the danger of chance contamination, which always exists. The natural water supplies of Connecticut are generally soft and of reasonably good physical quality. A considerable number of filtration plants is now in operation in the state. Filtration will be provided to an increasing extent to improve water of poor physical quality. Such treatment will also furnish an additional barrier against waterborne disease. Some further development of surface sources in clean watersheds can and should be made in the future, where possible. It does not appear necessary for several decades to contemplate obtaining supplies from large rivers, but the time may come and efforts in pollution abatement on these rivers should continue. Studies of groundwater potential for water supplies in the state should be undertaken on a greatly expanded basis, and unquestionably a cooperative survey of groundwater resources by the state and U.S. Geological Survey should be planned over the next decade.