ABSTRACT Natuna Regency is part of the Kepulauan Riau Province which is located at the very northern end of Indonesia. Natuna consists of a group of small islands with a total of 27 inhabited islands out of a total of 154 islands. The object of this research is Sedanau Island, which currently utilizes groundwater as a source of raw water in a limited amount to meet the needs of 6,086 people. Th…