Jannah, RaihanilAnita, Sofia2018-03-072018-03-072-03-07wahyu sari yenihttps://repository.unri.ac.id/xmlui/handle/123456789/9277Moringa oleifera is one of the natural coagulants in Indonesia. This study was conducted to see the effectiveness of moringa seed powder as natural coagulant as an alternative to coagulant chemical that has negative effect. This research was conducted for well water samples in Kelurahan Purnama, Sukajadi and Tanjung Palas in Dumai City. The parameters analyzed were chloride and turbidity as well as some additional parameters. Turbidity was analyzed using a turbidimetry method, while chloride was analyzed using a UV-Vis spectrophotometer. The results indicated that moringa seed powder could decrease turbidity and chloride in three kelurahans turbidity was of 62.06%, 60.51%, and 19.05%; while chloride was of 43.59%, 48.93%, and 50.50%. Based on paired t-test method (P = 0.05), moringa seed powder are effective to decrease chloride and turbidity on wells water in Kelurahan Purnama, Sukajadi and Tanjung Palas in Dumai City. Based on PERMENKES RI No. 492/MENKES/PER/IV/2010 about drinking water quality, chloride concentration was the limit of requirements for drinking water, but not for turbidity.enChloridecoagulation-flocculationwell waterMoringa seed powderArticle