ANALISIS FISIKA KIMIA KUALITAS AIR PERAIRAN SUNGAI BOYO DESA ONOWAEMBO KECAMATAN GUNUNGSITOLI KOTA GUNUNGSITOLI

Abstract

The Boyo Onowaembo River in Gunungsitoli District, Gunungsitoli City, is one of the main water resources for the community, used for domestic, agricultural, and economic activities. However, increasing anthropogenic pressure is feared to have an impact on water quality. This study aims to analyze the physical and chemical conditions of the Boyo Onowaembo River, evaluate its water quality status based on national quality standards, and identify the factors influencing its degradation. The research method used a quantitative descriptive approach with a cross-sectional design, where water samples were collected from three locations (upstream, midstream, and downstream) and analyzed in an accredited laboratory following the Standard Methods for the Examination of Water and Wastewater (APHA, 2017). The results of the study showed a decline in water quality from upstream to downstream. Physical parameters such as turbidity, TDS, and TSS increased significantly, while chemical parameters showed a decrease in dissolved oxygen (DO) accompanied by an increase in BOD, COD, ammonia, and phosphate that exceeded quality standards. Evaluation using the Pollution Index placed the upstream area in the lightly polluted category, the middle area in the moderately polluted category, and the downstream area in the heavily polluted category. These findings confirm that domestic activities, agriculture, and the decline in riparian vegetation are the primary factors causing water quality degradation. This study recommends the need for integrated waste management policies and strengthened community participation in maintaining the sustainability of water resources.