Water quality assessment using national Water Quality Index (WQI): a case study of the Song Be River, Bing Duong Province, Vietnam

Abstract The Song Be River is a vital water source in Binh Duong Province, Vietnam, playing a crucial role in supplying water for domestic use and agriculture, as well as supporting local ecosystems. However, due to the recent rapid economic and industrial growth, the river’s water quality has encountered significant challenges, particularly from the improper discharge of untreated wastewater from various sources and activities. This study conducts a comprehensive analysis of the Song Be River’s water quality by employing the Water Quality Index (WQI) in conjunction with Geographic Information System (GIS) technology. Subsequently, several strategies are also proposed to effectively manage and enhance the water quality of the Song Be River. Over the period from March 2023 to March 2024, 52 samples were collected from four monitoring points (SB1, SB2, SB3, and SB4) along the Song Be River, with a frequency of once per month. All analytical parameters (such as NH 4 + _N: 0.01–0.61 mg l −1 , NO 2 − _N: 0.014–0.03 mg l −1 , Fe: 0.01–0.81 mg l −1 , Chemical Oxygen Demand (COD): 4–26 mg l −1 , Dessolved Oxygen (DO): 3.8–6.6 mg l −1 , Suspendid Solids (SS): 5–69 mg l −1 , Coliform: 1200–4300 MPN/100 ml, Total phosphorous: 0.01–0.08 mg l −1 and Total nitrogen: 1.16–4.5 mg l −1 ) fell within the permissible limits according to the Vietnamese National Standards. Furthermore, the WQI ranged from 73 to 100, indicating that the water quality of The Song Be River is good and suitable for domestic use.