Hydrochemical Assessment of Bageshwori Pond of Nepalgunj (Nepal): Implications for Water Quality Management and Sustainability

Abstract

This study assesses the hydrochemistry and water quality status of Bageshwori Pond located in Nepalgunj, Lumbini Province, Nepal. The objective of the research was to evaluate the physicochemical characteristics of the pond and understand its environmental condition considering its religious and cultural importance. Water samples were collected from six different sites within the pond and analyzed for major hydrochemical parameters including temperature, pH, electrical conductivity, dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), turbidity, nitrate, ammonia, phosphate, chloride, alkalinity, hardness and iron using onsite measurements probes and standard laboratory methods. The results showed noticeable spatial variations in several physicochemical parameters across the sampling sites. Concentrations of ammonia (0.461 ± 0.010 mg/L) and phosphate (0.330 ± 0.233 mg/L) indicated localized nutrient variability, particularly for phosphate, which may be associated with organic matter decomposition, religious activities and urban runoff surrounding the pond. DO levels ranged between 3.10 and 4.10 mg/L, indicating moderate oxygen availability in the aquatic system. Turbidity values varied considerably (1-8 NTU), with Site 5 exceeding the NDWQS permissible limit of 5 NTU, suggesting differences in suspended particles and sediment disturbance. BOD values were relatively low (15.4 ± 2.10 mg/L), indicating limited biodegradable organic pollution, while comparatively higher COD values (159.33 ± 34.88 mg/L) suggested the presence of oxidizable organic and inorganic substances. The Weighted Arithmetic Water Quality Index (WQI) values ranged from 69.15 to 75.61 (mean 71.13), classifying all sampling sites within the "poor" water quality category. Overall, the hydrochemical analysis0 indicates that Bageshwori Pond currently maintains poor water quality conditions, although few parameters reflect the influence of anthropogenic activities and surrounding urban pressures. Considering the religious, cultural and aesthetic significance of the pond adjacent to Bageshwori Temple, regular monitoring, proper waste management, and effective conservation strategies are recommended to maintain the ecological health and sustainability of this important freshwater resource.