Assessment of Anwai river water quality using the weighted arithmetic water quality index (WQI) in Delta State, Nigeria

The weighted arithmetic water quality index method was used to assess the of anthropogenically-laden Anwai-river within Asaba-capital territory Delta State, Nigeria, in Stations 1(Otulu), 2(Isele- asagba) and 3(Anwai-Asaba) using pH, electrical conductivity (EC), total dissolved solids (TDS), biochemical oxygen demand (BOD), (DO), turbidity, phosphates, nitrates, hardness (TH) coliforms, determine its status suitability for humans aquatic biota. Aside from TDS, TH, other parameters such as pH (5.3-8.2), DO (2.0-2.8 mg/L), BOD (1.02-2.4 EC (110-113 µS/cm), turbidity(2.3-5.2 NTU), TDS (8.0-16.0 TH (30-62 phosphates (0.13-0.28 nitrates (0.05-0.27 mg/L) Coliform (25.75-45.5 cfu/ml) indicated non-significant variableness (p>0.05) between Stations. Water depth, phosphate, nitrate coliform were significant contributors Anwai-river's by Principal component analysis (PCA). first principal (PC1) exhibited 94.1% variance a 0.1860 loading factor, while second showed 5.9% 0.0117 factor implying flooding, excessive human activities sewage disposal important contaminants. Although individual physiochemical-based qualities below WHO recommended drinking values translated into poor at three Stations; 86.83, 75.02 81.27 Station's 1, 2 3 respectively, correspondingly very based on index. is serious health threat organisms thus, it should not be utilized untreated.