ABSTRACT
This study evaluates the water quality of five borehole water samples collected from various locations in Ekae Community, Benin City, Focusing on compliance with standard minimum distances from septic tanks using physicochemical parameters and the Water Quality Index (WQI) developed by Brown et al. (1972). Water quality parameters, including calcium (Ca), chloride (Cl), cadmium (Cd), nitrates (NO₃⁻ ), nitrite, electrical conductivity (EC), and pH, turbidity, TDS, TSS were analyzed and compared with World Health Organization (WHO) standards and the water quality index was calculated using the Weighted arithmetic index method (Brown et al.). Variance and standard deviation was calculated to understand the variability of water quality parameters across the different borehole locations. The WQI values for the sampling locations varied between 15.72489 and 61.04911, indicating water quality classifications ranging from excellent to poor. The findings revealed that BHF (WQI = 15.72489) and BHJ (WQI = 23.15213), which were located at control distances of 32m and 35m from septic tanks, respectively, had excellent water quality with minimal contamination, making them suitable for direct consumption with little to no treatment indicating the importance of complying to the acceptable distances between borehole and septic tanks which is 30-50m. BHK (WQI = 37.97593) and BHM (WQI = 37.97593), positioned at 24.81m and 21.99m from septic tanks, fell under the good quality category, indicating contamination that could be managed through basic treatment methods such as filtration and chlorination. The slight contamination may likely be from the untreated septic tank as a result of it not meeting the standard distance of WHO which is 30-50m and for the fact that other parameters checked for, were within safe limits. Conversely, BHW (WQI 61.04911), which was situated at a distance of 15.3m from the nearest septic tank, exhibited poor water quality, necessitating advanced purification techniques like reverse osmosis or activated carbon filtration to ensure its safety for consumption. The results indicates that the closer the septic tank is to the borehole, the more likely its going to be contaminated by infilteration from the septic tank. emphasize the impact of borehole-septic tank distance on water quality, highlighting the importance of adhering to recommended standards to minimize contamination risks.
