Evaluation of limnological variables in selected ground water sources in sokoto north local government area

Abstract

Well water is a vital water source for many communities globally, therefore, it’s important to
assess its quality to ensure public health, sustainability, and development. This study aimed to
evaluate the limnological characteristics of selected well water in Sokoto North Local
Government Area (LGA), Sokoto State. Key parameters analyzed included water pH, dissolved
oxygen (DO), total oxygen demand (TOD), total organic carbon (TOC), nitrate and phosphate
concentrations, water hardness, and total coliform bacteria. Water samples were analyzed using
standard procedures, MPN technique was employed for coliform enumeration. Results
indicated neutral pH levels across all wells, suggesting the absence of industrial or acidic
contamination. Dissolved oxygen levels ranged from 16.26 to 16.36 mg/L, within acceptable
limits for drinking water. However, water hardness exceeded permissible thresholds set by the
Nigerian Standard for Drinking Water Quality (NSDWQ) and the World Health Organization
(WHO), with Well A recording the highest value of 844 mg/L. Phosphate concentrations were
significantly above recommended limits. Microbial analysis revealed the presence of
pathogenic bacteria, including Salmonella spp., Escherichia coli, and Staphylococcus aureus,
with Wells 1 and 2 exhibiting microbial loads that rendered the water unsafe for direct
consumption. These findings reveal the urgent need for regular monitoring, effective treatment,
and community education to ensure the safety and sustainability of well water sources. The
implementation of filtration systems and routine water quality testing is recommended to
mitigate contamination risks.
Keywords: Contamination, Drinking-Water, Escherichia, Microbial, Sokoto