Assessment of Physical and Chemical Quality of Groundwater in Selected Communities in Katsina State, North West Nigeria

Groundwater constitutes the primary drinking water source for the majority of rural and peri-urban communities in Katsina State, yet its quality is frequently compromised by geological and anthropogenic factors. This study assessed the physicochemical quality of groundwater from hand-dug wells and boreholes in ten communities across three local government areas in Katsina State, North West Nigeria. Water samples were collected in pre-cleaned polyethylene containers and analyzed for pH, electrical conductivity, total dissolved solids, hardness, nitrate, fluoride, iron, and manganese using standard procedures. Results indicated that fluoride concentrations exceeded the WHO guideline of 1.5 mg/L in thirty-eight percent of sampled sources, predominantly from deeper boreholes in the northern communities. Iron concentrations surpassed the 0.3 mg/L aesthetic guideline in fifty-one percent of hand-dug wells. Total hardness exceeded the 200 mg/L WHO guideline in forty-seven percent of samples. pH values were within acceptable ranges across most sources. Nitrate levels were elevated in communities where pit latrines were located within fifteen metres of water sources. Dental fluorosis was clinically observed in a significant proportion of school-age children from high-fluoride communities. The study recommends defluoridation treatment options, community education on groundwater protection zones, and enforcement of minimum setback distances between latrines and water sources. Keywords: groundwater quality, fluoride, Katsina, physicochemical parameters, drinking water.