Assessing Spatial-Temporal Variability in Water Quality of Hand Dug Wells in Minna and Surrounding Areas, Niger State, Nigeria.
Abstract:
This study investigated the spatial-temporal variability of water quality in hand-dug wells in Minna and its surroundings, where water pollution from these wells is a significant concern. To address this issue, groundwater quality assessment was conducted using spatial analyst tools in GIS. The study focused on analyzing selected physicochemical and microbiological parameters of hand-dug well water through a mixed methods approach involving both quantitative and qualitative research methods.
A total of twenty-four water samples were collected during both the rainy and dry seasons from four locations and subjected to laboratory testing to assess physicochemical parameters (color, odor, pH, temperature, turbidity, conductivity, total dissolved solids (TDS), Cl–, SO4, NO3, acidity, alkalinity, total hardness (TH), and total suspended solids (TSS)) as well as bacteriological parameters (S. aureus, P. aeruginosa, E. coli, S. typhi). The obtained results were compared against the National Standard for Drinking Water Quality (NSDWQ) and World Health Organization (WHO) standards, using standard laboratory testing methods. Statistical analyses, including one-way ANOVA and Duncan PostHoc, were conducted to assess the data. Additionally, Water Quality Index (WQI) and Inverse Distance Weighted Technique in GIS were employed to analyze the spatial distribution of parameters.
The results revealed that the physicochemical parameters generally met the NSDWQ and WHO standards for both the rainy and dry seasons, except for color, odor, Cl–, and TH, which exceeded the permissible limits. Brownish color and odors were detected in a limited number of samples during the rainy season. TH levels were significantly higher during the dry season, particularly in the locations MK and MT, surpassing the NSDWQ and WHO limits. Similarly, Cl– levels were notably higher in MK and MR during both seasons, exceeding the permissible limits set by NSDWQ and WHO.
Concerning microbiological parameters, all well samples were found to be significantly contaminated with pathogenic bacteria, exceeding the NSDWQ permissible limit of 0 cfu/ml. Seasonal variation showed that S. aureus was not detected during the dry season in MR, and P. aeruginosa was absent in CH and MT during the rainy and dry seasons, respectively.
The WQI results indicated that the physicochemical aspect of water quality in the study area was classified as excellent and good during the rainy season, while the dry season exhibited excellent, good, and poor classifications.
In conclusion, the physicochemical parameters of the well water samples generally indicated suitability for drinking and domestic purposes. However, the high contamination of pathogenic bacteria suggested faecal contamination due to poor sanitation and hygiene practices. Recommendations include softening water hardness for domestic use using soda and vinegar, chlorinating contaminated wells with professional assistance, boiling water contaminated with pathogenic bacteria before use, providing protective covers for wells, ensuring proper hygiene and sanitation around well water environments, and implementing treated water/boreholes for all residents in Minna and its environs.
Assessing Spatial-Temporal Variability in Water Quality of Hand Dug Wells in Minna and Surrounding Areas, Niger State, Nigeria.