Groundwater quality

Groundwater and borehole water remain a vital source of drinking water in many Nigerian cities, yet their quality is often compromised by physicochemical and microbial contamination. This study assessed the physicochemical and bacteriological analysis on water sources in University of Benin Ekenwan Campus Benin City, Edo State, Nigeria. A total of eighteen water samples
were collected from six hostel locations including Notre Dame, Uniben Table Water, Bore-hole source Water, Boy’s hostel, Postgraduate hostel, and Girl’s hostel, and analysed using the method of A.O.A.C. The microbiological analysis was analysed using standard microbiological methods. The results revealed that physicochemical analysis revealed that pH values of the
water ranged between 4.58 and 6.38, falling below the FEPA acceptable limit of 6.5–8.5. Most physicochemical parameters analysed were below permissible limits, however, iron (0.56–1.06 mg/L) and chromium (0.10–0.25 mg/L) exceeded the FEPA limits of 0.3 mg/L and 0.05 mg/L respectively. Microbiological results showed high contamination across hostel water samples. Presumptive coliform counts ranged from 6.67×10³ cfu/ml (Notre Dame) to 2.83×10⁴ cfu/ml (Boys hostel), aerobic bacterial counts ranged from 6.67×10³ cfu/ml (Notre Dame) to 8.67×10⁴ cfu/ml (Postgraduate hostel), while fungal counts ranged from 1.00×10¹ sfu/ml (Notre Dame) to 2.00×10² sfu/ml (Boys hostel). The microbial results exceeded WHO and FEPA permissible
standards. Identified bacteria include Staphylococcus aureus, Corynebacterium spp., Aeromonas hydrophila, Pseudomonas fluorescens, Klebsiella aerogens, Enterobacter aerogens and Chromobacterium violaceum, Penicillium notatum, Aspergillus flavus, Aspergillus niger and Microsporum audouinii. Among bacteria, K. aerogens had the highest occurrence (21.9 %)
while A. hydrophila had the least occurrence (9.4 %). Among fungi, A. flavus (35.7%) was the most frequently occurring, while M. audouinii (14.3 %) had the lowest occurrence. Antibiotic sensitivity testing before plasmid curing showed multidrug resistance across isolates. Staphylococcus aureus displayed resistance to amoxicillin, augmentin, pefloxacin, azithromycin, and ceftriaxone, with the highest multidrug resistant index (MDRI) of 0.8. Pseudomonas fluorescens and Enterobacter aerogens each had an MDRI of 0.5, while Corynebacterium spp. and Chromobacterium violaceum exhibited MDRI values ranging from 0.2 to 0.3. After plasmid curing, resistance was lost in several isolates, with A. hydrophila, S. aureus, Corynebacterium spp., P. fluorescens, K. aerogens and C. violaceum showing susceptibility to tested antibiotics. This study demonstrated that while physicochemical parameters of water sources in Ekenwan Campus were largely within permissible limits except for iron and chromium, the
microbiological quality was grossly compromised. The detection of multidrug resistant organisms, both plasmid-mediated and chromosomal, highlights the public health risk associated with these water sources. The findings confirm that water supplied in these hostels is unsafe for direct consumption and requires adequate treatment and disinfection to reduce risks of waterborne infections and antibiotic-resistant outbreaks in the student community

A groundwater quality assessment was conducted in Ikpoba Okha Local Government Area, Edo State, to evaluate the levels of physicochemical parameters within the region. Fifteen (15) borehole water samples were randomly collected and analyzed to determine their physicochemical characteristics. Both statistical and cluster analyses were applied to interpret the data. The dendrogram, a key output of the cluster analysis, illustrated the Euclidean distance at which different elements and clusters merged. Four distinct clusters were identified, with Cluster 1comprising mainly heavy metalsshowing strong correlations and similarities among related parameters. The study examined parameters such as pH, turbidity, total dissolved solids (TDS), electrical conductivity, salinity, and total suspended solids (TSS). Anions including sulfate, phosphate, nitrate, and carbonate were also analyzed, while heavy metals and cations such as sodium (Na), potassium (K), calcium (Ca), and magnesium (Mg) were determined using a flame atomic absorption spectrometer. Results indicated that the pH of the groundwater samples ranged between 5.28 and 5.98, suggesting slight acidity. TDS values varied from 5.34 to 6.22 mg/L, while nitrate concentrations ranged from 1.54 to 2.12 mg/Lall within the World Health Organization (WHO) permissible limit of 10 mg/L. Copper concentrations were found between 0.039 mg/L and 0.086 mg/L, with borehole BH9 recording the highest value and BH15 the lowest. Manganese levels ranged from 0.05 mg/L to 0.35 mg/L, exceeding the WHO guideline of 0.1 mg/L in only one sample (BH8). Overall, the findings suggest that while some boreholes meet WHO standards, othersespecially wellsexceed acceptable limits for certain parameters, rendering them unsuitable for human consumption. The deterioration of groundwater quality in the area is likely attributed to
anthropogenic activities such as improper waste disposal and sewage discharge.