சுற்றுச்சூழல் பகுப்பாய்வு வேதியியல் இதழ்

The Vulnerability of Underground Water Resources to Bacteriological Indicators in Parts of Owerri West of Southeastern Nigeria

Abstract

Ubuoh Emmanuel Attah

The Vulnerability of the selected boreholes to bacteriological indicators in Parts of Owerri West of Southeastern Nigeria was determined using Vulnerability Index (VI). Distances between the selected boreholes and anthropogenic activities were measured. Sampled Borehole (SBH) 3, 5, 8 did not meet the 30 m WHO STD, while defecation, bathing and washing of clothes were found within the circumference of SBH 6, 9 and 10 respectively. Total bacteria, total coliform and faecal counts were evaluated using the standard plate count method and the Most Probable Number (MPN) technique, respectively. The mean total bacteria count of the selected bore water samples ranged from 0.08-2.73 × 102 CFU that constituted between 0.59-20.31%, with the mean value of 1.34 × 102 CFU/ml, Total coliform count ranged from 6-19 MPN/100 ml constituting 4.72-14.96%, with the mean value of 12.7 MPN/100 ml and Faecal coliform count ranged from 9-21 CFU/ml constituting 7.09-14.69% with the mean value of 14.3 (CFU/100 ml) all above the WHO STD respectively. The isolated and identified bacteria include: Enterobacter sp., Alcaligenes sp., Escherichia coli, Proteus sp., Klebsiella sp., Pseudomonas aeruginosa, Acinetobacter sp., Staphylococcus aureus and Bacillus sp. accordingly. From the result of Vulnerability Index (VI) calculated and rated, the selected boreholes are highly affected by faecal count rated 0.21 within the rating of 0 signifying highly vulnerable. Furthermore, results of total bacteria a, total coliform and overall result of bacteriology using VI rating recorded 1.98, 1.02, 1.07 respectively, indicating highly resilient in rating. The vulnerability of the selected boreholes to bacteria means that, water resources in this area is not suitable for human consumption, hence water borne diseases.