PHYSICO-CHEMICAL AND BACTERIALOGICAL ANALYSIS OF SHALLOW HAND-DUG WELL WATER IN ISOKO NORTH LOCAL GOVERNMENT AREA, DELTA STATE

Abstract

The study is aimed at assessing the quality of water from shallow hand-dug wells in Isoko North Local Government Area of Delta State from the month of September to November, 2015. The populace in the study area highly depends on this source of water for drinking and domestic activities. Water samples were collected from nine sites (W1, W2, W3, W4, W5, W6, W7, W8 & W9) from the study area. These samples were examined for heavy metal concentration using Atomic Absorption Spectrophotometer (AAS), bacteriological contamination and some physicochemical parameters. The results obtained were studied and compared with World Health Organization standard. The pH values obtained ranged from 4.22 to 6.08 showing that the water samples were slightly acidic. COD, DO and BOD values obtained all exceeded the permissible limit of  WHO standard showing that the water from the study area may cause detrimental effect to human life. Phosphates (15.84±5.70 – 17.87±5.20) and sulphates (520.02±91.69 – 544.18±96.26) contents were higher than the WHO permissible limit. The microbiological analysis showed that the total coliform and E.Coli count recorded values were not within WHO permissible limit which is an indication of faecal contamination. All other physic-chemical parameters (temperature (28.11±0.72 – 28.30±0.59), electrical conductivity (21.36±23.24 – 25.31±23.30), nitrate (5.73±0.93 – 5.86±0.98) and chloride (61.78±10.95 – 67.11±13.84)were within the acceptable WHO (2011) Permissible limits. The water samples from the wells had higher level of heavy metals. Mn (0.08±0.05 – 0.30±0.33), Fe (0.19±0.22 – 0.32±0.34), Zn (0.33±0.19 – 0.37±0.20), Cd (0.15±0.20 – 0.20±0.29), and Pb (0.19±0.24 – 0.19±0.32) were found to be above  the permissible limits of WHO specifications of 0.1 mg/l, 5mg/l, 0.5mg/l, 0.05mg/l and 0.05 mg/l for Mn, Fe, Zn, Cd  and Pb respectively except for Cr which was only detected in W6. The results obtained showed that the water from the study area were contaminated/polluted making the water unfit for drinking and other domestic uses. Contamination of this water source may have been caused by closeness of water source to pit latrine, domestic refuse dumps, stagnant water, bad sewage system and other human activities. Consequently, these ground water sources in thes study require treatment before they will be good for human consumption.