EVALUATION OF NITRATE SOURCES AND FATE IN SHALLOW HAND DUG WELLS IN AN URBAN AREA: A CASE STUDY OF ENUGU URBAN SOUTHEASTERN, NIGERIA.

This paper entails the results of nitrate analysis performed
in the shallow groundwater samples of Enugu urban. The study reveals
that unorganized sewage system, agricultural waste, solid waste and
industrial effluents have greatly threatened the shallow groundwater
resources in Enugu. Study also shows that hand dug well samples within
Ugwuaji, Gariki, Uwani and Awkunanow have shown nitrate (46.3
mg/l - 51.3 mg/l) content exceeding the limit of WHO and NSDQW
recommendations. However, hand dug well samples from Coal Camp as
well as Ugwuaji areas have shown to have phosphate (5.4 mg/l - 6.0
mg/l) content exceeding the WHO recommendation limit. Highest
concentration of nitrate (51.3 mg/l) was found in the hand dug well
sample from Ugwuaji at a depth of 5m. A significant observation reveals
that the contamination of nitrate is higher at depth zone of 5-10m.
However, the nitrate contamination in hand dug well is also decreases
with depth below 22m. Phosphate contamination of hand dug wells are
also observed to be decreasing with depth.