Evaluation of Groundwater Quality using Normal Statistical Probability Distribution in Egwi Etche, Rivers State, Nigeria

Abstract

A comprehensive physicochemical assessment of groundwater quality in Egwi Etche Local
Government Area, of Rivers State Nigeria has been conducted using experimental procedures and
normal distribution charts. The study sought to determine the physicochemical properties of
groundwater and its suitability for domestic purposes in the area. High nitrate and iron content
levels observed have been associated with wastewater from farms and homes. The pH values for
boreholes 1-6 are as follows; 6.73, 6.90, 6.69, 6.58, 6.71 and 6.60 respectively. From the results
obtained it is within the World Health Organization (WHO) and Nigerian Industrial Standard
(NIS) standard of 6.5-8.5. The iron content for boreholes 1-6 are as follows; 0.192, 0.207, 0.168,
0.170, 0.20 and 0.28 respectively. From the results obtained the iron content is not in line with the
WHO standard of 0.1mg/l but is within the NIS standard of 0.3mg/l. The sulphate concentrations
for boreholes 1-6 are as follows; 36.12, 41.30, 40.33, 21.80, 28.50 and 29.77 respectively.
Sulphate has no specific range of concentration from the WHO but is considered safe according to
the NIS standard of 100mg/l. The chloride concentrations for boreholes 1-6 are as follows; 8.40,
12.41, 6.58, 5.64, 4.90 and 3.048 respectively. Chloride has no specific range of concentration
from the WHO but is within the NIS standard of 250 mg/l. Some parameters from the
physicochemical properties like sulphate, conductivity, turbidity, TSS and Reactive silica followed
the normal statistical probability distribution. The groundwater quality of the area has been
classified as generally “safe” for domestic purposes.