Effect of Solid Waste Leachate on the Quality of Underground Water Around Ruhueli Dumpsite in Rumuomoi Community, Rivers State, Nigeria

Abstract

This study investigated the impact of open dumpsite leachate on groundwater quality by examining the physicochemical and microbiological properties of groundwater within the vicinity of a dumpsite in Ruhueli-Rumuomoi community, Rumuigbo, Rivers State, Nigeria. Groundwater samples were taken from three different boreholes in the study area at a distance of 30 m, 60 m and 90 m from the dumpsite. The results of the physicochemical parameters revealed that pH ranged from 5.54–5.85, temperature: 28.90–29.30^oC,turbidity:2.84–3.90 NTU, conductivity:44.19–91.13 μS/cm, salinity:78.9–83.12 mg/l, total dissolved solid:18.96–44.34 mg/l, total hardness: 36.11–48.30 mg/l, alkalinity: 59.97–62.31 mg/l, chloride: 72.92–73.60 mg/l, sulphate: 32.98–35.13 mg/l, nitrate: 2.27–3.06 mg/l, phosphate: 68.90–71.57 mg/l, calcium: 46.60–51.18 mg/l, magnesium: 0.029–0.040 mg/l, Iron: 0.196–0.270 mg/l, sodium: 19.80–23.06 mg/l, copper: 0.16–0.24 mg/l, total suspended solid: 3.47–3.90 mg/l, zinc: 1.03–1.41 mg/l, colour:3.40–4.14 Hazen, dissolved oxygen:6.21–6.60 mg/l, reactive silica: 2.80–3.66 mg/l, and bicarbonate: 17.29–22.19 mg/l. The microbiological results of the borehole water samples revealed that the counts of total heterotrophic bacteria (THB) ranged from 18.4–29.5 cfu/100 ml, total coliform: 15.6–32.6 cfu/100 ml and fecal coliform: 0–3.6 cfu/100 ml. The physicochemical parameters considered were below the WHO permissible limits for drinking water quality. However, the microbiological analytical values of the groundwater samples exceeded the WHO permissible standard for THB (1cfu/100ml), total coliform (0 cfu/100 ml) and fecal coliform (0 cfu/100 ml), indicating microbial pollution of the groundwater. Thus, it can be inferred from these results that organic matter from the dumpsite, has systematically infiltrated through the soil and contaminated the groundwater within the period of study. More so, the correlation analysis carried out for THB with respect to distances of the boreholes from the dumpsite gave a strong correlation coefficient of 0.964, attesting that groundwater pollution is affected by the distances between the boreholes and the dumpsite. Therefore, this study recommends that there is need for proper planning and strategic management of waste disposal and water treatment approaches.