ASSESSMENT OF OPEN WASTE DUMP IMPACTS ON SOIL PROPERTIES IN GWAGWALADA AND BWARI AREA COUNCILS, FEDERAL CAPITAL TERRITORY, NIGERIA

Abstract

This study assessed the impacts of open waste dump on soil properties in Gwagwalada and Bwari Area Councils, Federal Capital Territory, Nigeria. The study achieved two objectives: analysed the distribution of soil properties; and the correlation of the soil properties at dumpsites. A total of eighty-one (81) soil samples were collected from three purposely selected dumpsites (Mpape, Gwagwalada and Kwuba) and control sites. Samples of top and sub soils were collected at 0m, 20m, 40m and 60m from the three dumpsites and their control sites. Data were analyzed using range, mean, Standard deviation and correlation. Results shows that the mean concentrations of pH at dumpsites were 7.43 ± 0.65 and 7.42 ± 0.86 for the top and sub soils respectively the control point has a value of   5.20 and 5.47 in the top and subsoil respectively. Organic matter 5.50 ±0.89 and4.74 ±0.81 for the top and sub soils respectively, while the control site had a value of   2.65% and 2.49% in the top and sub soils respectively. The study found both positive and negative impacts of waste at the dumpsites. On the positive side, results indicate that waste add to soil organic matter and essential nutrients such as nitrate, potassium, phosphate, calcium, magnesium and sodium. On the negative side, it elevated the concentrations of heavy metals. The coefficient of multiple determination (R²) was 96%, thus, the soil quality parameters tested explained 96% of the overall soil quality leaving only 4% unexplained. In conclusion, the concentrations soil chemical properties show that waste dumps had both positive (addition of organic matter and essential nutrients) and negative (elevated heavy metals) impacts on the soils at the dumpsites. It was recommended that authorities in the study area should invest in waste management and environmental protection activities as high concentrations of heavy metals were recorded at the dumpsites than control site.