Environment and Ecology Research Vol. 7(4), pp. 220 - 238
DOI: 10.13189/eer.2019.070403
Reprint (PDF) (1087Kb)

Physico-Chemical Analysis in Surface Waters around the Closed Gaborone Sanitary Landfill in Botswana

R. D. Gwisai ^1,2,*, O. O. Areola ¹, E. M. Segosebe ^1
1 Department of Environmental Science, University of Botswana, Botswana
² Department of Environmental Science, Bindura University of Science Education, Zimbabwe

ABSTRACT

The aim of the study was to ascertain the pollution levels in water sources in the areas surrounding the closed Gaborone landfill site. The study focused on the physico – chemical analysis of surface water resources around the closed Gaborone landfill site. The specific objectives were to determine the properties of surface water around the landfill and compare them along a transect with the water sources upslope and downslope of the landfill. Furthermore, the probable impacts of the wastes on water resources are highlighted and the levels of heavy metal contamination in surface waters around the closed Gaborone landfill are shown, in addition to compare the findings in this study with set standards (WHO, USEPA, FAO, EU, USSR and BOBS) and other yardsticks from previous studies. Due to scarcity of water resources and poor drainage water levels, five (5) existing surface water samples were collected offsite along a spatial gradient transect while the sampling interval was based on the length of the slope below the landfill. Field sampling and laboratory analysis of surface water resources was done so as to ascertain physico – chemical and heavy metal pollution levels. The findings of the investigations show that physical parameters such as pH, Electrical Conductivity, turbidity, TDS and TCU levels at the closed Gaborone landfill are above the drinking water standards BOS 32: 2000, WHO (2004) and USEPA (1991) limits and there is a general decline in pH, EC, TSS, TVS, TSD and TCU with increasing distance from the landfill site. While the chemical properties show that alkalinity, nitrates, phosphates, sulphates, chlorides, calcium, magnesium, chromium, and ammonia levels for the closed Gaborone landfill are higher than BOS 32: 2000, WHO (2004) and USEPA (1991) limits indicating toxicity. The general trend patterns show that there is a general decline in alkalinity, BOD₅, sulphates, phosphates, nitrates, magnesium, calcium and chromium levels with increasing distance from the closed Gaborone landfill while chlorides levels are increasing. There was a significant decline in alkalinity, EC, sulphates, and calcium with increasing distance at P = 0.05. On the other hand, BOD5 levels can be classified as clean to moderately polluted. Overall, sanitary landfills have a far-reaching impact on the surrounding water resources and if left unmonitored increased pollution levels could lead to compromised drinking water quality, public health deterioration and descending environmental eminence.

KEYWORDS
Gaborone Landfill, Heavy Metals, Physico-Chemical, Surface Waters, Water Resources

Cite This Paper in IEEE or APA Citation Styles
(a). IEEE Format:
[1] R. D. Gwisai , O. O. Areola , E. M. Segosebe , "Physico-Chemical Analysis in Surface Waters around the Closed Gaborone Sanitary Landfill in Botswana," Environment and Ecology Research, Vol. 7, No. 4, pp. 220 - 238, 2019. DOI: 10.13189/eer.2019.070403.

(b). APA Format:
R. D. Gwisai , O. O. Areola , E. M. Segosebe (2019). Physico-Chemical Analysis in Surface Waters around the Closed Gaborone Sanitary Landfill in Botswana. Environment and Ecology Research, 7(4), 220 - 238. DOI: 10.13189/eer.2019.070403.