Environmental Impacts Of Active And Decommissioned Landfill Sites In The Accra Metropolis: A Case Study Of The Pantang And Mallam Landfill Sites

ABSTRACT The study investigated the impacts of the Pantang and Mallam landfill sites in the Greater Accra Region on the surrounding environment. The Pantang landfill site is an active site that still receives waste of all kinds from various parts of Accra. The Mallam landfill, on the other hand, was decommissioned over a decade ago. Samples of leachate from the two landfill sites and air in the vicinity of the respective sites were taken over a period of three months and analysed. Soil samples were also taken from locations upslope and down slope of the Pantang landfill site and ground water was sampled from two wells, one about 30 metres from the Pantang landfill and the other about 150 metres away from the Pantang landfill site. The leachate, air, soil and groundwater samples were analysed in the laboratory for their physical and chemical constituents. Leachate, air, soil and groundwater samples from the Pantang landfill were coded PL, PA, PS and PG, respectively, and leachate and air from the Mallam landfill were coded M1L, MA. The pH of leachate from Pantang landfill ranged from 8.00-8.9 pH units (mean 8.35). The highest pH of leachate from the Pantang landfill was measured in March and the least in April. The turbidity of leachate from the Pantang landfill ranged from 93-309 NTU (mean 213.97). The highest turbidity of leachate from the Pantang landfill was measured in March and the least in February. The PM10 in air sampled from the vicinity of the Pantang landfill a ranged from 250.00 - 680.56 ug/m3 (mean 527.78). The highest PM10 of air sampled from the vicinity of the Pantang landfill was recorded in April and the least in March. The TSP in air sampled from the vicinity of the Pantang landfill a ranged from ranged from 291.67 - 875.00 ug/m3 (mean 665.56). The highest TSP of air sampled from the vicinity of the Pantang landfill was recorded in April and the least in March. iv The pH of soil sampled from the vicinity of the Pantang landfill ranged from 8.07 - 8.97 pH units (mean of 8.51) and the soil organic matter content from 4.243- 10.659 mg/kg (mean 7.523 mg/kg). The highest pH of soil sampled from the vicinity of the Pantang landfill was measured in February and the least in March. The highest soil organic matter content was measured in March and the least also in March but at different sampling locations. The pH of groundwater sampled from the Pantang landfill ranged of 6.84-7.4 pH units (mean 7.180) for well one and 7.56-8.6 (mean 8.06) for well two. The turbidity of groundwater sampled from the Pantang landfill ranged from 3.1- 4.6NTU (mean 4.0) for well one and 31.4-35 (mean 33.70) for well two. The pH of the leachate sampled from the Mallam landfill ranged from 8.15 -8.90 (mean 8.39). The highest pH of the leachate sampled from the Mallam landfill was measured in February and the least in March. The turbidity of the leachate sampled from the Mallam landfill ranged from 194 – 127 NTU (mean 152). The highest turbidity of the leachate sampled from the Mallam landfill was measured in March and the least in February and April. The PM10 of the air sampled from the vicinity of the Mallam landfill ranged from 13.89 - 27.78 (mean 23.15). The highest PM10 of the air sampled from the vicinity of the Mallam landfill was recorded in April and the least in March. The TSP of the air sampled from the vicinity of the Mallam landfill ranged from ranged from 27.78 - 41.67 ug/m3 (mean 37.04). The highest TSP of the air sampled from the vicinity of the Mallam landfill was recorded in April and the least in March. The assessments from the study showed that leachates from both landfills are polluted and may be impacting on the surrounding environment possibly especially on the soil and groundwater system.