Abstract

This study investigated the impact of hydrocarbon recovery project activities on the surface water quality of a brackish coastal environment. Water samples were collected during both the dry and wet seasons, and physico-chemical characteristics were analyzed. Results showed that pH values ranged from 5.52 to 7.69, with more acidic values during the dry season. Conductivity and salinity values were normal for this ecosystem, ranging from 1.10 to 10.03 MS/CM and 150.3 to 3553.90 mg/l, respectively. Dissolved oxygen (DO) levels ranged from 2.5 to 6.41 mg/l during the dry season and 5.2 to 7.6 mg/l during the wet season. Biochemical oxygen demand (BOD) levels ranged from 26.70 to 110.60 mg/l during the dry season and 2.9 to 4.4 mg/l during the wet season, indicating higher eutrophication during the dry season. Turbidity, total solids, and total suspended solids levels were higher during the wet season. Nutrient and heavy metal levels were generally low, consistent with the ecosystem. Total hydrocarbon (THC) levels ranged from 0.01 to 79.42 mg/l, with the highest value recorded in one sampling location around the wellhead areas during the dry season. Overall, this study found that hydrocarbon recovery project activities had minimal impact on the surface water quality of the brackish coastal environment, but it is important to continue monitoring to ensure that it remains at acceptable levels.