Impact of rainfall on natural attenuation of diesel and waste oil within urban base transceiver stations

Very low grid power penetration in some urban areas has led to telecoms companies investing massively in the deployment of diesel generators (DGs). These deployments have led to diesel and waste oil spill at base transceiver station (BTS) sites during maintenance cycles, impacting the environment and human activities. The objective of this study is to evaluate the impact of different rainfall intensities on the amount of waste oil and diesel leached or retained in the soil during natural attenuation.   The soil at base transceiver station was analyzed using response surface methodology (RSM). The experiment was carried out following the design of experiment approach with a 33 factorial. Three factors include contaminant volume, rainfall intensity, and soil depth on which the two response variables (leached and retained were utilized. It was observed that rainfall intensities at 5mm/hr, 7.25, 9, and 10mm/hr has a significant impact on the amount of waste oil leached (1611.63mg/l) and retained (15888.9%) in the soil, though the amount of oil leached is inversely proportional to the amount retained as affected by different rainfall intensities considered in this work. Additionally, it was observed that rainfall intensity increases as the amount of oil leached decreases at higher soil depth while the amount of oil retained increases at lower soil depth. However, the significance of the impact of the different rainfall intensities is dependent on the soil depth.   The regression coefficient was found to be 72 % for waste oil retained and 67 % for the leached amount, hence the quadratic model developed in this study, demonstrated a higher accuracy for %retained rather than the amount of oil leached. However, this implies that the model is reliable, dependable, effective and accurate and thus recommended for use.