ENVIRONMENTAL IMPACT ASSESSMENT OF A PROPOSED TANKFARM
ABSTRACT
This study was carried out to assess environmental impacts of a proposed tankfarm which is to be situated at the Olokola Free Trade Zone in Ondo State (OKFTZ). It encompasses various field sampling which includes soil, air and noise sampling taken from the proposed site. These samples were tested in the laboratory for parameters such as Total Hydro Carbon, pH values, Total Mean Percentage of Organic Matter, Heavy Metal Investigation, cation concentration. The Total Hydro Carbon which ranges from 4.8 to 33.0 milligram per kilogram (mg/kg) in the wet season and 4.0 to 78.5 mg/kg for dry season. The THC is reflective of an unpolluted environment, and it is widely accepted that soils with a hydrocarbon level below 100 mg/kg are considered unpolluted. Heavy metals investigation showed that Iron had the highest mean concentration (2213mg/kg) followed by Zinc (4.82mg/kg) and Copper (3.78mg/kg) for dry season while for wet season, Iron had 2039mg/kg followed by Zinc (8.68mg/kg) and copper (3.0mg/kg). The concentration of the monovalent cation in the soils was generally high. Sodium (Na) concentrations ranged between 2,136 and 7,341mg/kg in the wet season and 6,175 and 10,308 mg/kg in the dry season while potassium (K) ranged between 0.09 and 0.15 mg/kg in the wet season and 0.04 and 0.45mg/kg in the dry season. The high sodium content could be attributed to the proximity of the study area to the ocean. Suspended Particulate Matter Levels for Wet and Dry Season on shows that there are more suspended particulate matter in the dry season as the result indicated a value of 196 µg/m3 against 64µg/m3 in the wet season. Comparing these findings with EGASPIN guidelines for national air quality standards, more air quality monitoring is needed during the dry season as it reaches a high of 196 though it is still within the EGASPIN (Environmental Guidelines and Standards for Petroleum Industries in Nigeria) limits. Noise measurements showed that the measured levels varied significantly in the different locations monitored and ranged from a low of 55.2dB to a high of 66.7dB, for the dry season and 52.7dB to a high of 67.9dB, for the wet season as compared to the World Bank standard of 45 dB(A) for residential areas during the daytime. It is recommended that environmental performance be monitored regularly to ensure compliance and those measures to be taken where necessary. The OKFTZ site is generally suitable for the proposed bulk fuel storage facility and all environmental risks can be minimized and managed through implementing preventative measures and sound environmental management systems.
CHAPTER ONE
INTRODUCTION
Environmental Impacts Assessment is an assessment or the analysis of the possible positive or negative impact that a proposed project may have on the environment together consisting of the environmental, social and economic aspects (International Association of Impact Assessment, 2002). Environment Impact Assessment or EIA can also be defined as the study of predicting the effect of a proposed activity/project on the environment. A decision making tool, EIA compares various alternatives for a project and seeks to identify the one which represents the best combination of economic and environmental costs and benefits. EIA systematically examines both beneficial and adverse consequences of the project and ensures that these effects are taken into account during project design. It helps to identify possible environmental effects of the proposed project, proposes measures to mitigate adverse effects and predicts whether there will be significant adverse environmental effects, even after the mitigation is implemented (IAIA , 2002). By considering the environmental effects of the project and their mitigation early in the project planning cycle, environmental assessment has many benefits, such as protection of environment, optimum utilization of resources and saving of time and cost of the project (Wikipedia, 2013).
Environment refers to the totality of natural resources including the intricate interrelations among living and non living things which constitute the ecosystem and biomes (Randall et al; 1987). Webster’s new collegiate dictionary (2012) defined environment as the aggregate of all the external conditions and influences affecting life and development of organisms. Sada and Odemerho (2001) conceive environments as a system within which living organisms interact with the physical elements. Environment is a common property not only of existing stakeholders but also of the future generations (Okonkwo, 2004) A Tankfarm is also known as an oil depot or oil terminal, a facility for storage of petroleum products or petrochemical products from which these products are usually transported to end users for further storage facilities. An oil tankfarm typically has tanks or either above or under the ground and gantries for the discharge of products into road tankers or other vehicles such as barges or pipelines. Tankfarms are usually situated close to oil refineries or locations where marine tankers or vessels containing products discharge their cargo.
A Tankfarm is a comparatively unsophisticated facility in that (in most cases) there is no processing or other transformation on site. The products which reach the depot from refinery are in their final form suitable for delivery to customers. Modern Tankfarms comprise the same types of tanks, pipelines and gantries as those in the past and although there is a greater degree of automation in site, there have been significant changes in depot operational activities over time (Wikipedia 2013). One of the key imperatives of Health, Safety and Environment (HSE) is that the operators of a Tankfarm must ensure that products are safely stored and handled. There must be no leakages which could damage the soil or the table water and these forms of undesirable activities gives rise to the analysis of some predictable and unpredictable impacts of Tankfarm to the existing environments and thus brought about the delivery of this project.
