Environmental Risk Assessment in a LNG Plant

Abstract

This study is devoted to implement an environmental risk assessment (ERA) methodology for a Liquefied Natural GAS (LNG) plant located in Spain. ERA also includes the estimation of the Environmental Damage Index (EDI) and the calculation of the economical guarantee established by the Environmental Responsibility Offer Model (EROM). This study has been carried out according to Spain regulations, in particular, Royal Decree 183/2015 of environmental responsibility. The environmental risk assessment was performed using the Spain Natural Gas methodology unified with ERA procedure established by AENOR in UNE-150.008-2008 standard. Applying the methodology, different hazardous agents were identified in the LNG plant such as diesel, THT, hydraulic oil, sodium bisulfite, natural gas and others. They were also considered different initiating events (including tanks failure, pipeline ruptures and cisterns leakage) reaching different accidental scenarios where marine water and seabirds were the resources affected. Seawater pollution with diesel was the accidental scenario selected to calculate the financial guarantee, because it has the highest percentage of risk. Environmental evaluation identified the affectation of 708 m3 of marine water, 4 threatened and 178 non-threatened seabird species. The marine water affectation covers 84.91% of the total guarantee estimation, representing the relevant damage to the environment by diesel spill.