Industrial discharges pose global ecological risks. This study investigates Algeria’s GL1K (gas liquification complex of Skikda) plant’s hazardous effluents. The impact assessment evaluates the environmental repercussions of the researched facilities, including the effects on populations and their way of life. Thus, it is possible to stress suggestions to improve facility design to remove or restrict negative effects and to minimize or compensate for the current facility’s unfavorable repercussions. This technique is consistent with establishing and monitoring the industrial plant’s environmental management system. The method utilized to determine impacts in this EIA can be used to evaluate the EMS’s significant aspects and effects and provide improvement options. An evaluation matrix can rate impacts, the grid and criteria are based not regulation but on “good practices” for this type of assessment, and results obtained from modelling the effects using PHAST software. Therefore, they can be modified to fit the facility’s activity. Based on examining activities and identifying elements likely to interact with the environment, environmental aspects are identified using the proposed grid and criteria. This study describes a section-by-section approach. Each determined environmental impact can be graded based on environmental factor criteria.