Produced water can cause environmental pollution because it contains hydrocarbon compounds as well as organic and inorganic substances. The high volume of produced water requires an appropriate treatment system to reduce its concentration. However, the treatment process can cause other environmental impacts from the equipment and machinery used, which have not been widely evaluated. The study aims to analyze the environmental impacts of the MGS WTP using a life cycle assessment (LCA) with gate-to-gate system boundaries. Operational data on energy consumption, chemicals, materials, and emissions were used for life cycle inventory and modeled in SimaPro using the CML-IA Baseline method. The analysis results show that climate change has the largest impact of 81.34 million kg CO2˗eq, followed by marine aquatic ecotoxicity of 141.32 million kg 1.4˗DB˗eq and abiotic depletion (fossil fuels) at 13.51 million MJ. The contribution analysis identified air stripping and biological processes as environmental hotspots, which contribute more than 75% of carbon emissions due to high electrical energy consumption. The study results show that energy efficiency can be achieved in high-energy consumption units by using low-carbon electricity sources and improving sustainable wastewater management in the oil and gas sector.