The supervision conducted by the Environmental Agency of Siak Regency regarding the licensing of the palm oil mill at PTPN V Lubuk Dalam plays a crucial role in preventing river pollution in Siak Sri Indrapura Regency. This study explores how the agency oversees compliance with environmental regulations, specifically focusing on the issuance of Environmental Impact Analysis (AMDAL) and feasibility tests required for the palm oil industry. The agency’s responsibilities include continuous monitoring, evaluation of compliance with environmental standards, and field inspections. Despite its importance, the supervision process
faces challenges such as limited staffing, which constrains the frequency and scope of inspections, and technological limitations that necessitate reliance on third-party
laboratories for environmental parameter measurements. To address these issues, it is recommended to increase the number of environmental officers, invest in modern technology for direct environmental monitoring, and improve scheduling coordination with PTPN V Lubuk Dalam. These measures aim to enhance the effectiveness of environmental oversight and ensure better prevention of river pollution, thereby contributing to the sustainability of the local ecosystem and public health in Siak Sri Indrapura.