This article presents a methodology for designing passive degassing systems for the reclamation of unauthorized solid municipal waste  landfills using BIM technologies. The study addresses the challenge of heterogeneous terrain in landfill bodies and aims to optimize the design process. The proposed approach integrates digital terrain modeling to account for uneven relief, enhancing the accuracy and efficiency of degassing system calculations.

The research begins with an analysis of the current state of waste management in Russia, highlighting the predominance of landfilling as the primary disposal method. The authors emphasize the environmental risks associated with landfill gas emissions, particularly methane, and the need for effective degassing solutions. Traditional methods often overlook terrain heterogeneity, leading to suboptimal system performance.
The methodology involves six key stages: (1) creating a digital terrain model using Autodesk Civil 3D, (2) restructuring the landfill body to meet regulatory standards, (3) calculating waste volumes, (4) estimating gas generation rates based on morphological waste composition, (5) placing degassing wells according to terrain-specific criteria, and (6) evaluating system efficiency. The study compares the proposed method with traditional approaches, demonstrating a 21% cost reduction and a 14.27% improvement in biogas extraction efficiency.
The results underscore the economic and environmental benefits of the new methodology, which leverages BIM technologies to optimize degassing system design. The authors recommend further research to account for vertical gas generation variability and regulatory constraints on emissions. This study contributes to the development of sustainable landfill reclamation practices, aligning with modern environmental standards.

Keywords: reclamation, landfill gas, passive degassing, BIM technologies, solid municipal waste, calculation methodology, ecology, biogas, unauthorized landfills, optimization