This research examines the legal responsibilities of Mining Business Permit (IUP) holders in implementing environmental mitigation measures related to sand mining activities on the slopes of Mount Merapi, Sleman Regency, with a focused
case study on PT. Jaya Abdi Perkasa Group. The study applies an empirical legal research method supported by a qualitative approach. Primary data were obtained through interviews with the company’s legal representative, the Environmental Agency (DLH) of the Special Region of Yogyakarta, and the Energy and Mineral Resources Office (ESDM) of the region, while secondary data were derived from
statutory regulations including the Mineral and Coal Mining Law and environmental protection regulations. The findings indicate that the company has fulfilled several administrative and social environmental obligations, such as the implementation of UKL-UPL documents, submission of reclamation guarantees, periodic environmental reports, and community-based Corporate Social Responsibility (CSR) programs. However, the effectiveness of mitigation remains suboptimal, as environmental degradation in the form of erosion, decreasing water quality, altered river morphology, and social disruptions continues to occur around the mining area. The constraints are primarily caused by limited environmental management budgets, weak regulatory coordination among authorities, and insufficient enforcement of environmental principles such as the polluter pays principle and the precautionary principle. Therefore, enhanced supervision, stronger regulatory synergy, and a more comprehensive reclamation program are required to ensure sustainable mining practices in the disaster-prone Merapi region.