The absence of Public Mining Area and continued use of mercury is responsible for the illegal gold mining and water pollution in Kahayan river. Efforts must be made to avoid and overcome environmental impact by strengthening coordination in central and regional level; empowering local community; and imposing sanction as law enforcement method. Belum adanya Wilayah Pertambangan Rakyat serta penggunaan merkuri mendorong terjadinya penambangan emas tanpa izin dan pencemaran air di Sungai Kahayan. Untuk mencegah dan menanggulangi pencemaran ini diperlukan koordinasi di tingkat pusat dan daerah; penyuluhan dan pendekatan di bidang sosial, ekonomi, budaya, hukum, dan teknologi; serta penegakan hukum secara tegas melalui penerapan sanksi.