JOURNAL OF DEGRADED AND MINING LANDS MANAGEMENT Volume 10, Number 2 (January 2023):4143-4153, doi:10.15243/jdmlm.2023.102.4143 ISSN: 2339-076X (p); 2502-2458 (e), www.jdmlm.ub.ac.id Open Access 4143 Research Article The feasibility of converting ex-coal mining void into aquaculture in North Kalimantan Yoppie Christian 1* , Andy Afandi 1 , Budi Prabowo 1 , Novit Rikardi 1 , Desmiwati 2 1 Center for Coastal and Marine Resources Studies (CCMRS) Bogor Agricultural University, Jl. Raya Pajajaran No. 1 Bogor, Indonesia 2 Research Center for Society and Culture, National Research and Innovation Agency (BRIN), Jl. Gatot Subroto No.10, Jakarta, Indonesia * corresponding author: lakulintang@gmail.com Abstract Article history: Received 2 September 2022 Accepted 24 October 2022 Published 1 January 2023 Ex-coal mining void has changed landscape shape, physical-chemical, and soil biological properties. As a form of post-mining management, the company must restore damaged land and increase its benefits for the surrounding community, one of which is as a freshwater aquaculture area. This study was conducted in a 50.26 ha void in the concession area of the coal mining company PT. Mitrabara Adiperdana (MAP) in Malinau Regency, North Kalimantan. The method used is by examining the physical quality of the environment in the laboratory using the quality standards in Indonesian Government Regulation (PP) No. 82 of 2001 and No. 22 of 2021. A study was also conducted on the assessment of community acceptance. The study found that freshwater aquaculture for pangasius (Pangasius sp.), snakehead (Channa striata), and tilapia (Oreochromis sp.) is appropriate to apply on location with several notes: reducing the concentration of suspended solids; reducing the content of phosphate and ammonia, and reducing the concentration of lead (Pb). Regarding these issues, two methods can be used: technology of turbine and nanobubble and natural-based solution through wetland ecosystem and void basin rehabilitation. At the same time, education and promotion of the surrounding community can be applied by involving communities during the piloting and demonstration plot process. Keywords: coal mining ecosystem freshwater aquaculture North Kalimantan voids To cite this article: Christian, Y., Afandi, A., Prabowo, B., Rikardi, N. and Desmiwati. 2023. The feasibility of ex-coal mining void into aquaculture in North Kalimantan. Journal of Degraded and Mining Lands Management 10(2):4143-4153, doi:10.15243/jdmlm.2023.102.4143. Introduction Coal mining is one of the industries that raises pros and cons in Indonesia regarding environmental problems and the impact on humans in the vicinity. JATAM (2017) reports that the existence of 17.5 million hectares of coal mines in Indonesia has left the problem of open holes without reclamation, damage to water sources, leaving lands that cannot be used in the long term, and declining agricultural and fishery products due to the use of leftover water from mining pits. JATAM also reported that from 17 sample locations, it was found that the content of aluminum, iron, manganese, and the pH of the water significantly damaged agricultural and fishery production. Acid mine drainage is also suspected to be a problem from coal mines in South Kalimantan due to the high levels of pH, temperature, color, BOD (biological oxygen demand), COD (chemical oxygen demand), TSS (total suspended solid), Fe, and Mn above the provisions of the Minister of Environment Regulation No. 113 of 2003 on Liquid Waste Quality Standard (Kiswanto et al., 2018; Kiswanto et al., 2022). On the other hand, mining contributes 7.2% to the GDP (gross domestic product) and plays a vital role in the livelihoods of many people (Owusu et al., 2019; Dyah and Dewi,