Nickel Mining Faces Runoff Challenges Amid Tropical Rains on Obi Island
Uncontrolled runoff from open areas can carry soil particles into nearby water bodies if not properly managed. This is especially concerning as company operational areas border water bodies that support marine life and serve as a livelihood source for local fishermen.
At Harita Nickel’s operational site on Obi Island, at least 52 sedimentation ponds have been constructed to retain water flow before it is discharged back into the environment. The largest, Tuguraci 2, spans approximately 43 hectares with a capacity of 924,000 cubic metres.
The Telapak Observation Team surveyed the runoff control areas at the mine. From the top of Tuguraci 2 pond, brownish water flows slowly into the storage area before further treatment.
The team also observed that sediment settled at the pond’s base is regularly dredged and reused for land reclamation activities.
“These ponds effectively capture runoff within the company’s area,” said Dickson Aritonang of the Telapak Observation Team in a written statement on Tuesday, 26 May 2026.
Mine runoff is treated through a wastewater treatment plant using coagulants and flocculants to reduce suspended particles before discharge. The resulting sludge is reused as planting media for reclamation.
For environmental researchers, water management is a key indicator of how mining operations are conducted in tropical regions with sensitive landscapes like Obi.
Within the planetary boundaries framework introduced by Earth systems scientist Will Steffen and the Stockholm Resilience Centre, water quality and aquatic ecosystem stability are crucial to keeping human activities within safe environmental limits.
Dickson believes the sedimentation pond areas could be strengthened through vegetative approaches. He noted that planting deep-rooted trees around the ponds is vital for reinforcing soil structure and acting as a natural filter.
In addition to sedimentation ponds, site managers have implemented buffer zones around water bodies and aeration technology to maintain oxygen levels and water circulation. Such vegetation-based and natural systems are increasingly used in modern environmental management as part of nature-based solutions.
ITB researcher Sonny Abfertiawan said environmental management in humid tropical regions requires approaches that continuously adapt to field conditions.
“Harita Nickel is one company that has seriously applied good mining practices, though on-site implementation always faces challenges due to dynamic natural conditions,” said Sonny.
According to Sonny, Obi Island has valuable water sources such as Akelamo River and Karo Lake, which need their quality preserved due to their potential for widespread use by local communities and the environment.
However, Sonny warned that high rainfall intensity and changing weather conditions necessitate adaptive and resilient runoff control systems to meet quality standards, even during extreme weather.
In tropical regions like Obi Island, runoff control is ultimately an evolving process adapting to natural dynamics. Amid changing weather and sensitive coastal landscapes, the system’s ability to continuously adapt is crucial for maintaining environmental quality around mining areas.