Dompu, May 5, 2025 — The Provincial Government of West Nusa Tenggara (NTB) and the Regional People’s Representative Council (DPRD) of Dompu Regency conducted a visit to PT Sumbawa Timur Mining’s (STM) copper exploration area in Hu’u District, also known as the Hu’u Project. This joint visit aimed to obtain a clear picture of STM’s environmental management programs within its working area, including water quality monitoring and land reclamation efforts.
The NTB Provincial Government was represented by the Energy and Mineral Resources Office (ESDM) and the Environmental and Forestry Office (LHK), accompanied by the Environmental Office (LH) of Dompu Regency. The Dompu DPRD was represented by the Chairman and Vice Chairman of the council, along with seven other members. During the visit, the delegation participated in a discussion session led by STM’s Head of Mining Engineering (KTT), followed by a direct field observation.
During the joint visit, the team reviewed the former drilling point of the Test Pumping Bore Program (TPBP), which tested a method for deep groundwater cooling. The TPBP was previously conducted to ensure that STM’s future underground mining can be carried out safely, as the Onto copper deposit lies 500 meters below the surface and is located near a geothermal system with temperatures ranging from 80 to 110 degrees Celsius.
Near the TPBP area, the visiting guests observed a deep groundwater holding pond that was previously used as one of the test facilities. This pond is still maintained today as it will be used for future testing. STM’s Sustainability Team routinely monitors and maintains the pond to ensure that it meets the applicable regulatory water quality standards.
The Acting Head of the NTB Environmental and Forestry Office, Mursal, S.P., M.Si., stated that STM is a verified company that complies with environmental procedures. He clarified that claims suggesting the TPBP support pond is a mining waste pond are inaccurate. “We have seen with our own eyes that the reports are not true — they do not match the actual facts,” he said.
This statement was reinforced by the Head of Dompu Regency’s Environmental Office, Jufri, ST, M.Si. He noted that STM pays serious attention to the environment around the holding pond. “STM is so cautious about soil contamination that they installed a geomembrane. The geomembrane in this pond prevents water from directly touching the ground. Its function is to prevent water from seeping into the soil — it is held back by the geomembrane,” he explained.
Chairman of the Dompu DPRD, Ir. Muttakun, also provided clarification regarding the circulating issue about an alleged discovery of a mining waste pond in STM’s exploration area.
“We’ve come here, and so far, we see that the pond is not as massive as claimed. This has been clarified,” he stated. According to Muttakun, the pond measures approximately 12×10 meters with a depth of around 1 to 1.5 meters.
“I saw two ponds. The first is a mud pond, and the other is a water pond. Each has a different function. The mud pond is used to collect water (with carried sediment) that comes out during drilling. Meanwhile, the water pond is used as a reserve in case of water loss during the drilling process. So, the water is indeed used to facilitate the drilling process,” Muttakun explained.
Vice Chairman of the Dompu DPRD, Kurnia Ramadhan, S.E., M.E., expressed appreciation for the transparency shown by STM through this visit. “STM is very open in sharing information regarding its exploration activities. This is important for us, the people of Dompu — that we must remain open to anyone who wishes to invest in our region, as long as the investment brings benefits and advantages to the area,” he stated.
STM’s Head of Mining Engineering (KTT), Yan Fuadi, emphasized that environmental conservation is an integral part of STM’s exploration journey. The company continuously strives to ensure that exploration activities coexist harmoniously with nature and surrounding communities. “PT Sumbawa Timur Mining consistently adheres to environmental management procedures and coordinates with the government in fulfilling its obligations,” he stated.
Beyond water monitoring, he also cited sustainable environmental management through land reclamation. “In 2024, STM exceeded its reclamation target by approximately 43.3 percent, successfully reclaiming 11.51 hectares of land compared to the planned 8.03 hectares,” he said. The remaining areas not yet reclaimed, according to Yan Fuadi, are still being used to support ongoing exploration activities and will be reclaimed in accordance with applicable regulations.
To support sustainable environmental management, STM also operates a 0.44-hectare nursery with a capacity of 20,000 ready-to-plant seedlings. The seedlings are dominated by pioneer plant species that accelerate natural succession and support the growth of local plant communities. This nursery is powered by renewable energy sourced from solar panels, reflecting STM’s commitment to emission reduction and environmental sustainability.
About PT Sumbawa Timur Mining
PT Sumbawa Timur Mining (STM) is a joint venture between Eastern Star Resources Pty Ltd (80%), a wholly-owned subsidiary of Vale Base Metals, and PT Aneka Tambang Tbk (20%). STM owns the Hu’u Project, a copper exploration project operating under the 7th Generation Mineral Contract of Work (CoW) in Hu’u District, Dompu Regency, West Nusa Tenggara Province, Indonesia.
The CoW also holds geothermal resources. To explore this potential, the company has completed the Preliminary Survey and Geothermal Exploration Assignment. The CoW area spans 19,260 hectares across Dompu and Bima Regency. STM is continuing its journey to achieve its vision of becoming a world-class copper mining operation supported by renewable energy.
For further information, please contact STM Communication Team
