A revised environmental review clears the way for a US$452 million zinc mine in North Sumatra

What happened

PT Dairi Prima Mineral (DPM) has obtained government approval for a revised feasibility study and an amended Analisis Mengenai Dampak Lingkungan (AMDAL) for its underground zinc and lead project in Dairi Regency, North Sumatra. The approval, reported this week by Koran Jakarta, Liputan6, Sindonews, and Bisnis.com, clears the company to move forward with the Anjing Hitam deposit, its first phase of development, at a planned processing capacity of one million tons of ore a year.

The approval matters because it follows a genuine regulatory setback. DPM's Contract of Work dates to 1998, with the Anjing Hitam and Lae Jehe deposits confirmed by 2002 and an initial AMDAL approved by the Bupati of Dairi in 2005. The government approved an AMDAL addendum in 2022, but in 2024 the Supreme Court ruled in favor of a lawsuit brought by community groups against that approval, and in 2025 the Ministry of Environment formally revoked it. The 2026 approval is the outcome of DPM redoing the feasibility study and the environmental review to meet the standard the court and the ministry required. Indonesia's Contract of Work for the project remains valid through December 29, 2047, giving the company a long runway once construction begins.

A resource base worth US$452 million

DPM's own disclosures, most recently at the Pekan Inovasi dan Investasi Sumatera Utara (PIISU) 2025 investment showcase in Medan, put the total investment for the project at US$452 million. The Anjing Hitam prospect carries an estimated resource of 8.5 million tons of ore grading 13.8 percent zinc and 7.9 percent lead, with reserves of 7.7 million tons at 12.5 percent zinc and 7.3 percent lead. A second, larger prospect, Lae Jehe, holds a resource of 27.9 million tons at roughly 6 percent zinc and 3.7 percent lead, with reserves of 10 million tons, and is earmarked for later development once Anjing Hitam is in production.

Separately, company materials from the PIISU showcase describe an expected mill feed grade of 6.9 percent zinc and 1.12 percent lead with a recovery rate of about 85 percent, a lower figure than the in-situ resource grade at Anjing Hitam. The discrepancy likely reflects blended mill feed across the ore body rather than a restated resource estimate, but Sirkularium notes it here rather than reconciling it silently, since the two figures describe different stages of the same mine plan. Liputan6 also reports a projected output, once the Anjing Hitam phase reaches full production, of 2.43 million tons of concentrate, containing an estimated 473,895 tons of lead and 821,150 tons of zinc over the life of that phase.

Why the AMDAL history matters

For Sirkularium's mining-sector audience, the significance of this story sits less in the tonnage and more in the process. Indonesia's environmental review framework, anchored in AMDAL and reinforced by the ecological damage and environmental economic loss methodology under Permen LH No. 7 Tahun 2014, functioned as designed here. A community objection reached the Supreme Court, the court ruled on the merits, the ministry enforced the ruling by revoking the prior approval, and the company returned with a revised study rather than contesting the outcome. The 2026 approval is not a bypass of that scrutiny. It is the product of it.

That sequence is a useful data point for government stakeholders weighing how to balance investment promotion with environmental governance. A functioning AMDAL system that can pause and correct a project, rather than simply rubber-stamp it, is also what gives the eventual approval its credibility with lenders, insurers, and downstream buyers who increasingly expect documented environmental due diligence on the minerals they purchase.

Mining without a tailings dam

The redesigned project also illustrates a genuine shift in how DPM is managing its ecological footprint. Widianto, the company's Technical Manager, described the tailings approach in comments carried by Koran Jakarta and Sindonews.

"Material tailing tidak dibuang atau ditempatkan dipermukaan, tetapi dipisahkan terlebih dahulu antara cairan dan padatan," Widianto said, meaning tailings are not disposed of or placed on the surface, but are first separated into liquid and solid components.

The solid fraction, mixed with cement, is pumped back underground as backfill using a combination of longhole stoping and cut-and-fill mining methods, removing the need for a conventional surface tailings storage facility. The processing stream also recovers a sulfur concentrate as a byproduct. From an environmental economics standpoint, eliminating a permanent surface tailings dam removes one of the largest long-term liabilities in a mine's closure and reclamation cost, and reduces the physical footprint that would otherwise need to be reclaimed, monitored, and eventually revalued against baseline ecosystem condition. The project's forest use permit, issued in 2012 for 53.11 hectares, gives a sense of the physical scale still under active land-use management.

What this means for the workforce and the district

DPM currently employs about 150 people, 72 percent of them from Dairi Regency, according to figures the company presented at PIISU 2025. It projects 600 to 1,000 direct jobs once the Anjing Hitam phase reaches full production. Radianto Arifin, DPM's Chief Legal and External officer, framed the investment in those terms at the same event.

"As a company committed to economic and social development in North Sumatra, we showcase mining technology and provide information regarding our investment in developing zinc and lead mining in Dairi District," Arifin said.

The company also reports a set of community programs alongside the mine plan: scholarships for twelve students to study in China, library renovations and teacher stipends, school supplies for 132 top-performing students, nutrition support reaching more than 1,200 infants and elderly residents, agricultural training for more than 200 coffee and cocoa farmers, and the planting of 10,000 coconut seedlings and 217,000 mangrove trees. Ownership of DPM is split between NFC Hongkong, a subsidiary of the state-owned China Nonferrous Metal Mining Group, at 51 percent, and PT Bumi Resources Minerals Tbk, part of the Bakrie Group, at 49 percent.

Sirkularium's view

This case is a template worth watching, not a one-off. A project that lost its environmental approval in court, then returned three years later with a materially improved design, a tailings method that avoids a surface dam, and a fresh AMDAL that has cleared review, gives government and financing counterparts a documented, court-tested basis for confidence in the current approval. That documentation has value independent of the legal outcome: a resource base, a reserve estimate, an investment figure, and a closure-relevant design choice like backfill-instead-of-TSF are all inputs that a rigorous, independently verified economic valuation can turn into a defensible number, whether the audience is KLHK, a lender, or a community counterpart.

Sirkularium's recommendation for operators and regulators watching this case is the same one it makes for mining projects generally. Commission GIS-based mapping and ground data on the ecosystem baseline, and update it through construction and operation, so that any future dispute over environmental impact starts from an agreed data set rather than competing claims. Treat that valuation as a continuous practice tied to the mine plan, not a one-time document produced only when a permit is challenged. For a project like Anjing Hitam, where the tailings design itself is being marketed as an environmental improvement, an independently verified valuation of the avoided land disturbance and the reclamation liability it removes would give both the company and the ministry a shared, defensible figure to point to, well before the next legal test arrives.