The Yongpyong Seokpo Refinery, located in Seokpo-myeon, Bonghwa-gun, Gyeongsangbuk-do, has been producing zinc since 1970. Situated at the upper reaches of the Nakdong River, the refinery has long been at the center of environmental pollution controversies. However, during a recent visit, the Nakdong River in front of the refinery appeared clear, and national water quality monitoring data indicated that levels of major heavy metals were below detection limits.
On September 4, the most notable feature at the Seokpo Refinery was its Zero Liquid Discharge (ZLD) system, which prevents wastewater generated during the refining process from being released into the environment. The ZLD system purifies process wastewater, then boils it to capture steam, which is condensed back into water for reuse in the process. Remaining impurities are solidified and treated separately.
The Seokpo Refinery began operating the ZLD system in May 2021. It currently has the capacity to treat up to 4,000 cubic meters of wastewater per day, with an average of 2,000 to 2,500 cubic meters being purified and reused daily. Im No-kyu, the plant manager, stated, "As the term 'zero discharge' implies, not a single drop of wastewater generated in the factory goes into the Nakdong River. We are reusing the water produced from treated wastewater as industrial water."
Additionally, a separate barrier has been established underground to prevent contaminated water from the factory from migrating to the Nakdong River and other external areas. The Seokpo Refinery has installed a groundwater diffusion prevention facility along the outer perimeter of its plants 1 to 3, covering approximately 2.5 kilometers.
This large-scale environmental investment stems from past pollution issues faced by the Seokpo Refinery. Investigations by environmental authorities confirmed that cadmium and other pollutants from past refining processes had leaked into the Nakdong River through soil and groundwater, leading to administrative penalties and operational suspensions.
Im emphasized, "We are reflecting deeply on the mistakes made by previous generations. Our goal is to eliminate the fundamental sources of pollution within a set timeframe to ensure that no further environmental issues arise from the factory."
Environmental investments have increased significantly since 2018, with substantial efforts ramping up in 2019. By the end of December 2025, a total of 540 billion won (approximately 400 million dollars) will be invested in ZLD, groundwater cutoff facilities, air pollution prevention systems, and soil remediation.
Despite the low profitability of the refining business, the continued environmental investments are supported by dividends received from Korea Zinc. Lee Taek-sung, head of the environmental department, noted, "While we earn revenue from product sales, we also receive about 100 billion won in dividend income from our stake in Korea Zinc, allowing us to invest around 100 billion won annually in environmental improvements."
Since the investments began, water quality indicators have shown significant improvement. According to national water quality monitoring data, levels of cadmium and other major heavy metals in rivers near the refinery have been reported below detection limits following the sequential implementation of the ZLD and groundwater diffusion prevention facilities.
However, the Seokpo Refinery's environmental challenges are not yet fully resolved. The most pressing issue remains the remediation of contaminated soil accumulated over decades. The current soil remediation rate stands at approximately 53.5%. Park Jeong-guk, head of the environmental planning team, explained, "It is difficult to excavate the soil located beneath the production facilities while the factory is operational. Remediation has progressed smoothly in plant 3, where there are no obstructions, but plants 1 and 2 are densely packed with operational buildings and equipment."
The refinery is gradually dismantling facilities that can be remediated to remove contaminated soil. With further remediation efforts, the rate is expected to rise to around 78%. Areas where remediation is challenging are being contained through a bottom barrier and a 2.5-kilometer cutoff wall to prevent further contamination and external diffusion. Park stated, "Given the nature of the operating industrial facility, we cannot dismantle all equipment. We are working on remediation in phases where possible, and the factory's profits will continue to be invested in environmental improvements and pollution source remediation."
* This article has been translated by AI.
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