SUWON — Gyeonggi Province Governor Choo Mi-ae said on the 7th that managing wastewater from the semiconductor industrial complex in Yongin requires attention to water quality, not just volume.
In a post on her Facebook page that morning, Choo said the province had previously issued administrative guidance to Samsung Electronics (005930) and SK hynix (000660), which will operate plants in Yongin, calling on them to raise their reuse rates for process water and cut the volume of wastewater they discharge. "If the first administrative guidance concerned volume, this time I am raising the issue of quality," she said.
Choo said she had ordered the Gyeonggi Institute of Health and Environment to test water quality in the Jukdang Stream, which carries discharge water from SK hynix's fab in Icheon that is currently in operation, and that the tests found high concentrations of chloride and sulfate ions.
According to the test results, chloride ions measured 745 milligrams per liter, more than double the Food and Agriculture Organization of the United Nations threshold of 355 mg/L. Sulfate ions came in at 1,606 mg/L, far above the threshold of 960 mg/L. Choo said the readings were "not suitable for agricultural water."
She argued that leaving such substances unaddressed over a long period could harm aquatic ecosystems. As sulfate concentrations accumulate, she said, the release of phosphorus increases, raising the likelihood of algal blooms.
Choo pointed to a bigger concern once the Yongin complex begins operating: the wastewater may flow not into a stream but into Gosam Reservoir, a freshwater lake used for farming. "If 640,000 tons of wastewater a day flows in over a long period, it raises concerns about algal blooms and crop toxicity," she said.
She added that while "companies may argue that chloride and sulfate ions pose little direct risk to the human body," high osmotic pressure "can harden soil and damage plants and freshwater organisms."
Gyeonggi Province plans to use the test results as grounds for asking the Ministry of Climate, Energy and Environment to set emission limits for chloride and sulfate ions. The province also intends to begin administrative guidance on water quality management for semiconductor complex wastewater in the near future.
