Gyeonggi governor presses Samsung, SK Hynix on semiconductor wastewater quality
In short
Gyeonggi Province Governor Choo Mi-ae said semiconductor wastewater needs water-quality management as well as volume controls, after tests of a stream receiving discharge from SK Hynix's Icheon plant found chloride and sulfate ion concentrations above FAO irrigation-water reference levels. Nine items covered by domestic river water standards passed, but the two ions have no domestic stream standard, and the province plans to ask the government to set permitted discharge limits. The governor had already told Samsung Electronics and SK Hynix in July to raise process-water reuse and cut discharge.
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Gyeonggi Province Governor Choo Mi-ae said management of wastewater from semiconductor industrial complexes must cover water quality as well as volume, after tests of a stream receiving discharge from SK Hynix's Icheon plant found chloride and sulfate ion concentrations above FAO irrigation-water reference levels. [ 1 , 2 , 3 ]
Gyeonggi Province and the Gyeonggi Provincial Health and Environment Research Institute announced the results on Oct 5, based on three surveys of Jukdang Stream conducted on Aug 26 and Sep 2 and 3. According to Asia Economy, all nine items covered by domestic river water quality standards met those standards, but chloride and sulfate — for which the documents say no separate domestic stream standard exists — exceeded levels the UN Food and Agriculture Organization uses to assess irrigation water. [ 1 , 2 ]
At a point 0.4 km from the SK Hynix outfall, average chloride measured 731 mg/L and sulfate 1,561 mg/L, Asia Economy reported; at 7.4 km downstream the figures were 513 mg/L and 1,060 mg/L. The FAO chloride reference is 355 mg/L and the reported typical sulfate range is 0 to 960 mg/L. Seoul Economic Daily quoted the governor citing chloride at 745 mg/L and sulfate at 1,606 mg/L, calling the water unsuitable for agricultural use; the outlets gave differing numbers. A dilution effect downstream was observed, and Asia Economy said the survey alone cannot establish crop damage or deterioration of Goha Reservoir. [ 2 , 3 ]
In July the governor issued administrative guidance to Samsung Electronics and SK Hynix, which are due to move into Yongin, to raise process-water reuse rates and cut discharge, citing global semiconductor companies such as TSMC. Dong-A Ilbo noted that administrative guidance is a procedure of direction, recommendation and advice, and that non-compliance alone cannot bring disadvantages. [ 1 , 2 , 3 ]
In her follow-up statement — a social media post that Asia Economy dated Oct 6 and Seoul Economic Daily dated the morning of Oct 7 on Facebook — the governor said the first guidance concerned volume while this one raises water-quality concerns. She argued that if such substances are left over the long term they can harm aquatic ecosystems, and that accumulated sulfate can raise phosphorus release and increase the risk of algal blooms. She cited the prospect of up to 640,000 tonnes of wastewater per day flowing over the long term into Goha Reservoir, an agricultural freshwater lake, and said high osmotic pressure can harden soil and damage plants and freshwater organisms, even if companies argue the ions pose low direct risk to human health. [ 2 , 3 ]
The province plans to ask the government — Seoul Economic Daily names the Ministry of Climate, Energy and Environment — to set permitted discharge standards for chloride and sulfate, and to issue administrative guidance on water-quality management for semiconductor-complex wastewater. Dong-A Ilbo reported that large-scale process-water discharge from SK Hynix's Yongin fab is scheduled to begin in February next year. [ 1 , 2 , 3 ]
Why it matters
Gyeonggi Province is the site of South Korea's largest semiconductor cluster, and the governor's move puts a regulatory question to the central government over substances that currently have no domestic river or discharge standard. The outcome could add water-quality requirements for fabs in Yongin, where SK Hynix is due to start large-scale process-water discharge, and for the Samsung and SK Hynix plants the province has already told to reduce discharge.
Key facts
- Gyeonggi Province Governor Choo Mi-ae issued administrative guidance in July to Samsung Electronics and SK Hynix, which are moving into Yongin, to raise process-water reuse rates and cut wastewater discharge. [ 1 , 2 , 3 ]
- Gyeonggi Province and the Gyeonggi Provincial Health and Environment Research Institute announced on Oct 5 the results of three surveys of Jukdang Stream, which receives discharge from SK Hynix's Icheon plant. [ 1 , 2 ]
- All nine items covered by domestic river water quality standards met those standards, but chloride and sulfate ions, for which the documents say there is no separate domestic river standard, exceeded FAO irrigation-water reference levels. [ 2 , 3 ]
- Chloride and sulfate concentrations were reported to fall with distance downstream, indicating a dilution effect. [ 2 ]
- Governor Choo said the concern is greater because process water from the planned Yongin semiconductor cluster would flow into Goha Reservoir, an agricultural freshwater lake, rather than a river. [ 1 , 2 , 3 ]
- The province plans to ask the government to set permitted discharge standards for chloride and sulfate and to press companies for measures to cut discharge and improve water quality. [ 2 , 3 ]
- Administrative guidance is a procedure in which an administrative body gives direction, recommendation or advice, and non-compliance alone cannot bring disadvantages, according to the Dong-A Ilbo. [ 1 ]
Confirmed by several sources
- Gyeonggi Governor Choo Mi-ae issued administrative guidance in July asking Samsung Electronics and SK Hynix to raise process-water reuse and reduce wastewater discharge. [ 1 , 2 , 3 ]
- Surveys of Jukdang Stream, which receives SK Hynix Icheon discharge, found chloride and sulfate concentrations above FAO irrigation-water reference levels. [ 1 , 2 , 3 ]
- The Gyeonggi provincial government plans to request national discharge standards for chloride and sulfate and to press companies on water quality. [ 2 , 3 ]
- Governor Choo argued that management of semiconductor-complex wastewater must address water quality, not only volume. [ 2 , 3 ]
Still unclear
- The measured concentrations differ between outlets: Asia Economy reports average chloride of 731 mg/L and sulfate of 1,561 mg/L at 0.4 km from the outfall, while Seoul Economic Daily quotes the governor citing 745 mg/L and 1,606 mg/L. Two outlets give different figures for the same survey without explaining the difference.
- Whether the concentrations will cause crop damage or degrade Goha Reservoir. Asia Economy states the survey alone cannot establish crop damage or reservoir water-quality deterioration.
- When and where the governor made her follow-up statement on water quality: Asia Economy says an Oct 6 social media post, while Seoul Economic Daily says Facebook on the morning of Oct 7. The outlets disagree on the date and the platform.
- Whether Samsung Electronics and SK Hynix will act on the guidance. No company response appears in the documents, and the guidance is not binding.
What local media are saying
Timeline, local time
- July 2026: Governor Choo Mi-ae issues administrative guidance to Samsung Electronics and SK Hynix to raise process-water reuse and reduce discharge, citing global semiconductor firms such as TSMC. [ 1 , 2 , 3 ]
- Aug 26, and Sep 2 and Sep 3: the Gyeonggi Provincial Health and Environment Research Institute samples Jukdang Stream three times. [ 2 ]
- On Oct 5, Gyeonggi Province and the research institute announce the survey results, including chloride and sulfate levels above FAO irrigation-water reference values. [ 1 , 2 ]
- On Oct 6–7, Governor Choo says water quality, not only volume, must be managed; outlets differ on whether the post was on Oct 6 or Oct 7 and on which platform. [ 2 , 3 ]