SK Hynix disclosed on 9 September 2026 that its South Korean chip plants cut water consumption by an average of 170,000 tons (approximately 44.9 million gallons) per day last year through an advanced wastewater recycling system, a figure the company says is the largest water reduction globally claimed by any semiconductor manufacturer on Earth Tech Times. The announcement was made at Korea International Water Week 2026, a three-day government and industry summit that opened Tuesday at EXCO in Daegu and runs through Friday Tech Times.
Key Takeaways
- SK Hynix's South Korean fabs reduced water consumption by 170,000 tons (≈44.9 million gallons) per day on average in 2025 through advanced wastewater recycling, a level the company calls the largest of any chipmaker worldwide Tech Times.
- The recycling system strings together ozone oxidation (AOP), activated carbon filtration, and multistage coagulation/ sedimentation, treating chemically complex fab effluent for reuse in scrubbers, cooling towers, and equipment wash-down Tech Times.
- At the Icheon plant, the wastewater facility produces 94,400 tons of reused water daily and routes it back to air pollution control systems on campus Tech Times.
- SK Hynix's cumulative savings reached 303 million tons through the end of 2025, exceeding the company's own 264 million ton target; annual water reuse grew 54 percent, from 47.88 million tons in 2022 to 73.59 million tons last year Tech Times.
- The Yongin Wonsam cluster, anchored by SK Hynix's four planned fabs on a 4.15 million m² campus, is expected to require roughly 390 million m³ of industrial water annually at full build-out — a single-year demand that exceeds SK Hynix's entire eight-year cumulative savings Tech Times.
What Happened: The Record And The Gap
SK Hynix's 170,000-ton daily reduction is the product of a three-stage treatment train, not a single technology Tech Times. The first stage is ozone oxidation, an advanced oxidation process in which ozone, often combined with ultraviolet light, generates highly reactive hydroxyl radicals that break apart organic molecules too persistent for conventional treatment; the target contaminants are tetramethylammonium hydroxide (TMAH), isopropyl alcohol, acetonitrile, and residues from photoresist stripping Tech Times. The second stage is activated carbon filtration, which removes the lower-molecular-weight organic fragments that ozone leaves behind; a gram of activated carbon contains up to 3,000 m² of internal surface Tech Times. The third stage is multistage coagulation and sedimentation, in which metal-salt coagulants destabilize fluoride compounds, heavy metals such as copper and arsenic, and colloidal matter; the resulting flocs settle out under gravity and are removed as sludge Tech Times.
The effluent from this combined train is suitable for reuse in applications that do not require ultrapure water (UPW) quality, including air pollution control scrubbers, cooling towers, and equipment wash-down; at the Icheon plant in Gyeonggi Province, the wastewater recycling facility produces 94,400 tons daily of reused water and routes it back to air pollution control systems on campus Tech Times. A separate milestone was set in 2023 at the Cheongju plant, which became the first Korean semiconductor facility to use treated wastewater piped in from a municipal sewage treatment plant and recycle it for industrial use Tech Times.
A structural ceiling limits how far in-house recycling can go. Semiconductor fabs require two fundamentally different water categories, and the more demanding one, ultrapure water (UPW) at electrical resistivity above 18 megohm-cm, total organic carbon below 1 ppb, and essentially zero particulate matter, must still draw on freshwater input; producing 1,000 gallons of UPW from municipal-grade feed water requires approximately 1,400 to 1,600 gallons of input Tech Times. Industry targets 70 percent recycling as best practice overall, with advanced systems approaching 85 to 90 percent; full circularity through zero liquid discharge remains practically unachievable in leading-edge fabs because each process step generates chemically distinct wastewater streams with incompatible residues Tech Times.
The political backdrop is unusually tight. Less than a month before the disclosure, Gyeonggi Province Governor Choo Mi-ae publicly issued administrative guidance demanding discharge cuts, saying the province had provided water "cheaply and abundantly" while the companies made "no effort" to cut what they discharge Tech Times. Set against the Yongin cluster's projected demand, the conservation figures shift in character: the semiconductor national industrial complex taking shape in Yongin's Wonsam district, anchored by SK Hynix's four planned fabrication plants on a 4.15 million m² (approximately 1,026-acre) campus, is expected to require roughly 390 million m³ annually of industrial water at full build-out Tech Times. The current water supply to the Yongin area from nearby river basins falls short of what the cluster will require, and the shortfall is structural; the Korea Ministry of Environment has committed to a two-phase rTech Times.
Specification Read
The headline figure of 170,000 tons per day equals 170,000 m³/day, or roughly 155 MLD (million litres per day) on a 24-hour basis — a single-site scale in the same order of magnitude as a mid-sized municipal plant serving on the order of 500,000 to 800,000 population equivalents (general industry range, not from the sources). The reported train bears directly on the tertiary / polishing end of a semiconductor treatment scheme: an upstream biological or physico-chemical primary and secondary stage would normally be expected ahead of the ozone/activated carbon / coagulation-sedimentation combination described, with the latter functioning as the advanced oxidation plus carbon polishing block that lets the effluent meet scrubber, cooling-tower, and equipment wash-down reuse targets. The Icheon reuse figure of 94,400 tons/day is a separate reuse stream and is included as a comparison data point, not an addition to the 170,000-ton reduction.
For a buyer running a facility with fab-style wastewater (high COD/BOD, recalcitrant organics such as TMAH, fluoride and heavy-metal loads, plus strict discharge consent pressure from a regional authority), this event is the market saying that in-house recycling of 85 to 90 percent of total demand is the upper practical band — and that the remaining UPW feed-water gap is structural, not a technology deficit, and must be met from municipal or surface sources. Procurement teams sizing a new fab or upgrade should therefore plan the make-up water line as a parallel investment, not a residual. For plants weighing biological vs. membrane-biological routes to handle the upstream load, the engineering trade-offs for a similar feed profile are detailed in the MBR vs Conventional Activated Sludge for Semiconductor Wastewater in Lake Havasu City, US (2026 Engineering Guide), while the polishing block that turns the secondary effluent into scrubber- and cooling-tower-grade reuse maps onto Mbr Membrane Systems and the broader Air Dust Treatment reuse envelope on the industrial side, with Chemical dosing for the coagulation step.
FAQ
What scale of plant is the 170,000-ton-per-day figure comparable to in buyer units?
170,000 m³/day is on the order of a mid-sized municipal wastewater plant serving roughly 500,000 to 800,000 population equivalents (general industry range, not from the sources). It is a single corporate-facility figure, not a municipal catchment figure Tech Times.
What is the realistic recycling ceiling for a leading-edge fab?
Industry targets 70 percent recycling as best practice, with advanced systems approaching 85 to 90 percent; full zero-liquid-discharge circularity is not achievable in practice because each process step produces chemically incompatible wastewater streams Tech Times.
How much extra feed water is needed to make ultrapure water?
Producing 1,000 gallons of UPW from municipal-grade feed water requires approximately 1,400 to 1,600 gallons of input, a structural loss ratio set by the multi-stage UPW purification train Tech Times.
What supplier-selection criteria does this event sharpen for an upgrade or reuse project?
Look for vendors that can document an advanced oxidation plus activated carbon plus coagulation / sedimentation block with measured reuse rates in the 85 to 90 percent band, plus a parallel UPW make-up line sized to the structural 1,400–1,600 gallon input per 1,000 gallon UPW output (general industry range, not from the sources) Tech Times.
