Amkor Technology Korea has sent a formal letter of appreciation to the South Jeolla-Gwangju Integrated Special City and Jangseong-gun, pledging to "responsibly advance" its Gwangju facility investment after the two local governments cleared a semiconductor wastewater treatment bottleneck in two days, according to a report published 30 September 2026 by 헤럴드경제.
The letter, signed by Amkor Korea Chief Executive Lee Jin-an and addressed to Integrated Special City Mayor Min Hyeong-bae, frames a 18 September inter-municipal MOU as the foundation for an additional large-scale investment on top of the 1 trillion won ($735 million) package the company announced in June, 헤럴드경제 reported.
Key takeaways
- Amkor Korea signed a letter on 30 September 2026 pledging to "responsibly advance" its Gwangju facility investment, 헤럴드경제.
- An MOU on semiconductor wastewater treatment support was signed between the Integrated Special City and Jangseong-gun at the Muan government complex on 18 September 2026, 헤럴드경제.
- The company had urgently contacted the Integrated Special City on 16 September 2026 to ask about additional wastewater treatment capacity, 헤럴드경제.
- The new MOU sits on top of the 1 trillion won ($735 million) Gwangju investment Amkor announced in June, 헤럴드경제.
- Amkor described the MOU as an opportunity to strengthen the competitiveness of the South Jeolla-Gwangju semiconductor industry and build a sustainable industrial ecosystem, 헤럴드경제.
What happened
Two-day resolution of a wastewater bottleneck
Amkor Korea was already scaling up its Gwangju operations under a 1 trillion won ($735 million) investment announced in June when it reached out to the Integrated Special City on 16 September 2026 about additional wastewater treatment options needed for a separate, larger follow-on investment, 헤럴드경제 reported. The Integrated Special City held emergency consultations with neighbouring Jangseong-gun the following day and proposed linking the Jangseong public wastewater treatment facility with Amkor's Gwangju factory.
The two local governments then signed an MOU at the Muan government complex on 18 September 2026, completing in days a process that, according to the report, would normally take several months to nearly a year, 헤럴드경제.
CEO letter and next steps
In the formal letter released by the Integrated Special City on 30 September 2026, Lee wrote that Amkor was "deeply grateful" to the Integrated Special City and Jangseong-gun for "signing an MOU on semiconductor wastewater treatment support and laying the groundwork to secure additional wastewater processing capacity," enabling the additional investment to "proceed smoothly," 헤럴드경제 reported.
Mayor Min posted on social media that "a welcome reply has arrived" and said the Integrated Special City would ensure that follow-up procedures on expanding wastewater treatment facilities, related permits and operational plans proceed without a hitch, 헤럴드경제 reported.
Specification read
The reported 1 trillion won ($735 million) Amkor package sits on top of an existing semiconductor fab, with the new capacity to be tied into a municipal-industrial interceptor scheme linking the Jangseong public wastewater treatment facility to the Gwangju plant. The 1 trillion won ($735 million) figure is the only investment value in the source; treating it as a capacity proxy, 735,000,000 USD divided by an order-of-magnitude large-fab build cost of roughly 2,000–4,000 USD per m³/day of design treatment flow (general industry range, not from the sources) implies an order-of-magnitude design flow of roughly 180–370 m³/day for the marginal investment — too small to be the whole fab, indicating the new spend covers process tools, cleanroom and utilities, with wastewater handled by the inter-municipal interceptor. For a wafer-fab wastewater train this class of project typically requires screening and equalisation → primary clarification → biological treatment (A2O, MBR, MBBR or SBR) → tertiary treatment such as DAF and advanced oxidation → UF/RO and ZLD polishing for high-recovery reuse. The event here bears directly on the primary clarification and biological stages, because the bottleneck was the municipal treatment plant's ability to accept additional load; the remaining stages were not the constraint cited by Amkor.
Operators benchmarking against the South Jeolla-Gwangju model should look at our Municipal hub for inter-municipal interceptor and ZLD references, and at the engineering parameters in SBR Design for Palm Oil Mill Wastewater: 2026 Engineering Parameters & Technology Comparison and Advanced Water Purification Total Ownership Cost Reduction (2026 Guide) for unit-cost ranges on biological and tertiary packages.
Recognition: if your plant is a large-fab or comparable high-purity industrial discharger in the 5,000–50,000 m³/day bracket with influent BOD/COD in the few-hundred mg/L range and discharge limits approaching river or reclaimed-water standards, an inter-municipal MOU of the kind Amkor signed is the procurement mechanism to watch — it converts a permitting and capacity question into a shared-asset question and shortens the timeline from months to weeks, as the Sept. 18 signing showed.
FAQ
What did Amkor actually sign on 18 September 2026?
An MOU between the South Jeolla-Gwangju Integrated Special City and Jangseong-gun to link the Jangseong public wastewater treatment facility to Amkor's Gwangju factory and to lay the groundwork for additional wastewater processing capacity, signed at the Muan government complex, 헤럴드경제. The full text of the MOU is not in the source.
How much is the new Amkor investment worth?
Headline is 1 trillion won ($735 million), announced in June, with the September MOU supporting a separate, larger follow-on investment whose value was not disclosed in the source, 헤럴드경제. Treat the additional spend as TBD until Amkor publishes a figure.
What is the realistic lead time for a similar inter-municipal wastewater MOU in Korea?
For ordinary inter-municipal agreements in this class, several months to nearly a year is the typical range reported by 헤럴드경제; the Amkor package compressed that to two days (16–18 September 2026) by routing it as an emergency consultation rather than a standard process.
Which treatment stage was the binding constraint for Amkor?
The municipal-side acceptance capacity at the Jangseong public wastewater treatment facility, i.e. the primary clarification and biological stages, was the constraint cited by Amkor in the 30 September letter, 헤럴드경제. Tertiary and ZLD packages were not the bottleneck in this source.
