Updated contract terms.

CORRECTION NOTICE FOR SINGLE SALES AND SUPPLY CONTRACT EXECUTION

Correction Date: 2026-09-18

1. Regulatory Filing Subject to Correction Single Sales and Supply Contract Execution

2. Original Filing Submission Date 2026-09-14

3. Reason for Correction Correction of contract amount and contract period due to contract extension

4. Correction Details

Corrected Items | Before Correction | After Correction 2. Contract Details - Confirmed Contract Amount (Total) | 6,963,039,000 | 8,963,675,000 2. Contract Details - Contract Amount (Total) | 6,963,039,000 | 8,963,675,000 2. Contract Details - Percentage of Recent Sales | 22.26% | 49.74% 3. Contract Period - End Date | - | 2026-09-30

10. Other Matters for Investment Consideration

Before Correction: - Total contract amount through July 31, 2026: 24,675,249,000 KRW (VAT excluded) - This contract represents the 3rd year of the overall contract, accounting for 6,963,039,000 KRW (VAT excluded) of the total contract amount - Overall contract period: 2024.10.01 ~ 2026.07.31 - Overall contract amount: 24,675,249,000 KRW (VAT excluded) - This contract period: 2026.01.01 ~ 2026.07.31 - This contract amount: 6,963,039,000 KRW (VAT excluded)

After Correction: - Total contract amount through September 30, 2026: 26,675,885,000 KRW (VAT excluded) - This contract represents the 3rd year of the overall contract, accounting for 8,963,675,000 KRW (VAT excluded) of the total contract amount - Overall contract period: 2024.10.01 ~ 2026.09.30 - Overall contract amount: 26,675,885,000 KRW (VAT excluded) - This contract period: 2026.01.01 ~ 2026.09.30 - This contract amount: 8,963,675,000 KRW (VAT excluded)

Additional Notes: - The company's recent sales are based on the 2024 K-IFRS consolidated financial statements; the counterparty's recent sales are based on the 2025 consolidated financial statements - The contract date above is the date the contract was received from the counterparty - Contract amendment execution may be delayed due to the schedules of relevant government agencies; a correction notice will be issued upon completion of the contract amendment - The scheduled contract amendment execution date is on or before September 18, 2026 (Friday); if the scheduled date changes, a correction notice will be issued

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SINGLE SALES AND SUPPLY CONTRACT EXECUTION

1. Sales and Supply Contract Details Operation and management services for Sudokwon Landfill power generation and ancillary facilities (3rd year)

2. Contract Details Conditional Contract Status: Not Applicable Confirmed Contract Amount: 8,963,675,000 KRW Conditional Contract Amount: - Total Contract Amount: 8,963,675,000 KRW Recent Sales: 18,020,084,141 KRW Percentage of Recent Sales: 49.74%

3. Counterparty Sudokwon Landfill Management Corporation - Recent Sales: 137,731,430,620 KRW - Principal Business: Waste treatment and waste resource recycling business - Relationship with Company: Other - Performance of similar contracts with company in past 3 years: Applicable

4. Sales and Supply Region Republic of Korea

5. Contract Period Start Date: 2026-01-01 End Date: 2026-09-30

6. Principal Contract Terms Contract Deposit/Advance Payment: None Payment Terms: Progress billing by installment (quarterly)

7. Sales and Supply Method In-house Production: Applicable Outsourced Production: Not Applicable Other: -

8. Contract (Order) Date 2026-01-07

9. Disclosure Reservation Reservation Period: - Reservation Reason: -

10. Other Matters for Investment Consideration 1) The contract amount above is exclusive of value-added tax.

2) The total contract amount through September 30, 2026 is 26,675,885,000 KRW (VAT excluded). This contract represents the 3rd year of the overall contract, accounting for 8,963,675,000 KRW (VAT excluded) of the total contract amount. - Overall contract period: 2024.10.01 ~ 2026.09.30 - Overall contract amount: 26,675,885,000 KRW (VAT excluded) - This contract period: 2026.01.01 ~ 2026.09.30 - This contract amount: 8,963,675,000 KRW (VAT excluded)

3) The company's recent sales are based on the 2024 K-IFRS consolidated financial statements; the counterparty's recent sales are based on the 2025 consolidated financial statements.

4) The contract date above is the date the contract was received from the counterparty.

Related Disclosures: 2026-01-07 Single Sales and Supply Contract Execution 2026-04-30 Single Sales and Supply Contract Execution 2026-05-08 Single Sales and Supply Contract Execution 2026-07-31 Single Sales and Supply Contract Execution 2026-08-14 Single Sales and Supply Contract Execution 2026-09-14 Single Sales and Supply Contract Execution