Contract analysis

1. Introduction and Purpose Calderwood & Harkness LLP represents the Cascadia State Infrastructure Authority ("CSIA"), a Washington State governmental instrumentality created and existing pursuant to Chapter 43.160A of the Revised Code of Washington, as issuer's counsel in connection with the above-referenced financing. We are writing to transmit the closing conditions and deliverable requirements applicable to Olymp

2. Transaction Summary The Series 2023A Bonds will be issued by CSIA in the aggregate principal amount of $220,000,000. The proceeds of the Bonds will be used to finance the design, construction, and commissioning of the Puget Sound Regional Advanced Water Treatment Facility (the "Project"), a state-of-the-art water treatment facility to be located at 7250 Deschutes Parkway, Tumwater, Thurston County, Washington. The

3. Surety Bond Terms The following is a summary of the principal terms of the Surety Policy to be issued by Olympia Guaranty in connection with the Series 2023A Bonds: Surety Policy Number: OG-2023-MUN-4718 Surety Amount: $11,610,000, which is equal to the maximum annual debt service on the Series 2023A Bonds. Debt-Service Reserve Fund Requirement. Under the Indenture, the Debt-Service Reserve Fund Requirement for th

4. Required Closing Deliverables from Olympia Guaranty Set forth below is an enumerated list of the documents and other deliverables that Olympia Guaranty must provide at or prior to the Closing Date of October 24, 2023. Each item is described in reasonable detail to facilitate Olympia Guaranty's preparation and internal approval processes. Where a proposed form of a document is enclosed with this letter, such form i

5. Wire Instructions for Annual Premium Payment As noted in Section 3 above, the first annual premium payment of $23,220 is due and payable by CSIA at or prior to the Closing Date of October 24, 2023. We request that Olympia Guaranty confirm the wire transfer instructions for receipt of premium payments, including the following information: • Bank Name: • ABA/Routing Number: • Account Number: • Account Name: • Refere

6. Coordination of Execution and Delivery Closing Date. As noted above, closing of the Series 2023A Bonds will take place on October 24, 2023. Pre-Closing Document Review. We request that Olympia Guaranty review and approve the final execution versions of the following documents no later than October 18, 2023: (i) the DSRF Surety Bond Agreement; (ii) the Bond Indenture, to the extent of provisions referencing the Sur

7. Key Contact Information For your convenience, the following is a list of key contacts for the parties involved in the closing of the Series 2023A Bonds. We ask that Olympia Guaranty direct any questions regarding closing logistics, document review, or deliverable requirements to the appropriate contact listed below. Calderwood & Harkness LLP (Issuer's Counsel): Michelle Tsao, Associate — Lead Contact for Closing L

8. Enclosures The following documents are enclosed with this letter for Olympia Guaranty's review:

1. Draft Debt-Service Reserve Fund Surety Bond Agreement (execution version for review)

2. Draft form of Surety Policy (for confirmation against Olympia Guaranty's standard form)

3. Relevant excerpts from the Bond Indenture and First Supplemental Indenture (Series 2023A) referencing the Debt-Service Reserve Fund and surety policy provisions

4. Master Closing Checklist (excerpt — items assigned to Olympia Guaranty are highlighted for ease of reference)

5. Form of Certificate of Authorization (proposed form for Olympia Guaranty's use or adaptation)

6. Form of Draw Notice / Claim Certificate (proposed form for review and approval by Olympia Guaranty)

9. Request for Confirmation We respectfully request that Olympia Guaranty take the following actions at its earliest convenience: (a) Confirm receipt of this letter and the enclosed documents; (b) Provide written confirmation that Olympia Guaranty will be in a position to deliver all of the required closing deliverables identified in Section 4 above on or before the Closing Date of October 24, 2023; (c) Identify any