SDP26-01 / SEPA26-05 Amazon Attalia Campus NOTICE OF APPLICATION Notice is hereby given on this date, 9/12/2026, that the application/proposal described in this notice has been filed with the Walla Walla County Community Development Department (CDD). The application/proposal may be reviewed at the CDD office at 310 W Poplar Street, Suite 200, Walla Walla, WA 99362. All interested persons and parties may comment on the application; appeal rights are outlined in Walla Walla County Code (WWCC) Chapter 14.11. 1. Applicant/ Property Owner: Amazon Data Services, Inc, 410 Terry Avenue North, Seattle, WA 98109 2. Application filing date: May 22, 2026 3. Date that application was determined to be substantially complete: August 24, 2026 4. Location: The subject property is located generally along Sundance Road, between Dodd and Worden Road, about 1.4 miles east of US-12, on a 134-acre property identified as Assessor Parcel Number (APN) 310835410003. 5. Description of proposed action: Amazon Attalia Data Center Campus. The campus will include three data center buildings, each approximately 220,000 sf. Additional structures include storage tanks, a security building (1,400 sf), and an industrial water facility (9,675 sf). Site work involves fencing, landscaping, retaining walls, stormwater and evaporation ponds, septic systems, and drainfields, as well as access roads, parking areas, and a pad for the construction of a substation to be completed by a future utility provider. 6. Zoning map designation for the location: Industrial Agriculture – Mixed (IA-M) 7. Comprehensive plan land use designation for the location: Industrial UGA 8. Shoreline Environment: N/A - outside Shoreline Jurisdiction 9. Required Permits: Walla Walla County: Land Use/Site Development Permit, Building Permits, Grading Permit, Access Permit, Utility Connection Permits; Washington Department of Ecology: Construction Stormwater General Permit, Individual State Waste Discharge Permit, Fuel Storage Permit, Water Right Change Application, Air Quality Notice of Construction and Second Tier Health Risk Assessment; Washington State Department of Health: Large On-Site Septic (LOSS) Operating Permit; Columbia Rural Electric Association: Substation Permit; US Fish and Wildlife / National Marine Fisheries Service: Endangered Species Consultation; State Historic Preservation Office: Section 106 SHPO Clearance 10. Development Regulations: WWCC 17.17 - Development Permits, WWCC 17.18 – Density and Dimensions, WWCC 18.04 – Environmental Policy, WWCC 18.08 – Critical Areas Protection The following identified documents are hereby incorporated by reference, and all or part of the documents may be used to evaluate the application/proposal. These materials are available for public review online and at the CDD office at 310 W. Poplar Street, Suite 200, Walla Walla, WA, during all applicable comment periods. Preliminary determinations and information contained herein shall not bind the County and are subject to continuing review and modification. SEPA Environmental Checklist, prepared by Amazon Web Services, dated August 21, 2026 Site Plan (Undated), submitted by Amazon Web Services, August 21, 2026 Determination of Completeness, issued by Walla Walla County Community Development Department, dated August 24, 2026 Acoustical Report, prepared by Landau Associates for Amazon Web Services, dated July 8, 2026 Traffic Impact Analysis (TIA), prepared by Kimley-Horn and Associates for Amazon Web Services, dated July 2026 Natural Resources Assessment, prepared by APEX Companies for Kimley-Horn and Associates on behalf of Amazon Web Services, dated June 2026 Notice of Incomplete Application (NOIA), issued by Walla Walla County Community Development Department, dated June 23, 2026 Zoning Land Use Application, submitted by Integrus Architecture on behalf of Amazon Web Services, dated May 22, 2026 Water Availability Form, submitted by Integrus Architecture on behalf of Amazon Web Services, dated May 20, 2026 Water Availability Form Supporting Memo, prepared by Integrus Architecture, dated May 20, 2026 Site Plan, prepared by Integrus Architecture for Amazon Web Services, dated May 15, 2026 Scoping Memo, prepared by Kimley-Horn and Associates for Amazon Web Services, dated April 30, 2026 Critical Areas Report, prepared by Geosyntec Consultants for Amazon Web Services, dated April 6, 2026 Special Warranty Deed, Auditor File Number (AFN) 2026-01859, identifying the Port of Walla Walla as the grantor and Amazon Data Services as the Grantee, dated March 19, 2026 Code Interpretation (CI25-03), issued by the Walla Walla County Community Development Department in response to a request by the Port of Walla Walla, extending the 2018 data center classification in the Industrial Agriculture – Heavy (IA-H) zoning district to the Industrial Agriculture – Mixed (IA-M) district, dated March 20, 2025 Zoning Determination Letter, issued by the Walla Walla County Community Development Department, classifying data centers as an analogue to "Warehousing and Storage" in the Industrial Agriculture – Heavy (IA-H) zone for the purposes of land use permitting decisions, dated February 12, 2018 REVIEW PROCESS AND PUBLIC COMMENT: The decision on this application will be made by the Walla Walla County Community Development Department (CDD) Director. This notice of application is required by Revised Code of Washington (RCW) 36.70B.110 and Walla Walla County Code (WWCC) 14.07.080. The comment period for this notice is thirty (30) days from the issuance of this notice; this period ends October 12, 2026. To be considered a party of record, send or deliver written comments to: planning@wwcowa.gov or "Melissa Shumake, Community Development Department, 310 W. Poplar Street, Suite 200, Walla Walla, WA 99362". Comments must be received by the CDD before 5 PM on the following date: October 12, 2026. Comments will be provided to the applicant and the CDD will consult with the applicant and applicable agencies/parties of record before issuing a SEPA threshold determination after the comment period has closed. When the SEPA threshold determination is issued, there will be an additional comment period specifically for the threshold determination. Once the SEPA comment period has ended, a Notice of Decision will be issued. APPEALS: The Director's decision may be appealed by the applicant(s) or parties of record to the Walla Walla County Hearing Examiner pursuant to WWCC 14.11.010 and 14.11.030. FOR MORE INFORMATION: For additional information please contact Melissa Shumake, Community Development Director, at 509-524-2610, planning@wwcowa.gov, or 310 W. Poplar Street, Suite 200, Walla Walla, WA 99362. IPL0373160 Sep 13 2026