Sources and Evidence

The claims on this site rest on primary sources: peer-reviewed research, government and agency records, regulatory filings, and recorded documents. This page collects them in one place so you can read the originals and cite them in your own SEPA comment. Each source is listed by its own name and links to the public original.

If you are writing a comment, the how-to guide explains how to tie a source to a specific environmental impact. Short and specific, backed by one of these, beats long and vague.

This library is expanding. More of the King County and City of Snoqualmie permitting records, and our correspondence with the agencies, are cited on the topic pages and are being added here.

Fire and battery safety research

• Larsson et al. (2017), “Toxic fluoride gas emissions from lithium-ion battery fires,” Scientific Reports 7:10018 — doi.org/10.1038/s41598-017-09784-z. Measured hydrogen fluoride release across 39 battery fire tests.
• Willstrand, Quant & Hynynen (2025), “Contaminations from Lithium-Ion Battery Fires: PFAS in Soot,” Fire Technology 61:2889 — doi.org/10.1007/s10694-025-01708-y.
• NIST Technical Note 2365 (2026), “Understanding the Risk of Lithium-Ion Battery Fires” — doi.org/10.6028/NIST.TN.2365. Multi-source data analysis from the National Institute of Standards and Technology.
• CROSS-UK Report 1166 (2023), “Battery Energy Storage System concerns” — cross-safety.org. Expert-panel safety commentary identifying fire-plume and contaminated-runoff as the principal BESS-fire consequences.
• American Clean Power Association (2025), “Assessment of Potential Impacts of Fires at BESS Facilities” — cleanpower.org. The industry association’s own fire-impacts assessment.
• NHTSA Recall 25E007000 (2025), Samsung SDI high-voltage battery packs — Part 573 Safety Recall Report (PDF). Cell-separator manufacturing defect, 180,196 units.

Documented BESS fires and their aftermath

• Energy Safe Victoria, “Statement of Technical Findings: Victoria Big Battery” (2021) — energysafe.vic.gov.au (PDF). The official regulator’s findings on the July 2021 Victorian Big Battery fire.
• WECC, “Moss Landing BESS Fire Report: Operations Analysis” (December 2025) — wecc.org (PDF). The Western Electricity Coordinating Council’s operations analysis of the January 2025 Moss Landing fire.
• Aiello et al. (2025), “Coastal wetland deposition of cathode metals from the world’s largest lithium-ion battery fire,” Scientific Reports 15:42113 — doi.org/10.1038/s41598-025-25972-8. Peer-reviewed measurement of metal deposition into wetlands after Moss Landing.
• City of Escondido, SDG&E battery fire air-quality report (2024) — escondido.gov (PDF).
• City of Escondido, SDG&E battery fire water-runoff / water-quality report (2024) — escondido.gov (PDF).
• EPA Region 7, Fredericktown battery-recycling fire air-sampling FAQ and data-review memo (2025) — response.epa.gov (PDF).
• KSDK, “Nearly 3 miles of dead fish found in Fredericktown after battery plant fire” (2024) — ksdk.com.

Battery technology and chemistry

• Samsung SDI, “Samsung Battery Box 1.5” (NCA chemistry), InterBattery Europe 2024 — samsungsdi.com.
• Samsung SDI, “SBB 2.0” (LFP chemistry), RE+ 2025 — samsungsdi.com. Together these show the Samsung SDI line spans both NCA and LFP, so naming the vendor does not pin the chemistry.
• Naumann et al. (2018), “Calendar aging of a commercial LiFePO₄/graphite cell,” Journal of Energy Storage 17:153 — doi.org/10.1016/j.est.2018.01.019.
• Preger et al. (2020), “Degradation of Commercial Lithium-Ion Cells,” Journal of The Electrochemical Society 167:120532 — doi.org/10.1149/1945-7111/abae37.

Seismic and site conditions

• USGS Fact Sheet 2025-3050 (2025), “Puget Sound Seismic Hazard” — doi.org/10.3133/fs20253050. Quantifies the 50-year earthquake probabilities for the region.

Local fire authority and emergency response

• Chief Will Aho, Eastside Fire & Rescue, written response (April 6, 2026) — hosted PDF. The responding fire district cannot confirm it is fully prepared for a fire of this type and scale.
• King County Fire Protection District 38 Board of Fire Commissioners, comment letter to the WUTC (June 2026) — WUTC docket (PDF). The fire district with jurisdiction over the site formally opposes the siting.

PSE record: siting, procurement, and the interconnection

• PSE ESS Location Study (Power Systems Consultants, June 2021) — hosted PDF. PSE’s own study screened 382 substations and recommended 14 candidates, none at Mt. Si.
• PSE–Cascadia Ridge Tolling Agreement, public version (WUTC Docket UE-240532) — WUTC docket (PDF). The operating parameters (state-of-charge, cycle rate, chemistry framework) that drive much of this site’s analysis.
• PSE 2024 All-Source RFP Proposal Summary (WAC 480-107-035(5)) — WUTC docket (PDF). All standalone battery proposals PSE received were lithium-ion.
• PSE 2024 RFP Evaluation Rubric — WUTC docket.
• PSE 2026 Voluntary Utility-Scale RFP — WUTC docket (PDF).
• PSE 2023 Electric Progress Report, Chapter 7 (Resource Adequacy) — PSE (PDF).
• PSE–Cascadia Ridge Engineering & Procurement Agreement (FERC Docket ER26-2343) — FERC eLibrary. The PSE Network Upgrades (Mt. Si substation expansion and new tap line) that the SEPA record does not disclose.
• FERC Informational Reports on Interlocking Directorates, Jupiter Power LLC — FERC eLibrary. Identify Cascadia Ridge Resiliency LLC as an indirect wholly-owned subsidiary of Jupiter Power.

Regulatory framework and permitting

• King County Ordinance 19824 (2024), the BESS regulatory framework — King County Legistar. The first BESS framework for unincorporated King County; Cascadia Ridge is one of the first projects through it.

Adjacent-jurisdiction actions

• City of Snoqualmie, Mayor-and-Council letter to the WUTC (June 2026) — WUTC docket (PDF).
• City of North Bend, comment letter to the WUTC (June 2026) — WUTC docket (PDF).
• Snoqualmie Valley School District Resolution No. 901 (2026) — PDF. Requests environmental review sufficient to evaluate student and staff safety.
• City of Duvall Ordinance No. 1353 (2026), 12-month BESS moratorium — June 2 City Council minutes.
• City of Snoqualmie, $450,000 appropriation for independent BESS review (June 2026) — Living Snoqualmie coverage.

Financial assurance and decommissioning (comparable regulation)

• Orange County, California Ordinance No. 25-017 (2025), BESS facilities — County ordinance (PDF). A peer jurisdiction that scales financial assurance to actual decommissioning cost and binds it to the project entity, where King County sets a flat $1,000,000 figure.

Recorded documents

The recorded covenants and agreements on the project parcels are hosted on the parcel pages and summarized under recorded documents, including the perpetual City of Snoqualmie Covenant and Grant of Easement (Rec# 20110429001446), the Pre-Annexation Development Agreement (Rec# 20110202001508), and the Private Water Supply covenant on parcel 3624079100 (Rec# 199810141781).

Media

• KOMO News, Snoqualmie Ridge battery storage project coverage (March 2026) — komonews.com. Includes Jupiter Power’s on-camera statement that the site was chosen “because it’s directly adjacent to the Mt. Si substation.”