What King County's Records Show

King County Department of Local Services responded to a public records request on April 13, 2026, producing roughly 730 MB of Jupiter Power’s permit application and related communications. Below are eight findings pulled straight from the application materials. The records are public. The analysis here is ours.

The files cited below all come from Jupiter Power’s withdrawn Commercial Site Development application, CMST25-0005, filed November 21, 2025 and withdrawn February 17, 2026. They are the design documents Jupiter Power has prepared for this site. The forthcoming clearing and grading application is expected to be built on the same design base.

The civil plans show 410 MW / 1,640 MWh, not 130 MW

The cover sheet of the 30% civil plan set (Westwood Engineers, October 24, 2025) identifies the project as 410 MW × 4 hr = 1,640 MWh on a 41.6-acre site. Jupiter Power’s public messaging has consistently described the project as 130 MW, most recently at the March 17, 2026 community open house.

The main transformer on the electrical single-line diagram (90/120/150 MVA, three cooling stages) is right-sized for 130 MW and does not on its own confirm 410 MW. But the cover sheet figure, the megawatt-hour arithmetic (130 MW × 6 hr = 780 MWh vs. 1,640 MWh on the plans), and Keyed Note 4 on the single-line (CCR-E-0001-01) reserving “a place holder for future augmentation requirements that is not part of the initial build out” point to a facility engineered to grow well beyond the initial 130 MW interconnection.

Source: CMST25-0005, Document 05.02 (Civil Plan Set), sheet C001; Document 06 (Electrical Single-Line Diagram).

SEPA review is scoped to the project as described. If the engineered design is three times larger in power and more than two times larger in energy than the described project, a checklist and a Mitigated Determination of Non-Significance is the wrong instrument for the job.

1,239 trees recommended for removal, zero replacement required

Dudek’s arborist report (Jonah Malenfant, ISA-certified arborist) inventoried 1,925 significant trees on the original 25-acre layout submitted with CMST25-0005. 1,239 of them (64.4%) are recommended for removal. The standing timber volume is 144,265 board feet, roughly 28 times the Washington Forest Practices Act threshold of 5,000 board feet.

The applicant claims zero replacement trees are required, citing the King County Code utility exemption at KCC 16.82.156(A)(6). The inventory covers only the 25-acre footprint as originally filed; the expanded 45-acre site Jupiter Power has since described publicly will cover more trees under the same exemption argument.

Source: CMST25-0005, Document 18 (Arborist Report).

Why the Forest Practices Act matters

RCW 76.09 (Washington’s Forest Practices Act) regulates commercial timber harvest on private forestland. The 5,000 board foot threshold is the exemption line: above it, a Forest Practices Application (FPA) is required with the Washington Department of Natural Resources. At 144,265 board feet, this is unambiguously a commercial harvest.

Conversion of forestland to a non-forest use like a BESS is a Class IV forest practice under WAC 222-16-050. On land with critical areas (steep slopes, Type F streams, wetland buffers, all mapped at this site by the Critical Areas Designation), a Class IV conversion is typically elevated to Class IV-Special, which triggers its own SEPA review with DNR as the responsible official, separate from King County’s SEPA process. DNR is a second regulatory agency with jurisdiction over this project.

The arborist report filed with CMST25-0005 notes the 5,000 board foot threshold but does not discuss the FPA process. The Project Description does not address it. The SEPA Environmental Checklist does not address it. The application materials have not engaged DNR at all.

King County’s KCC 16.82.156(A)(6) utility exemption answers the replacement-tree question under county code only. It does not relieve the applicant from Forest Practices Act requirements with DNR, and it does not substitute for DNR’s separate Class IV SEPA review.

The sound study predicts zero compliance margin at the closest home

Dudek’s acoustical analysis (Dana Lodico, PE, INCE) modeled the 25-acre / 130 MW layout as originally filed (392 Samsung battery containers, 98 SMA power conversion units, 3 transformers) against King County’s noise limits.

The predicted nighttime sound level at receptor R5, the closest residential property about 350 feet east of the facility, is 42 dBA. The applicable nighttime limit with the tonal penalty that applies here (the equipment has prominent tones at 3,150 Hz and 6,300 Hz from the power conversion units) is 42 dBA. Zero margin.

The study used substitute spectral data for three of the four equipment types because the actual 1/3 octave band data was unavailable. It took no nighttime ambient measurements near the eastern residences. It did not model alarm or emergency venting noise. It did not analyze low-frequency transformer hum.

Source: CMST25-0005, Document 20 (Sound Study).

A zero-margin prediction on the smaller layout is not a durable compliance case. The expanded facility adds noise sources.

28.3 acres of forest cleared and graded

The Site Areas Worksheet confirms 1,234,600 square feet, or 28.3 acres, of total ground disturbance on a site that today is 100% forest with zero existing pavement. That is roughly 21 football fields of trees cleared and the ground regraded to a flat industrial pad.

The underlying soils are Tokul gravelly medial loam over Vashon Till, rated by Terra-Geo at less than 0.1 inches per hour of infiltration. Water does not drain through the ground here. The forest canopy and understory are what currently slow and absorb the rain. Strip them, add 11.56 acres of new impervious surface, and the water has to be engineered off the site. The 30% civil plans show two large detention basins, multiple vegetated swales, and numerous culverts, all designed to route stormwater down into Fisher Creek. Fisher Creek joins the Snoqualmie River half a mile away and carries ESA-listed Chinook, steelhead, and bull trout.

Construction runs in two phases of 20 to 24 months each. For neighbors, that means roughly two years of trucks on 356th Ave SE, earth-moving vibration, dust, and bare graded ground where mature forest used to stand. The revegetation plan relies mostly on seeding, not replanted trees, so the mature forest is not coming back.

Source: CMST25-0005, Document 07 (Site Areas Worksheet); Document 05.02 (Civil Plan Set); Document 12 (Desktop Geotech); Document 22 (Schematic Landscape Plan).

The SEPA Environmental Checklist describes the habitat impact as “temporary” during construction with “permanent loss in developed areas.” That framing understates what 28 acres of mature forest conversion above a salmon-bearing stream, on soils where nothing infiltrates, does to the site’s hydrology, habitat function, and buffer against adjacent neighborhoods.

King County rejected the first application across all four disciplines

Jupiter Power filed CMST25-0005 on November 21, 2025. King County issued a Notice of Incomplete Application on December 18, 2025. Jupiter withdrew on February 17, 2026, 61 days after the NOIA was issued. The formal NOIA letter stating the cure deadline was not produced in the records release; a follow-up records request has been filed.

Each of the four discipline reviewers raised independent objections:

• Engineering (Lorie Hammerli). “NOT ACCEPTABLE FOR INTAKE.” Unmapped flood hazards require a separate Floodplain Development Application. 30% civil plans are insufficient. Financial Guarantees, Bond Quantity Worksheet, Declaration of Covenant, Grant of Easement, and Soil Management Plan are missing.
• Building (Paul Gneiding). “A complete Geotech Report will be required. The Desktop Geotech Report does not contain the needed information.” 100% structural plans required.
• Fire (Rian Cuthbert). Awaiting applicant information at the time of the NOIA. No fire access or hammerhead turnaround.
• Environmental (Greg Goforth). Pond 1 stream typing in dispute. Desktop aquatic assessment rejected. On-the-ground wetland delineation required per KCC 21A.24.355.

Source: CMST25-0005 TRIAGE, Combined SME Notice of Incomplete Application.

The application was not a near-miss. Every discipline rejected it on completeness grounds. The next filing is a fresh opportunity for the public and for King County to evaluate what is being proposed, not the continuation of a partly-approved design.

The battery supplier has not been selected

The Project Description filed with CMST25-0005 states plainly:

The battery energy storage enclosures supplier has not been selected at this time.

Six candidate manufacturers are named: Hithium, Sungrow, Tesla, Fluence, CATL, LG Chem. The reference product used throughout the application is the Hithium Infinity Block Gen 2, a 5.015 MWh container holding approximately 4,992 cells, actively cooled with a 50/50 water and ethylene glycol mix.

Source: CMST25-0005, Document 02 (Project Description).

Every safety, thermal, and chemistry claim in the application is tied to equipment that has not been procured. A facility permitted against this application could end up using cells from any of the six candidates, and augmented across the 30-year life with successor products that may not exist yet. SEPA review should treat that uncertainty as a significance factor, not assume the reference product.

The thermal runaway analysis models 20 cells out of roughly 2 million

Dudek’s Hazard Consequences Analysis uses AERMOD atmospheric dispersion modeling to evaluate off-site consequences of a thermal event. The scenario it models is 20 cells in simultaneous thermal runaway.

Each Hithium reference container holds roughly 4,992 cells. The 392-container facility contains approximately 1.96 million cells. The HCA scenario represents about 0.4% of a single container, or 0.001% of the facility.

The HCA also does not model hydrogen fluoride, the characteristic hazardous byproduct of lithium iron phosphate thermal decomposition (AEGL-2 of 12 ppm for 60 minutes). It does not model a fire scenario, only off-gassing. It does not model combustion products. Its “no adverse health effects” conclusion depends entirely on those scenario choices.

Source: CMST25-0005, Document 21 (Hazard Consequences Analysis).

Moss Landing burned 55-80% of the facility in early 2025. The Otay Mesa fire in San Diego County burned for 17 days. The scenarios that drive public concern at this scale are cascading events across many containers. This HCA does not evaluate them.

Every NFPA 855 fire safety deliverable is deferred to late 2026

The Fire Safety Approach (prepared by Fire & Risk Alliance for Jupiter Power) sets the delivery schedule for NFPA 855 compliance work:

The facility’s declared fire strategy is defensive water cooling only: a 32,000-gallon on-site tank, a municipal hydrant connection, and a dry manual fire department connection rated 1,000 gpm at 50 psi. There is no automatic fire suppression system.

Eastside Fire & Rescue’s fire marshal, Jeromy Hicks, pushed back on the reliance on municipal water and asked for a self-reliant on-site water supply. Jupiter’s response (Elvin Santos, December 1, 2025):

Based on industry standards, we recommend water use solely for exposure cooling and not for fire suppression.

The record does not contain a resolution.

Source: CMST25-0005, Document 13 (Fire Safety Approach); G015752 communications.

SEPA review of a facility for which every fire safety study is deferred to a date after the public comment window is SEPA review of a design that does not yet exist.

More in the record

The 730 MB records drop contains more than what appears above. Additional findings, including internal King County analysis of the critical areas code framework, King County’s own documented concerns about threshold-level environmental impacts, and Jupiter’s consultant errors caught on site by King County environmental scientists, will be folded into the public SEPA comment letter filed during the 14-day comment window. The comment letter will be published on this site after filing.

For the procedural context of the SEPA window and how to write a substantive comment, see Permitting Status and How to Write an Effective SEPA Comment.