The STNI SAMP Draft EA Public Comment (final)

Mr. Steve Rybolt
Port of Seattle, Aviation Environment and Sustainability
P.O. Box 68727
Seattle, WA 98168

Comments on the Sustainable Airport Master Plan Draft Environmental Assessment (SAMP EA)

On behalf of more than 1,300 members of Sea-Tac Noise.Info we are submitting these comments regarding the Draft Environmental Assessment (EA) for the Port of Seattle’s Sustainable Airport Master Plan (SAMP). After thorough review of the Draft EA documents, we have identified multiple significant areas where the environmental review appears inadequate to address the complex and far-reaching impacts of the proposed airport expansion. The following analysis demonstrates why a more comprehensive Environmental Impact Statement (EIS) is necessary to properly evaluate the environmental consequences of the SAMP.

Missing Past Growth
The Draft EA’s study period beginning in 2017 critically fails to account for the airport’s demonstrated growth pattern since 1996. Historical data shows operations increasing from 300,000 in 1996 to 450,000 in 2019, with projections reaching 540,000 by 2032. By discounting this established growth trajectory and excluding impacts from the 2008 Third Runway expansion, the SAMP’s forecasts appear to significantly undervalue both current and future operational impacts. A comprehensive EIS is required to properly analyze and account for these long-term growth patterns and their cumulative environmental effects over the full operational history of the airport.

Missing Past Construction
The Draft EA fails to account for significant construction projects completed since the 2015 SAMP announcement, most notably the International Arrivals Facility. These projects were originally intended to be evaluated within the SAMP’s environmental review framework, but have instead been segmented out of the analysis. This segmentation prevents proper evaluation of cumulative impacts from related airport expansion projects. A comprehensive EIS is required to assess the combined environmental effects of all recent facility expansions, including the International Arrivals Facility, in conjunction with proposed future development.

Missing Future Construction
The Draft EA artificially segments the SAMP’s environmental review by only analyzing Near Term Projects (NTP) while excluding already planned Long Term Projects (LTP) including the South Satellite. This segmented approach prevents proper consideration of cumulative impacts and likely understates the true environmental effects of the airport’s complete development plans. The interdependent nature of NTP and LTP components requires that both phases be evaluated together to understand their full environmental impact. A comprehensive EIS is therefore required to assess both NTP and known features of the LTP phases within a single environmental review.

Missing Freeway
The Draft EA fails to adequately address the interconnected impacts of SR-509 expansion and increased airport cargo capacity. The freeway’s 2003 EIS predated even the Third Runway’s completion, with only a limited update in 2018. The project’s explicit purpose of facilitating increased cargo aviation capacity, particularly for night flights to Asia, will have significant impacts on both ground and air operations. Additionally. plans for a southern entrance, were shelved in the 2018 plan only due to lack of funds. As airport operations increase, it will surely reappear. Current forecasts likely underestimate future aviation cargo volumes and associated truck traffic, especially near the 28th south access point. This underestimation leads to an incomplete assessment of combined road and aviation impacts on surrounding communities. A comprehensive EIS is required to evaluate the cumulative effects of increased cargo operations, night flights, and associated ground transportation infrastructure changes.

Missing Demand: active recruitment and tourism
The Draft EA’s fundamental assumption is that flight demand is organic represents a significant analytical flaw. The SAMP planning process fails to acknowledge or account for the Port’s aggressive role in stimulating demand through both airline recruitment efforts and billions of dollars in investments in tourism promotion. This artificial stimulation of demand directly impacts operational forecasts and subsequent environmental impact assessments. A comprehensive EIS is required to properly evaluate the environmental consequences of intentionally stimulated aviation demand, including specific analysis of how recruitment and tourism promotion programs affect flight operations and their associated environmental impacts.

Missing Geography
The Draft EA refers to the area of study as the Area of Potential Effect (APE), essentially the physical construction boundaries. This fails to acknowledge the variable geographic reach of different environmental impacts. Airport-related effects extend well beyond construction boundaries and vary significantly across resource categories including noise, air quality, water quality, trees and wetlands, wildlife, and socioeconomic impacts. The DNL65 noise contour alone demonstrates how aviation impacts extend far beyond the physical airport boundary. Each resource category requires its own scientifically determined impact area based on the unique characteristics of that impact type. A comprehensive EIS is required to properly delineate and evaluate distinct geographic impact areas for each environmental resource category, ensuring that all affected communities receive appropriate consideration.

Socioeconomic Impacts
The Draft EA’s treatment of Socioeconomics, Environmental Justice, and Children’s Health is severely inadequate, relegating this crucial analysis to Appendix K. Alone among all evaluated categories, this crucial aspect of community impacts was not assigned a subject matter expert for study. Over two-thirds of this appendix consists of a 2018 Port of Seattle Economic Impacts Study that focuses solely on purported economic benefits while failing to address community needs or public health impacts. This approach implies that economic benefits can somehow offset or compensate for negative health impacts on vulnerable populations, particularly children. The Draft EA fails to properly evaluate environmental justice concerns or assess how airport operations disproportionately affect sensitive populations. A comprehensive EIS is required to properly evaluate socioeconomic impacts, with particular attention to environmental justice communities and children’s health concerns, separate from any economic benefit analysis.

Incomplete Science: Water
The Draft EA fails to adequately address the airport’s extensive history of water quality impacts. Sea-Tac Airport’s location adjacent to multiple creek systems has resulted in documented damage to local water infrastructure, affecting both community drainage and the regional water system. The true Area of Potential Effect extends across multiple major Basin Plans and into Puget Sound itself. Furthermore, the Draft EA fails to address significant ‘unknown unknowns’ in water quality impacts and has no mention of the extensive use of ‘forever chemicals’ such as PFAS–despite the fact that the airport itself has recognized their carcinogenic properties for over a decade. Given the airport’s chronic problematic history with water quality during the Third Runway expansion and the complexity of interconnected watershed systems, a comprehensive EIS is required to properly evaluate both known and emerging water quality concerns across all affected basin plans.

Incomplete Science: Air
The Draft EA fails to adequately address emerging science regarding ultrafine particles (UFPs), which have only been recognized as a major component of jet engine emissions in the past 25 years. Recent scientific studies have linked UFPs to serious health conditions, including Alzheimer’s and cardiovascular disease, yet these particles remain unregulated and not even considered in the EA. The University of Washington MOV-UP Study has recently made it possible to distinguish between aviation and roadway emissions, representing a significant advancement in understanding aviation-specific air quality impacts. Given these scientific developments and their serious health implications, a comprehensive EIS is required to properly evaluate UFP impacts using current scientific methodologies and measurement techniques, particularly the new ability to differentiate aviation-specific emissions from other sources.

Incomplete Science: Ground
The Draft EA fails to comprehensively assess terrestrial environmental impacts across multiple aspects of airport operations and related development. FAA safety requirements extend wildlife habitat impacts up to three miles along flight paths, affecting even detention ponds like those at Des Moines Creek Business Park. The Flight Corridor Safety Program’s tree removal mandates, combined with the conversion of residential areas to industrial parks and SR-509 development, have resulted in the loss of over forty acres of forest and tens of thousands of trees. While a 2017 Port-funded study attempted to quantify tree loss in fence line cities, it failed to evaluate broader ecosystem impacts on wildlife and community resources. A comprehensive EIS is required to evaluate the cumulative effects of habitat loss, deforestation, and ecosystem disruption across the entire affected area, including both direct airport operations and related development impacts.

Incomplete Science: Noise
The Draft EA fails to incorporate significant scientific advances in understanding aircraft noise health impacts that have emerged since the Third Runway’s construction. Current research demonstrates more severe and wide-ranging health effects than previously recognized, requiring updated analysis methodologies and impact thresholds. Despite the airport’s voluntary Fly Quiet program, the Draft EA acknowledges that night flights will increase. The health harms from sleep disturbance of even a few such operations, especially for vulnerable populations is many times more severe than daytime operations. However, the SAMP relies on the outdated Part 150 process which fails to adequately recognize this. Even worse, Part 150 – and its DNL65 boundary has shrunk by almost two thirds since the Third Runway, contrary to both to science and common sense. Instead, the document should have relied on the use of an Alternative Noise Metric based on current best practice. A comprehensive EIS is required to evaluate noise impacts using current scientific standards and methodologies that reflect our improved understanding of aviation noise’s health effects on surrounding communities.

Impacts to cities: finance
The Draft EA inadequately addresses the complex financial impacts on surrounding communities. As airport operations increase, surrounding property values experience documented relative decline, eroding local tax bases and compromising cities’ ability to provide essential public services. This effect is compounded by the Port of Seattle’s acquisition of properties through buyout programs, converting taxable private property into tax-exempt Port holdings. While historical precedent existed for converting such properties into community assets like North Sea-Tac Park, recent decades have seen these properties developed solely for airport support services. Additionally, the FAA imposes significant unfunded mandates on airport properties, such as $124,000 bird deterrent systems at Des Moines Creek Business Park. The Port’s Economic Impact Study, included in the socioeconomic impacts category, contains gross inaccuracies that prevent meaningful analysis of true airport impacts on local economies. A comprehensive EIS is required to properly evaluate these complex financial impacts on municipal governments and local communities, including detailed analysis of property value effects, tax base erosion, and unfunded regulatory mandates.

The EA/EIS decision
The 2018 decision to proceed with a less rigorous Environmental Assessment rather than a comprehensive Environmental Impact Statement appears procedurally compromised. This concern is validated by Alaska Air’s 2018 scoping comments specifically requesting the FAA to reconsider and provide a full EIS. Evidence suggests the Port and FAA may have used the extended timeline not to develop community-beneficial plans, but rather to inappropriately compress EIS-level analysis into an EA framework. Additionally, the recent Marin Audubon Society v. FAA decision calls into question granting an EA under NEPA given that so much of its rationale for discounting community impacts depends so heavily on regulations promulgated by the Council on Environmental Quality (CEQ). Until there is clarity from the Federal courts on this pivotal question, the possibility of a FONSI must be removed from consideration, thus making a complete EIS the only functional option. Given these procedural concerns, stakeholder requests, including those from major airlines, and the highly uncertain legal situation, a proper EIS must be required to ensure a just environmental review.

Conflicts of Interest
The Draft EA’s integrity is fundamentally compromised by the Port of Seattle’s dual role as both project proponent and permit issuer. This conflict of interest in the environmental review process creates an untenable situation where the Port effectively self-regulates its construction projects, going so far as to provide a bonus to the City of SeaTac on the largest projects. Self-permitting undermines the objective analysis required by NEPA and other environmental regulations. A comprehensive EIS, conducted under proper federal oversight and independent review, is required to ensure unbiased evaluation of environmental impacts.

The EA Process
Given the scope of so many consequential projects the original 30 day comment period would have been inadequate even under the best of circumstances. But these were not the best circumstances. The five year interruption between the 2018 Scoping Period created a lack of community awareness that could not be overcome. Extending the comment period to 45 days gave nearby cities barely enough time to engage professional advice. Additionally, the August 24th cyberattack on the Port’s main web site left both professionals and concerned residents unable to research any information outside that provided within the Draft EA document and the Landrum & Brown site. The Port’s site was not fully restored until shortly before the comment period closed. Responses from the Port of Seattle’s representatives insisted that ‘all the information is there’ when clearly it was not.

Summary
The issues detailed above demonstrate fundamental inadequacies in the current Environmental Assessment process. From the artificial segmentation of project components to the failure to incorporate current scientific understanding across multiple disciplines, the Draft EA consistently understates or overlooks significant environmental impacts. The scope and complexity of these impacts – including air quality, water resources, noise, socioeconomic effects, and cumulative impacts – clearly exceed the appropriate bounds of an Environmental Assessment.

The Port’s role as both project proponent and permit issuer, combined with the documented concerns from stakeholders including major airlines, further emphasizes the need for a more rigorous and independent review process. Given the extensive history of environmental impacts from past airport expansion, the significant scale of proposed development, and the complexity of interrelated effects on surrounding communities, I strongly urge the FAA to require a comprehensive Environmental Impact Statement for the SAMP. Only through a full EIS can the true environmental consequences of this major federal action be properly evaluated and disclosed to the public.

Sincerely,

Sea-Tac Noise.Info