an excerpt from the 1997 Sea-Tac International Airport Impact Mitigation Study
Overview
There is no doubt that the expansion of Sea-Tac International Airport will have a positive economic benefit for the region and the State. However, the costs associated with these improvements are disproportionately borne by those communities immediately surrounding the Airport.
Communities such as Burien and Des Moines are projected to be impacted by noise, traffic congestion, and socio-economic hardship merely because of their location near the Airport. Of the estimated $2.95 billion in potential mitigation costs, $2.3 billion (almost 80%) is projected to be required for Burien and Des Moines alone. Other environmental, transportation, and socio-economic costs have not yet been calculated.
Project Parameters
This report was produced under a grant from the State of Washington to analyze the proposed Third Runway project at Sea-Tac International Airport. The City of Burien, acting in the capacity of the grant manager, supervised the consultant team.
Study Area
The study examined the potential impacts of the Airport project on neighborhoods in the surrounding communities of:
- Burien
- Des Moines
- Federal Way
- Normandy Park
- Tukwila
Potential impacts on facilities owned and operated by the Highline School District and Highline Hospital were similarly examined.
Key Study Parameters
- Basic premise: The Third Runway project would be constructed
- Mitigation focus: Preservation and protection of neighborhood integrity
- Economic importance: Sea-Tac International Airport’s economic value was never questioned
- Neighborhood boundaries: Established by each community through their comprehensive planning process
Funding and Responsibility
This study does not assign mitigation costs to any particular agency. While the Port of Seattle and the Federal Aviation Administration will be financially responsible for a portion of the mitigation costs, funding from other sources is also expected:
- Transportation funding: Available through the Washington State Department of Transportation and the Federal Highway Administration
- Environmental mitigation: May be eligible for State and Federal EPA funding
- Acquisition and redevelopment: May be shared between private and public-sector interests
Environmental Impacts
Neighborhood Acquisition and Redevelopment
Costs: Approximately $2.4 billion
The most significant environmental impacts require potential acquisition and redevelopment of 5 neighborhoods in 2 communities:
Neighborhoods Identified for Potential Acquisition and Redevelopment
Burien:
- North East
- West Central
Des Moines:
- North Central
- East Central
- South Des Moines
Mitigation of these neighborhoods is estimated at approximately $1.9 billion – 80% of the total environmental impacts. These 5 neighborhoods are the closest to the proposed project and will experience significant impacts, due primarily to noise and vibration of aircraft operations.
Important Note: Acquisition and redevelopment is the most far-reaching mitigation measure for these areas, but it will also fundamentally change these neighborhoods. The study recommends that a “specific area plan” be developed for each of these 5 neighborhoods to determine if other mitigation measures are appropriate. Acquisition and redevelopment is recommended only if all other mitigation measures are unsuccessful.
Other Community Impacts
- Federal Way: $148 million (LDN contours and overflights)
- Normandy Park: $56 million (LDN and SEL noise, overflights)
- Tukwila: $114 million (LDN and SEL noise, overflights)
Mitigation in these 3 communities would involve primarily sound abatement insulation and the purchasing of avigation easements.
School Impacts
The study recommended replacement or relocation of 8 schools in 3 communities:
Schools Identified for Potential Replacement or Relocation
| Area | Elementary Schools | Middle Schools | High Schools |
|---|---|---|---|
| Burien | Sunnydale, Cedarhurst | (none) | (none) |
| Des Moines | Midway | Pacific | Mount Rainier |
| Unincorporated King County | Beverly Park, White Center | (none) | Satellite Alternate |
Twenty-six other schools in the Highline School District were identified for sound abatement insulation and avigation easements.
Transportation Impacts
Estimated costs: Approximately $479 million
The study examined 4 general transportation areas and 21 specific potential impacts:
Impact Categories
- Congestion: Level of service, accidents, school bus operations, transit bus operations, police and emergency vehicle operations, parking and pedestrian access, traffic noise
- Physical damage: Local streets, state roads, state bridges, increased maintenance and reconstruction
- Construction impacts: Truck haul routes, barge/rail/conveyor system, traffic diversion, traffic control, construction staging and phasing, work-force traffic, concurrent construction projects
- Post-construction impacts: Additional traffic, increased operation and maintenance costs, master plan update
Cost Distribution by Community
- Tukwila: $192 million (40%) – due primarily to State-jurisdiction roads and bridges
- Burien: $117 million – due to close proximity to Airport’s west side
- Des Moines: $73 million – due to close proximity to Airport’s south side
- Normandy Park and Federal Way: Lowest costs due to location relative to Airport
Study Limitations
While the EIS analyzed transportation impacts well, it did not study a large enough area. The Airport serves the entire Central Puget Sound Region, yet the transportation impacts studied stopped at the Airport’s “driveways.” Additional studies are needed to determine the true scope of transportation-related impacts.
Socio-Economic Impacts
The Inequity Problem
There is a significant inequity regarding the benefit of the Airport to its immediate neighbors. While the study acknowledges the benefit of the Airport to the region and the State, these benefits are not experienced locally in the 5 impacted communities:
- Only 5% of persons utilizing the Airport live in the area most impacted
- 95% of Airport passengers and employees come from elsewhere in the region
Financial Impact on Communities
The 5 communities were projected to experience a loss of $39.9 million during the period 2000 through 2020 as a result of the proposed project.
The “Blighting” Effect
Socio-economic impacts create a cascading effect:
- Property value depression: Homes in impacted areas don’t rise in value as fast as similar properties elsewhere
- Tenure change: Single-family homes that cannot be sold become rental properties
- Demographic shift: Non-owner-occupied areas have lower average household income and utilize more social services
- Revenue vs. cost mismatch: While property values and tax revenues are depressed, the cost of providing social services increases
This has already been observed: homes take longer to sell in neighborhoods adjacent to the Airport, and the local real estate market acknowledges aviation activity’s impact.
Key Recommendations
Environmental
- Oversight Commission: Establish a working group to interact with the Port of Seattle during implementation
- Specific Area Plans: Develop plans for each of the 5 most impacted neighborhoods before considering acquisition
- Monitoring Programs: Establish permanent noise monitoring to verify EIS projections are not exceeded
- DOT Section 4(F) Resource Mitigation: Preserve and protect significant open spaces, parks, and recreational areas
Transportation
- Origin-Destination Survey: Determine the amount of regional traffic attributable to Sea-Tac International Airport
- Cost Recalculation: Assign costs to Port of Seattle only for impacts attributable to Third Runway traffic
- Continuous Monitoring: Monitor level of service, school bus impacts, public safety response times, and roadway conditions
Socio-Economic
- Revenue Off-setting: Port of Seattle should make partial payments to the 5 impacted communities to mitigate local government revenue losses
- Quality of Life Monitoring: Create a quality of life indicator model for the impacted cities
- Public Health Analysis: Fund University of Washington School of Public Health to conduct an Airport health impact assessment
- Economic Development: Assess Airport operations to determine functions that could benefit the 5 impacted cities
Overall Planning
- South King County Comprehensive Plan: Develop a comprehensive plan that addresses the needs of all interests in the area – communities, residents, businesses, schools, hospitals, the environment, and the Airport
Summary of Costs
Total Identified Mitigation Costs: $2.95 Billion
| Impact Category | Estimated Cost |
|---|---|
| Environmental | $2.4 billion |
| Transportation | $479 million |
| Socio-Economic | $38.7 million |
Important Note: The $2.95 billion does not represent the total potential mitigation amount. Many costs have not yet been determined, including:
- Costs for relocating, insulating, and granting easements to Highline School District facilities
- Costs for insulating Highline Community Hospital
- Additional significant environmental and transportation-related impacts
Implementation Requirements
It is the recommendation of this study that all known environmental, transportation, and socio-economic impacts be mitigated prior to construction of the Third Runway.
Ongoing Requirements
- Continuous monitoring and mitigation during and after construction through at least the Year 2020
- Community voice in ongoing efforts through the recommended working group/oversight commission
- Multiple additional studies to be completed prior to the Record of Decision being granted
Validation Approach
The study recommends that EIS projections be assumed as accurate and that any required mitigation programs be based on the Airport meeting – not exceeding – these projections. Should parameters be exceeded, the EIS should be re-conducted and additional mitigation programs developed.
This approach positively works with the Port of Seattle to assure both the Airport and Airport-area communities that the EIS will be a valid document.