Pierce County Airport - Thun Field Master Plan

  Project Update

Feb. 1, 2024

Thun Field Environmental Assessment accepted by the FAA

On Jan. 26, 2024, the Federal Aviation Administration accepted the Final Environmental Assessment for Pierce County Airport – Thun Field. The signed Environmental Assessment and signed Finding of No Significant Impact (FONSI) are now available. 

The County is now cleared to begin the project design and construction phases. See Project Timeline below.

Thank you to everyone who visited our online open house, attended the public meeting, and submitted comments during the Environmental Assessment process. 

  Planning for the Future: Airport Master Plan


Pierce County initiated the work to update the Master Plan, including the Airport Layout Plan, for Pierce County Airport - Thun Field (Thun Field) in October 2017. The Master Plan serves as a 20-year improvement plan for the airport and identifies long-term needs for facilities, equipment, and services to position Thun Field to accommodate community growth.  

The Master Plan Advisory Committee (MPAC) – made up of representatives from the aviation community, businesses, local and state government and more – participated in working sessions throughout the process to develop recommendations.

The Federal Aviation Administration (FAA)/Seattle ADO approved the Airport Layout Plan for Thun Field on June 9, 2021, making Thun Field’s facility improvement plan eligible for FAA grant funding.

The Final Master Plan was approved by Resolution No. R2023-70 by the Pierce County Council on June 6, 2023.

The Master Plan focuses on these areas:

  • Positioning the airport to meet community growth and interests
  • Accommodate existing and future aviation demands as envisioned by Pierce County
  • Align recommendations with Pierce County revenue and return benefit
  • Meet FAA safety standards and grant assurances


The goal of the Thun Field Master Plan is to provide a strategic framework for airport improvements that will create opportunities for economic development and capitalize on current airport infrastructure assets.

  Master Plan Narrative Chapters 

The Thun Field Master Plan includes the following narrative report chapters used to document findings and decisions made during the planning process. Narrative chapters will be uploaded to this webpage following review by Pierce County, the FAA, and the Washington State Department of Transportation (WSDOT).


Rod Propst
Airport Manager / Assistant Airport & Ferry Administrator

[email protected]

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Key activities and improvements called out for implementation as part the Thun Field Master Plan are be funded through a series of grants from the FAA, Pierce County, and the Washington State Department of Transportation (WSDOT). Funded improvements are dependent on all partners providing funding.

  About Pierce County Airport - Thun Field

Thun Field is located in South Hill community and serves the general aviation needs of Tacoma, Puyallup, and the larger area of Pierce County, Washington.

Thun Field accommodated an estimated 106,300 aircraft takeoffs and landings and had 253 based aircraft in 2018, with that number expected to increase to 137,200 and 312, respectively, in 2037.

The airport is owned and operated by Pierce County and is classified as a regional general aviation airport by the Federal Aviation Administration (FAA).

  Environmental Assessment 

All projects that receive federal funding are required to be reviewed under the National Environmental Policy Act (NEPA) to ensure that the proposed projects consider, and when possible, minimize environmental impacts. 

An Environmental Assessment was conducted in fall 2023 for the FAA to determine the environmental impacts of the selected runway extension and widening. The assessment will also identify aeronautical hazards or obstructions based on FAA guidelines. As part of this process, Pierce County held a 30-day public comment period from Nov. 20 to Dec. 20, 2023. 

The following projects are included in the Proposed Action: 

  • Obstruction/Tree Removal: Remove approximately 1,600 trees and 3.2 acres of brush on the airport property to clear obstructions to the runway’s Part 77 surface and the airport’s Automated Weather Observing System. 
  • Runway 17-35 Widening, Extension & Strengthening: Widen Runway 17-35 from 60 to 75 feet, extend the length from 3,650 to 4,000 feet, and strengthen the pavement from 12,500 to 20,000 pounds. 
  • Taxiway Relocation & Reconfiguration: Relocate Taxiway A4 and reconfigure the pavement edge for Taxiways A2 and A3 to provide for safer operations and bring existing taxiways into compliance with FAA standards.

These projects will not change the existing airport footprint.

The environmental assessment is 90% funded through an Airport Improvement Program (AIP) grant from the FAA. The remaining funds are covered by Pierce County.

If the Proposed Action proceed forward, future phases of the projects (design and construction) are also anticipated to be funded by 90% FAA AIP grants for all eligible costs. The County will also be applying for matching funds through other sources, including the Washington State Department of Transportation Aviation Division.

  What is Federal Aviation Regulation Part 77?

The Code of Federal Regulations (CFR) Title 14, Chapter 1, Subchapter E, Part 77 (Part 77) consists of rules and regulations that are designed to maintain safe skies for airplanes and other aircraft.

Imagine the sky as a carefully managed highway system for planes. Part 77 acts as a rulebook that helps prevent obstacles from getting in the way of these flying vehicles. These obstacles could range from trees and tall buildings to antennas.

Part 77 regulations help spot these potential obstructions and require them to be marked, lit, or removed to keep air travel safe. The FAA uses these regulations to determine if certain objects could be hazardous to air navigation.

  1. Timeline
  2. Master Plan Advisory Committee

Nov. 21, 2000:  Pierce County Council approves the 2000 Master Plan

September 2017: Pierce County selected Mead & Hunt to evaluate the then-current state of the airport, develop recommendations on how best to meet the community’s 20-year development needs, and prepare a draft Master Plan, including the Airport Layout Plan.

 October 2017: 2021 Master Plan Development kicks off.

 June 9, 2021: FAA approves the Airport Layout Plan.

Aug. 31-Sept. 22, 2021: Pierce County hosts Master Plan Online Open House.

May 2022: Century West, the County’s on-call aviation planning consultant, begins drafting the Environmental Assessment.

June 6, 2023: Pierce County Council approves the Final Master Plan by Resolution No. R2023-70.

Nov. 20 - Dec. 20, 2023: Draft Environmental Assessment published for a 30-day public comment period.

Dec. 12, 2023: Public meeting at the South Hill Pierce County Library.

December 2023: Pierce County and FAA to review the public comments.

December 2023 / January 2024: 
Reasonable comments received during public comment will be addressed within the Final Environmental Assessment.

January 2024: 
  • FAA to provide Determination on the Environmental Assessment 
  • FAA to issue finding of environmental impact.

Anticipated Project Timeline


  • Complete design for Obstruction Removal project.
  • Complete design for Runway 17-35 Widening, Extension, and Strengthening project.

Summer 2026: 

  • Construct Obstruction Removal project.
  • Construct Runway 17-35 Widening, Extension, and Strengthening project.

Spring 2028: Complete design for Taxiway Relocation and Reconfiguration project.

Summer 2028: Construct Taxiway Relocation and Reconfiguration project.