GNOSS FIELD AIRPORT SUPPLEMENT TO THE FINAL ENVIRONMENTAL IMPACT STATEMENT FINAL CHAPTER ONE BACKGROUND This document is the Final Supplement to the Final Environmental Impact Statement (SEIS), prepared in support of the Federal actions related to the proposed runway and parallel taxiway extension at Gnoss Field Airport (DVO or Airport). This Final SEIS updates the previous National Environmental Policy Act of 1969 (NEPA) analyses to address changes in the forecasted aviation activity and the critical aircraft at DVO and adds an additional alternative for environmental impact evaluation. The SEIS has been prepared pursuant to the NEPA and its implementing regulations found at Title 40, Code of Federal Regulations (CFR) §§ 1500-1508. The Federal Aviation Administration (FAA) published a Final Environmental Impact Statement (EIS) in June 2014 in support of the Federal actions related to the proposed runway and parallel taxiway extension at DVO. During the preparation of the response to comments on the June 2014 Final EIS, the FAA informally reviewed aviation operations activity from the FAA Traffic Flow Management System Counts (TMFSC) database associated with aviation activity at DVO. After that evaluation, the FAA concluded that existing conditions regarding the aviation activity at DVO may have changed from those described in the June 2014 Final EIS.1 Therefore, a formal analysis was required to verify the current aviation activity level and critical aircraft for DVO. That formal analysis was contained in an April 2016 Purpose and Need Working Paper, which was circulated for public review and comment. The April 2016 Purpose and Need Working Paper identified that the critical aircraft classification and associated runway length requirement at DVO had changed from what was described in the June 2014 Final EIS. This new information needed to be added in a supplement to the June 2014 Final EIS, and therefore, the FAA did not issue a Record of Decision (ROD) on the June 2014 Final EIS. However, many commenters on the April 2016 Purpose and Need Working Paper stated that they believed that the number of operations identified for jet aircraft in that document, specifically for the critical aircraft identified in the June 2014 Final EIS (the Cessna 525), did not account for all of operations for that aircraft at DVO. In order to resolve whether the number of aircraft operations, particularly of the most demanding critical aircraft, had been undercounted, the FAA gathered additional data. An Updated Purpose and Need Working Paper with an increased focus on the operating levels of the Cessna 525 aircraft was subsequently prepared. That evaluation was needed before the FAA prepared a Supplement to the June 2014 Final EIS. Therefore, the FAA subsequently issued an Updated Purpose and Need Working Paper in February 2018 and accepted public comments on that document. The evaluations in the February 2018 Updated Purpose and Need Working Paper identified additional operations of jet aircraft compared to the April 2016 Purpose and 1 FAA San Francisco Airports District Office January 9, 2015 letter to Mr. Craig Tackabery, Marin County Department of Public Works. Landrum & Brown Chapter One – Background January 2020 Page 1-1 GNOSS FIELD AIRPORT SUPPLEMENT TO THE FINAL ENVIRONMENTAL IMPACT STATEMENT FINAL Need Working Paper. However, the February 2018 Updated Purpose and Need Working Paper was consistent with the conclusion of the April 2016 Purpose and Need Working Paper that the critical aircraft classification for DVO had changed from the critical aircraft identified in the June 2014 Final EIS, the Cessna 525 business jet, to the family grouping of B-II turboprop aircraft. This determination is discussed in detail in Chapter 2, Purpose and Need, and Appendix C-1, Aviation Activity Forecast. The February 2018 Updated Purpose and Need Working Paper evaluated the necessary runway length for the new critical aircraft to meet the purpose and need for the project to allow existing aircraft, as represented by the family grouping of critical aircraft at DVO, to operate without operational weight restrictions under hot weather conditions. This purpose and need statement is slightly different from the purpose and need statement contained in the June 2014 Final EIS. The purpose and need statement was revised to be fully consistent with allowable runway length determination factors identified in the FAA Advisory Circular (AC) 150/5325-4B Runway Length Requirements for Airport Design. The Updated Purpose and Need Working Paper concluded that a 300-foot runway extension would meet the purpose and need for the proposed project for the current critical aircraft at DVO. Therefore, the FAA has prepared this SEIS to provide an environmental impact evaluation of an additional alternative, a 300-foot runway length alternative, not included in the prior June 2014 Final EIS. In accordance with FAA Order 1050.1F, Environmental Impacts: Policies and Procedures Paragraph 9-3 (a), no additional public scoping was required prior to preparation and issuance of this Final SEIS for public comment. The range of potential environmental impacts of the proposed action and alternatives was previously identified during public scoping prior to preparation of the Draft EIS, and in comment letters received on the December 2011 Draft EIS and June 2014 Final EIS. A runway extension would require changes to the Airport Layout Plan, which must be approved by the FAA. That approval constitutes a FAA Federal action requiring NEPA review (see Chapter Two, Purpose and Need, Section 2.3 for a full list of Federal actions). In addition, construction of any runway extension would require a Clean Water Act (CWA), Section 404, permit authorization2 from the U.S. Army Corps of Engineers (USACOE) to fill waters within CWA jurisdiction. The USACOE determination regarding whether to issue a CWA, Section 404, permit is a USACOE Federal action requiring NEPA review. The USACOE is a NEPA cooperating agency for this SEIS. The purpose of preparing an EIS is to investigate, analyze, and disclose the potential impacts of a proposed action and its reasonable alternatives on the environment. 2 In order to make this EIS easier for the reader to understand, the EIS text has used the term “Clean Water Act (CWA) jurisdiction” to represent all USACOE jurisdiction, which also includes areas within Rivers and Harbors Act (RHA) jurisdiction and is sometimes referred to collectively as “waters of the United States.” Similarly, the term “CWA, Section 404, permit,” is used to represent the broader term sometimes used by the USACOE of “Department of the Army (DA) permit,” to represent a permit that addresses a permit authorization for waters within CWA and RHA jurisdiction. Landrum & Brown Chapter One – Background January 2020 Page 1-2 GNOSS FIELD AIRPORT SUPPLEMENT TO THE FINAL ENVIRONMENTAL IMPACT STATEMENT FINAL This SEIS includes an additional alternative not considered in the June 2014 Final EIS that evaluates the potential impacts associated with shifting Runway 13/31 106 feet to the north and extending Runway 13/31 and its associated parallel taxiway, to the northwest by 300 feet, thereby increasing the total runway length from 3,300 feet to a total length of 3,600 feet while maintaining the 75-foot width of the runway. Additionally, in order for the extended runway to become operational, the FAA would need to develop air traffic control and airspace management procedures regarding the safe and efficient movement of air traffic to and from the runway. Such actions could include, but not be limited to, the establishment or modification of flight procedures and the installation and/or relocation of navigational aids. This SEIS assesses the foreseeable environmental conditions that would be expected in 2024, for each of the alternatives evaluated in detail. These are discussed in Chapter Five, Environmental Consequences, of this document. This timeframe corresponds to the anticipated opening of extended Runway 13/31. In addition, specific Airport activity levels and their associated air quality and noise impacts are evaluated for a condition five years beyond the opening year (2029).3 The information contained in this SEIS will be taken into consideration by the FAA and the USACOE as the agencies consider their respective Federal actions associated with the runway extension project. The FAA will issue a Record of Decision (ROD) on the SEIS. The FAA ROD will not be issued until at least 30 days after the distribution of this SEIS to the public. The USACOE will review the CWA permit application for the project and issue a separate memorandum for record and/or ROD regarding the permit application. This chapter contains the background, history, and description of DVO. Descriptions of the Airport layout, facilities, and services, as well as aviation activity, both actual and forecasted, are also presented so that the reader may understand the operations of the Airport and the context in which the proposed development actions and its alternatives are set. 1.1 OWNERSHIP AND LOCATION DVO is a general aviation airport owned and operated by Marin County, California. The Airport is located in unincorporated Marin County north of the City of Novato, California and serves as an essential regional transportation resource by providing general aviation facilities in the northern portion of the San Francisco Bay area. Public access to the Airport is available from the Atherton Road exit of Highway 101. Exhibit 1-1, Airport Location Map, shows the location of the Airport. 1.2 AIRPORT HISTORY Use of what became Gnoss Field Airport dates to 1939. In that year, William Wright, who owned the property, built a private grass-landing strip. After trying to sell his airport to Marin County for $1,000 an acre in 1945-1946, Wright leased the field to 3 FAA Order 1050.1F, Environmental Impacts: Policies and Procedures, Appendix B, Section B-1.5 and B-1.6 Landrum & Brown Chapter One – Background January 2020 Page 1-3 GNOSS FIELD AIRPORT SUPPLEMENT TO THE FINAL ENVIRONMENTAL IMPACT STATEMENT FINAL Woody Binford.