The Divert Activities and Exercises EIS prepared by the U.S. Air Force analyzes environmental impacts associated with the proposal to improve an existing airport or airports and associated infrastructure in support of expanding mission requirements and to achieve divert capabilities in the western Pacific. This page is a guide to NEPA and the EIS process; and the Divert Activities and Exercises proposal.

About NEPA


The National Environmental Policy Act (NEPA) of 1969 was enacted to address concerns about environmental quality. NEPA's main objectives are as follows:

What is an EIS?

An Environmental Impact Statement (EIS) is the most detailed analysis prescribed by the Council on Environmental Quality (CEQ) regulations for implementing NEPA. An EIS is a detailed public document describing a proposed action, all alternative actions that were considered, and the environmental impacts of implementing the Proposed Action and reasonable alternatives. Federal agencies are required to prepare an EIS for actions that could significantly affect the human or natural environment. An EIS is required to "provide a basis of consideration and inform decision-makers and the public of the reasonable alternatives.

The U.S. Air Force has determined that improving an existing airport or airports and associated infrastructure in the Mariana Islands region constitutes a major Federal action as defined by NEPA and, thus, has prepared an EIS..

General steps in the EIS Process

The EIS process includes the following defined steps:

For more information on NEPA and the EIS process, please see the NEPA Overview Fact Sheet.

About the Proposed Action

The U.S. Air Force seeks to improve an existing airport or airports and associated infrastructure in the Mariana Islands in support of expanding mission requirements and to achieve divert capabilities in the western Pacific.

What is the Purpose of the Proposed Action and why is it Needed?

The purpose of the Proposed Action is to establish additional divert capabilities to support and conduct current, emerging, and future exercises, while ensuring the capability to meet mission requirements in the event that access to Andersen Air Force Base (AFB) or other western Pacific locations is limited or denied.
The need for the Proposed Action is derived from the following operational requirements necessary to support the PACAF mission successfully:

In summary, the Proposed Action is needed because there is not an existing divert or contingency airfield on U.S. territory in the western Pacific that is designed and designated to provide strategic operational and exercise capabilities for U.S. forces when needed and humanitarian airlift and disaster relief in times of natural or man-made disasters.

Description and Elements of the Proposed Action

The Proposed Action consists of:

2012 Draft EIS Release

In June 2012, the U.S. Air Force released a Draft EIS for Divert Activities and Exercises. The Draft EIS described the Proposed Action to improve an existing airport or airports through the construction of facilities and infrastructure in the Mariana Islands to support a combination of cargo, fighter, and tanker aircraft and support personnel for periodic divert landings, joint military exercises, and humanitarian assistance and disaster relief efforts. The Draft EIS analyzed two alternative locations in the CNMI for the Proposed Action; Saipan International Airport and Tinian International Airport. The Draft EIS identified Saipan as the Preferred Alternative.

Revised Draft EIS Release

The Revised Draft EIS was published in the Federal Resgister for public review on October 17, 2015 ChST (October 16, 2015 EDT). The Revised Draft EIS is a modification of the original Divert Activities and Exercises Draft EIS that was released for public review on June 9, 2012 ChST (June 8, 2012 EDT). The USAF’s purpose of and need for the divert activities and exercises Proposed Action have not changed since release of the Draft EIS in June 2012.  However, the USAF determined the policies and objectives of NEPA would be best served by preparing and releasing a Revised Draft EIS to seek additional comments on changes made as a result of comments received on the 2012 Draft EIS.  This Revised Draft EIS presents modified alternatives that represent a reduced capability from that analyzed in the 2012 Draft EIS.  The modified alternatives meet USAF operational selection standards presented in the 2012 Draft EIS, while incorporating input received during the 2012 Draft EIS public review period.  The Revised Draft EIS was available for public review until December 15, 2015 ChST (December 14, 2015 EST).

Final EIS Release

The U.S. Air Force (USAF) has announced the availability of the Final Environmental Impact Statement (EIS) for Divert Activities and Exercises, Commonwealth of the Northern Mariana Islands, as published in the Federal Register.  As stated in the Final EIS, the USAF preferred alternative is Alternative 2- Modified Tinian Alternative.  In accordance with federal regulations that guide the EIS process (40 CFR 1500-1508), the USAF will issue a Record of Decision (ROD) on whether and how to implement the Proposed Action no sooner than 30 days after release of the Final EIS.  A Notice of Availability for the ROD will be published in the Federal Register and local newspapers.
The Final EIS takes into account public input and comments received on the Revised Draft EIS, which the USAF released for public review in October 2015.  It analyzes potential environmental impacts of the modified alternatives which were presented in the Revised Draft EIS.  The modified alternatives meet USAF operational selection standards while incorporating input received during the 2012 Draft EIS public review period.