# Notice of Intent To Prepare a Supplemental Environmental Impact Statement/Overseas Environmental Impact Statement for the Mariana Islands Training and Testing (ID# EISX-007-17-USN-1744382878)
**AGENCY:**
Department of the Navy (DoN), Department of Defense (DoD).
**ACTION:**
Notice.
**SUMMARY:**
Pursuant to the National Environmental Policy Act (NEPA), the National Environmental Policy Act of 1969, DoN regulations, and Presidential Executive Order 12114, the DoN (including both the United States (U.S.) Navy and the U.S. Marine Corps (USMC)) as the lead agency, jointly with the U.S. Air Force, the U.S. Army, and the U.S. Coast Guard (referred to as “Action Proponents”), announce their intent to prepare a supplement to the 2015 Mariana Islands Training and Testing (MITT) Environmental Impact Statement (EIS)/Overseas EIS (OEIS) and the 2020 MITT Supplemental EIS (SEIS)/OEIS. The MITT SEIS/OEIS will include an analysis of training activities (referred to as “training”); research, development, testing, and evaluation (referred to as “testing”) activities; and range modernization and sustainment that will be conducted in the MITT Study Area beginning in July 2027. When discussed together, these activities are referred to as “military readiness activities.”
**DATES:**
The 45-day public scoping period begins on June 7, 2025, and ends on July 22, 2025, Chamorro Standard Time (ChST). The scoping period is extended 15 calendar days (from the usual 30-day period) to allow more time to provide comments. The DoN will host a virtual presentation and have public outreach material on the project website during the scoping period to provide information related to the Proposed Action, its purpose and need, alternatives under consideration, environmental resource areas to be analyzed in the SEIS/OEIS, the NEPA process, the consultation under Section 106 of the National Historic Preservation Act (NHPA), and public involvement opportunities.
**ADDRESSES:**
Comments on the scope of the SEIS/OEIS or information regarding the project's potential to affect historic properties pursuant to section 106 of the NHPA through the project website at *www.nepa.navy.mil/mitteis* or by mail to: Naval Facilities Engineering Systems Command Pacific, Attention: MITT SEIS/OEIS Project Manager, 258 Makalapa Drive, Suite 100, Pearl Harbor, HI 96860-3134.
**FOR FURTHER INFORMATION CONTACT:**
U.S. Pacific Fleet Command, Attention: Ms. Heather Paynter, Environmental Public Affairs Specialist, 808-471-3769, *[email protected],* or visit the project website at *www.nepa.navy.mil/mitteis.*
**SUPPLEMENTARY INFORMATION:**
Within the DoN, the lead action proponent is Commander, U.S. Pacific Fleet. Additional DoN action proponents include Naval Sea Systems Command, Naval Air Systems Command, Office of Naval Research, and the U.S. Marine Corps (USMC). In addition to DoN action proponents, this SEIS/OEIS includes certain activities by the U.S. Air Force, U.S. Army, and U.S. Coast Guard when those activities are similar to Navy or USMC activities and are scheduled on DoN controlled at-sea ranges.
Proposed military readiness activities are generally consistent with those analyzed in the 2015 MITT EIS/OEIS and the 2020 MITT SEIS/OEIS and are representative of activities that the services have been conducting off Guam and around Commonwealth of the Northern Mariana Islands for decades.
The MITT Study Area (hereafter referred to as the “Study Area”) is the same Study Area used for the 2015 MITT EIS/OEIS and the 2020 MITT SEIS/OEIS analysis, which includes in-water areas within the Mariana Islands Range Complex (MIRC), areas on the high seas to the north and west of the MIRC, a transit corridor between the MIRC and the Hawaii Range Complex, and pier side within Apra Harbor. The Study Area excludes land-based training areas located on Guam, Saipan, Tinian, and Rota that were included in the 2015 MITT EIS/OEIS. Similar to the 2020 MITT SEIS/OEIS, this action does not propose any changes to land-based activities on these islands that were analyzed in the 2015 MITT EIS/OEIS. Thus, activities on these islands are not reanalyzed in this supplement. As in the 2020 SEIS/OEIS, the only land component included in the Study Area is Farallon de Medinilla.
The Proposed Action is to continue to conduct military readiness activities within the Study Area. These activities include the use of active sonar and explosives while employing appropriate marine species protective mitigation measures.
The purpose of the Proposed Action is to ensure the U.S. military services, to include the U.S. Coast Guard, can organize, train, and equip service members and personnel to meet their respective national defense missions in accordance with their Congressionally-mandated requirements [^1] and advance joint interoperability in Navy led exercises with other military services including foreign allies. A SEIS/OEIS is considered the appropriate level of analysis as there are updated activities which are similar to those analyzed in the 2015 MITT EIS/OEIS and the MITT 2020 SEIS/OEIS, and scientific information and acoustic effects criteria that are relevant to understanding the environmental effects of the Proposed Action. New information since the 2015 EIS/OEIS and the 2020 SEIS/OEIS will be considered in furtherance of NEPA and will support Marine Mammal Protection Act (MMPA) authorization requests.
[^1] 10 U.S.C. 8062 (Navy), 8063 (USMC), 9062 (U.S. Air Force), and 7062 (U.S. Army); and 14 U.S.C. 101-102 (U.S. Coast Guard).
The Action Proponents have identified two preliminary action alternatives to carry forward for analysis in the SEIS/OEIS along with the No Action Alternative. Alternative 1 reflects a representative year of training and testing to account for the natural fluctuation of training cycles and deployment schedules that generally limit the maximum level of training and testing occurring every year over any seven-year period. Alternative 2 reflects the maximum number of training and testing activities that could occur within a given year and assumes that the maximum level of activity would occur every year over any seven-year period. As required by NEPA for the purpose of establishing a baseline for analysis, a No Action Alternative will be evaluated which represents a scenario where no military readiness activities are conducted in the Study Area. The tempo and types of military readiness activities have fluctuated because of the introduction of new technologies, the evolving nature of international events, advances in war fighting doctrine and procedures, and changes in force structure (organization and basing of ships, submarines, aircraft, weapons, and Sailors). Such developments influence the frequency, type, duration, intensity, and location of required military readiness activities. The MITT SEIS/OEIS will reflect the current compilation of training and testing activities required to fulfill the military readiness requirements, and therefore both action alternatives include the analysis of newly proposed activities and changes to previously analyzed activities. Additionally, both action alternatives will include range modernization and sustainment necessary to support military readiness activities.
Environmental resources that are determined to be potentially affected are carried forward for full analysis. Resources to be evaluated include, but are not limited to, biological resources (including marine mammals and other protected species), sediments and water quality, air quality, noise, cultural resources, socioeconomics, and public health and safety. The Action Proponents will also analyze measures that would avoid, minimize, or mitigate environmental effects. The Action Proponents will conduct all coordination and consultation activities required by the MMPA, NHPA, ESA, Magnuson‐Stevens Fishery Conservation and Management Act, Coastal Zone Management Act, Clean Air Act, and other laws and regulations determined to be applicable to the project. As part of this process, the DoN will seek the reissuance of authorizations under MMPA and ESA to support at-sea military readiness requirements within the Study Area beginning in July 2027.
Pursuant to NEPA, the Action Proponents invited the National Oceanic and Atmospheric Administration's National Marine Fisheries Service to be a cooperating agency in preparation of the SEIS/OEIS.
The scoping process is helpful in identifying public concerns and local issues to be considered during the development of the SEIS/OEIS. Federal agencies, Territorial agencies, the public, and interested persons are invited to comment on the scope of the SEIS/OEIS, including identifying potential alternatives or issues that should be addressed in the NEPA analysis, relaying environmental concerns, and providing information or analysis relevant to the Proposed Action or the project's potential to affect historic properties pursuant to Section 106 of the NHPA.
Scoping comments submitted via the project website or mailed to the address provided in the *ADDRESSES* section will be considered during the development of the Draft SEIS/OEIS. Scoping comments should be postmarked or received online by 11:59 p.m. ChST on July 22, 2025, for consideration in the Draft SEIS/OEIS.
After the scoping period, the Action Proponents will coordinate with participating and cooperating agencies to develop a Draft SEIS/OEIS. The Action Proponents intends to release the Draft SEIS/OEIS in the winter of 2026, release the Final SEIS/OEIS in the winter of 2027, and sign a Record of Decision following the 30-day Final SEIS/OEIS wait period.
Dated: May 21, 2025.
A.R. DeMaio,
Lieutenant Commander, Judge Advocate General's Corps, U.S. Navy, Federal Register Liaison Officer.