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18 December 2023

From Navy Region Southwest Public Affairs

The DoN, in cooperation with the U.S. Coast Guard, U.S. Army, and U.S. Air Force, is preparing an EIS/OEIS to assess the potential environmental effects associated with the HCTT Study Area.
SAN DIEGO— The Department of the Navy (Navy) (including both the U.S. Navy and the U.S. Marine Corps), in cooperation with the U.S. Coast Guard, U.S. Army, and U.S. Air Force, is preparing an Environmental Impact Statement/Overseas Environmental Impact Statement (EIS/OEIS) to assess the potential environmental effects associated with the Proposed Action to conduct at-sea military readiness activities within the Hawaii-California Training and Testing (HCTT) Study Area (referred to as the “Study Area”). The Navy also proposes to modernize and sustain its ranges in a manner necessary to support training and testing activities. The Navy invites the public to comment on the scope of the EIS/OEIS including identification of potential alternatives and environmental concerns, information and analyses relevant to the Proposed Action, issues that should be addressed in the National Environmental Policy Act (NEPA) analysis, and the project’s potential to affect historic properties pursuant to Section 106 of the National Historic Preservation Act (NHPA).

At-sea military readiness activities, which were last analyzed in the 2018 Hawaii-Southern California Training and Testing (HSTT) EIS/OEIS and the 2022 Point Mugu Sea Range (PMSR) EIS/OEIS, include training and research, development, testing, and evaluation activities (referred to as “training and testing”). Proposed training and testing activities may include the use of active sonar, explosives, and other sources of underwater sound. The Navy would continue to employ appropriate marine species protective mitigation measures when conducting these activities. Modernization and sustainment proposals include new special use airspace in Southern California, an expansion of an underwater training range near San Clemente Island, and installation and maintenance of mine training areas off Hawaii and Southern California. The Navy invited the National Marine Fisheries Service and the Federal Aviation Administration to be cooperating agencies in the preparation of the EIS/OEIS.

The Proposed Action is needed to ensure U.S. military services are able to organize, train, and equip service members and personnel to meet their respective national defense missions in accordance with their Congressionally mandated requirements. Proposed training and testing activities are similar to those analyzed in previous environmental impact analyses and are representative of activities that have been conducted off Hawaii and California for more than 80 years.

The HCTT Study Area consists primarily of the Hawaii Operating Area (OPAREA) and Temporary OPAREA, the California OPAREA, and the transit corridor connecting the two. The Study Area includes only the at-sea components of the range complexes, Navy pierside locations and port transit channels, bays, harbors, inshore waterways, and civilian ports where training and testing activities occur, as well as transits between homeports and operating areas. For this EIS/OEIS, “at-sea components” include the marine environment around San Nicolas Island where marine mammals haul out on the shoreline. Missile and target firings from San Nicolas Island that could disturb the marine mammals are included in this analysis. Aside from this one exception, no other terrestrial impacts will be covered in the EIS/OEIS.
The HCTT Study Area differs from the 2018 HSTT Study Area in that it includes:
•    An extended Southern California Range Complex
•    Special use airspace corresponding to the new extensions in California (the proposed W-293 and the proposed W-294)
•    Two existing training and testing at-sea ranges, the PMSR and the Northern California (NOCAL) Range Complex
•    Areas along the Southern California coastline from approximately Dana Point to Port Hueneme
•    Four amphibious approach lanes providing land access from the NOCAL Range Complex and PMSR

Maps of the Study Area are available on the project website. 

In the EIS/OEIS, the Navy will evaluate the potential environmental impacts from a No Action Alternative and two action alternatives. Resources to be evaluated include, but are not limited to, biological resources (including marine mammals, reptiles, fishes, vegetation, invertebrates, habitats, birds, and other protected species), sediments and water quality, air quality, cultural resources, socioeconomic resources, and public health and safety.

The development of the EIS/OEIS will help sustain the readiness of the Navy and other participating U.S. military services by supporting current and future training and testing requirements, increasing flexibility in conducting training and testing activities, modernizing and sustaining range capabilities, updating environmental impact analyses using the best available science and analytical methods, and supporting Marine Mammal Protection Act and Endangered Species Act consultations for the reissuance of federal regulatory permits and authorizations within the Study Area.

Public Participation
The Navy is hosting a virtual open house presentation on the project website during the scoping period from Dec. 15, 2023, to Jan. 29, 2024. The presentation provides information about the Proposed Action, its purpose and need, environmental resource areas to be analyzed in the EIS/OEIS, the NEPA process, the NHPA Section 106 process, and public involvement opportunities. The public can view the virtual open house presentation and submit comments at anytime during the scoping period.

The Navy welcomes and appreciates the public’s participation during the scoping period. Comments must be postmarked or received online no later than 11:59 p.m. PST on Jan. 29, 2024, for consideration in the Draft EIS/OEIS. Comments may be submitted via the project website at or by mail to:

Naval Facilities Engineering Systems Command Pacific
Attention: HCTT EIS/OEIS Project Manager
258 Makalapa Drive, Suite 100
Pearl Harbor, HI 96860-3134

This public scoping effort will also support consultation under Section 106 of the NHPA and its implementing regulations at 36 Code of Federal Regulations part 800, as members of the public are invited to participate, provide comments, or raise concerns. Comments submitted via the project website or by mail will be considered under NEPA and pursuant to Section 106 of the NHPA.

There will be a public comment opportunity when the Draft EIS/OEIS is available, which is scheduled for fall 2024.

Visit the project website at to learn more about the project, view maps of the Study Area, review prior NEPA-related documents, learn about the NHPA Section 106 consultation process, and submit comments.

Media seeking further information should contact the [Hawaii/Southwest] Regional Public Affairs Officer at or 808-473-0662/ or 619-705-5242.

Please help inform your community by sharing the information in this news release.
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