Formerly Used Defense Sites


Marpi Point Field (RI/FS)

Program Background

The U.S. Army Corps of Engineers (USACE) conducted a nationwide effort to identify, manage, and prioritize future response actions at Formerly Used Defense Sites (FUDS). The 410-acre Marpi Point Field (MPF) munitions response site (MRS) is one of these sites. In November of 2009, a Site Inspection (SI) field effort consisting of instrument-aided qualitative reconnaissance and munitions constituent (MC) environmental sampling was conducted. The objective of the SI was to evaluate the likelihood and significance of the potential residual presence of munitions and explosives of concern (MEC) and associated munitions constituents (MC). A Remedial Investigation/Feasibility Study (RI/FS), the next phase of the process, was recommended (this study) to assess the nature and extent of MEC and MC contaminant concerns.

The results of the RI/FS will provide the foundation for the Proposed Plan and Decision Document used to document the decision to conduct a Remedial Action (RA) at the MRS. Following implementation of an RA, the MRS will be periodically reassessed as part of a Recurring Review process to ensure the selected remedy remains protective of human health and the environment.

Site History

Saipan was acquired as part of a U.S. invasion in support of Operation FORAGER in June/July of 1994. The MPF MRS is located in the extreme northern portion of the island and includes what was a partially completed Japanese airfield that subsequently was completed in 1945 by the 51st Naval Construction Battalion and designated as Marpi Point Field. The airfield was renamed Naval Air Base Marpi Point and used until 1947 and abandoned in 1950; however, much of the stored ordnance remained. The MRS was used for various training by the Navy Technical Training Unit (NTTU) between 1950 and 1962 during which Saipan was transferred to the Department of the Interior as part of a Trust Territory status. In 1978, Saipan was approved by the Congress to become part of the Northern Marianas Commonwealth. The land was designated as public land and controlled by the Mariana Public Lands Corporation.

In 1950, the Army reinitiated cleanup as part of "Operation Torch" during which large stockpiles of munitions were destroyed by burning. The action ceased after less than one year due to preparations for the impending Korean War. Despite significant reported munitions remaining, additional cleanup was not deemed cost effective and the northern portion of the island was fenced off to civilian access. In 1962-1964, U.S. Navy Explosives Ordnance Disposal (EOD) detachment out of Guam worked to clear accumulated ordnance following public concerns over the languishing prior cleanup effort. Although over two million pounds of ordnance was destroyed, to include "...artillery projectiles, bombs, grenades, land and beach mines, rockets, pyrotechnics, incendiaries, assorted fuzes and boosters, all in various stages of deterioration and sensitivity", approximately 6,594,000 pounds were estimated to remain in the Marpi area. The last formal clearance effort was conducted by the Navy in 1967. Thousands of tons of ordnance were recovered and disposed of via detonation, dumping, and burial. Only "visual detection methods were used in uncleared heavy jungle" with the report stating "about half" of the munitions were left in the area.

Project Description

The MPF MRS was identified as eligible for inclusion in the DERP FUDS Program in 1995 following conduct of a Site Survey during which high-explosive ordnance was confirmed and resulted in the preparation of an Inventory Project Report documenting site eligibility.

The RI/FS fieldwork was completed in December 2015 (after significant delay associated with Typhoon Soudelor) and included digital geophysical mapping (DGM) to identify subsurface metallic anomalities. The presence of both surface and subsurface MEC was confirmed as well as the nature and extent distribution throughout the MRS. Sixty-six hazardous MEC items were recovered from within the MRS; thirty-three on the surface. In addition, elevated MC contaminants detected during the SI was further evaluated revealing elevated levels of lead and zinc in MRS soil as well as trace explosives in some areas. The RI/FS data, in conjunction with other advanced classification techniques conducted in tandem as part of a Treatability Study, will be used to recommend viable and cost-effective remedial options for the MRS as part of the current FS.

Public Involvement

Public involvement is an important and critical part of the RI/FS activities.  A Community Relations Plan was developed in an effort to reach out to local interested parties and keep them informed of the project activities.  Public Meetings have been held periodically.  Any members of the public who would like to remain apprised of the progress of the project should plan to attend the public meetings as well as visit the project Administrative Record maintained at:

Joeten-Kiyu Public Library (

Beach Road and Insatto Street

Saipan, MP 96950 (670) 235-7322

Administrative Record Contact: Erlinda C. Naputi

For More Information

3 Rs' of UXO Safety

The USACE wants the public to be a part of study efforts as we work hard to ensure the public’s safety, the safety of our onsite workers, and to protect the environment.  For more information about the FUDS MMRP and the MPF MRSs RI/FS project, contact the USACE Honolulu District (Ms. Helene Takemoto) at 808-835-4088 or E-mail: (Source: USACE)

If you should find an object you suspect may be ordnance, DO NOT TOUCH IT!  Remember the Three R’s:

   1.  RECOGNIZE – Be aware that the object may be dangerous;              

  2.  RETREAT – Move away from the object and do not touch it; and             

  3.  REPORT - Call 911 or local police department immediately. 

Supporting Documents:

1) U.S. Army Corps of Engineers: Marpi Point Field (Fact Sheet)


Last Updated 12/19/2017 11:32:17 AM