Substance Abuse, Addiction, and Rehabilitation (SAAR) Recover Center, Marpi
Historical Background
The U.S. military landed on Saipan on 15 June 1944, ending the organized Japanese resistance in Saipan on 9 July 1944. By 31 August 1945, the military developed the northern end of Saipan primarily for the Naval Air Base Marpi and ammunition storage for both the U.S. Army and U.S. Navy. The ordnance storage areas located within the Marpi area included the following: the Naval Ammunition Depot, the Matoisa Ordnance Depot, the Naval Magazine, and the Army General Depot.
In preparation for the planned invasion of Japan, the ammunition storage areas in north Saipan were filled far above capacity. On 27 May 1949, a disastrous brush fire took place at Matoisa Ordnance Depot, causing explosions and scattering ordnance all over the northwestern portion of Saipan. The progressive explosions and fires lasted until 5 June 1949, and, according to reports, approximately 16,000 tons of ammunitions were affected by the various explosions, either by being detonated or by being scattered as unexploded missiles through a wide area. The 6 July 1949 report of the damages resulting from the explosions noted the presence of unexploded 8-inch gun, 155mm howitzer, 105mm howitzer, 75mm gun, 81mm mortar shells, and fragmentation hand grenades scattered around an area approximately 2 1/2 miles long by 1 mile wide. The May and June 1949 explosions caused a co-mingling of unexploded munitions and MD attributable to the post-capture munition storage/stockpile mission by U.S. forces with munitions attributable to acts of war.
The U.S. Army 560th Composite Service Company began an ordnance removal and disposal operation in February 1950 that consisted of “pick[ing] and pil[ing]” shells in stacks, followed by priming the stacks with C-3 composition, then tying them together with primer cord and detonating all in one explosion. The disposal operation continued until 26 July 1950. Approximately 300 acres were cleared of the following: 3,736 tons of ammunition detonated, 619 tons shipped off the island, 1,762 tons burned, and 2,527 tons dumped at sea. During the 1950s and early 1960s, the U.S. Navy implemented public awareness campaigns about the dangers of the UXO at the former Matoisa Ordnance Depot; however, disposal operations did not continue due to the lack of funding to execute a cleanup program.
Current and Future Land Use
Today, the 14-acre area of concern (AOC) consists of the HOPE Recovery Center. The Substance Abuse, Addiction, and Rehabilitation Program operates the HOPE Recovery Center facilities, which provides clinical care and social services to individuals and their families living in CNMI. The site contains residential living facilities available for staff members and individuals currently in the program. There is no anticipated future change to the land use.
Executive Summary of the Time Critical Removal Action (TCRA) Quality Assurance Project Plan (QAPP)
The Quality Assurance Project Plan (QAPP) has been prepared by the Contractor team to support the Time Critical Removal Action (TCRA) at a 14-acre area of concern (AOC) within the 4,240-acre Ordnance Plan Formerly Used Defense Site (FUDS), Property No. H09CN0060, Military Munitions Response Program (MMRP) Project No. 01, Matoisa Ordnance Depot, Saipan. The objective of this project is to mitigate and minimize the threat posed by munitions to temporary residents, staff members, and visitors in a 14-acre AOC consisting of the Hinemlu O’hala Para Enteramenti (HOPE) Recovery Center within the former Matoisa Ordnance Depot. The TCRA is being performed per the Action Memorandum signed April 5, 2021, in compliance with the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended, and U.S. Department of Defense (DoD), U.S. Army, and U.S. Army Corps of Engineers (USACE) regulations and guidance to include interim guidance and all applicable data item descriptions (DID). The Contractor team has prepared this QAPP to provide the scope of work and field protocols required to implement the MMRP services at the site.
During a site reconnaissance performed on January 28, 2020, a USACE site visit team encountered multiple munitions debris (MD) items on the surface of the HOPE Recovery Center and surrounding areas. The team found the highest concentration of surface MD in the visitors parking area, located in the eastern portion of the 14-acre AOC. The MD items found included: U.S. 5-inch projectiles, U.S. M51 37millimeter (mm) Armor-piercing capped – tracer (APC-T) projectiles, U.S. M49 60mm mortars, and U.S. Mk II hand grenades. All MD items identified during the 2020 site visit were unfired, indicating they had been involved in an explosion that was not by design (e.g., stockpile explosion). Previous investigations including the March 2020 Remedial Investigation (RI) have indicated that munitions and explosives of concern (MEC) and MD are present within the 14-acre AOC.
The planned field activities for this project will take place in the 14-acre AOC at the HOPE Recovery Center within the FUDS Property No. H09CN0060 Ordnance Plan, MMRP Project No. 01, Matoisa Ordnance Depot (Figure 1, Appendix M). Field activities at the HOPE Recovery Center will include vegetation removal, analog instrument assisted removal to 1 foot (ft) below ground surface (bgs), real-time kinematic location recordings of any intrusively investigated analog anomalies remaining below1 ft bgs, digital geophysical mapping (DGM), the use of advanced sensors to detect and screen anomalies in saturated polygons as needed, and the subsurface removal of anomalies identified by the DGM survey excluding anomalies previously recorded below 1 ft bgs.