Ordnance Reef (HI-06) Site Description and History

Site Description

Ordnance Reef, Sea Disposal Site Hawai‘i 6 (HI-06), is a near-shore site in U.S. coastal waters along the western or Leeward side of O‘ahu Island. The nearest communities are Wai‘anae, Mā‘ili, and Nānākuli. The northern portion of Ordnance Reef (HI-06) extends into Pōka‘i Bay to the northeast and is north and northwest of the Wai‘anae Wastewater Treatment Plant sewer outfall. Ordnance Reef (HI-06) encompasses an area approximately 1 nautical mile (1.8 kilometers) in length in the north-south direction by 0.5 nautical miles (0.9 kilometers) in width in the east-west direction. It has a surface area of approximately 1,700 acres and ranges in water depth from approximately 30 to 230 feet (10 to 70 meters). The Ordnance Reef (HI-06) study area, which was revised as more data became available, is based on mapping done during the 2002 and 2006 investigations and the expressed concerns of the affected communities.

Site History

In 1980, researchers conducting a current survey for the Wai‘anae Wastewater Treatment Plant sewer outfall outfall extension discovered .50-caliber bullets in the area. During a subsequent 1992 survey of the Wai'anae Wastewater Treatment Plant sewage outfall area, the City and County of Honolulu (C&C of Honolulu) discovered underwater military munitions (UWMM) between 0.25 and 0.5 nautical miles (0.5 and 1 kilometer) northwest of the existing sewage outfall's diffuser. UWMM were observed at water depths between approximately 30 and 160 feet (18 and 50 meters). The UWMM present were suspected to include clipped .50 caliber small arms ammunition and projectiles (possibly 3- to 5-inch naval projectiles) of various types, some between one and three feet in length. The C&C of Honolulu's oceanographic team also discovered UWMM south of the sewage outfall and just west of a State of Hawai‘i-designated fish haven.

In 2002, the Department of Defense (DoD) tasked the U.S. Army Corps of Engineers (USACE) to conduct a study of Ordnance Reef (HI-06) to determine its eligibility for the Defense Environmental Restoration Program - Formerly Used Defense Site (DERP-FUDS) Program. At USACE's request, the U.S. Navy Explosive Ordnance Disposal Detachment provided diving and underwater survey support at Ordnance Reef (HI-06), called the Offshore Wai’anae Sewage Outfall site by USACE at the time. The Explosive Ordnance Disposal Detachment identified roughly 2,000 UWMM that it categorized as discarded military munitions, not unexploded ordnance (UXO), and determined the munitions’ coordinates using a global positioning system unit. In 2005, Ordnance Reef (HI-06) was determined to be ineligible for a response under the DERP-FUDS program because DoD never owned, leased, otherwise possessed the site, nor did it ever exercise control over it, except to use Ordnance Reef (HI-06) for the disposal of military munitions. Subsequent study efforts, including the 2011 Ordnance Reef (HI-06) Technology Demonstration were conducted as part of the Army’s Environmental Quality Technology program.

Ordnance Reef (HI-06) Timeline

1980 – Researchers conducting a current survey for the Wai‘anae Wastewater Treatment Plant sewage outfall extension discover .50-caliber bullets in the area

1992 – Munitions are discovered during a survey conducted for the extension of the Wai‘anae Wastewater Treatment Plant ocean outfall

1996 – USACE completes a DERP-FUDS Inventory Project Report for Offshore Wai‘anae Sewage Outfall (FUDS number H09HI047500)

2002 – U.S. Navy Explosive Ordnance Disposal Detachment conducts a diver survey of the area for USACE to identify munitions and map their extent

2005 – USACE determines that the Offshore Wai’anae Sewage Outfall site is ineligible under DERP-FUDS

2005 – Members of the Wai’anae community identify their concerns with Ordnance Reef (HI-06) during discussions with the Army

2006 – National Oceanic and Atmospheric Administration (NOAA) conducts a field survey of Ordnance Reef (HI-06) consisting of mapping the extent of munitions; and the sampling and analysis of fish and sediment for explosives and metal levels

2007 – NOAA completes its screening-level survey: “Ordnance Reef, Wai’anae, Hawai‘i, Remote Sensing Survey and Sampling at a Discarded Military Munitions Sea Disposal Site, Marine Sanctuaries Conservation Series NMSP-07-01”

2007 - The Deputy Assistant Secretary of the Army for Environmental Safety and Occupational Health establishes the Ordnance Reef Coordinating Council

2007 – The U.S. Army Technical Center for Explosives Safety produces a report evaluating explosives safety risks at site

2007 – The U.S. Army Center for Health Promotion and Preventive Medicine (now U.S. Army Public Health Command) reviews the NOAA screening-level survey and concludes that chemicals detected do not present a public health hazard to adults and children who rely on the area for subsistence amounts of these species

2007 – The Center for Disease Control, Agency for Toxic Substances and Disease Registry completes a public health consultation and finds little probability of health impacts but concludes additional data is needed to fully evaluate the public health implications

2007 – The U.S. Army initiates outreach programs through public school systems in Hawai'i to increase public awareness of the dangers of munitions

2008 – USACE issues a contract to the University of Hawai‘i (UH) for an Environmental Study to address the data gaps from the 2006 NOAA screening-level survey. The proposed risk assessment is to include human health and screening ecological risk assessments

2009 – Two rounds of field sampling for the UH Environmental Study are completed

2009 – The National Defense Center for Energy and Environment completes a report on technologies to address UWMM (Task 501) titled: “Hawaii Region-Undersea Munitions Response Assessment, Final Preliminary Systems Requirements Report”

2009 – NOAA deploys nine current monitors for measuring ocean current direction and speed off the Wai‘anae coast

2010 - The U.S. Army obtains federal interagency support from NOAA to develop a Coral Avoidance and Minimization of Injury Plan during preparation of an environmental assessment for the Ordnance Reef (HI-06) technology demonstration

2010 – NOAA recovers the current monitors after their having been deployed for a year

2011 – National Environmental Policy Act documentation (Environmental Assessment and Draft Findings of No Significant Impact) for the Ordnance Reef (HI-06) technology demonstration is provided for public comment and subsequent to that, the demonstration is completed

2011 – The technology demonstration recovers 74 medium and large caliber munitions and 2,300 small arms and destroys them at sea

2011 - UH begins sampling for the technology demonstration follow-up environmental investigation to determine the impact of the demonstration on the concentrations of munitions constituents

2011 – Munitions recovered during the Technology Demonstration are provided to UH for a study of the corrosion process

2012 - NOAA completes its report: “Ocean Circulation and Predictive Modeling Study of Two Sea-Disposed Military Munitions Sites in Hawai‘i: Ordnance Reef (HI-06) and HI-01”

2012 – UH conducts a second round of sampling for the follow-up environmental investigation

2013 – UH conducts a third round of sampling for the follow-up environmental investigation

2014 – UH produces the "Final Environmental Study, Ordnance Reef (HI-06), Wai'anae, Hawai'i" report based on the 2009 sampling

2014 – The Ordnance Reef (HI-06) technology demonstration report: “Report of Findings, Ordnance Reef (HI-06) Technology Demonstration for The Remotely Operated Underwater Munitions Recovery System (ROUMRS) and Energetics Hazard Demilitarization System (EHDS)” is completed

2014 – UH completes its Ordnance Reef (HI-06) report: “Follow-up Investigation Assessment Report”

Last Modified: 13 March 2015 at 05:59