In support of the Fort Irwin Directorate of Public Works Environmental Division, the Army Environmental Command and U.S. Army Corps of Engineers Sacramento District are conducting a Supplemental Site Inspection of two former Fort Irwin range areas, also known as Munitions Response Sites. The work is being conducted under the U.S. Army Military Munitions Response Program. PIKA Pirnie Joint Venture, LLC is the contractor executing the Supplemental Site Inspection work is PIKA Pirnie Joint Venture, LLC.
The Supplemental Site Inspection Study Area is located in the cantonment area, on the construction footprint of the new hospital facility. The Supplemental Site Inspection includes surveying the site for the potential presence of unexploded ordnance/munitions of explosive concern and conducting an intrusive investigation to search for munitions of explosive concern and munitions constituents that could pose a potential hazard to human health or the environment.
A 2009 Military Munitions Response Program Site Inspection identified eight Munitions Response Sites at the National Training Center and Fort Irwin, all of which will be part of an upcoming Remedial Investigation. Because of the need to construct a hospital within the boundaries of two of these Munitions Response Sites, a Supplemental Site Inspection is required to ensure the construction area is safe for use. The planned hospital construction area and Supplemental Site Inspection Study Area is within the Hand Grenade Range Munitions Response Site and the southernmost portion of the Pistol Range Munitions Response Site. Due to historical usage of these areas, there is a potential for the presence of unexploded ordnance/munitions of explosive concern within the Supplemental Site Inspection Study Area, as well as elevated concentrations of metals and explosives in soil.
Previous munitions related items found within the Supplemental Site Inspection Study Area
Subsequent to the 2009 Army Military Munitions Response Program Site Inspection, which identified this area as potentially impacted by unexploded ordnance/munitions of explosive concern, an unexploded ordnance surface clearance for the Hospital Construction Project was conducted in December 2010. To date, no unexploded ordnance/munitions of explosive concern items have been found in the Supplemental Site Inspection Study Area. Howerver, many small arms munitions, practice rounds, and fragments of hand grenades and 3.5-inch rockets have been identified and removed by qualified unexploded ordnance personnel.
Supplemental Site Inspection goals
The primary goals of the Supplemental Site Inspection are: to gather sufficient information to determine if an environmental regulated release has occurred at the location of the new hospital site; if a munitions of explosive concern/munitions constituents hazard is identified, to remove it, and; dispose of any soil affected by munitions of explosive concern and munitions constituents.
Supplemental Site Inspection Activities
- Site Preparation: Equipment mobilization, fence installation, site-wide survey, surface sweep, vegetation removal, delineation of areas for initial excavation.
- Initial Excavation: Armored heavy equipment will remove surface debris that may interfere with subsequent steps of the field effort, and transport it to the Laydown Area north of North Loop road.
- Digital Geophysical Mapping: The geophysical mapping effort will identify subsurface anomalies that may require intrusive investigation (digging) to determine whether they are unexploded ordnance/munitions of explosive concern items.
- Intrusive Investigation: Excavation to identify and address potential subsurface unexploded ordnance/munitions of explosive concern hazards.
- Sifting and Sorting: Soil and debris will be processed in the Laydown Area.
- Unexploded ordnance/munitions of explosive concern Disposal: In the event that a munitions item is encountered that requires detonation, a controlled detonation will occur where the item is located. Sound from the controlled detonation may be heard in the area.