THOROUGH DECON OPERATIONS 

Thorough decon operations reduce contamination to negligible risk levels. They restore combat power by removing nearly all contamination from unit and individual equipment. Thorough decon enables troops to operate equipment safely for extended periods at reduced MOPP levels. A small risk remains, so periodic checks with the CAM, M8/ M9 paper, or M256-series kit must be made after each operation. After thorough decon, the unit moves out of the decon site into a tactical assembly area. The unit, while in this tactical assembly, may undergo reconstitution or prepare for future operations.

Operational decon requires fewer resources but physically removes only surface contamination. Thorough decon is the most effective type of decon

Weather conditions, agent used, mission requirements, time, troops, and supplies available may all combine to make weathering the decon option of choice. Based on the recommendation of the CBR officer, the COC decides which type of decon is the most efficient and effective for their unit.

A limiting factor that must be considered when planning any decontamination operations is the availability of water. A typical vehicle will require 500 gallons of water during detailed equipment decon. In a water-scarce environment, such as deserts, the CBR officer must cordinate a water resupply plan with other units in the area of operation. A water resupply plan can include selecting a series of link-up points along a route. The unit can link up with a bulk water truck from other units. More complex water resupply plans include linking up with bulk water trucks, caching water throughout the area of operations, coordinating for the movement of water bladders by aircraft, and the identification of water sources in the area of operation of the unit. The use of nonpotable, salt, and brackish waters should be considered.

The thorough decon site consists of four main areas: the predecon staging area, the postdecon assembly area, the detailed troop decon (DTD), and the detailed equipment decon (DED). Selection of all four areas are based on operational guidance, road network, available cover and concealment, and water supply.

The predecon staging area is used by the contaminated unit to ready them for detailed equipment decon (DED) and detailed troop decon (DTD) operations. The process at the DED includes removing, neutralizing, or reducing contamination on interior and exterior surfaces of equipment to negligible risk. The DTD is the process of decontaminating individual fighting equipment to negligible risk and removing contaminated MOPP gear from the troops.

The postdecon assembly area is the location where vehicles and troops exiting the DED and DTD are linked. This is done before moving from the decon site.

PREDECON STAGING AREA 

The contaminated unit, by company, moves to a predecon staging area approximately 250 to 500 meters downwind of the thorough decon site. Here, the contaminated unit conducts the required predecon actions that are designed to prepare the unit for the thorough decon operations. Predecon actions include the following:

1. Segregate contaminated vehicles from uncontaminated vehicles, if possible.

2. Allow vehicle crews to dismount and prevent further transfer/ spread of contamination.

3. Prepare vehicles for detailed equipment decon. 4. Move contaminated vehicles and troops to the detailed troop and equipment decon lines.

Segregate Vehicles Check all vehicles for contamination, using detection equipment. For chemical contamination, use the CAM and M8 detector paper. Also, visually check the vehicles for contamination using M9 paper. M9 paper affixed to vehicles reveals the presence of contamination and provides an indication of the level of contamination (fig. 6-6).

Figure 6-6.- Contamination levels.
When using the chemical agent monitor (CAM), such as the M256A1, ensure there is sufficient distance between vehicles. If the vehicles are parked too close together, vapor drift from contaminated vehicles may falsely identify uncontaminated vehicles as contaminated.

For radiological contamination, use the AN/ PDR-27- series or AN/ PDR-43 radiac detectors. If the vehicle only has isolated areas of contamination, use a portable decontaminating apparatus (M11) to decontaminate the chemically contaminated area. Vehicles found to have no contamination are sent to the reconstitution assembly area.

Crews Dismount The vehicle crews, except drivers, dismount. As the crews dismount, they remove all equipment from the top of the vehicles. Once crew members have exited the vehicle, they will not reenter. This prevents further contamination from being spread into the vehicle interior.

Prepare Vehicles The crews prepare their vehicles for processing through the detailed equipment decon (DED). All heavy mud and debris are removed from the vehicle by the crew. The crew should concentrate on the vehicle undercarriage. The reason for this is twofold: (1) contamination will most likely collect here and (2) the undercarriage is the hardest place to decontaminate. Tools used by the crew are placed back on the vehicle when finished.

Seat covers (when applicable), canvas items, camouflage netting, and any other materials that can absorb liquid contamination are removed from the vehicle. These items create a potential transfer hazard and are not easily decontaminated. Appendix V provides guidance on hard-to-decon items. Left untreated, absorbed chemical agents will desorb after being decontaminated and create a vapor hazard. Items that cannot be decontaminated by the standard methods used in detailed troop decon (DTD) are also removed and placed at a collection point.

Move To DED and DTD In coordination with the decon petty officer in charge (POIC), the contaminated unit will begin to send contaminated vehicles and personnel to the DED and DTD. The COC has prioritized the vehicles for processing, sending the most important first. Communication is maintained between the predecon staging area and the POIC. All assistant vehicle drivers are the first individuals sent through the DTD to ensure there is a driver exchange at station 3 of the DED.

POSTDECON ASSEMBLY AREA 

The company assembles in the postdecon assembly area after completing DTD and DED operations. The unit occupies this area before moving to a reconstitution location. The decon POIC will select the general location. It should be big enough to hold the entire unit undergoing thorough decontamination with proper cover and concealment. The assembly area should be located approximately 1 kilometer upwind from the DED and DTD.