Military Field Hydration

Military units require certain minimum supplies to operate and water is high on the list. An adequate supply of potable water (safe and palatable drinking water) must be maintained or mission effectiveness will rapidly disappear. The Quartermaster Corps defines water supply as "a combat multiplier as well as the center of gravity in arid environments."

Field Hydration is complex and is intertwined with field sanitation and other topics. This page reviews some of the basic ideas regarding water and how it gets to the operating units.

Personnel of 574th Supply, 51st Maintenance Bn, Task Force 51, from Mannheim, Germany, set up two Reverse Osmosis Water Purification Units (ROWPUs) and eight chlorinators that produce fresh water for the people of Goma and Rwandan refugees located in Zaire, 11 Aug 1994
Personnel of 574th Supply, 51st Maintenance Bn, Task Force 51, from Mannheim, Germany, set up two Reverse Osmosis Water Purification Units (ROWPUs) and eight chlorinators that produce fresh water for the people of Goma and Rwandan refugees located in Zaire, 11 Aug 1994.

Today in WW II: 14 Jan 1943 Churchill and Roosevelt begin the Casablanca conference.   

Individual Hydration Requirements for Soldiers

Although modern military operations involve highly sophisticated equipment, the individual warfighter is still the foundation of every military force. The well-being of the Soldier or Marine is critically dependent on proper hydration, first among human maintenance requirements. The importance of hydration was shown by the Israeli Defense Forces (IDF) who developed a highly successful heat doctrine for desert operations, demonstrated during the 1967 war with Egypt. The Israeli forces experienced minimal losses from heat injury and illness, while the Egyptians suffered 20,000 casualties from heatstroke alone, representing approximately 50% of the total Egyptian war casualties.

US Air Force TSGT Ramano Cedillos, deployed from the Phoenix Air National Guard, stands by an M149 Trailer (Water Buffalo), Soto Cano Air Base, Honduras, 29 Oct 2008
US Air Force TSGT Ramano Cedillos, deployed from the Phoenix Air National Guard, stands by an M149 Trailer (Water Buffalo), Soto Cano Air Base, Honduras, 29 Oct 2008.

The human body is almost two-thirds water. Blood is 92 percent water; the brain is 75 percent water; muscles are 75 percent water; and bones are 22 percent water. Therefore, water is essential to the functioning of nearly every part of the human body. Water moistens oxygen for breathing, regulates body temperature, carries nutrients and oxygen to all cells in the body, protects and cushions vital organs and joints, helps to convert food into energy, and removes waste. Even a small shortage of water can be devastating to a soldier's performance.

Depending on the heat and activity level, a Soldier may need to drink from a half-canteen (one pint/one-half liter) to three canteens (3 quarts/liters) of water per hour. In hot, dry climates this can total as much as three gallons (12 liters) per day. Drinking water is a must in order to prevent heat injury. Military doctrine insists upon adequate hydration to maintain effectiveness and military logistics must provide the water.

Unit leaders are tasked to monitor and enforce hydration standards:

  • Encourage frequent drinking, but not to exceed 1.5 quarts/liters per hour or 12 quarts/liters per day
  • If possible, make water more palatable by cooling
  • Do not allow individuals to empty canteens to lighten their load (consider imposing a penalty in timed events)
  • Ensure participants are well hydrated before training. Ask about urine; urine is clear if well hydrated
  • Frequently check Riley Card (water record) or Ogden Cord (one knot = one canteen drunk)

Military Unit Water Supply

Water is delivered to the unit under company or battalion control in 5-gallon jerry cans, as bottled water, by water trailers, or in collapsible containers. When a centralized feeding area is established, a water point is set up in the mess area and each person fills his/her canteen as they go through. When the company distributes rations, it can resupply water either by collecting and filling empty canteens or by distributing water cans to the platoons.

Water trailers ("water buffaloes") exist in several versions. Earlier versions are either steel or insulated double wall fiberglass construction, while new items are insulated double-walled stainless steel. Tests by the Army indicate that both types of insulated water buffaloes are excellent for maintaining cool water in hot climates, and will do equally well for keeping hot water hot. A typical small trailer has a capacity of 400 gallons (M106, M107, M149, M1112) while larger units range up to the 2,000 gallon HIPPO water tank rack system for the HEMTT Load Handling System. See Military Trailers for more information.

Five gallon water cans (jerry cans) and the various canteens are for individual or squad use. The cans and canteens are not insulated, and will permit rapid warming of their contents in hot weather. Jerry can insulation covers, developed by the Army, are also procured by the Marine Corps.

In 2010, R&D continues on logistically convenient alternative water supplies such as the Water Packaging System (WPS) that puts one to three liters of water into plastic bags. WPS is trailer mounted and can be fed by field water purification units, producing large numbers of the unitized water bags as an alternative to remotely manufactured bottled water. Five or six gallon plastic bags of water are also being tested as an alternative to jerry cans.

See also Lyster bags, an older method of unit water supply and sterilization.

Emergency Water Supply Situations

Standards do not apply when military personnel are cut off from supply lines and treated water is not available from Quartermaster supplies. In such cases, each individual should select the clearest, cleanest water with the least odor available and treat the water using one of the authorized canteen water purification procedures.

Directions and procedures for disinfecting individual water canteens can be found in TB MED 577 (Sanitary Control and Surveillance of Field Water Supplies) and FM 21-10 (Field Hygiene and Sanitation). The procedures include boiling, using iodine tablets, dry calcium hypochlorite, household bleach (sodium hypochlorite solution), and Chlor-Floc. The canteen water purification procedures page has more details.

Raw water that is treated by small unit individual, handheld commercial off-the-shelf (COTS) devices which have not been evaluated and approved by the Office of The Surgeon General (OTSG) should be additionally treated with approved military disinfection materials or chlorine compounds. The use of unapproved COTS individual or unit water treatment devices is solely at the risk of individual military personnel and their commanders.

Tactical Water Supply

Tactical Water Purification System (TWPS)
Tactical Water Purification System (TWPS).

Quartermaster units are responsible for water production, purification, storage, transport, and chilling on the battlefield. They supply not just drinking water, but all water that comes into contact with human skin, such as for hand washing stations and showers, as well as for food prep and cleaning mess areas. The QM units are equipped with an array of automatic equipment for pumping, purifying and storing water that can be set up in areas without infrastructure and are effective with almost any water source. The purified water can be distributed over any range through pipelines, tanker trucks, and portable bulk storage containers (tanks, bags). The varieties of tactical military Medium Trucks and Heavy Trucks include, in each truck series, liquid-transporting tankers for both water and POL.

Among the most significant purification equipment in use since the 1980s is the skid-mounted Reverse Osmosis Water Purification Unit (ROWPU) that creates clear, clean and drinkable water by pressure straining local water through microscopic-level filters. The local source can be fouled, salt water, or even NBC-contaminated water. An ROWPU of the right capacity (600gph and up), supported by pumps, hoses, storage bladders, generators and other auxiliary units can produce thousands of gallons per hour of potable water to combat units in the area of operation. ROWPUs were the principal sources for the land-based production of drinking water for American troops in the Gulf War.

The ROWPU worked well enough, but it required intensive maintenance and had difficulty coping with very salty water as well as other operational problems. Its successor is the Tactical Water Purification System (TWPS) that can produce 1,500 gallons of potable water per hour, 900 more than the small ROWPU, using less manpower and other resources. TWPS began replacing the ROWPU during FY2007.

Also replacing the ROWPU in smaller applications, is the Light Water Purifier (LWP), a small unit with 125 gph capacity from freshwater, that uses reverse osmosis and ultrafiltration technology to produce potable water from any source. LWP has automated backwash cycles every 15 minutes to simplify operations.

Bulk Distribution of Military Water Supplies

Distribution of water requires intermediate storage capacity as the water moves from source, through purification, and out to the final users. A variety of tanks, bladders, and other large containers are used for these purposes along with pumps, hoses, and pipelines to connect everything together. Flexible bladders are available in a range of sizes including 3,000-gallon collapsible fabric tanks ("onion skins" or "blivet") as well as 20,000 gallon and 50,000 gallon collapsible tanks. A 5,000 gallon fabric tank installed on a flatbed trailer is used for bulk transport of water.

The Tactical Water Distribution System (TWDS) is a six-inch collapsible fabric hose line that can be run up to 10 miles to deliver potable water. Typically, a TWDS line is laid from the bag farm at a water source (eg where a ROWPU is filling the bag farm) to a distribution point or consumption site such as an S&S [Supply and Services] company providing laundry and bath services. TWDS cannot operate if temperatures fall below freezing and, in unsecured zones, is subject to interdiction or poisoning.

Find More Information on the Internet

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