MSSG-22 Filters Salt from Sea Water to Accomplish Mission

12 Jun 2002 | Gunnery Sgt. Keith A. Milks

For a Navy ship underway, one of its most important commodities is fresh water.  Used for cooking, drinking, bathing, and host of other needs, a ship's supply can be easily exhausted through the myriad daily requirements of its crew and embarked Marines.

Such demands leave little water surplus for routine, yet essential, tasks such as the cleaning of vehicles.  Aboard the USS Oak Hill, one of the three ships carrying the 22d Marine Expeditionary Unit (Special Operations Capable), the Marines of MEU Service Support Group 22 have come up with a way to ensure their vehicles are kept in top-notch condition without depleting their ship's fresh water supply.

"In order to remove salt and other contaminates from our vehicles and equipment while underway, we conduct ROWPU operations to prevent rust and corrosion and keep our gear in a high state of readiness," said Staff Sgt. Robert M. Mathes, of Memphis, Tennessee, the platoon sergeant for MSSG-22's engineer platoon.

ROWPU stands for Reverse Osmosis Water Purification Unit, a piece of equipment that gives the MSSG-22's engineer platoon the capability to convert salt water straight from the ocean into fresh, potable water.

Setting the ROWPU up on the flight deck of the Oak Hill, a portion of Mathes' engineer platoon began the operation by filling a five thousand galloon collapsible bladder with sea water.  The water was then tested to determine its salt level, and the unit's filtering system was set to cleanse the salt from the water to acceptable levels.

Over the next several hours, a large diameter hose pumped the now-fresh water into a second collapsible bladder.  It was from this bladder that the water was drawn to spray down the 'convoy' of forklifts, tractors, five-ton trucks and Humvees brought onto the Oak Hill's flight deck.

The ROWPU is run by a small team of hygiene equipment operators who are responsible for maintaining and operating the equipment, as well as ensuring the quality of the converted water is up to par.

Normally, the ROWPU is established on a beach where is it used to supply fresh water to Marines and Sailors conducting operations ashore.  Operating the unit aboard ship provides a number of benefits to the system's operators.

"It helps us get used to setting up the gear and taking it down," said Lance Cpl. Michael Runyon, a hygiene equipment operator from Pike Country, Kentucky.  "Every time we use it helps keep us on top of what we do."

Cpl. Vester R. Lawson, another hygiene equipment operator, echoes Runyon's sentiments. 

"Using the ROWPU underway helps us keep our knowledge of operating the system sharp for when we need to us it ashore," said Lawson, a six-year Marine veteran from Arma, Kansas.  "We're a tight group and everyone knows what their job is and does it in a safe manner."

More than 20 vehicles were thoroughly cleansed during the underway ROWPU operation that helped ensure the MSSG-22's equipment would be ready when the time came.

For more information on the 22d MEU (SOC), visit the unit's website at
22nd Marine Expeditionary Unit