The ERDLator was a field water treatment

Water treatment

Water treatment describes those processes used to make water more acceptable for a desired end-use. These can include use as drinking water, industrial processes, medical and many other uses. The goal of all water treatment process is to remove existing contaminants in the water, or reduce the...

 device developed during World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

 at the U.S. Army's United States Army Engineer Research and Development Laboratory

United States Army Engineer Research and Development Laboratory

The United States Army Engineer Research and Development Laboratory was a United States Army Corps of Engineers research facility located at Fort Belvoir, Virginia. Among other things, it was responsible for the creation of the ERDL woodland camouflage pattern in 1948 and it established the first U.S...

 at Ft. Belvoir, Virginia.
Technically named the "Water Purification Unit, Van-Type, Body Mounted, Electric Driven", the acronym was incorporated into the name of the purification device itself, creating the name by which it was most widely known, ERDLator, pronounced "erd-a-later".

The device was introduced into the field as a van-type body-mounted mobile unit, and proved vitally important to the operational effectiveness of deployed units under harsh field conditions, providing not only the water needed for survival, but clean potable water for staying healthy. This passage from a description of the United States Marine Corps

United States Marine Corps

The United States Marine Corps is a branch of the United States Armed Forces responsible for providing power projection from the sea, using the mobility of the United States Navy to deliver combined-arms task forces rapidly. It is one of seven uniformed services of the United States...

 Engineer Battalion illustrates the ERDLator's significance:

"One of the most important units was the water supply platoon. This platoon operated...water purification plants called Erdalators [sic] that could remove silt and suspended matter, filter, and purify even contaminated stream water. Producing from 1-3,000 gallons (about 4,000 to 12,000 liters) per day -- the larger number was achieved using separate large rubberized settling tanks -- one unit could adequately supply an infantry battalion under adverse conditions"

The unit was replaced in the 1979 by the Reverse Osmosis Water Purification Unit

Reverse Osmosis Water Purification Unit

A reverse osmosis water purification unit is a portable, self-contained water treatment plant. Designed for military use, it can provide potable water from nearly any water source. There are many models in use by the United States armed forces and the Canadian Forces...

 (ROWPU) ("Row-pew"), also developed by a U.S. Army laboratory. Developing water purification systems for military use has led to technological breakthroughs which have benefited the civilian community; the ERDLator was evaluated for technology transfer to the civilian sector for the decontamination of water polluted with asbestos

Asbestos

Asbestos is a set of six naturally occurring silicate minerals used commercially for their desirable physical properties. They all have in common their eponymous, asbestiform habit: long, thin fibrous crystals...

fibers.