Low-Energy Expeditionary Water Reuse

Over the course of the past five years the Air Force (AF), through the Air Force Research Lab / Advanced Power and Technical Office (AFRL / APTO), has engaged and invested in the research, development, test and evaluation (RDT&E) of a gray water reuse capability specifically for use in expeditionary, austere environments. A prototype system, known as the Expeditionary Waste Water Processing System (EW2PS) or Expeditionary Gray Water System (EWRS), was a first attempt at the AF bringing gray water reuse to the expeditionary battlefield and was developed in conjunction with the AF Basic Expeditionary Airfield Resource (BEAR) technical office as the stakeholder. The EWRS endured multiple rounds of both laboratory (in-lab & in-situ) and field testing (Ft. Devens & Yuma Proving Grounds) proving itself capable of producing water that meets the US Army Public Health Center’s TB-MED-577, Chapter 9 and TG-364a requirements for gray water reuse in the field. The EWRS prototype proved to be a successful demonstration asset and the results from testing will support the development of an acquisition requirement/specification for BEAR, but more extensive testing will still be required to fully develop this specification. While the prototype was successful, it did have technical deficiencies including problems with the microfilter backwash, the dosing of chemicals into the system, and low flow rates caused by the lack of a second microfilter and a too-small carbon filter size. These physical deficiencies were joined by a deficiency in operator training that led to the producing of non-spec water. In order to rectify these deficiencies, upgrades to the prototype design and more field testing were required to remediate the noted problems. Unfortunately, on October 10, 2018, Hurricane Michael made landfall on the panhandle of Florida, in the general vicinity of Tyndall AFB’s 9700 Research area – the spot where the EWRS prototype was being stored. The conceived upgrades and further testing to the EWRS prototype were rendered moot because the storm destroyed the EWRS prototype unit. While unfortunate, it also gives the AF an opportunity to pause and look at proceeding with the project in a different direction moving forward.