There is no such thing as “pure” water coming from most utilities.  There is always some amount of contamination permitted because the cost of total removal is prohibitive.  Still, certain contaminants pose immediate risks to health that must be considered for anyone dispensing potable water.

Some of these contaminants are not chemicals or metals in the water, but rather biological contaminants.  Bacteria, viruses or spores can multiply rapidly under the proper conditions such as stagnation and moderate temperature in very short time periods.

To eliminate these issues, the stagnant water should be flushed from the lines used to distribute or dispense Potable Water so that a chance of health risk is removed.  How to accomplish this on a live gate condition without manual labor required or wasting water by frequency of flushing takes some ingenuity and experience.

Case Evaluation – Semler Industries IntelliFlush® design

The IntelliFlush® was an evolution from the need for automatically protecting against biofilm growth in the line.  Semler Industries recognized the risk for bacterial growth in moderate temperatures and decided to work toward a proprietary product that resolved this issue.

In the early 2000s the president, plant manager and director of strategic accounts worked out a design that would monitor temperature, time and cabinet conditions to automatically flush the water in the lines only when conditions were present that would be conducive to microbial growth.  In this fashion, stagnant water is removed and biofilm growth is prevented.  It assures clean water is boarded on aircraft and water is conserved by unnecessary manual flushing before on-boarding water.

These potable water cabinets were then patented and remain the best “think-for-itself” option on the market.

Equipment Description

Besides the normal requirements for a potable water cabinet such as the enclosure, electrically operated hose reel and temperature warning light, this equipment is designed with condition-monitoring instrumentation & controls to automatically flush the lines when conditions conducive to bacterial growth are present.  The volume of flushed water is equivalent or slightly more than that of the holdup in the cabinet piping and components.  This conserves water, as it minimizes the flushing of “good water” from the supply source, and eliminates the guess work of manually flushing the units.  In this manner, only potentially compromised water is eliminated, and enough water is flushed through the system to remove the potentially stagnant liquid with clean, cold, fresh, city-chlorinated water that is suitable to put on board the aircraft.  The “guess-work” of manual flushing is eliminated, water is conserved, and the quality of water being introduced to the plane is greatly improved.

Since flushing directly to the gate apron would potentially cause icing in colder conditions, the flushed water can be sent to a retention area or it may be sent directly to disposal piping.  This is determined and included in the specific design of each cabinet, based on the exact application.


Considering the health and liability risks associated with poor quality water, labor costs and the volume of water wasted by manual flushing, the IntelliFlush® is not only a simpler way to maintain clean potable water for aircraft, it is also an economical decision.  If you have already settled on Semler Industries providing you the highest quality potable water cabinet or other equipment, the IntelliFlush® is a logical choice to consider in this decision-making process.


  1. Semler Industries Brochure “IntelliFlush®” The Smart Potable Water Cabinet, 2008
  2. Semler Industries “Aircraft Watering Point Biofilms”, 2005
  3. Semler Industries Product Release Briefs
  4. Semler Industries IntelliFlush Training Manual

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