Envirowash® - Filtronics Efficient Backwash/Reclaim System

Among the key features to any of the Filtronics Electromedia® filters is the efficient use of water for backwash. For a typical application:

A. Our Electromedia filters only require a four minute backwash.
B. The backwash to filtration ratio is less than one percent.
C. Recover after backwash is short, generally five minutes.

With a raw water turbidity of 15 NTU or less, we conservatively estimate the interval filter run time duration to be 18 hours. The backwash to filtration ratio for a typical 750 gpm application is:

¬ 750 gpm x 18 hours x 60 minutes = 810,000 gallons produced.

¬ The backwash cycle lasts four minutes at 1800 gpm and surface wash lasts one minute at 180 gpm. (The backwash rate assumes 20 degrees Centigrade temperature of the source water).

¬ The total volume of water used for surface wash and backwash total 7,380 gallons.

¬ The backwash to filtration ratio is 7380/810,000 = 0.009 or 0.9% for a 99+% efficiency.

Filtronics systems have a very short recovery after backwash. The filter system produces a filtrate of less than 0.2 NTU in only five minutes after a backwash. Thus, not only adding to the efficiency of the system but producing a high water quality quickly to the potable water system.

Assuring a two minute rinse to waste water cycle, the overall efficiency is 98.9%.

To further reduce the amount of water lost, many applications include our highly efficient Envirowash®, a backwash water reclaim system to recover more than 99.999% of the water used for backwash. That’s water that can be sold to the customer, meeting the same effluent requirements as the raw source.


This video shows a 22MGD plant with a four minute backwash. When you view the video, think about the sheer volume of water saved by such a short backwash cycle. As stated above, this water can be reclaimed and sold to the customer. Efficient AND Revenue generating! :)