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What is Backwash?

Backwash is a process that allows the flow of water to be sent back through the filtration media in order to refresh the filter by knocking loose accumulated dirt and debris leaving the media clean and ready for further use. The filter unit is backwashed with chlorinated water upon shut down (filling the reservoir) to maintain a clean, disinfected filter and to prevent short circuiting or bacteriological growth in the filtration system.

The system is programmed to backwash automatically based on filtration time, a differential pressure override and upon filling the resevoir or satisfying the demand for water. Filtronics Electromedia® backwash cycles have a four minute duration. Backwash water can be disposed of directly into the sewer system or into a backwash reclaim system.


Take advantage of our quality backwash reclaim engineering. Save money. Save the environment.

What is Reclaim?

Filtronics Electromedia® filter systems use the reclaim module to automatically recycle the water used for purge (filter to waste) and backwash. Normally, more than 99% of this water is recovered through decanting and pumping.

The primary equipment arrangement for reclaim is to have a holding tank for three backwash volumes. Water used for purge and backwash is put to the reclaim tank to allow for the treatment residuals from backwash to sink to the bottom of the tank, allowing the supernatant to be recycled. Any time the water level is above the reclaim start level set point and a filter is in filtration, the reclaim timer begins its cycle. At the end of the timing cycle the reclaim pump will start as long as a filter is in filtration. The reclaim pumps are started by the Filter Control Panel.

The US EPA limits the flow of reclaim water to 10% of the water being filtered for surface water applications. Most of the states have applied this universally to all treatment plants for well and surface sources. On a typical Filtronics system, the supernatant from the reclaim tank has lower contaminant levels than the source water.

The reclaim water, when blended with the well water at the headworks of the treatment system will slightly increase the chlorine residual. Typically, we see it rise between 0.1 to 0.3 mg/L depending upon the site.

What is a Backwash Reclaim System?


Water used for purge and backwash is run through a reclaim tank to allow for the treatment residuals from backwash to sink to the bottom of the tank, allowing the supernatant to be recycled.




Any time the water level is above the reclaim start level set point the reclaim timer begins its cycle. The reclaim timer cycle allows the residuals to settle.

The average settling time is 20 to 60 minutes.

At the end of the timing cycle, the reclaim pump is started by the Filter Control Panel. The reclaim pump will only start when the filter is in filtration and the well pump is running.

The water is “reclaimed” back through the filtration system to be useable water.

Multiple pumps or variable speed pumps are used for multiple well and filter applications.


The residuals are stored in the bottom of the reclaim tank. Periodically, the reclaim tank is drained to the sanitary sewer, drying bed, or hauled off.

More than 99% of the water used for backwash and purge is recycled using the reclaim system.

 

Cost Benefits of a Backwash Reclaim system.

A backwash reclaim system allows you to reclaim more than 99% of your backwashed water resulting in:

  • Lower Electricity/Pump Costs - If you are a pumping water out of a well, reclaiming backwashed water lets you save valuable additional pump costs.

  • Lower Sewage Costs - Rather than paying high sewage costs to dispose backwashed water, backwash reclaim reduces the amount of residuals to be dumped. In some cases, it can be dried and hauled off to a land fill for regeneration into the earth.

  • Water Cost Savings - In ALL instances, you are reclaiming 99% of the backwashed water, resulting in maximized water production & lower water costs.

  • Environmental Savings - Minimal waste discharge means maximum savings for our environment.
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