CW as a buffer to maintain river life: An Italian-Israeli collaborative project

 

In Israel, natural water sources such as springs and wells are harnessed for drinking water, leaving treated water as the sole water source for rivers. However the quality of treated water that flows into rivers is frequently varied, and in many cases inferior.

 

Take for example the case of Ramat Hasharon activated sludge factory, with state of the art facilities that meet both Israeli and European standards.  Is the effluent from this sludge factory sufficient to support life in the Yarkon River?

 

Long term chemical and biological monitoring of the river showed:

  1. An activated sludge factory is sensitive to fluctuations, and cannot guarantee a constant quality.
  2. Even though at times it complies with BOD and TSS regulations, other parameters make the water unsuitable to maintain river life.
  3. Along its course the river acquires non-point and illegal wastewater sources that dramatically affect quality. 

 

The conclusion drawn from this case was that releasing treated yet inferior quality water to the river, together with the effect of the non-point effluent along the way, is disastrous. Outcomes range from total extinction of species to sex change in fish.

 

 

If an activated sludge plant receives water with high pollution content, it will supply the river with the same high content. The sludge plant cannot serve as a buffer. CW however can take a broad range of fluctuations contained in the system, and still release good water.

 

Ofra Aqua Plants is a key participant in the Shafdan project, a collaborative program financed by the Italian Ministry for Environment and Territory (IMET).  It checks the ability of CW to polish the secondary water to a level which ensures safety for all living creatures, and to serve as a buffer in cases of high pollution catastrophes and severe fluctuation of water quality.

 

Special attention is given to parameters affecting the river that are not addressed by regulators, for example the effects of endocrine disruptor chemicals.

 

To evaluate CW as a buffer to maintain river life, we constructed a system containing 21 ponds, each set of 3 comprising a full treatment.  The system receives secondary effluent from the activated sludge factory, and the last pond in each row simulates the river, the end point.  This project has been designed to function for 5 years.

 

Another project in which Ofra Aqua Plants had designed and constructed, is situated on the bank of the Yarkon River.  Water is pumped from the river to a 3,000sq.m system of 5 ponds with different substrate composition, flow forms and plant varieties.  The treated water is returned to the river by gravitation. 

 

This project demonstrates the ability of CW to not only treat the source water but to be a part of the river and its bank activities.  It serves as a tourist and educational attraction while maintaining the balance that propagates life in that section of the river.

 

These two projects aim to give government regulators, landscapers and local authorities a tool to maintain living rivers where natural fauna and flora can flourish, and human beings can find peace and beauty in an environment conducive to health.

 

 

 

By pass on the Yarkon Bank

By pass on the Yarkon Bank

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Clean water returning to the river

Clean water returning to the river

The Shafdan research site

The Shafdan research site

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