Make full use of wastewater

In many small and medium towns, domestic wastewater is already being put to use by farmers. A look by S. Vishwanath

Summer is here and the scenario with the water storage in reservoirs is grim. It will be a tough ask to nurse them through to June when the rains are expected and that too only for drinking water. In such a water-scarce scenario, it is imperative we think of all forms of water, particularly wastewater, and put it to productive use. Sadly the State lacks a meaningful policy on urban water and sanitation management which would have encompassed the reuse of wastewater too. A simple wastewater policy as a guideline document to design projects and draw investments would be a good first step.

Here are some guidelines to consider while preparing such a policy:

It is important to differentiate between industrial wastewater and domestic wastewater. In no case should the two be allowed to be mixed.

Each city and town will have to develop its own strategy for managing wastewater. There could be a broad framework to understand and design schemes but no rigid template.

Supplement to fertilizers

In many small and medium towns, domestic wastewater is already being put to use by farmers who grow all sorts of crops and vegetables with it. They make use of the nutrient component of the wastewater too as a supplement to fertilizers.

By pushing for safer use practice, by changing the crop palate, it may be possible to eliminate the need for wastewater treatment plants in many small towns, especially in arid and semi-arid parts of the State.

There is a strong component of ecosystem needs for treated wastewater. Wetlands and lakes can be kept alive and full provided the treatment is adequate. Fishing too is an activity which can be done in these tanks filled with treated wastewater.

Industrial, construction and other non-potable use of wastewater can have commercial potential especially where the opportunity cost of water is high. A market for wastewater can only be created by regulating groundwater in the surroundings from over-exploitation.

The reuse of wastewater can also be for recharging aquifers firstly by indirect means especially through lake and tank re-fillings and later by direct managed aquifer recharge.

Treatment technologies

Treatment technologies exist which can take wastewater to potable standards. They should be fully used in a scientific fashion by linking it with and blending with freshwater in river and stream flows and in lakes. Once a certain ecological journey has been undertaken by this wastewater, it can be used for potable purpose by overcoming the “ýuck” factor.

The Bangalore Water Supply and Sewerage Board has come out with advertisements making available treated wastewater at very reasonable prices, which is the first step in putting it to good use.

With a comprehensive policy encompassing eco-system use, it can substitute the use of fresh water, refill lakes, replenish aquifers and bring back into the hydrological cycle a vast quantity of water.

It is time to come together quickly on a wastewater re-use policy. That would be water wisdom.

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