One of our most important challenges at the moment is in finding an answer to what we do with Reverse Osmosis reject water - in many cases the concentration of salts is low enough that it can be used to recharge wells and grow vegetables - but that is no solution.  BUT, we are in places where water is a problem, and the inability for us to directly use every drop of water we extract is an issue that bothers me like a splinter in my brain.

In looking for an answer, we've learned all kinds of fascinating things - the stats are not exact, but will give you a sense of what the situation is:

88% of water use in India is for agricultural irrigation.

EIGHTY EIGHT PERCENT!

Of the remaining 12%, some 8% is for industrial use.  Three quarters of that use is for a single purpose:  Thermal Power Plants.  

Direct human consumption, non-agricultural, and non-industrical use makes up 4% of the total fresh water use in India.

So lets get this clearly - of all water use:

88% Agriculture
6% Thermal Power Plants
2% Industrial Use
4% Everything Else

That suggests that if we want to make a real contribution to water use and management, there is massive need to find solutions that help reduce water use in Agriculture.  I mean MASSIVE need.   I'm told that simply laser-leveling paddy fields can reduce water use by 30%, and paddy is grown in some of the most water-scarce areas in India!

So, back to the point:

One option is to think about dealing with our water reject issue with a water-balance solution, that is, helping save more water in other areas (such as agriculture) near our franchises than we actually reject.   My guess is that this stuff is already on its way to a cap-and-trade kind of answer that will emerge when we actually value water as much as we talk about carbon.   Could be a solution.

However, the real challenge is in looking for low-cost or even revenue-generating solutions to our water rejection issues - ones that actually deal with the water rejection.

I'm open to any and all ideas:  anand {at} sarvajal.com

This issue is not just disposal - to do so easily - we could dilute and let it into the ground or use it for a garden, we could incinerate and boil away the water, there are many ways.

However the more interesting options we are looking at:

(1) Using the water for a pay-and-use toilet / sanitation facility - perhaps co-locating nearby.

(2) Rural laundry/laundromat

(3) Creating a bio-fuel - perhaps growing algae and collecting it, or using reject water as a component of a bio-waste methane generator (somewhat complex in making the logistics work correctly).

Any thoughts?