Closing the loop

A village near Bengaluru sets an example of wastewater use by innovatively using the reject water from a community RO plant installed to eliminate fluoride contamination.
The RO plant in Sonnahallipura village.
The RO plant in Sonnahallipura village.

With a total population of 1200, Sonnahallipura village in Hoskote taluk of Bangalore rural district has 250 homes. This village was chosen by the Rotary Club of Bangalore, Indiranagar to start a micro-credit programme for 10 women’s self-help groups (SHG) and a low-cost sanitary napkin manufacturing unit.  

Vidya Chandy with some SHG leaders from Sonnahallipura village.Vidya Chandy, a former member of the Rotary Club, always wanted to work in the rural development sector. In January 2015, Vidya began a professional sabbatical and gave a proposal to the Rotary Club to deepen the engagement in several areas of development in this village, one of which was water. This was the start of Vidya's continued engagement as the Rotary's partner in rural development.

Going by Vidya’s design of the intervention, local representatives were appointed in many areas like water, waste management and health to encourage participation and ownership from the community. These local champions worked as coordinators and also leveraged public funding and schemes as much as possible.

The grim water situation

The water in this village tested positive for fluoride, with levels found to be above permissible limits for human consumption. Fluoride in water causes a health condition called fluorosis, of which there are two types-- dental and skeletal. Fluoride-contaminated water needs treatment to avoid the adverse health impacts from prolonged consumption.

The local MLA agreed to fund a borewell in Sonnahallipura, which fortunately struck water at the first drilling attempt. A Reverse Osmosis (RO) plant was also set up under the S. K. Patil scheme to purify water from the borewell. Thus, public funds and systems were used to put the hardware in place to ensure a safe, secure source of water for the village.

What remained to be addressed was the issue of wastewater management. About 30 percent of the output from RO plants is reject water, which is a challenge to deal with safely. With smaller household RO plants, the reject water can be used for gardening or flushing the toilet. With larger community level RO plants like this one in Sonnahallipura, however, the quantity of reject water is much more that if let into the ground or stormwater drains, it can contaminate soil and groundwater, causing other long-term problems.

Innovative use of wastewater

Wastewater from the RO plant gets diverted to a nearby brick kiln.In Sonnahallipura, the RO plant was conveniently located across, not one, but two brick kilns. Following advice from water experts, it was a simple process to divert the wastewater to the brick kiln and prevent the concentrated-fluoride wastewater from compromising the groundwater quality. Allowing the wastewater to seep into the ground would only contaminate the source of water further, exacerbating the problem and rendering the RO plant useless. In this case, the brick kiln utilised the wastewater from the RO to make bricks.

Some awareness building was required with the community, the local panchayat, the MLA's office and the ZP WSD (zilla parishad water supply department) executive engineer. Once the importance of the issue was understood, the villagers set up the system with the involvement of the two brick kiln owners. They took a pipe across the pond and attached it to a tank, and then pumped it up to the brick factory's Sintex water storage tank which was on a slightly higher ground. From there, the water is now being utilised in making bricks. The kiln owners plan to swap the system between the two kilns as needed. The villagers are happy with the system and to have saved their drinking water. 

For now, Sonnahallipura is one village that is responsibly managing its RO wastewater. The (fluoride-concentrated) wastewater from the new community water purification plant is piped, pumped and collected to supply water to make bricks at the nearby kiln. Zero contamination. Zero wastage.

The question about other surrounding villages remains. After all, the groundwater is connected, so all RO plants with similar effluents have to address the issue similarly. 

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