A natural wetlands area in India has been developed into an effective wastewater treatment system that organically processes sewage through bio-remediation – no need for a treatment plant!
The East Kolkata Wetlands in India processes almost 198 million gallons of wastewater and sewage produced by the region’s population every day, relying on nothing but nature. What was once a mix of lowland salt marshes and silted rivers is now a sprawling complex of manmade wetlands framed by greenspace.
With the help of local farmers and fishers, the wetlands are maintained in good health to organically clean sewage using sunlight, oxygen, and beneficial microbes. This process, known as bio-remediation, cleans wastewater within three weeks – a remarkably quick turnaround that highlights the great power of natural solutions.
Wastewater from the city is directed into small inlets, each one controlled by a local fishery cooperative. The cooperative then separates the dense polluted water from clearer surface water, which flows into the large wetland while the wastewater decomposes and becomes fish food through organic processes. This water is then used to raise fish in ponds known as bheries or grow crops on the banks of the wetlands. In addition to its wastewater and agriculture services, the East Kolkata Wetlands also act as a flood control system, absorbing excess water from the nearby city.
Former city sanitation engineer Dhrubajyoti Ghosh has served as the Wetland’s guardian for several decades. After realising the enormous value of the wetland’s environmental services, he defined the formal limits of the area and successfully protected it from real estate developers.
Today, Ghosh recognises the challenges and opportunities facing the wetlands and others like it. “I am still learning how this delicate ecosystem works, how to further refine it, and why some places are better suited than others,” he told The Better India.
“I am happy to give any advice or help absolutely free. This is the best system of its kind in the world and could be helping millions of people. If I have failed in one thing it is this; not enough people know about it or are benefiting from it.”