This is a wastewater treatment system that cleans half of the sewage for a city of 12 million people without the use of chemicals. It was born a few hundred years from a group of Bengalese farmers who were living on the outskirts of Kolkata. There is a group of farmers that treats sewage water coming out of the Hoogly River.

Bheri wastewater aquaculture. (2024, February 17). Philippine Daily Inquirer, p. B2.