THE odor of ammonia exudes a pungent smell as soon as the door is opened. One step inside, two large red ball-shaped tubes are visible in the middle of the hall. Pipes of all sizes entwine one another, channeling the water. “Those are the tubes where the liquid waste undergoes a final process. Afterward the sewage is kept in a storage tank,” said Wahid, operator of the sewage-processing installation.

Wahid and his co-worker, Ade Suhairi, exp