New excavations at the Rakhigarhi site have uncovered a 4,500-year-old industrial hub focused on environmental management. The discovery of a Harappan Urban Slag-Filtration System reveals how ancient metallurgists managed the waste products of copper and bronze smelting within the city limits.
The system utilizes tiered terracotta basins filled with graded sand and charcoal to filter toxic residues from water used in smelting processes. Archaeologists note that this finding highlights the advanced awareness of urban hygiene and industrial sustainability practiced by the Indus Valley Civilization during its mature phase.