Around 1854.
https://en.wikipedia.org/wiki/1854_Broad_Street_cholera_outb...
Which about ten years later resulted in the Victorians building over 100 miles of sewers.
https://en.wikipedia.org/wiki/1854_Broad_Street_cholera_outb...
Which about ten years later resulted in the Victorians building over 100 miles of sewers.