Jacob Riis did not give away the explicit reason for the stench of the sink in the tenements. His only clue was the line "that all the tenants may have access", the reader would have to understand the living condition of the tenements for them to realize that the stench is the result of the over-populated tenement which lacked new plumbing.
You can look this up in the sparknotes website on the web. its easier than relying on someone on here
