By the nineteenth century, the mills were long gone and the Castle Mill-pond was part of the city's makeshift sewerage system. Streets up to a mile away drained into it, via open ditches and culverts. The surface was covered in green scum, and the smell must have been unbearable on a hot day. At its southern end, the pond was less than 100 yards from the boundary of the Infirmary (the old General Hospital) which must have been an uncomfortable thought for the unfortunate patients.
In 1853, Dr Henry Bull presented a report to the General Board of Health on the subject of infectious diseases. He was convinced that the state of this pond was one of the contributing factors to the regular outbreaks of infectious diseases such as typhoid, cholera, scarlet fever and dysentery in the area. This report lead to the Hereford Improvement Act being passed in 1854, allowing for a complete rebuild of the city's drains and sewers.
Work began in 1855. Underground sewage pipes were laid and the Castle Mill-pond filled in, leaving just the pond we know today as the Duck-pond. The street was renamed Mill Street that year.
Originally published in JABA 6 by Sarah Willetts of Park Street.
Sources: Shoesmith (1992), Roberts (2001), Spiers (1961)