This interesting photo shows the twin pump rooms used for pumping water from the treatment works to Middle and High Service. By 1904 a 30'' diameter had been laid from Little Eaton High? Level works to St Mary's Bridge. (as far as I know this is still in use and burst at least twice on the railway embankment at Breadsall.) I assume both beam engines would have been powered by coal and that the treatment would have been by the simple settlement in tank shown on the right. This received water from infiltration tunnels which drained ground water into the works by gravity. I'm not sure if there were sand filters then, but later in the 1960s the then new works were built over the settlement tank - by then known as the sump. Built in the centre was the Accelator? - a device for flocculating water solids by mixiing with chemicals. By the 1960s new pyramoidal sttlement tanks and back washed sand filters were also used. A new pump hall using electic pumps was constructed rendering the old stream driven pumps redundant.
caption John Simpson - photocopy from the Water Supply of Derby 1848 -1948.