Nob End is the site of a former waste tip, and now a Site of Special Scientific Interest (SSSI) near Kearsley, Bolton, England.
Standing at the confluence of the River Irwell and River Croal it was used around 1850-70 as a tip for alkaline waste from the production of sodium carbonate (soda ash) by the Leblanc process.[1] The waste was known as 'galligu' and was a blue sludge (from reduced iron compounds) dominated by calcium sulphide and smelling of bad eggs.[2] The toxicity of the calcium waste has subsided and calcicolous vegetation has colonised the site.[1] The 8.8 hectare site became a SSSI in 1988 and a Local Nature Reserve (LNR) in 2000.[3]
In 1936 a major breach in the now defunct Manchester Bolton & Bury Canal occurred east of the Nob End locks which was never repaired.[4]