Seaway officials will dig into a buried canal remnant in Thorold, after local explorers stumbled across a smelly yellow substance now identified as sulphur. Rene Ressler, a heritage buff who runs the Welland Canals Advocate website, found a wide expanse of "sulphur smelling" material atop what he believes to be the filled-in southern approach to Lock 25 of the third Welland Canal earlier this year. The overgrown area between the current Welland Canal and Beaverdams Rd. is owned by the St. Lawrence Seaway Management Corp., but is criss-crossed with informal trails popular with cyclists and hikers.