With having no trains to Waterfoot the best public transport links are by the X43 ‘Witch Way’ bus from Manchester to Rawtenstall, Rossendale (just over a mile from Waterfoot). These are reasonably frequent, and the journey takes about 40 minutes. From Manchester Chorlton Street Bus Station. The bus continues on to Burnley and Nelson.
From Rawtenstall you can take a 464 Accrington-Rochdale bus to Waterfoot. These are every 15 minutes and it’s 10 minute journey.