Hartley is, unfortunately, a very common surname in Lancashire. The earliest members in my tree are John Hartley and Hannah nee Holt who were married in Rochdale in 1775. Their son Samuel and his wife Alice (also nee Holt) moved to Bury between 1835 and 1838. He was a Weaver and later a Carter.
John Edward Pilkington Hartley married Sarah Jane Duckett who was born in Ironbridge. Going back a few generations from Sarah Jane to my 4 x great grandparents, Thomas Potts and James Lloyd, would have been living in Broseley when the Ironbridge was built.
Some other surnames associated with the Hartley side of the family:
Duckett, Potts, Lloyd, Pilkington, Isherwood.