Outside the fact that in this case it is a whole service (They are in Sale, just outside Manchester) in my experience a lot of people working for councils are not always people who live in that borough. I know some people who work for Southwark council but commute from Kent. Nothing stops you applying for a job for a specific council and to commute from across London.

In the case of the service above, the company they work for probably provide the same service to a lot of other councils accross the UK.