Trencherfield Mill

Does anyone know what job is being carried out on the Tower at Trencherfield Mill? The tower is surrounded by scaffolding.
Could it be that they are refitting the Lighthouse.
Well, Wigan has a Pier, as we all know, so surely a Lighthouse wouldn't be out of the question.
You can watch Mick Byrne's video from 12 years ago, of the Lighthouse on YouTube at Wigan Lighthouse.wmv
Not sure about the music though.