Check-out the Document archive to see a couple of videos of the Wickwar Quarry taken at 8:15am on 17th May.

www.wrag.org.uk/component/option,com_docman/task,cat_view/gid,7/Itemid,8/

They clearly show something that very much looks like dust emitting from the main building and also from the tower. (I have seen much larger clouds in the past!) They also show the emissions from the chimney.

Environmental Health are looking into it...

It turned out that there was a leak in the ducting/filtering. The dust emmitting was super fine and probbaly hazardous to health.

Cemex were unaware of the problem.

Colin wrote:
Cemex were unaware of the problem.

Well, that's reassuring to know