They went to the Corsehill depot near Annan, operated by Dumfries and Galloway Council, to see what happens to householders’ waste.
And they also enjoyed a tour of the MacRebur plastic roads factory in Lockerbie, where waste plastics are turned into road construction products.
Pictured in Annan are, left to right: Archie McDonald, Ian Lochhead, Mayor Isa Akeky, visit organiser Thomesena Lochhead, Corsehill manager Kirk Telfer, Daniel Kawes and Dr Jim McHardy