Plombières official until 1919 Bleyberg is a municipality of Wallonia located in the province of Liège, Belgium. On 1 January 2006, Plombières ha…Plombières official until 1919 Bleyberg is a municipality of Wallonia located in the province of Liège, Belgium. On 1 January 2006, Plombières had a total population of 10,401. The total area is 53.17 km² which gives a population density of 200 inhabitants per km².