Saint Sulpice la Foret : a 1000 PE waste stabilization pond boosted to 1950 PE by addition of reed bed filters. A 2,400 m², vertical flow reed bed (French system), a 1,950 m² second stage vertical flow, unsaturated plus a 10,000 m² of willow plantation and a 5,000 m² pond treating 400 m3/d of domestic effluent.