FRANCE

a communal wastewater treatment plant-WTP, one of the largest (4000/6000 PE) and most efficient in France (especially in removing nitrogen and phosphorus)... The WTP discharges into the river a water quality similar to that released by the usual intensive treatment processes, with operating costs twice as low, a markedly lower carbon impact and a greater reliability. Integration of the initial ponds into the treatment process improves nitrogen and phosphorus removal in the summer - the most sensitive period for the receiving streams... The septage plant discharges very little water (less than 5000 m³/year at nominal load) of good quality into the river (BOD5 < 25 mg/l; COD < 125 mg/l; SS < 150 mg/l). The filtrate is treated in existing ponds during the winter and spread in the summer on a tree plantation operated as Short Rotation Coppice-SRC whose wood production feeds a communal heating system.

Primary location: Nègrepelisse France