The Forum Area is located in the south-east end of the city of Barcelona, by the coastline. The area was renewed in 2004 alongside the celebration of the “Forum of the Cultures”, a global event on sustainable development, peace and cultural diversity. It was a controversial process due to the massive high-level property building and coastline changes involved, although from an urban planning point of view, it was a clever movement because it allowed to bring the Diagonal Avenue (one of the main city arteries) up to the sea and to revitalise a traditionally depressed area. However, the odour emitting activities already present in the area, treating more the half of the urban solid waste and the wastewater generated in the city, were not acknowledged.
The area contains several waste treatment facilities, such as a bio-methanisation integral waste treatment plant, a waste incineration plant, and a pneumatic collection station; plus a covered WasteWater Treatment Plant (currently underneath the Forum Plaza), with a treatment capacity of 3M inhabitants, the biggest in Catalonia; and a wastewater sludge treatment plant. The odour problems caused by these plants are well known in the city, and depending on the time of the day and the meteorological conditions, one can smell fresh wastewater, sludge, fresh waste, decomposed residue or biogas.
The communities living nearby have been complaining about these problems for many years. The variety of the odour emitting sources and the area’s demographic, socioeconomic, cultural and urban diversities makes this case study a complex and challenging one to validate the D-NOSES methodology based on citizen science to improve environmental odour management.