Increased infiltration, water retention and flood protection
The constructed wetlands system (CW), in addition to treating the wastewater from the Castelluccio village and tourism facilities, contributes to the groundwater recharge thanks to the infiltration of the final effluent.
Biodiversity conservation or increased biodiversity
The CW may provide a new wildlife habitat and exploit the ecological benefits of the CW (not only their function as a treatment facility (Knight, 1997; Stefanakis, 2019). The main characteristics of the CW (i.e., presence of water and vegetation) make its suitable for the creation of a new ecological habitat, by attracting wildlife species, especially birds, and establishing a green area (Stefanakis, 2019). Increased biodiversity can be an important added value of the CW and rain garden. (IRIDRA, 2021).
Increased quality and quantity of green and blue infrastructures
The constructed wetlands (CWs) system in Castelluccio di Norcia fits into the general plan for the redevelopment and enhancement of the rural centre of Castelluccio di Norcia, implemented by the Region of Umbria. After the completion of the sewerage system of the village, a constructed wetlands system has been designed in replacement of an old activated sludge plant no longer adequate. The choice of a constructed wetlands system was dictated not only by the necessity of inserting the treatment plant in a context of very high landscape value such as the Pian Grande di Castelluccio (one of the few uplands of Italy, nestled in the Sibillini Mountain National Park), especially from having to face a strong fluctuation of the inhabitants, from a few dozen in the winter, to 1000 p.e. during summer and weekends. Treated person equivalent: 1000 PE. (IRIDRA, 2021).
Improved aesthetic value
In contrast to conventional treatment systems, nature-based solutions of the wastewater treatment (such as CWs) may also provide indirect benefits such as aesthetic improvement of the landscape (Goulandris Natural History Museaum, 2021).
Drought and heat risk
Investigations of mutation in the compound occurrence of drought and heat conditions have identified many hotspots of compound drought and extreme heat conditions in Europe. These include, among others, France, Benelux countries, Italy and Balkan Peninsula. Trend detection has shown that these areas were characterized by a rising trend in the compound occurrence of drought and heat extremes. (Bezak, Mikos, 2020).
Good health and well-being (SDG3)
Clean water and sanitation (SDG6)
Industry, innovation and infrastructure (SDG9)
The plant represents an innovation in the national scene as it uses a particular technique (French system) of purification, in which the primary treatment lacks the sedimentation phase and is composed by a grid and an equalization tank: in the first stage with "French " vertical flow reed bed filters (RBF) the solids accumulate on the surface and then it will be removed after 15-20 years and used as organic fertilizer in agriculture. (IRIDRA, 2021).
Sustainable cities and communities (SDG11)
Climate action, resilience, mitigation and adaptation (SDG13)
Yes, the main characteristic of CWs is very low greenhouse gas emission (Stefanakis et al., 2014; Stefanakis, 2015).
Aquatic biodiversity (SDG14)
Yes, rare aquatic plants typical of the Castelluccio plateau have been planted in the pond.