Until 2013, the farm was equipped with a conventional technological solution for the treatment of the liquid fraction of pig manure, an activated sludge followed by a membrane stage, designed to discharge to surface waters according to Italian law. During the renewal of the authorisation to discharge the regional Environmental Authority (ARPAV) requested to change the authorisation terms, requiring more stringent water quality standards to discharge on soil. After a successful pilot test and thanks to local funding (Rural Development plan, PSR as per the Italian terminology), the farm owner decided to install a “nature-based” treatment system which, thanks to lower operational and maintenance costs, was expected to make the re-opening of the farm financially sustainable. Due to limited available space, the chosen solution was a “hybrid” solution (NB and technological): an aerated constructed wetland (CW) plus a reverse osmosis (RO) final polishing stage. The new system was sized to treat the liquid fraction of the manure produced by half of the farm capability, i.e. 3000 pigs, maintaining the possibility of an upgrade to 6000 pigs just installing a new treatment stage, while the RO and the primary treatment (a centrifuge for solid/liquid separation) was designed for the full capacity of the farm, i.e. 6000 pigs.