IDL Principina a Mare Wastewater Treatment Plant, Grosseto, Tuscany

IDL Principina a Mare is a wastewater treatment facility located in the Principina a Mare district of Grosseto, in the Tuscany region of Italy. The plant serves a population of approximately 2,448 people, classifying it as a small agglomeration under Italian and EU regulations. The plant provides secondary treatment, which is the standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for discharges into coastal waters. With a designed capacity of 5,000 cubic meters per day and an average discharge volume of 484.62 cubic meters per day, the plant operates well below its capacity, indicating room for future growth or seasonal variability. The treated effluent is discharged into the local drainage network, which ultimately reaches the Tyrrhenian Sea. The coastal location and proximity to the sea make the plant's performance critical for protecting marine water quality and the sensitive ecosystems of the Tuscan coast.

The plant discharges into the Rio Grande canal, which flows into the Tyrrhenian Sea near Principina a Mare. This coastal area supports diverse marine life and is part of a region known for its seagrass meadows and fish nurseries. The discharge point is within 10 km of the coast, making nutrient and pathogen removal essential to prevent eutrophication and protect bathing waters.