St Jakob iD Wastewater Treatment Plant, Sankt Jakob in Defereggen, Tirol

St Jakob iD is an advanced wastewater treatment plant located in Sankt Jakob in Defereggen, a municipality in the Defereggen Valley of Tirol, Austria. The plant serves a small population of 1,178 residents, reflecting its role in a rural alpine community. The plant employs advanced treatment processes, which go beyond the secondary treatment standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. With a designed capacity of 5,000 m³/day and an actual discharge volume of 808.24 m³/day, the facility operates well below its capacity, indicating room for future growth or seasonal variations. The treated effluent is discharged into the local watershed, which ultimately drains into the Drava River via the Isel River. The Drava flows through Austria, Slovenia, Croatia, and Hungary before joining the Danube. The advanced treatment helps protect the sensitive alpine aquatic ecosystems and downstream water quality in the Danube basin.

The plant discharges into the Defereggen Valley's stream system, which feeds into the Isel River and then the Drava River. The Drava is a major tributary of the Danube, flowing through multiple countries. The alpine watershed supports sensitive cold-water fish species and oligotrophic conditions, making advanced treatment crucial for maintaining ecological balance. The region's steep terrain and seasonal snowmelt influence flow dynamics and pollutant transport.