Tretten renseanlegg - Wastewater Treatment Plant in Tretten, Innlandet, Norway

Tretten renseanlegg is a municipal wastewater treatment plant located in Tretten, a town in Øyer municipality, Innlandet county, Norway. The plant serves a population of about 4,242 people, placing it in the small agglomeration category under Norwegian regulations. As a Norwegian facility, Tretten renseanlegg operates under the national implementation of the EU Urban Waste Water Treatment Directive (91/271/EEC), which requires secondary treatment for discharges to freshwater and estuaries from agglomerations of this size. The plant's treatment processes are designed to meet these standards, ensuring compliance with Norwegian water quality regulations. The treated effluent is discharged into the local watershed, which ultimately drains into the Gudbrandsdalslågen river, a major watercourse in Innlandet. The river flows southward into Lake Mjøsa, Norway's largest lake, and continues via the Vorma River to the Glomma River, which empties into the Oslofjord. This downstream chain supports diverse aquatic life and is important for regional ecology and recreation.

Tretten renseanlegg discharges into the Gudbrandsdalslågen river, which flows into Lake Mjøsa, Norway's largest lake, and eventually via the Vorma and Glomma rivers to the Oslofjord. The watershed supports diverse aquatic ecosystems, including fish species such as brown trout and Arctic char, and is an important corridor for migratory birds. The plant's treatment helps protect water quality in this sensitive freshwater-to-marine continuum.