Saha biotiigid Wastewater Treatment Plant, Lagedi, Estonia

Saha biotiigid is a wastewater treatment plant located in Lagedi, a small settlement in Harju County, Estonia. The plant serves a population of 15 and has a designed capacity of 320 m³ per day, with a reported discharge volume of 3.46 m³/day. It provides secondary treatment, which is the standard level required under the EU Urban Waste Water Treatment Directive for small agglomerations. As an Estonian facility, Saha biotiigid operates under the national implementation of the EU Urban Waste Water Treatment Directive (91/271/EEC). For plants serving fewer than 2,000 population equivalent, the directive requires appropriate treatment to meet local environmental objectives. The plant's secondary treatment process ensures reduction of organic matter and suspended solids before discharge. The plant is situated within 10 km of the Baltic Sea coast, making its discharge potentially influential on coastal water quality. The treated effluent likely flows into local watercourses that drain into the Gulf of Finland, a sensitive marine environment supporting diverse aquatic life and important for regional fisheries and recreation.

The plant is located near the Baltic Sea coast, within the drainage basin of the Gulf of Finland. Treated wastewater from Saha biotiigid likely enters small streams or ditches that ultimately reach the Baltic Sea, a brackish water body with limited water exchange and high ecological sensitivity. The coastal zone supports spawning grounds for fish and habitats for migratory birds, making nutrient and pollutant control critical for maintaining water quality.