Kasevalja Wastewater Treatment Plant, Suurupi, Estonia

Kasevalja wastewater treatment plant is located in Suurupi, a village in Harku Parish, Harju County, Estonia. The plant served a small population of 14 people and is now closed. It was situated near the Baltic Sea coast, within 10 km of the shoreline. The plant provided advanced treatment, which is a high level of purification beyond secondary treatment. Although the plant is closed, its designed capacity was 120 m³/day, indicating it was built to handle a larger load than the population served. The actual discharge volume was 3.23 m³/day. Under Estonian regulations, small plants like this would typically be subject to national water management requirements aligned with EU directives. The plant's proximity to the Baltic Sea means its treated effluent would have discharged into a sensitive coastal environment. The Baltic Sea is a brackish inland sea with limited water exchange, making it vulnerable to nutrient pollution. Advanced treatment helps reduce the environmental impact on marine ecosystems.

The plant is located near the Baltic Sea coast, a semi-enclosed sea with fragile ecological balance. The Baltic Sea suffers from eutrophication due to nutrient inputs, so advanced treatment is crucial for protecting marine life. The local watershed drains into the Gulf of Finland, which supports diverse aquatic species and is an important migratory corridor for birds.