UNDERGOUND SPACE AS A LOCATION FOR A WASTEWATER TREATMENT PLANT

City of Opatija is elegant tourist destination, which lies at the centre of the Libutnis Riviera with the longest tradition of tourism in Croatia. Wastewater treatment plant of city of Opatija is a central part of a sewerage system of the wider urban area. The purpose of constniction of the wastewater treatment plant is determined by the needs of urban communities in the coastal agglomeration; and can be detennined with a few basic principles of environmental protection from pollution by sewage water: protection of coastal waters for certain purposes (tourism activities: for various recreational activities of citizens and tourists, boating, etc.), ensuring environmental stability and sustainable development in the area of Riviera (Rijeka Bay), and protecting the health of residents and visitors of all villages, protection of marine environment of the Rijeka Bay (plant and animal species), and protection of underground, ground water and torrential flows. Due to lack of appropriate location, and an overall environmental protection from unpleasant side-effects (visual, air quality, etc.), the integral parts of central plant for a wastewater treatment is located in a completely enclosed underground space. This paper presents general information about investigationworks, design process and construction works on underground structure and detailed information aboutwastewater treatment plant.