Treatment plant project’s background

​In 2005, Espoon Vesi commissioned a development plan for the wastewater treatment of Espoo and its surroundings. Its objective was to find the best solution for processing the city’s increasing wastewater in the future so that impacts on the environment, nature and housing would be as minor as possible. Because it turned out that intensifying the operations of the Suomenoja treatment plant would become too expensive and its expansion possibilities were limited, the City of Espoo decided that a new treatment plant would be built in the bedrock in Espoo. During the assessment of the environmental impacts, residents participated in an interaction project that gathered the opinions of Espoo residents on location options for the treatment plant and ideas on the Suomenoja treatment plant.

​After the assessment of the environmental impacts, urban structure reports were made, for example, on the land use of the Suomenoja area and focus points of the sewerage area growth. Espoo City Council decided on 12 October 2009 that the treatment plant to replace Suomenoja would be located in Blominmäki. Since 2010, designing has been implemented under HSY’s lead in collaboration with the City of Espoo and other parties.

​Time​Phase
​2014−2020​Treatment plant implementation
​2014−​2016Detailed design
​2009−2014The 3rd phase regional land use plan, partial master plan of the treatment plant area and city plan were prepared and confirmed.
​​​​2013−​2014​Review of the general plan/design development.
​12/2013The submission of environmental permit applications for HSY’s wastewater treatment plants
​​2010−​2011Preparation of the general plan
​​2008−​2009​Espoo City Council decided on 12 October 2009 that the treatment plant to replace Suomenoja would be located in Blominmäki.
10/2007−11/2008  
The assessment programmes, statements and assessment reports according to the Act on Environmental Impact Assessment Procedure were completed.
​11/2007−05/2008Interaction workshop: workshops for residents, residents’ associations and regional delegations as well as the review of the location options alongside the environmental impact assessment.
06/2007
The environmental permit decision of the Suomenoja treatment plant. Time Phase with a provision for the completion of the new treatment plant in 2017
Autumn 2006
Locations of the treatment plant in the bedrock were included in the master plan proposal of Espoo’s southern sections.
​10/2005−04/2006Espoon Vesi commissioned a development plan for the wastewater treatment of Espoo and its surroundings. The plan proposed two basic options: the development and expansion of the current treatment plant located in Suomenoja or building a new wastewater treatment plant in the bedrock located in the vicinity of Suomenoja. It was decided to continue the planning of a treatment plant in the bedrock. The development plan was accepted by the City Board on 12 September 2006.​​