Wastewater treatment plant, Blominmäki, Espoo

The modern Blominmäki wastewater treatment plant will serve as a more efficient replacement for the current Suomenoja wastewater treatment plant, both in terms of purification efficiency and capacity.

The new wastewater treatment plant will handle the wastewater of approximately 400,000 residents from the areas of Espoo, Kauniainen, Kirkkonummi, Siuntio, and Western Vantaa.

The construction of the new wastewater treatment plant in Blominmäki, Espoo, began in 2018 after the completion of excavation works in the area. The modern Blominmäki treatment plant will be more efficient in terms of both treatment capacity and purification performance compared to the current Suomenoja wastewater treatment plant. The new plant will handle the wastewater of approximately 400,000 residents from Espoo, Kauniainen, Kirkkonummi, Siuntio, and Western Vantaa.

The wastewater treatment plant is being commissioned by HSY (Helsinki Region Environmental Services Authority), and the project management contractor YIT selected ARE as their partner for the technical project management. ARE has experience in implementing building services in demanding rock space projects. ARE is responsible for the HVAC, sprinkler, electrical, instrumentation, and automation works of the treatment plant.

The treatment plant has been excavated mainly within the rock, and the actual water purification takes place underground. The above-ground structures include administration, maintenance, sludge drying, and power buildings, among others. The underground facilities at Blominmäki allow for future expansion to handle wastewater from even over a million residents. The plant utilizes the latest technology to remove nitrogen and phosphorus from the wastewater. The goal is to purify over 96 percent of phosphorus and organic matter and over 90 percent of nitrogen contained in the wastewater.

Once completed, the Blominmäki project will be one of the most modern wastewater treatment plants in the Nordic countries. The construction site is of massive scale, and the project’s magnitude is also reflected in the amount of materials used.

“The underground construction site, which is equivalent in size to ten football fields, includes various components, such as 12,000 meters of ventilation ducts. The working conditions at the construction site vary, as the underground caverns are at their deepest point 40-50 meters below the ground.”, according to ARE’s Project Manager Jukka Järvinen.