The removal channel project at Kakolanmäki in Turku has progressed to the UV plant construction phase

Turun seudunpuhdistamo Oy’s removal channel project has progressed to the UV plant construction phase, which began in May 2021. The preceding jacking and excavation work has been completed. Fimpec has provided project management and supervision services for the project since May 2020.

A particular feature of this removal channel project was the stretch of removal channel implemented through jacking, wherein the ground was only excavated at the start pit for the pipe at the harbour area (image No. 2) and at the end pit in Hansapuisto park (3). The stretch of pipe between the pits measures 804 metres and has a diameter of 2.5 metres. It was implemented by jacking the pipe elements from the start pit at the harbour to the end pit at Hansapuisto park. The final 25-metre stretch of removal channel from the start pit in the harbour area to the sea (4) was partly carried out within an area bordered by pile walls.

The excavation contract excavated space for the UV disinfection plant (1) in connection with the existing Kakolanmäki wastewater treatment plant. Space for the UV disinfection plant was excavated in challenging conditions in the immediate vicinity of the treatment plant, which was in operation, and a day-care centre. In addition, the contract excavated an approximately 300-metre-long removal tunnel from the UV disinfection plant (1) to the end pit at Hansapuisto park (3), where the excavated removal tunnel and the jacked stretch of pipe connect.

Implementation of the removal channel and its associated earthworks and foundation work, and rock engineering played a key role in earlier phases of the project. Once the project moved to a new contract phase, the construction of the UV disinfection plant, focus shifted to construction-technical, mechanical, and device-technical work, and to the integration of the new UV plant’s operations into the existing plant. It is also essential to ensure that the existing plant can operate without disruption while the UV disinfection plant is under construction.

The UV plant construction phase began in May 2021

The construction phase for the UV disinfection plant began in May 2021. The UV plant contract is implemented for Turun seudunpuhdistamo by Skanska Infra Oy.

The contract will implement the construction of a UV disinfection plant in connection with the existing wastewater treatment plant, in a space excavated from rock in a previous contract. In addition, the contract will see installation work carried out at a plant that is actively operating.

“The construction of the UV plant is a cross-disciplinary and challenging part of the removal channel project. Once it is complete, the constructed removal tunnel and channel will be taken into use. It is a joy to oversee this project, because I get to work together with Fimpec’s experienced professionals!” says Jarno Arfman, Technical Manager at Turun seudunpuhdistamo Oy.

“This is an important and significant infrastructure project for Fimpec, and it’s great to collaborate on the project with our customer, Turun seudunpuhdistamo Oy,” says Fimpec’s Project Manager Esa Kunnassaari.

The entire project will be completed in 2023

After treatment and UV disinfection, the treated wastewater that is discharged into the sea will meet hygiene requirements set for swimming water, and the hygienic environmental load on the Turku sea region will be significantly reduced. The entire project will be completed in spring 2023.

Turun seudunpuhdistamo Oy is a regional service provider owned by 14 municipalities. It offers its owners a high-quality and cost-efficient wastewater treatment service. The company is responsible for operating the Kakolanmäki wastewater treatment plant and for the results of the treated wastewater.

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