Adjacent to the Eiranranta residential area is Helen's Munkkisaari heating plant with a chimney which draws out flue gases, as well as exhaust air from the Munkkisaari-Mäntymäki sewer tunnel to a height of 80 metres. This so-called sewer tunnel ventilation is to prevent the generation of odours and slow the erosion of the sewage system.
However, the moist exhaust air from the sewer tunnel has corroded the flue gas pipes and concrete structures inside the chimney. Also leaks that cause odours in the environment have occurred. For these reasons we will separate the sewer ventilation entirely from the chimney of the Helen heating plant and we are having separate pipes for the ventilation of the sewer tunnel built on the side of the chimney.
During the construction project, ventilation for the sewer gases will be interrupted. However, the project is designed in such a way to minimise odours.
What will be done in the area?
The project has been granted building permission from the Helsinki City Public Works Department 02.02.2017. The project has been approved by the HSY Board of Directors 21.04.2017.
Why does this construction project need to be carried out?
Sewer tunnel ventilation is to prevent the generation of odours and slow the erosion of the sewage system. However, the moist exhaust air from the sewer tunnel has corroded the flue gas pipes and concrete structures inside the chimney. Also leaks that cause odours in the environment have occurred.
When will the construction work be carried out? Why is the construction project carried out in the summer?
The renovation work needs to be done outside the district heating season when the chimney is not in use. Therefore, the construction work is concentrated in the period between May and October. The contractor will begin work immediately after the first of May on 2.5. and the work will continue through October. The work must be completed no later than 30.11.2017. On-site work will be carried out on weekdays between 7.00AM and 4.00PM.
Who is the contractor?
The contractor is Skanska Infra Oy. Possible feedback during the construction period can be sent by email to palaute(at)hsy.fi
Who has access to the area and is access to the area prohibited?
The construction site is fenced off. Only the contractor's employees are allowed access to the construction area. They have passes for the area, showing personal and employer ID.
The background of the Eiranranta sewer ventilation
The Munkkisaari heating plant and Munkkisaari wastewater treatment plant were built in the late 1960s. The heating plant chimney was originally used not only to draw out flue gases, but also to draw out the wastewater treatment plant exhaust air. When the wastewater treatment plant was closed down in the early 1990s, the chimney began to be used to draw out the sewer tunnel exhaust air. The chimney has been used for this purpose to this day.
The Munkkisaari heating plant is one of the Helen Oy heating plants which are required when heating and hot water consumption is high, which is, in practice, in cold weather. The heating plant is located at Hylkeenpyytäjäntie 1b.