The installation of PE pressure
sewer pipe line between Harjavalta and Pori is on time. The pipe line
started in Harjavalta with pipe diameter of 400 mm. The first part of
the pipe line was 8 kilometers long. When the pipe line reached to town
of Nakkila the pipe diameter expanded to 500 mm due to increased volume
of waste water. The second part of the pipe line with the bigger pipe
diameter was 11 kilometers and the destination was the sewage treatment
plant in Ulvila. Now in the city of Pori the pipe line has reached to
the end. The third and the last part of the pipe line was carried out
710 mm diameter pipe. The length of the last part was 11 kilometers.

The purpose of the new pressure
sewer pipe line is to reduce the stress of river Kokemäenjoki. Now all
the waste water from towns of Harjavalta, Nakkila, Ulvila and Pori are
handled in the sewerage treatment plant in Pori. Also one of goals is to
reduce the number of sewerage treatment in the area of the new sewer
pipe line.

The winter has created a
challenging working environment for the contractor Maa- ja vesirakennus
Kiri Oy. When the temperature is below – 15 ° C the installation has to
be stopped due to polyethylene pipe cannot be handled in such cold
weather. – There hasn’t been winter like this for two years, says Timo
Kiri, site superviser. Occasionally the installation site had to be
closed down due to weather but we still are going to be finished at the
end of June, right on time.

The last part of pipe line is
going to be installed with No-Dig method. No-Dig methods are used
specially in park areas and going under roads. The surface of the soil
does not have to dig up and therefore it causes less harm for traffic,
landscape and people. - There has been many challenges on
the way but this is so unique project in Finland that in overall this
has been really interesting project, Timo Kiri sums up.