Estimations for 2008 show that there are around 35 200 kilometres of municipal wastewater pipelines in the whole country (not including separate storm water pipelines), which is equal to approximately 88 per cent of the circumference of the earth at the equator.

A total of 4.6 per cent of the municipal wastewater pipelines were installed before 1940, while 49.2 per cent were installed in 1980 or later. In addition, for 8.2 per cent of the pipelines, the installation date is unknown, but it is likely that they are old. The renewal rate for this category is relatively large at 2.38 per cent. By comparison, there was a 0.66 per cent renewal rate for wastewater pipelines installed before 1940 and a renewal rate of 0.12 per cent for pipelines installed in 1980 or later.

According to the 2008 figures, there were 97 sewage overflows per thousand kilometre of municipal pipeline system in the country. The figures are not only related to the age of the pipeline systems, but there is a tendency that older pipelines give rise to more sewage overflows. In municipalities where the average age was below 25 years, the figure was 64 sewage overflows per thousand kilometre of pipelines, while this figure was 112 in municipalities with pipelines older than 50 years.

The renewal of wastewater pipelines is of critical importance to preventing damage to buildings and pollution to through leakages. Leaking pipelines can also contribute to higher treatment costs as surface water and groundwater can enter the pipelines.

More information under ssb.no.

Quelle: Statistics Norway

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