Secret of Finland’s drinkable tap water

CNC reporting from Helsinki
Added On March 23, 2013

Just like Toronto's clean air, the quality of tap water in Finland has been considered one of the best in the world.

The country's biggest daily newspaper Helsinki News made a blind contest, the result of which indicated that the taste of tap water was even better than bottled water.

At the eve of the world water day, CNC correspondents visited Pitkakoski water plant in Helsinki, to have a look into the purification process of the best-tasted drinking water.

During the modern industrialization, the water sources in Finland were once polluted severely.

After efforts over nearly a century, the the water bodies have been largely restored.

The lake of Paijane, located 120 north of Helsinki, has been chosen to be the source of drinking water.

Pure water is abstracted from deep inside the lake, into an underground tunnel of 80 years old.

The tunnel is still in good shape, providing drinking water supply for over 1 million citizens around Helsinki area.

The abstracted water was then purified in three plants in suburbs of Helsinki, among which Pitkakoski is the biggest one.

The high quality of tap water in Finland could be mainly contributed to the lucidity of lakes, the maintenance of pipes, and the high standard of purification. Besides, citizens have to trust the water plants as well.

"You have to trust the company who is making your drinking water and then, they have to be proud of their work, so that's also really important. And then also they follow the laws."

In Pitkakoski water treatment plant, there are three major buildings, in which the processes of flocculation, sand filtration, ozonization, activated carbon filtration, UV disinfection and high pressure pumping take place.

The first step is to flocculate the piped water, which look slightly red after ferrous sulphate is put in to optimize the PH value. The raw water is mixed and stirred in order to improve clarification. The ferrous sulphate and humus are then separated in water tank and sand filters.

SOUNDBITE (ENGLISH) TUUKA LAKSO, Pitkakoski water plant
"So they are mixing old organic materials and iron. So sometimes it makes foam, sometimes it doesn't. What is right to have here is that, if you can see that, small particles."

The second and the third buildings are where the water is further disinfected and filtrated. To improve the taste, ozonization is used to kill microbes. The remaining organic matter is removed in activated carbon filtration system. And the water is disinfected with UV light before chlorine is added to limit microbial growth in the distribution network.

Pitkakoski water plant has been doing regular tests of the water that goes through it every day, and samples are taken at the pipe entrance in the Paijane lake every season. In the past 7 years, the samples were twice detected to be richer in organics. The first time was in 2008, and the second time was in 2012.

SOUNDBITE (ENGLISH) TUUKA LAKSO, Pitkakoski water plant
"We just noticed there is a little more organic materials in the water than they used to be. And now, it's 2012, it's been going up a little. An explanation I've heard is that it' s been rainy so much that just the rainwater takes the organic materials from soil and it ends up in the lake.

After purification, water is led into pools, where it is pumped into the distribution network across Helsinki.

In Finland, tap water is directly filled in glasses on dinner tables, as this kind of soft, drinkable water is preferable and the quality is always trusted.

"And we discuss shortly, one thing is the attitude. So nature is important, so we do not have any right to spoil it."

In the Finnish central government, there are 12 ministries, half of which are related to water, including the environmental ministry, the agricultural and forestry ministry and the employment and economic ministry, and so on.