Residents of Central and East Helsinki will be drinking River Vantaa water by the weekend
As was reported earlier, from this week onwards around one million residents of Helsinki, Espoo and Vantaa will gradually be getting their drinking water from the River Vantaa.
Initially what will be running through the pipes will be a mixture of water from Lake Päijänne and the Vantaa.
In Central Helsinki and the eastern suburbs, people will be drinking solely water from the River Vantaa by the end of this week.
For those living in the western parts of the capital and in Espoo and Vantaa, things will go more slowly, as the changeover to filtered Vantaa River water will not take place until mid-May.
Under normal circumstances, the entire Greater Helsinki area draws its drinking water from Lake Päijänne, from whence it comes by tunnel, but scheduled repair work on the tunnel begins from today, Tuesday.
The tunnel will be out of service until the end of the year.
The Päijänne Water Tunnel, which dates from 1982, is 120 km long and can carry 2.5 billion litres of water.
The last occasion when residents of the metropolitan area drank water pumped from the River Vantaa was in 2001, when repairs were carried out on the northern end of the tunnel.
A questionnaire survey carried out at the time suggested that satisfaction with the quality of the water fell appreciably, though there was no great flood of protests to Helsinki Water over the matter.
Whilst there have been suspicions voiced about the water in the river, the Helsinki Water Operating Manager Veli-Pekka Vuorilehto insists that the change in the source of drinking water will go quite unnoticed in normal life.
The most significant differences are in the mineral content of the water, and this will affect those users who use the water pumped by Helsinki Water as feed for their own processes. For example power stations will need to fine-tune their own desalination procedures accordingly.
One minor flaw is that the Lake Päijänne feed is drawn from some depth (around 25 metres) and thus in the summer months it remains colder and fresher than the river water - but the refrigerator can go a long way to resolving this issue.
Previously in HS International Edition:
Helsinki drinking water to be drawn from River Vantaa from mid-April (31.3.2008)