Intense chlorination of Nokia city water underway

Norovirus to be flushed out of system

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Intense chlorination of contaminated water mains began at the Koskenmäki and Kartano areas of the City of Nokia in an effort to rid the supply of bacteria and viruses that had contaminated the municipal water supply in late November.
     Earlier in the evening, a megaphone car had driven around the streets of the neighbourhoods reminding residents of the purification operation.
     In Vihola, Markus Salokannel was busy preparing a newly-installed access well for the chlorination operation. The well was to be used to add a sodium hypochlorite solution to the water, in an effort to raise the chlorine content in the system to about 10 milligrams per litre of water. The primary aim is to destroy the remaining traces of norovirus.
      Juha Menonen, director of the Nokia water works, says that the main water network is already clean, and that the purpose of the present operation is to flush out the contaminants in the pipelines going to individual buildings.
     The area where contamination has still been detected has been divided into three parts, where purification is being implemented in stages, one area at a time.
     The intense chlorination is to take about one day in each of the areas, and the whole process should be complete by Tuesday morning.
     To increase the effectiveness of the chlorine, the pH value of the water is being brought down to about seven. Normally, city water in Nokia has a pH of slightly over eight, and the chlorine content is about 0.1 milligrams per litre.
     
For the chlorination to be effective, residents are being asked to run at least 50 litres of water a day from their faucets during the operation.
     All taps in each household should be used, and both hot and cold water should be run.
     The purification of the water supply will not be endangered even if individual households neglect to run the necessary amount of water. However, in such a case, the water in the pipes of the house in question might still contain viruses.
     
Water should not be used for drinking, food preparation, or bathing during the chlorination. It can be used for machine-washing of clothes or dishes, and for cleaning. However, hands should be protected against exposure to the chlorine.
     Although residents are warned against drinking the chlorinated water, accidentally tasting some of it is not considered to be harmful.
     If the chlorination operation is successful, restrictions on the use of water will be lifted in two to three weeks. Until then, residents are advised to continue to boil water intended for food preparation and drinking.
     After the chlorination operation, the water running operation should be continued on a daily basis until restrictions on the use of water are lifted.


Previously in HS International Edition:
  Investigation underway into deaths possibly linked to tainted Nokia city water (19.12.2007)
  Nokia water crisis eases (10.12.2007)
  Contaminated water crisis continues in Nokia (7.12.2007)
  A thousand Nokia residents believed to have had symptoms after consuming contaminated drinking water (3.12.2007)

Links:
  Nokia, Finland (Wikipedia)

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