Swedish city takes fight to water parasite

Ozone and chlorine are among the measures deployed by Östersund municipality in northern Sweden to try kill off the parasite which has afflicted the stomachs of thousands of residents and rendered the water undrinkable.

• Stomach bug outbreak prompts criminal probe (30 Nov 10)
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Many Östersund residents have called the municipality to report that they have noticed the strong smell of chlorine in the water. But this is nothing to worry about, underlined Jörgen Vikström at the municipality.

"It is a question of trying to make the living conditions of the parasite as poor as possible. That is why we use ozone, cut the pH value, and change the chlorine level," he said.

The municipality has also confirmed that it will allow sector organisation Svenskt Vatten to inspect the city's water system in response to expert opinion that the system is poorly constructed with intake and outtake points in the Storsjön lake too close to one another.

"There have emerged details in certain media that our construction and works have been wrongly constructed. We plan to consult Svenskt Vatten, which is an independent expert, to check if our system is correct," Bengt Marsh at the municipality said to the local Östersunds Posten daily.

According to Jari Hiltula, the head of environment policy at the municipality, the source of the parasite is thought to be the water treatment works in Göviken.

The Local reported on Tuesday that a local prosecutor has launched a probe into possible criminal negligence, while police closely follow the work being carried out to track how the Cryptosporidium parasite ended up in Östersund’s drinking water.

More than 5,000 residents have taken ill after ingesting water from the city’s water supply, many suffering from diarrhea, vomiting, and severe stomach cramps.

Residents of the city, roughly 50,000 of whom are connected to the municipal water system, can expect to have to boil tap water for several weeks, an expert with the Swedish Institute for Infectious Disease Control (Smittskyddsinstitutet) told the TT news agency.

Once the source of the parasite has been found and shut off, it will take at least a month before it’s possible to drink water directly from the tap.