Following the contamination of Skellefteå’s water supply by a diarrheal disease causing parasite, the municipality hired Ramboll as the chief consultant for the upgrade of its water treatment plant. The new plant was recently delivered and uses oxidation, filtration and disinfection techniques that are able to neutralise the parasite.
A number of locations around that world are already undergoing water stress. As populations grow and a range of industries continue to require water for their productivity, sometimes limited supplies become overtaxed, and, eventually, run dry. A water crisis is ranked as the number three most impactful global risk in a recent World Economic Forum report, with climate change likely to exacerbate an already daunting water problem for Brazilian mega cities, including São Paulo and Rio de Janeiro, while California too has been suffering under sustained drought. While water sources are an issue in a number of locations, the supply is also not always potable – even wealthy developed countries can find themselves in crisis, as was recently highlighted by the lead poisoned pipes in the US and a micro-parasitic invasion in Scandinavia.
Skellefteå, in Sweden, is a small city whose municipality has approximately 72,000 residents. The municipality is situated in Västerbotten County in the north of the country. Like much of Sweden, the city enjoys a relatively temperate climate, with plenty of rainfall and access to local water. Five years ago, however, it was discovered that the city’s water supply was contaminated with cryptosporidium, a parasite that results in diarrheal disease. Following the discovery of the contamination, residents were required to boil water for seven months. The parasite is highly resistant to chlorine based disinfection, with boiling, oxidation and UV being considerably more effective treatments to contaminated water.
To rid itself of the pathogen, the municipality decided to upgrade the water treatment system. The new water treatment plant uses the practice of artificial groundwater recharge, whereby groundwater reservoir levels are artificially increased, as well as leveraging modern oxidation, filtration and disinfection techniques to ensure that the city’s groundwater is safe to drink.
Engineering and consulting firm Ramboll served as chief consultant during the project, which is the largest of its kind in Sweden. The team working on the project includes the firm’s experts from ten different offices in Sweden. “As this case clearly demonstrates, clean drinking water is never a matter of course. It takes a constant focus and ability to change the way things are done, if the situation requires it,” says Anette Seger, Country Manager for Ramboll Water in Sweden.