High quality drinking water

The waterworks of Øvre Årdal are said to produce the best drinking water in western-Norway, even though the groundwater source lies beneath an old waste disposal site.

Øvre Årdal in Western Norway needed new waterworks facilities. The best alternative ended up being only a few metres from Lake Årdal. Some of the challenges were: would it be possible to pump large volumes of water from the aquifer? Would seepage of surface water from Lake Årdal occur? To make the alternative even more challenging, the selected site was located near the outlet from a county treatment plant for spillwater, and situated on top of an old waste disposal site.

Several test and survey wells were drilled prior to the decision of constructing the waterworks. The wells were used to predict how much water could be pumped up from the aquifer. The results enabled NGI to build a groundwater model of the aquifer. Model analyses revealed the high capacity of the aquifer, with possible pumping of at least 500 litres water pr second without risk of infiltration of water. This was sufficient guarante against infiltration of the contaminated water from the county outlet.

Årdal County obtained its water earlier from the hydro power station in Øvre Årdal, owned by Hydro Energy Sogn. The work by NGI was contracted by the waterworks of Øvre Årdal in the province of Sogn and Fjordane in western Norway.

The waterworks in Upper Årdal was built on an old waste disposal.