ÅRHUS
The facility in Århus is serving a residential catchment with a total area of 55 ha (impermeable area of 26 ha). The facility discharges to a nearby located sensitive lake (Brabrand Soeen). The pollutant load on the catchment is in the low range as 80% of the catchment is multi-story housing buildings and the remaining 20% is roads and highway. This facility will demonstrate the efficiency of the treatment concept for slightly polluted stormwater runoff. The capacity of the treatment units are accordingly designed for low pollutant loads.

Treatment technologies
In the facility in Århus, the bottom sediments of the pond have been supplemented with iron salts. This serves to increase the binding capacity for phosphorus and heavy metals in the sediment layers. The iron salts have been added in such a concentration that the binding capacity is sufficient for 1-2 years of operation. Before discharge of the runoff water to the nearby lake, the water is filtered through a sand filter that efficiently removes suspended particles.


Layout of the pond
The images below show the location of the pond next to the lake (left side image) and the pond layout (right side image). The inlet to the pond is located at the south-east end of the pond and the outlet is at the opposite end. This layout minimizes potential dead volumes where water is not replaced during runoff events. It is imperative for the treatment performance that the entire pond volume and bottom area are utilized for pollutant removal.



The images below give an impression of how the pond is integrated in the surrounding lake environment. It is a key objective of the TREASURE project to demonstrate that the treatment systems can contribute to an improved urban environment by replicating semi-natural lakes.





Panoramic view of the pond. The inlet structure is visible in lower right corner.


See images from the construction phase (pdf-file)