Hazardous old coating on concrete tank, replaced with 1100 sq.m. drinking water-approved PE liner
Nukissiorfiit, Nuuk
Guaranteed winter drinking water supplies
The client was struggling to find a durable renovation solution for their winter water tanks (drinking-water tank) in East Greenland, as the tanks were made of steel, which had resulted in widespread corrosion of surfaces.
Among the issues observed, there was pitting at the bottom of the tank, indicating punctual corrosion of the metal surface in large clusters. This made it difficult for Nukissiorfiit to renovate the tank with other solutions such as sandblasting and coating, so they opted for a plastic liner solution in order to ensure safe drinking water.
Pitting in the bottom of the steel tank, with widespread corrosion of remaining surfaces.
Efficient and quick renovation was needed
Greenland’s cold climate makes renovation of winter water tanks problematic, because the building’s residents depend on the tank for drinking water for much of the year.
Drinking water in Greenland is usually produced from meltwater from drinking-water lakes or rivers, but obtaining water from frozen lakes during the long winters is obviously impossible. The water supply is therefore obtained directly from winter water tanks, which must be filled before frost sets in. For this reason, tanks can only be shut down for renovation during a short period from June to August.
3x water tanks of 1400 m3
Nukissiorfiit chose to renovate the winter water tanks using solid PE plastic liner, which is a fast and safe renovation method compared to other solutions. This made it possible to renovate the tanks during the short shutdown period.
The assignment concerned a total of three 1400 m3 winter water tanks. First, we cleaned and painted the bottoms of the tanks to ready them for lining with the PE liner, which comprises 4mm solid plastic sheets that are mounted directly on the steel surface.
Renovation using PE plastic sheets was the right solution
The construction of the plastic sheets creates a small gap from the existing structure, which means that should water seep into the steel tank, it will never be able to come into contact with the drinking water.
The plastic material is also corrosion-resistant, unlike steel. The winter water tank, along with the quality of the residents' drinking water, is thus now guaranteed for many years to come.
Thanks to the plastic lining of the drinking water tank, we can now safely use the winter water tank as a source of water supply during the winter months.
There has been good collaboration throughout the project, and Dansk Plast has adapted the solution to our needs. We have chosen to renovate several of our tanks with the Dansk Plast solution, as it can significantly extend the life of the existing tanks in a safe way.
Kenneth Larsen
The end result, with the steel tank lined inside with solid 4mm plastic liner