Published: 17. Feb 2023

High-quality drinking water requies protection

Sprøjtefri Kampagne Large

Aarhus Vand supplies drinking water of the best quality merely by filtering and aerating the water on its way to the citizens’ taps. However, we can only do this because we think ahead and always take the groundwater into consideration.

In recent years we in Aarhus Vand have entered into voluntary agreements with landowners regarding pesticide-free cultivation of the vulnerable areas. Through investments in afforestation we contribute to the plantation of new forests. In selected areas, we successfully run information campaigns together with the local waterworks and joint councils for the purpose of reducing the use of pesticides in private gardens.

Aarhus Vand extracts drinking water from about 90 groundwater wells. The wells are between 30 and 140 metres deep – most of them are between 60 and 80 metres deep.  All wells are surrounded by a ten-metre protection zone and a 300-metre hygiene zone within which there must be no percolation of wastewater.Thanks to the geological qualities of the soil and general precipitation, we can collect clean drinking water from the ground. Drinking water which is generated by nature’s own geological treatment plant and has a natural content of minerals and a quality that makes it perfectly fit for drinking.

This is why we at Aarhus Vand can supply drinking water of the best quality merely by filtering and aerating the water on its way to the citizens’ taps. The groundwater is however vulnerable to pollution with especially pesticides, and analysis of some 20 years of monitoring data has shown pesticides in about every third well, with the drinking water threshold being exceeded in about one in every six wells. The present threat of groundwater pollution in Denmark has been a main driver in developing new methods in mapping of the geology and the groundwater resources, pinpointing vulnerable areas and defining policies to protect the groundwater.

Aarhus Vand has been working with the protection of the areas most vulnerable to contamination in more than 15 years in order to ensure sufficient clean drinking water in future. Information campaigns have been implemented in drinking water areas and farmers have been offered compensation for pesticide-free production. This voluntary scheme has only had limited effect and since 2013 it has been supplemented by a possibility of imposing pesticide free production in groundwater protection zones (vulnerable areas). Aarhus Vand also contribute to the plantation of new forests.

Another result of the detailed geological mapping of the geology and groundwater surveys, is that impact on streams and wetlands can be assessed and minimized. This way we can be sure of a sustainable supply.