Water pollutants from green roofs and façades

Biocidal agents used in modern construction products have two typical applications: As in-can preservation they prevent paint or lacquers from fouling in the bucket. As film preservation they protect treated surfaces against microbial growth. Usually those products are used for façades or green roofs.

To be effective the agents have to combine completely with the product. This, however, can only be made possible by a certain water solubility. As a result the biocides, as well as other chemicals like foaming agents or shrink reducers, might be washed out by rainwater and enter soil and groundwater.

Currently, there are no existing regulations limiting the leaching of biocides from products. All the more it is important to get an overview over the release of those substances and to analyze and identify the biocides.

Source: Watersolutions, DIV Deutscher Industrieverlag, Issue 1/2017, p. 35