In the autumns of 2019 and 2020 brief surveys were carried out for the presence of aquatic molluscs in the cooling-water basin of a well-known coffee factory in Joure, province of Friesland, the Netherlands. Only 15 different species were encountered, among them four exotic invasive species: Potamopyrgus antipodarum from New Zealand, and three North American species: Physella acuta, Ferrissia californica and Euglesa compressa. Among Physella acuta was one specimen with an aberrant colour pattern. Among the indigenous species was one, i.e. Pisidium pseudosphaerium, which is considered an endangered species in the Netherlands. Noteworthy was the absence of species belonging to the Lymnaeidae.