CKU was owned by the Schmidheiny family in Heerbrugg for decades and was also the most important and largest employer and taxpayer in the municipality of Quarten for decades. In the 1930s in particular, CKU was a highly sought-after employer. At that time, many workers still travelled on foot from Oberterzen, Mols and Murg for normal and shift work. The CKU mainly employed local people. At the beginning of the 1980s, the first guest workers were hired as seasonal labourers.

The raw material for the production of cement was transported to Unterterzen from two locations. The coarse stones from the Lochezen Walenstadt quarry were transported by sea from the Lochezen loading station to Unterterzen on a 300 tonne leather ship. The gravel was removed from Gäsi near Weesen. A floating dredger was stationed in Gäsi, with which many thousands of tonnes of sand were dredged, loaded onto a small leed ship (150 tonnes) and transported to Unterterzen. The ships were unloaded in the CKU harbour using a crane (bucket capacity 1.7 m3). The CKU’s location directly on the lake in Unterterzen was therefore ideal.

After the production of cement and lime was discontinued in 1977, the plant continued to be operated as a cement grinding plant, with the clinker (burnt raw meal) being delivered by rail from Untervaz. Customer orders, metal moulds for concrete elements and general construction work were then carried out in the workshop. In 1991, the grinding plant was also shut down and almost everything from the workshop was sold to the Bartholet company in Flums.

The entire site was then sold by the Schmidheiny family to a property company. From 2001 to 2004, the production halls, the administration building, the cement loading silo at the railway station and the residential buildings on the cement site were demolished. The demolition of the buildings and chimneys required 360 explosive charges and 43 kg of explosives.