You can tank the water but there is no space to empty dirty one.
Aire de repos du Schauinsland (avec raccordement à l'eau, eau potable non garantie)
Schauinsland rest area (with water connection, not guaranteed drinking water)
Raststätte Schauinsland (mit Wasseranschluss, nicht garantiert Trinkwasser)
You can tank the water but there is no space to empty dirty one.