Abstract: A waste water collection arrangement for combining the waste water discharge of several different plumbing fixtures includes a water receiving trap having a chamber in which water is received to provide a gas-tight seal. At least two inlet assemblies deliver waste water to the chamber and at least one outlet assembly discharges water from the chamber. The chamber has a lid part through which the inlet assemblies pass at least substantially perpendicular to the lid part. The inlet assemblies are mounted on the lid part so as to be movable as required to desired positions for connection to waste water conduits. The chamber is essentially isolated from the ambient air.