Table 2.3 Concentrations of Triclosan in wastewater samples collected from WWTPs in Switzerland (Lindström et al. 2002) Influent to the biological stage Final effluent WWTP Persons (PE) Sampling time Triclosan (µg/L) Methyl Triclosan (µg/L) Triclosan (µg/L) Methyl Triclosan (µg/L) Maur 4,500 Mar 2001 0.98 <0.001 0.650 <0.002 Pfäffikon 9,200 Feb 2001 1.044 0.004 0.250 0.004 Uster 36,000 Feb 2001 1.300 0.0025 0.110 0.011 Wetzikon 19,000 Mar 2001 0.584 <0.001 0.183 <0.002 Gossau 11,000 Jan 2001 0.970 <0.001 0.136 0.035 Gossau 10,500 Oct 1997 1.000 a 0.100 a Gossau 10,500 Dec 1997 0.500 a 0.070 a a: All samples were methylated, precluding differentiation between Triclosan and Methyl Triclosan.