of aliquots drawn from various points throughout the system. Additionally, nanoparticles were observed immediately prior to the point of discharge to municipal wastewater, indicating a high probability that these materials enter the municipal wastewater stream. As characterization of nanoparticles becomes more difficult with increasing matrix complexity , and that nanomaterials may adversely affect biota in publically owned treatmentworks, it is important to study the contents of wastewater before it is discharged to the municipal waste stream.