Microplastics are an emerging challenge in wastewater treatment and reuse. Many studies have indicated that microplastics are widely existing in our environment. Wastewater treatment plants (WWTPs) are a significant reservoir of microplastics in our natural waterways. Some preliminary studies have demonstrated that microplastics may cause harm to the environment and human health. Thus, it is imperative to control the flux of microplastics from WWTPs into the environment, and the occurrence and fate of microplastics in WWTPs should be examined. In this study, we systematically monitor the concentration and composition of microplastics at a WWTP in Saskatchewan, Canada. The WWTP consists of a grit chamber, sedimentation tank, biological treatment, and UV disinfection. The occurrence and removal of microplastics at each of these steps will be examined. A state-of-the-art microscopic Fourier transform infrared spectroscopy (FTIR) imaging system and conventional fluorescence microscopy are used for microplastic detection and characterization. We evaluated how the WWTP helps control microplastic pollution in the region. We found that significant portions of microplastics can be removed from wastewater at the plant, but the microplastics remaining in the wastewater should not be ignored. The outcomes of this study are expected to provide new perspectives on the microplastic nexus in wastewater pollution and treatment.