Microplastics, small plastic particles less than 5 millimeters in size, have emerged as a global environmental concern due to their persistence and potential health risks. While numerous studies have documented microplastic pollution in oceans and rivers, limited research has focused on drinking water treatment systems. This study presents a detailed case study of microplastic contamination and removal efficiency at the Potsdam Drinking Water Treatment Plant in New York, USA. Water samples were collected monthly over the course of a year from six key stages of the treatment process, including the source river water, raw water intake, sedimentation tank, post-filtration water, backwash water, and treated tap water. Our findings indicate that while the treatment plant significantly reduces microplastic concentrations, some particles persist in the final tap water. These results underscore the importance of optimizing treatment technologies and monitoring strategies to ensure safe drinking water and reduce microplastic exposure in communities.