Microplastic pollution has emerged as a critical environmental concern affecting water quality worldwide. This study presents a novel approach for detecting microplastics in local water sources using Fourier-transform infrared (FTIR) spectroscopy. We collected water samples from 15 different sources across Silicon Valley and Jakarta and developed a systematic protocol for microplastic identification and quantification. Our results reveal significant variations in microplastic concentrations, with urban water sources showing 3.2 times higher contamination levels than rural sources. The study provides accessible methodologies for high school students to contribute to environmental monitoring while raising awareness about plastic pollution.