This paper describes the structure and impact of an NSF-funded ITEST project designed to enrich STEM education using educational modules that teach students to construct, program, and test a series of sensors used to monitor water quality. During the four years of the SENSE IT project, over 60 teachers across New York, New Jersey and Washington State were provided with equipment and professional development, and then implemented the modules in their classrooms with over 2,500 middle and high school students. Project evaluation results indicate that the curriculum was well received by teachers and students, could be integrated into several different subject areas and types of courses, and was effective for a wide range of students.