Roadways are literally soaked with petrochemical byproducts, oils, gasoline, and other volatile substances that eventually run off into sewers and end up in rivers, waterways, and other undesirable places. Can the roads be cleaned of these wastes, with their proper disposal? Can vehicles, robots, or other devices be designed that could be driven along the roads to gather these harmful materials up for disposal? This article describes a classroom activity where students are asked to design vehicles and devices that could be maneuvered along the nation's roads--and perhaps its large parking lots, too--to clean up petrochemical-based wastes. The activity provides an excellent challenge for students, showing them how environmentally-related systems must also go through an engineering process, a STEM-based analysis. Cleaning the environment has costs and concerns just like any other application of technology.