In this activity, students visit two sites to practice their field water sample collection and water quality assessment skills. They use a vertical well-water sampler and downhole water quality probes to measure groundwater conductivity, pH, and temperature at different depths in a landfill. Collected water conductivity data is contoured to map the distribution of a contaminant plume. Students then study acid mine drainage by using water quality meters to compare pH and conductivity values up and down stream of an open-pit mine. Learning goals, context for use, teaching tips, materials, assessment tips and related resources are provided.