Kaltura Share to Google Classroom What is run-off pollution? The West Columbia Riverwalk helps prevent run-off pollution by planting trees and shrubs. Grades: 3 4 5 6 7 8 Subjects: ScienceLife ScienceEnvironments & HabitatsEarth ScienceEarth's Natural Resources Collection: Environmental AwarenessETV StreamlineSC Series: Earth Today Kid Minutes