Abstract: A method and system for detecting and monitoring noncompliant interstate transportation of materials is disclosed. The method and system include providing a detection and monitoring network whereby multiple ports-of-entry are each equipped with a detection system that is in communication with a central computer. The detection systems are then used to detect levels of a material in vehicles passing through the ports-of-entry. The method and system further include associating the levels of material detected for each vehicle with the respective vehicle, and saving the vehicle material levels on a computer. The material levels detected at each port-of-entry are then uploaded to the central computer for monitoring and review.