Sometimes the cause is obvious. Sometimes the investigation requires the digging out of a collapsed building. The unit is outfitted with all the equipment needed to tackle these tasks as well as some sophisticated sampling devices. The unit will conduct surveillance of the suspects and the concerned properties in an attempt to catch them in the act. These types of investigations can be lengthy.
Violators take steps to go undetected.
After all, if they don't want to pay the cost of proper disposal, they certainly don't want to pay for fines. They also risk the confiscation of their property, vehicles and equipment if discovered.