RFID-Based Verification System Improves Landfill Billing

The Nuevo Leon State Landfill Site is located outside Monterrey in northern Mexico and is operated by the state government. The purpose of this landfill is to receive both domestic and industrial garbage from the surrounding cities (municipal governments) and private companies that handle a lot of waste. Two years ago, a study made by the landfill operations department showed that the collection operation was based only on the memory and knowledge of the cashier-operator. A truck would approach the entrance weigh scale station and the cashier-operator would look up the company name and its six-digit access code, then enter the code into the computer-based collection system.

After the truck finished the disposal operation, it approached the exit weigh scale station and the cashier-operator performed the same steps as when it entered the facility. The cashier-operator then collected the disposal fee if the company was not on a preapproved credit account with the landfill, or they made the driver sign a promissory note for the payment.

MANUAL PROCESSES WASTE TIME
The listing of all the company code numbers were in a notebook at the facility, but also in the memory of the cashier-operator. If that person was on vacation or out sick, the weigh scale operation became very slow due to substitute cashier-operators having to search the list of notebook codes for every truck.

The landfill implemented a hands-free automatic ID solution based on Wavetrend active RFID (radio frequency identification) technology, composed of RFID readers, RFID tags from AAID, and a PreVision Software database developed by Contecnica, a Mexican systems integrator. With the solution, RFID tags are placed on the trucks' windshields; the vehicles are identified instantly as they arrive at the weigh scale station by truck number, company name, type of waste, time, and date. The system makes the truck stop until the weigh scale is reasonably stable so that it gets the 'real weight,' then opens the barrier gate.

The truck then dumps its waste or garbage and returns to the weigh scale station exit lane; the new weight is compared to the original weight and the difference in weight is used to derive a charge for the materials deposited at the landfill. All of the activities of this operation are digitally photographed by a camera connected to a digital image recorder that stores the image of the truck at the exit lane. Text is inserted on the photograph with all the information of the entrance/exit procedure including entrance weight, exit weight, date, time, truck tag number, company name, and the amount paid.