City of Lethbridge using AI to detect, reduce contamination rate in blue, green carts

LETHBRIDGE — A new pilot program is helping to find, track and remove contaminated materials from Lethbridge's green and blue carts using artificial intelligence (AI).

In partnership with Prairie Robotics, three cameras have been mounted on two collection trucks to check green and blue carts for materials that shouldn't be there.

"We're looking for mainly things like bagged materials, household hazardous waste, so lithium-ion batteries are becoming more and more of an issue, tires as well as yard waste materials," said James Nicholls, collections manager with the City of Lethbridge.

The year-long pilot program replaces a city employee walking the streets to manually check carts with AI – cutting the cost of cart audits to nine cents per audit, or one-tenth of the cost of a manual audit.

Nicholls says those employees are on a term and have been reassigned to other tasks, meaning no jobs have been lost.

"Last year, in our annual report, we showed an 87 per cent success rate in terms of the material that was going into the blue cart, so we're really targeting that last 13 per cent of material that shouldn't be in the blue cart," he said.

The system uses three cameras – one to read the serial number and two to see the items being dumped into the hopper and the AI uses the footage to detect contaminates.

"It uses machine learning to detect AI," said Mark Molesky, waste and recycling engineer with the city.

"So the basic process for that is it just takes large amounts of data and recognizes patterns. So the patterns of shapes and sizes of contamination are recognized and we kind of get flagged what we don't want in the software."

The pilot program will run until the spring and will be used to monitor about 25 per cent of carts in the city.

"Yes, we're spending a bit of money on the auditing process, but what we find is that the value of the end product that we get at the material recovery facility goes up and we're able to recoup some of those costs," Nicholls said.

He says the new program is a faster and safer way to complete the job.

"The exciting thing about this system is you get rid of that safety and health concern and it allows you to cover a lot more ground and it audits the entire content of the blue cart, as opposed to that first 10 per cent," he said.

If contaminated materials are found in a bin, area residents will receive a postcard in the mail that shows the items that were not supposed to be in there and the "ins and outs" when it comes to recycling.

"The purpose of the postcard isn't to scold or shame anyone, it's to help increase knowledge and awareness of what things should and shouldn't go in carts," Nicholls said.

"The lower the contamination rate, the better the end product, which benefits the city, the community and the environment."

Regina, Leduc and Medicine Hat currently use the program.

Nicholls says this is just the tip of the iceberg when it comes to AI use.

"Our industry is always looking for ways to do things more efficiently to make sure utility rate payers are getting the best bang for their buck," he said.

"So reducing contamination is the first thing we're looking to do, but again, from a work-management perspective, I could see this being beneficial."

The city says the software only identifies selected items that do not belong in the cart and automatically blurs out license plates, people and the surrounding area.