PORTLAND — City officials are investigating two employees who were caught on video throwing trash and recyclables into the same truck during curbside pickups in a downtown neighborhood Wednesday morning.

In the cellphone video, shot by West End resident Mel May, two men are clearly shown throwing large purple bags filled with household trash into the back of a garbage truck along with recyclables that residents had sorted and placed at the curb in blue plastic containers and paper bags. The two men appear to mix the materials from several separate buildings on the street, all of it going into the back of the same truck.

May sent copies of the video to the city and also alerted the Portland Press Herald.

It wasn’t the first time she had complained about the practice. May said she first witnessed city employees mixing trash and recycling three years ago and complained to the city. Officials told her the problem would be addressed, but May said she has seen public works employees putting trash and recycling in the same truck on other occasions.

“We’re big recyclers in this house. We are on it,” May said. “When I see they are doing something they are not supposed to, it got me ticked off. It was a real bummer to see it again and again.”

Normally, the city’s public works department collects recycling and trash in separate trucks and employees are not allowed to mix trash and recyclables, except in special cases.

Despite May’s complaints, city officials said they believe the mixing incident is an isolated case.

“It is a violation of policy,” said Bob Leeman, interim director of public works. “It is not the norm. We do take this very seriously. . . . It is not acceptable. We follow our disciplinary process when that happens, and we will in this case.”

It’s not clear what disciplinary action might be in store for the workers, whom the city would not identify. One of the men is a unionized city employee and the other is a temporary worker, Leeman said.

Although it seems to be clear what was happening in the video, city officials said they will conduct a full investigation to learn why the two men decided to mix trash and recycling.

“Obviously, we have the video, but we need to find out what was going on here,” said Operations Manager Steve Earley.

CITY ASSURANCES: ‘IT’S NOT COMMON’

Portland has curbside pickup for trash and mixed recycling. Three trucks collect trash, left in special purple bags that residents have to purchase, and three collect recyclables placed out in blue plastic bins. The trucks, staffed with two employees each, typically start their routes together, but there is no order for when trash and recycling are collected, Leeman said.

The only times that crews are allowed to commingle trash and recycling is during inclement winter weather, when managers decide it is unsafe to have too many drivers on the streets. “We will have them do that just as a safety factor, but that is a decision made by management,” Earley said.

Although May said she previously had complained to the city, Earley had not heard of the issue happening before.

“This is the only occasion I know of when an employee took it on himself to commingle,” he said.

City spokeswoman Jessica Grondin said May lodged her first complaint before Earley was hired as operations manager. Grondin has worked at City Hall for two years and can remember one other complaint, but it happened on a winter day when crews were authorized to collect trash and recycling together, she said. She said there is no central log she can check to see how many complaints the city may have received.

“It’s certainly possible that this could have happened before, given there are times when ‘temp’ workers are used. However, we can assure you that it’s not common,” Grondin said.

‘WE … WANT PEOPLE TO BE RECYCLING’

Portland sends its solid waste to the ecomaine recycling facility and waste-to-energy incinerator in Portland. Portland had a 38 percent recycling rate between July 2015 and the end of April, ranking fifth out of the 27 towns and cities that send waste to ecomaine, the nonprofit said.

The city’s high recycling rate makes it unlikely that crews would be breaking the rules regularly, said ecomaine spokeswoman Lisa Wolff.

“They would not have reached that high percentage rate if this was common,” she said.

Wolff was surprised to hear about the Portland incident. “This is not something we encounter with any kind of frequency,” she said.

Grondin doesn’t believe this incident will deter people from recycling.

“I think Portland has a really good reputation for being a sustainable community. We certainly want people to be recycling,” she said.

The apparent violations also are not representative of the public works department, Leeman said.

“The actions of this one crew doesn’t reflect the whole solid-waste section. They are a hard-working crew and they follow the rules,” he said. “They take their job and recycling seriously.”

But May said the repeated mixing she’s witnessed have left her uncertain about the city’s recycling program.

“I’ve sent them videos before, pictures before,” she said. “Hopefully, they will actually do something about it this time.”