A USM study was cited by Portland leaders as the city began rolling out thousands of lidded recycling bins to homes.
In 2015, Travis Wagner, a professor of Environmental Science and Policy, took a crew of students from USM's Muskie School of Public Service into Portland streets and documented the loose trash.
They found 20,950 pieces of litter for every 1,000 households, or the equivalent of 3.74 tons of litter annually for every 1,000 households, according to the report. Much of the culprit was trash blown from unlidded recycling bins.
In a Portland Press Herald story about the rollout of the new lidded bins, Portland Sustainability Coordinator Troy Moon noted the USM study and the finding that recycling bins contributed to more than a ton of litter a week to Portland streets.
Read the full story here.