2022 WA State Litter Study Highlights
Composition, generation and sources of litter in Washington State
Why did we measure litter?
Litter impacts road safety, our environment, and the wellbeing of our communities. Washington State Departments of Transportation and Ecology (Ecology) together spend more than $9 million annually on litter cleanup efforts, but they can clean up only a small portion of the material that is littered and accumulates on the ground. If we know the types and amounts of litter present, we can help develop strategies to prevent the accumulation of litter and littering behavior. To inform future anti-litter campaigns, Ecology studied the types and amounts of litter found in key areas across the state.
The focus sheet and final report will be available here.
How did we measure litter?
In this study, we collected litter from 182 randomly selected sites across Washington state. Sites were categorized into five main groups: 1) roadways, 2) interchanges (on and off ramps), 3) rest areas, 4) parks, and 5) recreational areas. We sorted the litter by type (such as glass bottles, cigarette butts, and plastic film), counted the number of pieces of litter, and weighed the samples of litter. Using this data from 182 sites in Washington, we estimated the yearly average pounds and pieces of waste.
Where did we measure litter?
We measured litter along roadways, interchanges, and at high-use areas of rest areas, parks, and certain public lands. Many of these sites were used in the 1999 and 2004 litter studies, and we used the Washington Environmental Health Disparities Map to ensure representation across diverse communities.
How much is littered in WA each year?
Statewide, 37.8 million pounds are littered per year, which is 4.8 pounds per person per year. These pounds are made up of 7.1 billion items per year, which is 897 pieces of litter per person per year.
In total, roadways get the most pounds per year (nearly 18.5 million pounds) and high-use areas of state and county parks get the most pieces per year (3.4 billion pieces). But the picture changes when we consider how large each area is. When we look at litter per acre, interchanges get the most pounds and pieces per year, and roadways get the fewest.
How much litter is on roadways?
Interstates get the most litter (1,579 pounds and 73,580 pieces per mile per year). They get almost as much litter as all other roadways combined and are also the most difficult and dangerous roadways to clean. Local roads get the least (143 pounds and 18,051 pieces per mile per year). Urban roads get two to four times more litter than rural roads. Urban roads get 402 pounds and 48,903 pieces while rural roads get 151 pounds and 11,559 pieces of litter per mile per year.
What items are littered the most?
The most littered items vary by site type and by whether we’re measuring pounds or pieces. The top three littered items across site types by pounds are glass beer bottles, construction and demolition debris, and cardboard boxes. The top three littered items across site types by pieces are cigarette butts, construction and demolition debris, and food wrappers and snack bags.
How much of Washington’s litter is taxable?
Washington’s Litter Tax was established in 1971 to help meet the costs of litter cleanup statewide. The tax rate and 13 covered items have not changed in over 50 years, and today’s revenues do not cover today’s costs to clean up the the amounts or types of litter we find today.
Today, 69-76 percent of littered pieces are covered by the litter tax, while only 42- 62 percent of littered pounds are covered. The difference is because many of the items covered by the tax—such as cigarette butts, food wrappers, and snack bags—are lightweight, while many of the heavier littered items are not covered.
