We were knee-deep in a small, murky stream in Richmond, VA, and our trash bags were prematurely heavy. Barely 10 meters from our starting point at a road culvert, our bags contained countless food wrappers, Styrofoam cups, cans and cigarette butts. Somewhere, someone was missing a ceiling fan blade; shrouded in a pair of boxer shorts filled with sediment.

Of all the materials the team collected that day, the most abundant were plastic shopping bags. Trees lining the stream banks were decorated like avant-garde fashion show models, and because much of our time and energy was spent wrestling shredded plastic “THANK YOUs” from the branches, we did not finish our assigned route.

Each year, volunteers who participate in hundreds of Project Clean Stream sites across the watershed repeat this story time after time.

The 2013 James River Regional Cleanup, sponsored by the James River Advisory Committee and the Alliance for the Chesapeake Bay, included more than 900 volunteers at 15 cleanup sites who removed 486 bags of trash and 225 bags of recyclable materials, including plastic and glass bottles, aluminum cans, paper and cardboard. They also removed tires and other large items, such as grills and deck furniture from the river. Plastic bags, though, continue to be a major problem on the river, as this year’s results showed.

While volunteer efforts like these are important to urban stream health, they also show that we are locked in a cycle of ‘end-of-the-line’ waste mitigation. Isn’t the ultimate goal of cleanups to have clean streams, so repeated cleanups are no longer needed? Achieving healthy local streams and a healthy Bay means stopping pollution at its sources, including perhaps the retailers that churn out plastic bags like they’re as harmless as autumn leaves.

Americans consume around 100 billion plastic bags annually. And even if bag charges are not visible on one’s receipt, they are paid for indirectly; a hidden cost translating to more than $4 billion per year for retailers. Taxpayers also end up paying the bill to clean up streams, parks and highways, to the tune of millions of dollars annually.

The true impact of these plastic bags last generations, even though their practical life is limited to one or two uses. In addition to the obvious effect of spoiling a natural view, or choking and trapping wildlife, the breakdown of plastic releases toxins, which build up in the food chain in a process known as bioaccumulation. Large-scale plastic pollution is a nasty situation.

In 2009, the Ocean Conservancy Coastal Cleanup found plastic bags to be the second most common trash pollutant, making up 10 percent of total trash.

Locally, the Anacostia River near the District of Columbia — one of only two rivers in the watershed classified as water quality “impaired” because of trash — surged with 17,000 pounds of plastic items, more than half of which were plastic bags.

Both Montgomery County, MD, and DC enacted a 5-cent-per-bag tax om January 2010. The Alice Ferguson Foundation, which runs stream cleanups in and around DC, reported a 50 percent decline in plastic bags the first year after the Montgomery County bag fee went into effect. According to the city, the number of single-use plastic bags used in DC had dropped from a monthly average of 22.5 million to 3 million per month by the end of 2010. Although the impact was not as immediate in the streams, the Anacostia River has also begun to show increasing reductions in plastic trash with the bag tax now in its third year.

Other cities in Maryland and the states of West Virginia, Delaware and Virginia are considering such fees. Some have tried multiple times.

In Virginia, a 2011 bill would have required customers to pay 20 cents per bag used to carry products home. The latest version, introduced on Earth Day 2013, would impose a 5-cent-per-bag tax. Businesses would keep one cent of the rate — 2 cents if they implemented a reusable bag credit program.

These fees are meant to be an incentive to change behavior: reduce bag consumption and thus pollution. In the interim, revenue from the tax would go to the Virginia Water Quality Improvement Fund, which sponsors pollution control projects and consumer education. If the fee works to change behavior, it would not generate revenue for very long.

There is plenty of opposition to any new fee, and one on plastic bags is no exception. Some argue that plastic bags make up only a small fraction of the total municipal solid waste stream, so any tax on them wouldn’t accomplish much for water quality. But percentages can be deceiving. The EPA measures the solid waste stream in millions of tons, but weight hardly reflects environmental damage. Simply because bags are featherlight does not mean they’re not abundant or harmful. Their ecological impacts far outweigh their weight.

Reusable bags are sold at most stores for less than $2 each, and many are given away free as promotions, thus reducing the perceived impact on low-income residents. Avoiding the fee mostly requires a little forward thinking, such as storing reusable bags permanently in the car or remembering to grab them before a shopping trip.

All things considered, small changes in our behavior as a society can break the cycle of cleanup needed for many urban streams. As the Bay’s population continues to grow, we are learning that when a change in our daily behavior is mirrored by millions of others, the impact can be amazing. We’ve already witnessed the impact of plastic trash, and we’ve witnessed the profound benefits that can come from five pennies’ worth of incentive.

It is worth supporting the states and localities that are considering a plastic bag fee as a part of their collective work to preserve healthy streams and nurse troubled ones back to life. The sooner we reduce plastic pollution, the sooner cleanup efforts can show more lasting results.

Maybe next year, the 900 volunteers on the James River can actually finish scouring their assigned riverbanks.