Trash piled up June 18 near the Iwo Jima Memorial in Arlington. (Photo: Courtesy of an In the Loop Fan)

We’ve written several times about the Park Service’s new policy, begun on Earth Day in April 2013, to start removing trash cans from sites along the George Washington Memorial Parkway — the Iwo Jima Memorial, Great Falls and Roosevelt Island — making visitors take their empty water bottles, food wrappers and such with them when they leave.

The Park Service called it the “Trash Free Parks” initiative, to reduce the amount of garbage the government has to haul away. Think of it as a way to have self-reliant Americans clean up after themselves rather than rely on the federal government.

We were skeptical then, thinking most folks would just throw their trash on the ground if the cans were removed. And we wrote that, two months after the project began, plenty of trash was piled up, though near the porta-johns and a small, forelorn — and overfilled — trashcan.

But G.W. Parkway officials were optimistic. “It’s a mindset shift,” one told us, adding that the program has been successful in other parks, including Catoctin Mountain Park. Another officials said older “well established. . . programs. . . have an 80-95 percent success rate.” So after a while park workers will only have to “deal with litter left behind by a small percentage,” we were told.

But mindsets and ingrained habits — like putting your trash in a receptacle — are not easy to change. So we thought things might improve. And Lee Werst, acting superintendent of the G.W. Parkway, tells us that that is indeed the case. “We have had a reduction in trash coming out of there,” he said.

A Loop Fan who lives near the Iwo Jima Memorial told us that trash and litter have continued to be a constant problem since the cans were taken away — as a picture he sent us indicates.

Werst said that photo might have been taken early in the morning after a parade the previous evening, but he assures us that the trash was picked up later that day.