Half a mile east of the Tumacacori Mission, halfway between Green Valley and the border, the Santa Cruz River should flow straight under the shade of a small Mesquite Bosque. Stop instead.

For at least the next thousand yards, the river will be dammed by a fifteen-acre-wide garbage dam. Plastic bottles, detergent troughs and deflated bowls are all bleached pale straw blondes interwoven with twigs to create an impermeable barrier.

Every time it rains, the dam is strengthened by a new wave of garbage. “It’s a kind of artificial watershed,” says Luke Cole, director of Resilient Communities and Watersheds at the Sonora Institute. “Anywhere in Tucson, all that trash will end up in the Santa Cruz River.”

The Santa Cruz River flows backwards on both sides of the dam, flooding Tumacacori National Historical Park and crossing the Anza Trail, forcing rangers to lay wooden planks to bridge the new course of the river. I didn’t.

Since 2020, volunteers at the institute have removed more than 1,800 bags of trash from the Santa Cruz River basin in Tucson, but Cole says the problem isn’t going away.

So Cole changed his plan from garbage picking to Garbology, which collects, weighs, and analyzes garbage.

Preliminary results from his new study, conducted by the Sonora Institute, may help locals along the Santa Cruz River find the source of the river’s pollution problems. Meanwhile, research has already suggested some possible solutions, and Cole hopes the data will shed some light on Tucson’s assumptions about trash.

“Garbage, Garbage, Garbage”

In 2019, the Pima County Flood Management Authority asked local residents how they could improve the river. Out of over 100 projects, 20 made it to the ballot. The brilliant answer had nothing to do with floods, access or infrastructure. It was garbage.

“Trash suddenly appeared on the front lines,” Cole said. “And I kept whispering ‘trash, trash, trash’ in the King’s ear.”

With funding from the county, Cole designed a study based on a similar study done on the Anacossia River in Washington, DC. While volunteers continued to pick up trash from the bottom of the Santa Cruz river, Cole and his team of interns began investigating the trash itself, starting with the worst.

“We went to a place full of garbage,” Cole said. “So we walked along the river and said, ‘Oh, that’s a big chunk of garbage. Let’s go over there and see what’s inside.'”

The researchers climbed a horse ramp down into the river, placed 10 by 10 quadrants, and began counting. Three years after this study was conceived, he discovered the Camino del He spent days tallying litter from Cerro to Marana, resulting in a huge litter database of his 52 types of litter, divided into nine major categories. It’s done.

Isabella Catalina Feldman is a graduate student in molecular biology at the University of Arizona and a litter researcher. She studies the Amazon River, which she admits is “completely different” from the Santa Cruz River.

“First, you can actually see Santa Cruz,” she said. “But the Amazon River is definitely much bigger.”

During 200 hours of field work, Feldman and his research partners have trudged miles along riverbeds, scrambled riverbanks, and confronted wildlife. However, the research itself is very simple. “We’re just counting,” Cole said.

As published in the institute’s latest “living rivers” report, previous studies have found that food packaging makes up the bulk of the trash that flows into rivers. More importantly, as-yet-unpublished data show that recyclable trash is less than one-fifth he, and most of it floating.

“At the end of the day, the question is what do we do with this,” Cole said. “I have the data, but what happens?”

Dealing with trash sustainably isn’t easy (Cole suggested ByFusion, a new startup opening in Tucson later this year that compresses non-recyclable plastic into building blocks), but the amount of floating trash is huge. Parts may be collected in garbage traps. It is placed in a river where the bag will not be swept away even if a flash flood occurs.

In the next phase of the study, the researchers plan to move away from the river’s apparent “garbage dump.” “If we get a bigger map from this randomized phase of research, we’ll definitely identify some hotspots where we see a lot of trash,” Cole said.

“Then we can start identifying more specific trash to determine its ultimate source.”

Certain items already provide hints. An eerie swath of mud-stained doll parts near Tumacacori points to a closed toy factory in Mexico across the border. According to one researcher, more glass bottles closer to a university could keep drunk students coming back.

Cole hopes that each clue will one day help clean up Santa Cruz’s tainted history for good.

“Clean water, full of trash”

Only 15 years ago, Santa Cruz was home to only extremophiles, organisms that could thrive in extreme environments. In some places the river was completely dry, in others it was completely polluted.

“It was rotten,” Cole said. “Only the most invasive and pollution-insensitive insects and fish can survive in water.”

The situation changed in 2009. That was when the Nogales International Wastewater Treatment Plant, just south of Rio Rico, underwent a multi-billion dollar renovation. His two factories in Tucson, the Tres Rios and Agua Nueva factories, also followed him in 2012.

“We’ve had a brand new ecosystem here in Tucson for 10 years,” Cole said. “We are dealing with flashes in both geological and ecological times. We are very early in the recovery of these systems.”

The unique river ecosystem has been regenerated by improving the quality of the wastewater discharged into the river from the three factories. In 2022, the native small fish, the native longhorn dace, was reintroduced for the first time in a century. Further south, the number of fish species that biologists can find in the water has quadrupled.

“We are finally rebuilding after generations of relief,” Cole said. “But when we throw people into the river and the river fills with garbage, we shoot ourselves in the foot.

“When you finally go down to the river to see this clean water, you will see mattresses and garbage bags. You know what I mean? increase.”

Aside from appearances, trash introduces dangerous amounts of microplastics (small plastic threads that break down from larger items) into the ecosystem. UA researchers say 99 percent of river sediments already contain microplastics.

As microplastics are ingested by fish and make up the food chain, they have been shown to disrupt endocrine function in fish and mammals, impairing or causing abnormalities in growth and reproduction.

The Santa Cruz River should be enjoying the process of redemption, but until the garbage problem is resolved, the river is stuck in a contradiction.

“We’re looking at getting clean water and the return of birds and native fish,” Cole said. “But when I go out to celebrate, I see trash everywhere.”

blame game

The researchers hope their data will also help dispel long-standing prejudices in Tucson in the process of finding permanent trash solutions.

“We believe that most of the litter in river systems comes from homeless people who literally tend to be forced out of other places and live there,” said Feldman, the researcher. Stated. By no means.

Rather, the type of litter they encountered suggests a bigger problem across the community.

“They’re not going to get rid of perfectly fine clothing or weird kid snacks and lollipops,” she says. “Yes, there may be some circumstances, but we don’t throw televisions and shopping carts into the river.”

For example, without such a fulfilling garbage collection, Feldman would not have been able to spend time with his research partner Kyung-hee Kim.

“When I go to the river for long expeditions, I try to count how many costumes I find in the river. There are a lot of one-of-a-kind shoes and weird hats,” she said. “We’ve come up with stories behind some of the weirdest clothing we find, like an old trench coat.

For Cole, the local pointing reveals both an “inherent bias” and Tucson’s desire to avoid responsibility for itself. “As the Tucsonan environmental community, we are walking a very dangerous path by pointing out certain groups of people without the data to back it up.”

“Usually it is the very progressive, very green and environmentally focused people and groups who blame the homeless as the only source of garbage in the river.” Mr Cole said. “It’s amazing how certain and terrifying their expressions about the uncontained are.

“That’s where the data comes in.”

Rethinking Garbology

Cole may have modeled his work on his work in Washington, D.C., but Tucson’s own history of trash was right in front of us, even half a century ago.

In 1973, UA Professor William L. Razzie shifted his focus from Mayan archeology to the Tucson trash cans. What came to be known as the “garbage project” began as a sort of alternative census to collect, weigh and analyze the waste generated across household incomes.

Wilson Hughes led the fieldwork for the project. “There were no ‘how-to’ books,” he told the university in 2012. “So we developed what is now called Garbology.”

Eventually, the program grew to sample landfills across the country and made several breakthroughs in understanding what garbage decomposes and what doesn’t.

Cole didn’t know about the Garbage Project until the lab began studying garbage, but the similarities were clear. “I hope this is kind of a continuation in the spirit of that research.”

Fifty years after Razzie brought archeology to the trash can of Tucson, fieldwork in Santa Cruz still holds historic surprises for researchers like Feldman.

“One of my favorite things I found was the bottom of a teacup from the late 1800s and early 1900s. rice field. “It’s still on my desk at home.”

As research moves into phase two, Cole hopes the Santa Cruz will be able to complete its redemption story. “Clean water, full of trash – what are we doing?” he said. ”

If you can do one, you can do the other. ”