BREVARD COUNTY, Fla. — This month, the Women’s History and Cultural Center in Orlando unveiled a new exhibit showcasing the work of Girl Scouts who earned the Gold Award — the organization’s highest award.

On display is the work of Brevard County Girl Scout Sophia Weiner, whose invention helps to protect the Indian River Lagoon.

What You Need To Know

  • Sophia Weiner invented muck-rete, which is concrete created with muck from the Indian River Lagoon

  • Muck is a pollutant that can cause habitat destruction and algal blooms

  • Muck-rete uses muck dredged from the lagoon and keeps it out of landfills

  • Muck-rete is strong enough to be used for sidewalks and pavement

Sophia Weiner came up with the idea of muck-rete in sixth grade, after hearing about muck in the Indian River Lagoon. 

“When I first learned about muck, I heard the statistic that there is actually enough muck in the Indian River Lagoon alone to pave a road from the Keys to Maine,” she said. “That's kind of what sparked the whole thing. 'Let's actually try to pave a road with this concept,’ and that's how it was born.”

In a research project, the recent high school graduate discovered that muck could be used as an aggregate when making concrete.

"The whole idea was if muck has some of the similar sediments that sand and gravel does, why can’t it also be used as an aggregate?” she said.

Muck is a pollutant in the Indian River Lagoon. Mara Skadden, the Director of Science at the Marine Resources Council, said muck is caused by human impact and runoff pollution. It can cause habitat destruction and even algal blooms.

“It's fine-grained, organic, rich sediment that settles at the bottom of the lagoon due to nutrient pollution and runoff,” Skadden said. “It does need to be removed, because it accounts for 47 to 49% of the nitrogen and phosphorus in the lagoon.”

Restoration projects have been working to remove muck from the lagoon, and researchers have been figuring out what to do with it. In freshwater, muck can be repurposed as fertilizer, but Weiner and Skadden said the salt content in the lagoon is too high for that, meaning some of the muck ends up in landfills.

“So many people were trying to dilute the salt content to try to repurpose it for plants, and we weren't really coming up with the solution,” Weiner said. “So I decided, let's try to take an entirely different route and actually use this muck for an entirely different purpose.”

Weiner’s muck-rete solution gives muck a new purpose and can keep it out of the landfill. As a lifelong Brevard County resident, Weiner said she grew up hearing about environmental concerns in the lagoon and wanted to do something to help.

“There's been a variety of things throughout the years, like fish kills, that have really brought concern to our communities,” she said. “I wanted to find out like, what are the root causes of this and how can I personally help make a difference?”

To make muck-rete, she collected muck from dredge sites and set up a workspace in her driveway. She said she had to learn a lot about the concrete process.

“Right now, I'm putting all of the dry ingredients together, and that's the first step of any concrete process,” she said.

The dry ingredients in muck-rete are gravel, cement and sand. After mixing them together, Weiner adds muck into the mixture, and then water to start the hydration process. 

“Adding the water is a really important step, because it's just activating the cement,” she said.

This step starts the curing process. Once fully mixed, Weiner pours the muck-rete into a paver mold. She said it takes about 28 days for it to reach its full strength. 

“Muck-rete is strong enough, after lots of testing, to be used for sidewalks, pavements, that sort of thing,” she said.

Weiner used muck-rete pavers to create the walking path in the mangrove nursery at the Marine Resources Council in Palm Bay. She said muck-rete could also be used for statues, garden structures and even lagoon restoration projects in the future. She said working on muck-rete since sixth grade developed her love of research and engineering.

“This was my introduction to not only learning engineering, but also learning how to do research and really falling in love with research,” she said. “This really sparked a passion of mine that will definitely direct me the rest of my life.”

Weiner is attending North Carolina State University this fall to major in biomedical engineering, a career path inspired by her time spent developing muck-rete. You can learn more about her work on the muck-rete website.

Weiner’s work is currently displayed at the Women’s History and Cultural Center as part of the “Going Gold, An Exploration of Girl Scouts’ Nationally Recognized Award” exhibit until Aug. 31. Her pavers can also be seen at the Marine Resources Council. 

Reagan Ryan is a 2023 — 2025 Report for America Corps Member, covering the environment and climate across Central Florida for Spectrum News 13. Report for America is a nonprofit national service program that places journalists in local newsrooms to report on under-covered issues.