Stumps of dead cypress trees poke out of the water in Bayou Bienvenue, the remnants of what was once a cypress swamp. Saltwater intrusion killed the trees. Now, the bayou’s bank is littered with trash.
“This was an illegal dump, which you can start to see how much trash is on this site, even into the bayou,” said Franziska Trautmann. “It’s a ghost swamp now.”
Trautmann gathered with more than a dozen others in Chalmette over the weekend to start restoring the degraded marsh. Behind her are dozens of giant, white sacks filled with sand.
But unlike most restoration projects, this one is not just using sand dredged from the river. Some of this sand is made from crushed glass.
Trautmann cofounded Glass Half Full, Louisiana’s only glass-recycling facility, with a fellow Tulane student while drinking a bottle of wine. They had the dream of one day using recycled glass bottles to help rebuild the state’s sinking coast. Four years later, that dream has become a reality.
“We're taking trash, we’re turning it into sediment that can breathe life and hopefully bring some cypress back to this swamp,” she said before wading into the water to start distributing sand on the bayou’s bottom.
Alongside partners from Tulane University, Glass Half Full plans to build two new islands in Bayou Bienvenue using a mix of river sand and recycled glass. The project will use over 120 cubic yards of recycled glass sand, the equivalent of more than a half-million beer bottles. The sand islands will have 30-foot diameters and be held together by a circle of stitched-together coconut husks.
Tulane chemical engineering professor Julie Albert said the biodegradable husks will naturally break down in one to two years — leaving behind stable islands.
“We plan to plant those with bald cypress trees and local marsh grasses, and hopefully at that point, the grasses and the trees will have taken root and stabilized the islands,” Albert said.
Trautmann and Albert hope the cypress trees and marsh grasses will thrive now that the bayou’s salinity has stabilized with the closure of the Mississippi River Gulf Outlet – a canal that funneled salt water inland from the Gulf of Mexico and led to disaster during Hurricane Katrina in 2005.
The work that Glass Half Full is helping lead is the result of a $5 million Tulane study into the use of glass sand in coastal restoration projects. Researcher found that the recycled glass safely blends with the environment when processed properly. Glass itself is made by superheating sand to more than 3,000 degrees Fahrenheit, until it melts into a clear liquid.
Glass Half Full pulverizes glass bottles into tiny granules soft enough to avoid any harm to wildlife. Albert said the glass sand is chemically the same as what’s found in nature.
“I wasn't personally surprised. Essentially what Fran is doing is crushing the glass back into a sand particle,” she added.
Mixing the glass sand with sand from the Mississippi River helps to address the state’s ongoing sand shortage, and Albert said the glass can be especially useful for repairing “blowouts” in a marsh after storms.
Trautmann said they chose the site in part because her company plans to open a new facility across the street in St. Bernard Parish. What started as a free drop-off service in New Orleans has expanded to cover Baton Rouge and the Northshore, offering paid residential and commercial pick-up.
“We've come really far. We've really just significantly increased the amount of glass that we're collecting, that we're recycling,” she said. “We give people guilt-free drinking, a reason to crack open another one, because you're contributing to coastal restoration here in Louisiana.”
The group has another project planned in Terrebonne Parish later this year that is aimed at helping to slow erosion near the Pointe-au-Chien Indian Tribe.
