Picture a beautiful beach spanning miles of coastline, gently lapped by aqua-colored water — and sprinkled with glass.
Ouch? Think again. It feels just like sand, but with granules that sparkle in the sunlight.
Faced with the constant erosion of Florida's beaches, Broward County officials are exploring using recycled glass — crushed into tiny grains and mixed with regular sand — to help fill gaps.
It's only natural, backers of the idea say, since sand is the main ingredient in glass.
"Basically, what we're doing is taking the material and returning it back to its natural state," said Phil Bresee, Broward's recycling manager.
The county would become the first in the nation to combine disposal of recycled glass with bolstering beach sand reserves, Bresee said.
"You reduce waste stream that goes to our landfills and you generate materials that could be available for our beaches," said Paden Woodruff of the state Department of Environmental Protection.
Sand is a valuable commodity in South Florida, where beach-related business generates more than $1 billion a year for Broward alone.
Sand to replenish eroded beaches is typically dredged from the ocean floor and piped to shore — about 13 million tons of it since 1970 in Broward. That's enough sand to fill the Empire State Building more than 12 times over.
Dredging damages reefs
But with reef preservation restricting future dredge sites, sand is becoming scarce. And the price is rising as construction and fuel costs rise and dredge operations are pushed farther offshore.
In 2005, dredging brought in about 2.6 million tons of sand at a cost of $45 million. A similar operation in 1991 brought in about 1.3 million tons of sand for just $9 million.
The county would create only 15,600 tons of the glass material each year, not enough to solve its sand shortage, but enough to create a reserve for filling eroded spots before they can worsen, Bresee said.
Most of Broward County's 24 miles of beaches are considered critically eroded, and more than a quarter of Florida's 1,350-mile coastline falls into the same category. About $80 million is spent annually restoring Florida's beaches.
The glass-sand idea grew from the unintentional consequences of an ocean dump site off Northern California near Fort Bragg. Beginning in 1949, garbage — including lots of glass — was dumped over a cliff into the ocean, said Charles Finkl, a marine geologist with Boca Raton-based Coastal Planning and Engineering.
'Glass Beach' precedent
Finkl said that while organic material degraded over the years, the glass broke up and became smooth as it tumbled in the surf. The area is now known locally as Glass Beach. Another dump site in Hawaii produced similar results, Finkl said.
"You talk about glass beach and people have images of sharp glass shards but it's not that way at all," he said.
Recycled glass also has been used for beaches along Lake Hood in New Zealand and on the Dutch Caribbean island of Curacao.
It's unclear how much the project would cost Broward County, or if the project is even feasible. The state and county have so far spent about $600,000 just on tests and engineering.
The county tested a small patch of glass sand on a dry patch of beach last year, using sensors to measure effects of heat and moisture. Scientists have also conducted laboratory tests that show organisms and wildlife can thrive in the material just like natural sand, they said. The county is awaiting a permit to test glass sand in the surf zone.
Some people are raising caution flags.
"There's no way that you can predict all the environmental consequences of an action like this," said Dennis Heinemann, a senior scientist with the Ocean Conservancy. "There always will be unforeseen consequences."
One example sits just off shore.
The state and Broward County are spending millions to remove some 700,000 old tires that were placed on the ocean floor off Fort Lauderdale in the 1970s and fastened together to create an artificial reef. The tires came loose, moving around and scouring the ocean floor and wedging against natural reefs, killing coral.