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29 Sep 07
US beach erosion forces officials to search for alternatives to sand
Yahoo News 26 Aug 07
Crushed Glass to Be Spread on Beaches
By Brian Skoloff, Associated Press Writer
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.
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.
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.
Channel NewsAsia 29 Sep 07
US beach erosion forces officials to search for alternatives to sand
FORT LAUDERDALE, Florida: Parts of the United States are facing a shortage of sand, and officials are working on innovative ways to fix the problem.
In Florida, experts said beach erosion – caused by a rising sea level and severe weather – is threatening the state's heavily populated coastline and valuable tourism industry.
But traditional supplies of sand used since the 1970s are running low, so local agencies are investing millions of dollars to explore alternative methods of repairing beaches and preventing erosion.
The John U Lloyd State Park on Florida's Atlantic coast is typical of many beaches in the state – it is a magnet for tourists and people wanting to buy properties with a sea view.
Beaches protect coastal cities from hurricane damage and are a haven for wildlife, including sea turtles. That is why local officials have spent nearly 24 million dollars to restore this beach, along with another nine kilometres of coastline, in a process called "beach re- nourishment".
Steve Higgins, who is responsible for re-nourishing 40 kilometres of coastline, said development crowds the beach front and flattens beneficial sand dunes.
"So there is not a lot of sand in the system. So when we do have storms and sea-level changes and so forth, and we lose beach, there is no reservoir of material to restore it naturally," he said.
Rock barriers have been built to slow down erosion caused by waves, but a major port just north of the state park blocks sand from naturally replenishing the beach.
Higgins said more than one million cubic meters of sand was dredged from the north of the port, adding between 10 and 80 meters of beach. But he said he now has to go further offshore to find sand, which costs more and could harm turtles and coral reefs.
Higgins is experimenting with alternatives to sand such as crushed glass. He said: "Glass is made from sand actually. So we have already run quite a few tests on the material and so far we cannot find any significant differences."
Tests are continuing to find out how animals react to the man-made material and how it stands up to crashing waves.
Marine geologist Charlie Finkl said there is only enough crushed glass to re-nourish " erosional hotspots". "These are just localised areas where there is a higher rate of erosion than the background, or the average," he said.
Coastal engineers also use a method called ‘by-passing’, which involves channelling or moving sand around obstacles such as ports. And as sand runs low on Higgins’ section of the coast, he is not ruling out the possibility of using sand from other countries such as the neighbouring Bahamas.
A re-nourished beach can be expected to last up to 15 years. More projects are planned for this part of Florida next year. - CNA/so
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