2 New Orleans students crushed millions of discarded bottles into recycled glass sand to fight coastal erosion; the result transformed Louisiana's sinking marshes by anchoring new grass and helping rebuild one of America's most vulnerable coastlines

Glass bottles are one of the most common forms of household and commercial waste. Although glass can be recycled repeatedly, practical and economic challenges can prevent used bottles from reaching recycling facilities. In some places, the material ends up in landfills simply because there is no nearby market or affordable way to process it.

A project in New Orleans is taking a different approach. Instead of treating unwanted bottles as waste, two college students developed a way to crush them into sand and gravel and put the material to use along Louisiana's vulnerable coastline.