When Georgia Department of Transportation construction crews prepared to widen the State Route 2 bridge over the Cartecay River in Gilmer County, they had to preserve the water quality for a threatened fish species called the goldline darter (named for the gold stripe on its belly). But they didn't have enough space on the steep, narrow project site to construct a traditional sediment basin for trapping and filtering bridge-construction runoff. So they used a "portable" sediment basin: three 10-foot wide concrete septic tanks linked together and surrounded by gravel. The pipe carrying the filtered water from the third tank back into the river was covered with filter fabric. The innovative solution worked well and took less than a day to install.
--Apr 25, 2003
|Georgia Department of Transportation photo|
|Sediment basin under construction|