Evolving U.S. EPA regulations such as the National Pollutant Discharge Elimination System (NPDES) permit program and Effluent Limitation Guidelines (ELGs) have prompted States to re-examine their Erosion Control Manuals. Currently most states are revising their manuals to move toward more performance-based practices for stormwater management.

In many cases, the shift toward more sustainable BMPs is being led at the State, regional, or municipal level. Recently the Georgia Environmental Protection Division (EPD) notified the Georgia Department of Transportation (GDOT) that silt fence check dams installed in ditches and arranged in either upstream V shapes or W shapes (as shown on GDOT Construction Detail D-24D), should no longer be used.

EPD’s decision comes after testing by the Georgia Soil & Water Conservation Commission (GSWCC) that yielded failed results on the effectiveness of silt fence fabric check dams. The issues noted were:

1 – Ineffective at retaining silt on the upstream side, and
2 – Excessive scour to the ditch on the downstream side due to water running around the ends and top of the fabric check dams.

“This is the beginning of the end for silt fence. As more states move toward performance-based standards, silt fence just won’t cut it—it simply cannot match the filtration capacity of compost filter sock,” said Andy Hull, Filtrexx® Southeast Region Representative.

Three acceptable options remain for check dams in Georgia:

• Stone Check Dam (Cd-S) (Pay-Item 163-0527) (refer to GDOT Standard 1031)
• Baled Straw Check Dam (Cd-Hb) (Pay-Item 163-0529) (no current GDOT detail available – refer to the GSWCC Manual for Erosion and Sediment Control in Georgia 6th Edition)
• Compost Filter Sock Check Dam (Cd-Fs) (no current GDOT pay-item or specifications for installation and maintenance available – refer to the GSWCC Manual for Erosion and Sediment Control in Georgia 6th Edition).

Of the three options Filtrexx® offers the most cost-effective solution. Stone check dams are difficult to remove stone by stone. Baled straw check dams are difficult to install because they require deep trenching to prevent scouring on the leeward side of the dam. Neither method compares to the sediment stopping capacity of Compost Filter Sock Check Dams. Compost Filter Sock Check Dams are easy to install and remove, and can be used on top of any substrate, including concrete.

“We’re seeing an increase in the use of Filtrexx SiltSoxx™ to replace traditional BMPs like silt fence,” said Dr. Britt Faucette, Director of Research for Filtrexx International. “Our technology provides a high performance, easy to use option that proves to be more cost effective over the life of a project.”

Filtrexx® will host a free webinar on the topic of Sediment Control on October 15 at 11:00 a.m. EDT. This one-hour webinar reviews the latest performance research, technical specifications, and design criteria for Filtrexx sediment control applications, including perimeter control, inlet protection, check dams, sediment traps, slope interruption, and bio-filtration applications. To register, visit www.filtrexx.com