South Carolina

South Carolina Stabilized Construction Entrance

Located on the eastern shore, South Carolina is home to rich water resources including rivers, marshlands, and over 180 miles of coastline. To protect the surface waters, the South Carolina Department of Health and Environmental Control (DHEC) administers the NPDES Program under the Clean Water Act. The DHEC website offers guidance to contractors as they prepare the permit application including resources such as the Best Management Practices (BMP) Handbook, design aids, and technical documents.

To obtain a stormwater permit, contractors must submit a stormwater application, Storm Water Pollution Prevention Plan (SWPPP), and a Notice of Intent (NOI) prior to beginning construction. The SWPPP is reviewed by DHEC and feedback may be provided about the BMPs chosen to mitigate pollution on the project. The SWPPP serves as a guideline for the contractor and subcontractors to ensure compliance with stormwater regulations.

South Carolina NPDES Construction Stormwater General Permit

For many projects between one acre and two acres, contractors can apply for the Construction General Permit (SCR100000) which has predefined guidelines and effluent limits. In addition, contractors can use a simplified SWPPP template which does not need to be completed by a qualified individual. Contractors on projects that disturb an area of two acres or greater are required to submit a Comprehensive Stormwater Pollution Prevention Plan (C-SWPPP) which includes site plans and a SWPPP document. SWPPPs specify which BMPs and strategies will be used to contain sediment and erosion pollution.

Many BMPs are listed in the SC DHEC BMP Field Manual.

South Carolina Coastal Counties Critical Area Permit

Additional pollution preventative measures must be taken for land disturbing activities in the coastal counties including: Charleston, Berkeley, Dorchester, Georgetown, Horry, Jasper, Beaufort, and Colleton Counties. These eight counties require contractors operating within 0.5 miles from a coastal receiving water to obtain Coastal Zone Consistency certification. Contractors opening in these regions are required to obtain a Critical Area Permit to authorize stormwater discharges. The DHEC's Office of Ocean and Coastal Resource Management issues coastal permits for projects in these sensitive areas.

Read more about Critical Area Permitting.

S.C. DHEC BMP Stabilized Construction Entrance

One BMP that is installed prior to site work is a stabilized construction entrance at each point of vehicular ingress and egress, typically adjacent to a roadway or parking lot. A traditional stabilized construction entrance is a temporary stone-stabilized pad located at all points of vehicular ingress and egress on a construction site to reduce the amount of sediment and debris that is transported onto public roads by motor vehicles equipment and runoff. Construction entrances provide an area where mud, dirt, and rocks are removed from vehicle tires before entering a public road.

Rock Construction Entrance

A traditional rock stabilized construction entrance or rock vehicle tracking pad consists a 6 inch thick layer of D50 aggregate (2 to 3 inch) installed over a permeable non-woven geotextile fabric. Rock entrances are installed 24 ft wide x 100 ft long (15 ft wide x 20 ft long for smaller projects). The entrance must have tapered edges to provide a wide radius as vehicles turn onto the roadway. In addition to the rock, a basin must be established to ensure runoff does not leave the job site.

The entrances must be inspected every week to ensure necessary repairs are completed. Additional inspections must be completed during wet seasons, and within 24 hours after each rainfall event (1/2 inch).

As sediment builds up in the aggregate, maintenance must be completed to ensure performance. Maintenance includes immediately sweeping the road when there is rocks, sediment or debris on the roadway, washing or replacing the aggregate, and reshaping the entrance. In addition, any paved roads that are damaged must be repaired immediately. Contractors must be sure that sediment is cleaned off the roadways before it is washed down a storm drain.

Additional common situations that require maintenance are listed in the SC HDEC Field Guide:

n heavy use cases or in wet weather conditions, construction access points can require frequent maintenance. As recommended in the SC DHEC Guide, alternate methods should be considered. One alternate method that is mentioned in the SC DOT Standard Specifications is the use of a wash rack with a sediment trap to catch drainage. Wash racks use pressurized streams of water to rinse sediment from vehicle tires. These solutions are effective, yet costly to install.

Additional Alternatives include:

FODS Reusable Construction Entrance System
Shaker racks
Wheel washer/wash rack solutions

FODS Reusable Construction Exit

The FODS Reusable Construction Entrance System provides an effective, durable, and portable solution to construction entrances. The system can be easily installed over any substrate including dirt, concrete and asphalt.

The Trackout Control Mats are formed into a pattern of pyramids which deform vehicle tires as they drive across. As the tires flex, the trapped sediment and debris becomes dislodge from tire treads and falls to the base of the pyramids. Because tires only reach down 1/4 inch from the tops of the pyramids, they will not come into contact with the sediment that collects at the base of mats.

FODS Trackout Control Mats are highly effective at minimizing sediment and debris from tracking onto the road. Independent testing done in a high traffic volume land development setting showed a 59% reduction in street sweeping after switching from rock to FODS construction entrance.

Because FODS is a rockless system, contractors can reduce the risk of rock becoming lodged in dual tire vehicles or large vehicle treads. The mats are extremely durable and each mat can support over a million pounds. FODS are designed be cleaned using a FODS shovel or skid steer with broom attachment.

Compared to traditional techniques FODS allows contractors can easily install and relocate their entrance, quickly clean the mats to ensure continued performance, and save costs on each project. The standard layout is a 1x5T which provides 35’ of travel and a wide turning radius. This layout is commonly used as a replacement for a 70’ rock stabilized construction entrance.