Best Erosion Control Practices for Protecting Soil on Construction Sites

Humans were reshaping land before construction of the pyramids. Today, excavation and construction companies face one of the same problems as the ancients: erosion control.

Erosion is the process by which natural forces wear away a land surface. Water, wind, ice and gravity act relentlessly upon soils, detaching them from their base and carrying them away – often into waterways.

This happens frequently during rain as drops strike the soil, sending it airborne. On a construction site, shallow sheets of water can flow over the land and draw away loosened soil. Low areas are vulnerable to erosion as flows cut small channels to transport the washed-out material.

Negative impact of erosion
 
The problems associated with erosion go far beyond issues of land shape and aesthetics. Runoff can transfer soils into lakes, ponds, rivers, streams and other waterways, fouling them with turbidity and excessive silt. According to the Florida Department of Environmental Protection, about 4 billion tons of eroded materials enter waterways in the United States every year.

Erosion is bad news: It can disrupt storm water systems by plugging culverts and other areas designed to receive runoff. It also harms ecosystems by blocking sunlight in the water, inhibiting the growth of aquatic vegetation. Heavy turbidity can adversely affect fish populations by diminishing food sources, interfering with spawning and even clogging gills.

Basic controls

One of the best means of controlling erosion is vegetative cover. It imposes a barrier between the falling rain and the soil, stabilizes soil particles, slows runoff velocity and promotes absorbency. Mulch can also be effective in slowing the erosion process. These measures are particularly important on long slopes and banks.

But on a job site, such methods of erosion control are not always practical or even possible. That’s why contractors dealing with runoff issues should be eminently familiar with perimeter controls.

Combating erosion at the perimeter

One crucial line of defense is the silt fence. Erosion Control Silt Fencing from GEI Works is a highly effective means of handling displaced materials. They are available in three grades: Economy, Contractor and DOT Fabrics. Made of geotextiles, silt fences come in standard models and in reinforced wire-back models for greater strength. They are simple to implement, an indispensable tool in erosion prevention.

Sediment retention

Other erosion control tools include a line of biodegradable mats, blocks, logs and wattles. Contractors can lay these over erosion-prone areas to keep them stable. GEI Works has a number of products made of coir, the material between the inner and outer shells of a coconut. These stay in place on the site for years until they decompose, enriching the surrounding soil. 

Coir Erosion Mats are effective in stabilizing slopes, hillsides and stream banks. Vegetation can grow up through the mats, further enhancing erosion control at the site. GEI Works also offers Coir Blocks, Logs and other products to shore up areas and prevent them from washing out.

Dewatering

Removal of water from a project site carries the risk of discharging sediments that will find their way into area waterways. Taurus Dewatering Bags from GEI Works receive the discharge hose (2-, 3- and 4-inch) and fill up to capacity, filtering the exiting water safely from the sides of the bag. The debris and sediments stay behind for disposal. GEI Works also offers the Taurus Pipe Dewatering Sock for smaller applications. The larger, more heavy-duty Geotextile Dewatering Tubes are ideal for more substantial dewatering projects at such sites as agricultural ponds, paper mills and aquaculture facilities.

Turbidity Barriers
 
When erosion occurs and sediments do end up clouding a body of water, turbidity curtains are the last line of defense. The Triton line of turbidity barriers and silt curtains from GEI Works restrict suspended particles, promoting settling. Made to perform in varying levels of conditions – wave action, current, wind, etc. – the curtains hang in the water vertically and stop about a foot from the bottom, surrounding the source of turbidity. Suspended particles strike the curtain and change course toward the bottom where they settle beyond the containment area.
  
Erosion is a force of nature we will always manage imperfectly. But with the proper tools and best management practices, contractors can wage an effective battle. GEI Works is your ally in that battle. For more information on erosion control products, please feel free to contact the experts at GEI Works.

No comments: