Erosion and Sediment Control
Best Management Practices for Construction Activities
Erosion and Sediment Controls
Any site where soils are exposed to water, wind or ice can have soil erosion and sedimentation problems. Listed are seven ways to limit and control potential problems:
- Leave as much vegetation onsite as possible
- Minimize the time that soil is exposed
- Prevent runoff from flowing across disturbed areas
- Stabilize the disturbed soils as soon as possible
- Slow down the runoff flowing across the site
- Provide drainage ways for the increased runoff
- Remove sediment from storm water runoff before it leaves the site
Selecting the best set of sediment and erosion preventive measures for your industry depends upon the nature of the activities and other site-specific conditions (soil type, climate and season). The local AgriLife Extension Service, a part of the Texas A&M University system, can provide information on special measures necessary to promote the establishment of vegetation.
Vegetative ControlsVegetative cover reduces erosion potential in four ways:
- By shielding the soil surface from direct erosive impact or raindrops
- By improving the soil's water storage porosity and capacity so more water can infiltrate into the ground
- By slowing the runoff and allowing the sediment to drop out or deposit
- By physically holding the soil in place with the plant roots
Common Vegetative Practices:
- Preservation of Natural Vegetation
- Buffer Zones
- Stream Bank Stabilization
- Mulching, Matting, and Netting
- Temporary Seeding
- Permanent Seeding and Planting
- Chemical Stabilization
Structural practices used in sediment and erosion control divert stormwater flows away from exposed areas, convey runoff, prevent sediments from moving offsite, and can also reduce the erosive forces of runoff water. The controls can either be used as permanent or temporary measures. Measures can include the following:
- Interceptor Dikes and Swales
- Pipe Slope Drains
- Subsurface Drains
- Filter Fence/ Silt Fence
- Straw Bale Barrier
- Brush Barrier
- Gravel or Stone Filter Berm
- Storm Drain Inlet Protection
- Sediment Trap
- Temporary Sediment Basin
- Outlet Protection
- Check Dams
- Surface Roughening
- Gradient Terraces
All sediment and erosion control practices must be inspected every 14 days and within 24 hours after a 0.5 inch or more rain. If any visible sediment is leaving the site, corrective action must be taken. The Stormwater Pollution Prevention Plan (SWP3), consists of phases and activities to characterize your site and then, select and carry out actions which prevent the pollution of stormwater discharges. The SWP3 and weekly reports must be kept and made available for authorized inspectors.
A Notice of Intent (NOI) is a formal notice to the Texas Environmental Commission on Environmental Quality (TCEQ) submitted by the owner/ operator of a construction site 1 acre or greater. The NOI provides information about the permit, location of discharge, type of discharge and certifies that the permit owner will comply with conditions of the general permit. A copy of the NOI and Permit number should be kept at the construction site with the SWP3.
Storm Water ManagementUsing the BMP measures to control soil erosion and sedimentation is an important part of stormwater management. Other methods of management may include:
- Detention structures or retention structures;
- Velocity dissipation devices;
- Sequential systems (which combine several practices); and
- Control flow by use of open vegetative swales and natural depressions.
Good Housekeeping for Material Storage
- Provide curbs and dikes to contain contaminants, should any spill.
- Contain and clean up any spills immediately.
- Handle potential contaminants as infrequently as possible.
- Follow recommended application rates and methods.
- Designate a specific area for delivery and storage.
- Store material in a dry, covered area.
- Stockpile topsoil in a central location and re-vegetate or cover until it is needed.