Construction site Sediment control
When people modify the landscape, oftentimes the soil underlying the construction site is bared. This allows the land to become more susceptible to erosion, allowing sediments to flow into our waterways and negatively affect water quality.
In order to mitigate these effects, there are Best Management Practices (BMPs) defined by Wisconsin’s Department of Natural Resources’ Technical Standards (TS). Construction BMPs can be split into two different groups: Erosion Control BMPs and Sediment Control BMPs.
Sediment Control BMPs “Aid in removal of sediments from water after the erosion process has already begun . This is accomplished by using barriers, containments, or other devices to filter or reduce the velocity of the water so soil particles can no longer remain suspended.” - Wisconsin Costruction Site Erosion Control Field Guide. Read on to learn a bit more about Sediment Control BMPs.*
BMP 1: Water Application of Additives for Sediment Control (TS 1051)
Additives for sediment control, such as polyacrylamide and other water soluble additives, are added to water to clarify it before it is allowed to leave the site, leaving behind sediments.
BMP 2: Vegetative Buffer for Construction Sites (TS 1054)
Vegetative buffers, or filter or buffer strips, slow runoff velocity and halt eroded materials from washing away with densely planted vegetation.
BMP 3: Sediment Bale Barrier (TS 1055)
Sediment bale barriers slow or stop sheet flow and erosion by reducing the length of the slope of the exposed site. The hay or straw bales are anchored to the slope in rows, slowing the flow of water and the removal of sediment.
BMP 4: Silt Fence (TS 1056)
A silt fence, like a sediment bale barrier, shortens slope length and reduces the velocity of sheet flow, allowing eroded sediments to settle behind a permeable geotextile fabric.
BMP 5: Trackout Control Practices (TS 1057)
Trackout control practices are measures taken to reduce the amount of sediment “tracked out” by construction vehicles.
BMP 6: Storm Drain Inlet Protection for Construction Sites (TS 1060)
A storm drain inlet protection creates a barrier around a storm drain to prevent sediments from entering the storm sewers.
BMP 7: De-Watering (TS 1061)
De-watering allows water to be trapped in a settling basin or filter so that the sediments that it would carry from the construction site can be retained.
BMP 8: Ditch Check (TS 1062)
Ditch Checks are are temporary dams made from stone, straw barrels, or other approved materials that can be placed in the path of flowing water to reduce flow velocity. This allows turbid waters to drop their sediments as well as reduces active erosion.
BMP 9: Sediment Trap (TS 1063)
Sediment traps allow sediment to settle out of runoff water so that it does not leave the site.
BMP 10: Sediment Basin (TS 1064)
Sediment basins capture and slow runoff from the site in an excavated ditch, allowing sediments to settle before the water leaves the site through an permeable outlet.
BMP 11: Construction Site Diversion (TS 1066)
Construction Site Diversions utilize temporary berms or channels to either collect or divert runoff. This channels clean water away from the site, where it would cause erosion, and redirects turbid waters to an area where they can settle and drop sediments
BMP 12: Turbidity Barrier (TS 1069)
Turbidity barriers are similar to silt curtains, but are less permeable and therefore cannot be placed perpendicular to the direction of flow. They contain sediment within a waterbody or waterway.
BMP 13: Silt Curtain (TS 1070)
A silt curtain captures sediments already in a waterway by creating a permeable barrier perpendicular or parallel to the flow of water behind which sediments can drop from the water column.
BMP 14: Interim Manufactured Perimeter Control and Slope Interruption Products (TS 1071)
Interim manufactured perimeter control and slope interruption products are other types of barriers similar to sediment bale barriers and silt fences. They shorten slope lengths and reduce the velocity of runoff to allow any eroded sediments to settle.
*Montgommery Associates Resource Solutions LLC. and Earth & Road Erosion Control and Geotextiles. (2016) Wisconsin Construction Site Erosion Control Field Guide. Last accessed Sept. 25, 2018 at https://dnr.wi.gov/topic/stormWater/documents/WIconstECfieldGuide.pdf