Temporary BMPs

Often, when a construction site is completed a few things are overlooked. However, failure to remover all temporary BMPs results in failure of the stormwater structures. 

Generally, the first thing to go into a construction site is silt fence. This fence is in place to hold sediment on the construction site. More silt fence is often added around storm drains to prevent sediment from getting into the new stormwater system. The silt fence, and all other temporary BMPs (Best Management Practice), must be in place until the disturbed area is stabilized. Stabilization is the establishment of mulch, straw, or established grass. 

Stabilization keeps the soil in place, and once the disturbed area has adequate cover the temporary BMP can be removed. These temporary BMPs must be removed, but are often over looked. The grader misses it, the MS4 regulator misses it and the BMP is simply left. Years later the temporary BMP catches enough sediment that it can clog a drain box. 

That is the case here in Columbia, SC. The silt fence held sand and eventually became covered with sediment. To fix the isue, we had to use an excavator, dig out the silt fence and re-stabilize the soil.  

This issue was caught during a routine annual inspection. Though the issue was caught during dry weather, Major rain events would be a problem for this site as stormwater was not able to flow off the property. Fortunately, the issue was caught and fixed. Today, the stormwater structures are free and the property is not in danger of flooding during the next rain event.