Certified Inspector Of Sediment And Erosion Control (CISEC) Practice Exam

Silt fences are a preventive, early line of defense against sediment entering downstream waters, so they must be in place before any soil disturbance begins and kept up during active construction. Installing them before work starts ensures that as soon as the soil is exposed by grading or other activities, runoff encounters the barrier and sediment is trapped on site rather than leaving the site. Maintaining the barrier throughout construction continues to provide protection as the site evolves and more soil is exposed. Waiting to install until after grading is completed means sediment could already have moved off site. Relying on installation only after project approval or waiting until the final inspection provides no protection during active work and allows erosion to occur unchecked.