School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Check dam and polyacrylamide performance under simulated stormwater runoff

Document Type

Article

Publication Date

11-15-2013

Abstract

Highlights

  • We present a simple method for turbidity control in construction site runoff.

  • Granular polyacrylamide applied to fiber check dams reduced turbidity the most.

  • Rock check dams wrapped with erosion control blankets are also effective.

  • Polyacrylamide was necessary for successful turbidity control.

Abstract

High levels of turbidity and fine suspended sediments are often found in stormwater discharges from construction sites even when best management practices (BMPs) for sediment control are in place. This study evaluated turbidity reduction by three check dam types: 1) rock check dam representing a standard BMP, 2) excelsior wattle representing a fiber check dam (FCD), and 3) rock check dam wrapped with excelsior erosion control blanket (rock + excelsior ECB) representing an alternative FCD. Three check dams (all same type) were installed in a lined, 24-m ditch on a 5–7% slope and three consecutive simulated stormwater flows were run in the ditch. Additional tests were performed by adding granular polyacrylamide (PAM) on the check dams in the same manner using two sediment sources differing in clay content. Without PAM treatment, significantly higher effluent turbidity (>900 nephelometric turbidity units (NTU)) exited the ditch with rock check dams than with excelsior wattles or rock + excelsior ECBs (<440 >NTU). The extent of sediment deposition between the check dam types was in the order of excelsior wattle > rock + excelsior ECB > rock check dam, indicating better water pooling behind the wattle. The PAM treatment reduced turbidity substantially (>75% relative to no PAM treatment) for all check dam types and it was very effective in excelsior wattles (<57 >NTU) and rock + excelsior ECBs (<90 >NTU) even during the third storm event. This study demonstrates that the passive treatment of runoff with PAM on FCDs (or rock + excelsior ECB) in construction site ditches can be very effective for sediment retention and turbidity reduction.

Comments

Copyright © 2013 Elsevier Ltd. All rights reserved.

Publication Title

Journal of Environmental Management

DOI

10.1016/j.jenvman.2013.08.023

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