Date of Award

5-2019

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Division of Agriculture (SAFES)

Committee Member

Charles V Privette, Committee Chair

Committee Member

Calvin B Sawyer

Committee Member

J.P. Johns

Abstract

Erosion and sediment loss vary widely across distinct ecoregions. Regulations on construction runoff require improved sediment and erosion control practices to decrease total suspended solids (TSS) and turbidity. This study measures the efficiency of three different best management practices (BMPs) with and without the application of polyacrylamide (PAM) in three distinct regions of South Carolina. Sediment tubes, rock ditch checks (RDC), and rock ditch checks with washed stone (RDC-WS) were evaluated to determine the effects of adding PAM. These BMPs were placed within constructed channels on active highway construction projects. Half-inch rain events or greater that produced runoff were analyzed to determine the removal efficiency of these BMPs on turbidity and TSS. Analyses were conducted to not only determine the effects of PAM, but also each BMP. Results from this study demonstrate that treating construction runoff with combinations of BMPs and PAM reduces sediment discharge from active linear construction sites.

Based on collected data, it was observed that both RDC and RDC-WS with a PAM treatment were most effective in reducing turbidity with an average turbidity decrease of 58-63%. Wattles with a PAM treatment reduced turbidity values on average by 36%. Without PAM, a small increase in turbidity by an average of 5% occured for RDC-WS while RDCs showed a 57% increase. These increases are partly believed to be caused by resuspension of sediment in the channel. Wattles without PAM decreased turbidity by an average of 26%. It was also observed that RDCs, RDC-WS, and wattle structures with PAM decreased mean TSS values. Based on this research and site observations, proper maintenance and regular inspections must be a priority to reduce turbidity and TSS.I Infrequent or improper BMP maintenance can result in higher TSS and lower trapping efficiencies.

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