Implementing Silt Socks on Tile Risers to Reduce Sediment and Nutrient Transport.

Implementing Silt Socks in Tile Risers to Reduce Sediment and Nutrient Transport

Abstract

Given the outgrowing environmental problems associated with eutrophication in surface waters receiving agricultural runoff, there is a need for low-cost and high impact management practice solutions. Tile risers located in closed depressions within agricultural fields act as direct pathways for sediment and nutrient transport to surface waters. This study was undertaken to determine the impact of remediation agents in silts socks to remove sediment, phosphorus and nitrogen from surface runoff. Five series of experiments were tested accordingly: tile riser without silt sock (TWS), tile riser with silt sock only (TSO), tile riser with silt sock and biochar (TSB), tile riser with silt sock and steel slag (TSS), and tile riser with silt sock and FGD gypsum (TSG). Runoff water was collected from a 9.75-m by 3.66-m laboratory soil box placed under a rainfall simulator. Treatments were exposed to four runoff events lasting one hour each at a 50 mm h^-1intensity. Differences between treatments were conducted using Kruscal-Wallis tests. While previous findings have demonstrated silt socks to be effective at removing sediments in runoff, preliminary results conducting isotherm adsorption tests suggest that remediation agents in silt socks can further improve water quality by removing soluble nutrients. Results from this project will be presented.