Transport, speciation, toxicity, and treatability of highway stormwater discharged to receiving waters in Louisiana.
Advanced Search
Select up to three search categories and corresponding keywords using the fields to the right. Refer to the Help section for more detailed instructions.
Clear All

Transport, speciation, toxicity, and treatability of highway stormwater discharged to receiving waters in Louisiana.

Filetype[PDF-6.74 MB]

Select the Download button to view the document
This document is over 5mb in size and cannot be previewed
  • English

  • Details:

    • Publication/ Report Number:
    • Resource Type:
    • Geographical Coverage:
    • Edition:
      Final report.
    • NTL Classification:
    • Abstract:
      Stormwater from transportation land uses is a complex heterogeneous mixture of particulate matter, nutrients (phosphorus and nitrogen), heavy metals, inorganic, and organic compounds with variations in flow and mass loadings by orders of magnitude during a single hydrologic event. To effectively manage stormwater, the transport, toxicity, and viability of treatment must be examined. Management is particularly challenging in Louisiana where many transportation-related discharges are directly to receiving waters. This study investigated: (1) transport and treatability of particles and phosphorus in urban rainfall-runoff on an event-basis, (2) influence of hydrology on rainfall-runoff metal element speciation, (3) toxicity of particulates in urban rainfall-runoff, (4) event-based treatability with hydrodynamic separation, and (5) gravimetric evaluation of hydrodynamic separation. With respect to transport and treatability of particles and phosphorus in urban rainfall runoff, a screened hydrodynamic separator (HS) was used on a test site draining the bridge deck on the I-10 over City Park Lake in Baton Rouge, Louisiana. Mass separation efficiencies (from 38 percent to 70 percent for particles and 8 percent to 49 percent for total phosphorus) of the screened HS and coarse particle size distributions (d50m of 270 to 2202 μm) exhibited very large variability. Regarding the influence of hydrology on rainfall runoff metal element speciation, it was found that Cd and Zn dominated the dissolved species, while Pb was predominately associated with dissolved organic matter and Cu was predominately associated with carbonate species or DOM. The toxicity of particulates in runoff is a concern because many chemicals are bound to particles and transported through the aquatic environment. Early post-larvae life stages are more sensitive to toxicity from runoff containing particulates. Testing of screened HS units revealed that suspended sediment concentration treatment efficiency were generally less than 50 percent even when units were cleaned after every treatment event to ensure no scour. Treatment is a function of surface loading rate, screen size, and scour. After extensive testing of screened HS units, results indicated that treatment and maintenance requirements were not sustainable and, therefore, four additional green infrastructure treatment designs were examined. These results indicated that either Buoyant Adsorptive Media (BAM) filters in the lake or cementitious permeable pavement (CPP) with a BAM network met treatment requirements, were sustainable, and provided context-sensitive implementation.
    • Format:
    • Main Document Checksum:
    • File Type:

    Supporting Files

    • No Additional Files

    More +

    You May Also Like

    Checkout today's featured content at

    Version 3.17.1