Measuring and Removing Dissolved Metals from Storm Water in Highly Urbanized Areas

Starting in the late 1980s, efforts to address polluted runoff have increased significantly, and the requirements for treating the runoff also have gotten more stringent. Not long ago, most highway runoff could be treated using a few simple treatment methods such as bioswales, wet ponds, or vegetated filter strips. However, lately the treatment requirements have been shifting to include the removal of dissolved metals. In Washington State, besides oil and phosphorous control, there are two significant groups of Best Management Practices (BMP), these are basic treatment BMPs and enhanced treatment BMPs. The basic treatment BMPs target the total suspended solids (TSS), and enhanced treatment BMPs not only target the TSS, but also the removal of dissolved metals. While the specific requirements for removing metals may be different from one state to another, there is a trend nationwide that dissolved metals in stormwater is becoming more of a concern to the regulatory agencies, particularly in highly urbanized areas where traffic volumes are high and treatment options are limited. The current available and approved enhanced treatment BMPs that are effective in removing dissolved metals include the following: media filter drains (previously known as ecology embankment), compost-amended vegetated filter strips (CAVFS), constructed stormwater treatment wetland, sand filtration treatment BMP (amended or large sand filter), two facility Treatment trains, and bioretention. In highly urbanized areas, the ability to utilize these current BMPs is limited significantly by the lack of available space. The objective of this project is to develop one or more enhanced treatment BMPs that could be used in highly urbanized areas. Task would include the following: (1) Gather all available information and the facts about enhanced treatment BMPs through literature review and talking to other researchers, stormwater treatment vendors, and professors in universities and other public agencies such as department of transportation from other states. The gathered information could be the available technologies to remove dissolved metals in stormwater, BMPs that could be used in highly urbanized areas, the pros and cons for each BMPs, maintenance concerns, etc. The approving authority agencies would be involved during the developing process to get early buy-in. Timeframe: 3 months to 6 months. Come up with one or more practical enhanced treatment BMPs potentially that could be used in highly urbanized areas. Various tests will be done in the labs to validate the conceptual designs. Mini models would be built to test the conceptual designs. Seek conceptual approval from appropriate agencies such as Washington State Department of Ecology. Timeframe: 6 months to 12 months. If the conceptual designs work and the lab tests validate the design theories, the full scale models would be tested in situ. Timeframe: 1 year to 3 years. The proposed BMPs could have small footprints that could be easily installed under the sidewalks. Low impact development (LID) would be considered in the development process; in this regard, landscape areas in the median or between the curbs and the sidewalks would be considered to see if the landscape areas can be utilized as part of the treatment mechanism. The BMPs would likely remove the sediments and dissolved metals by using gravity feed, filter systems and uptake by plants. To achieve a small footprint, a highly effective filter will be essential. The more effective the filter, the greater the pollutant decrease, resulting in a smaller footprint requirement compared to other less effective filter systems. The targets for enhanced treatment BMPs are the removal of 80% or more of total suspended solids (TSS) and the ability to provide a significantly higher rate of removal of dissolved metals than basic treatment BMPs for influent concentrations ranging from 0.003 to 0.02 mg/L for dissolved copper and 0.02 to 0.3 mg/L for dissolved zinc. Long term operation and maintenance costs would be considered during the BMP's development. <div></div>


  • English


  • Status: Proposed
  • Contract Numbers:

    Project 25-32

  • Sponsor Organizations:

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  USA  20590

    American Association of State Highway & Transportation Officials

    444 North Capitol Street, NW, Suite 225
    Washington, DC    20001

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  USA  20001
  • Project Managers:

    Hedges, Christopher

  • Start Date: 20090519
  • Source Data: RiP Project 22375

Subject/Index Terms

Filing Info

  • Accession Number: 01464178
  • Record Type: Research project
  • Source Agency: National Cooperative Highway Research Program
  • Contract Numbers: Project 25-32
  • Files: TRB, RiP, USDOT
  • Created Date: Jan 3 2013 2:37PM