Advancing the Use of DWTR in Stormwater Treatment Features to Enhance Phosphorus Removal for Transportation Projects

Details

• Creators:
  Roy, Eric ; Hurley, Stephanie ; Schambura, Micayla
• Corporate Creators:
  University of Vermont
• Corporate Contributors:
  Vermont Agency of Transportation ; United States. Department of Transportation. Federal Highway Administration
• Subject/TRT Terms:
  BMPs Catchment Areas Drainage Drinking Water Drinking Water Treatment Residuals Filters Infrastructure Phosphorus Phosphorus Removal Runoff Sand Sand Filter Stormwater Controls Transportation Transportation Planning Urban Areas Urban Stormwater Treatment

  More +
• Publication/ Report Number:
  2025-01
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States ; Vermont
• Edition:
  Final Report: 2022-2024
• Corporate Publisher:
  Vermont Agency of Transportation
• Abstract:
  Stormwater runoff from urban areas threatens water quality and ecosystems around the world. For freshwater ecosystems, phosphorus (P) is often a primary concern, as excess P loading can cause eutrophication, symptoms of which include harmful algal blooms and oxygen depletion. Dissolved P forms are taken up by primary producers and are therefore a particular concern for water quality. To mitigate these threats, stormwater control measures are often employed to reduce P loading. Sand filters are a type of stormwater management practice that primarily function to trap particulates and thereby reduce downstream sediment and P loads. However, sand filters typically exhibit a negligible capacity to retain dissolved P forms, due to low P sorption capacity of sand. To target both particulate and dissolved P species in stormwater, a P-sorbing material amendment can be added to sand filter media to increase P sorption capacity. This project examined the use of alum-based drinking water treatment residuals (DWTRs), a waste byproduct of drinking water treatment plants, to enhance P removal in sand filter media. The research centered on a field study to determine stormwater P load reductions provided by DWTR-amended sand filters in transportation projects under real-world conditions. Two stormwater sand filters enhanced with DWTRs (3-5% of the sand layer by volume) were monitored from Fall 2022 to Spring 2024 in Chittenden County, VT. One filter receives runoff from a small catchment (1.8 acres) at a residential site (A) and the other from a larger catchment (4.5 acres) in an industrial/commercial area (B). The composition of influent stormwater was markedly different between sites, dominated by dissolved P at the residential site, and mostly particulate P at the more industrial/commercial site. Due to this difference in influent water quality, >99% of the total P removed at the residential sand filter was in the form of dissolved P, while only 4% of the total P load removed at the industrial/commercial site was dissolved P. Because removal of dissolved P by sand filters tends to be negligible, the dissolved P load reductions observed at both sites are likely attributable to the DWTRs. Overall, the two systems reduced total P loads by 65-78% during the monitored events. This field study indicates that including DWTRs in sand filter media is an effective way to couple both physical and chemical P removal mechanisms and thereby enhance water quality improvement performance.
• Format:
  PDF
• Funding:
  VTRC022-003
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:b525d873bfe26939cc7dfe24edd220a2e377455d3b60f876f5ef961b9228670583523d6da26dab4fa0959323811da94fdb0b56d8066de2b27eb769466952fa11
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/88818/dot_88818_DS1.pdf
• File Type:
  [PDF - 1.75 MB ]