Caltrans studied the effects of runoff from highway surfaces and cut slopes on the primary productivity of algae. Runoff waters from three highway sites and two cut-slope locations were tested during the winters of 1976 through 1977. Roadway runoff samples were collected near Placerville (Route 50), Walnut Creek (I-680), and Los Angeles (I-405). Cut-slope runoff was collected in the Sierra Nevada foothills. The response of indigenous algae to various levels of runoff was measured by the 5-day bioassay using the C14 carbon uptake method. Chemical characteristics of the pavement runoff are included for samples assayed. This report presents the findings of this study. Depending on types and concentrations of contaminants, road runoff can be either stimulatory to algal growth or, in cases where runoff comes from heavily used highways, mildly to severely inhibitory. This information will be used in assessing the environmental effects of proposed transportation projects. (FHWA)

Media Info

  • Pagination: 241 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00319108
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: FHWA-CA-80-24 Final Rpt.
  • Contract Numbers: A-8-25
  • Created Date: Nov 19 1980 12:00AM