Paper No. JAWRA-09-0182-P of the Journal of the American Water Resources Association (JAWRA). Discussions are open until six months from print publication.
Seasonal Flushing of Pollutant Concentrations and Loads in Urban Stormwater†
Article first published online: 3 DEC 2010
© 2010 American Water Resources Association
JAWRA Journal of the American Water Resources Association
Volume 47, Issue 1, pages 136–142, February 2011
How to Cite
Schiff, K. C. and Tiefenthaler, L. L. (2011), Seasonal Flushing of Pollutant Concentrations and Loads in Urban Stormwater. JAWRA Journal of the American Water Resources Association, 47: 136–142. doi: 10.1111/j.1752-1688.2010.00497.x
- Issue published online: 27 JAN 2011
- Article first published online: 3 DEC 2010
- Received November 23, 2009; accepted September 28, 2010.
- storm water management;
- nonpoint source pollution;
- transport and fate;
- urban areas
Schiff, Kenneth C. and Liesl L. Tiefenthaler, 2011. Seasonal Flushing of Pollutant Concentrations and Loads in Urban Stormwater. Journal of the American Water Resources Association (JAWRA) 47(1):136-142. DOI: 10.1111/j.1752-1688.2010.00497.x
Abstract: Despite broad observations of first flush within storms, the scientific understanding of seasonal flushing remains incomplete. Seasonal flushing occurs when initial storms of the season have greater concentrations or loads than storms later in the season. The goal of this study was to census stormwater concentrations and loads from an arid, urban watershed to quantify seasonal flushing. Samples were collected every 15 min during the 1997-1998 wet season from the Santa Ana River and analyzed for total suspended solids. Initial storms of the season generated event mean concentrations 3-10 times the event mean concentration of storms later in the season. Cumulative flow-weighted mean concentrations were calculated as the season progressed. Early season storms discharged only 6% of the annual volume, but influenced flow-weighted mean concentrations well past the midpoint of the wet season. Mass-based estimates also indicated a disproportionate load in the early portion of the year; over 52% of the annual load was discharged in the first 30% of the annual volume from the highly urbanized lower watershed. Other stormwater pollutants, including six trace metals (Cd, Cr, Cu, Pb, Ni, Zn), were highly correlated with total suspended solids and also exhibited a significant seasonal flush.