Skip to main content

Urban Nutrient Source Characterization For the Newport Bay Nutrient TMDL

Buy Article:

$17.50 plus tax (Refund Policy)

Or sign up for a free trial


A nutrient characterization of dry weather urban runoff was performed in four representative areas of the Newport Bay watershed in Orange County, California in the summer/fall of 2004. The study was performed to determine the contribution of dry weather urban runoff to nutrient loading to the Bay, and to identify the extent to which specific urban activities contribute to urban nutrient loading. Characterization involved continuous flow measurement, intermittent composite water quality sampling of collective discharge from the study areas, and collection of 160 "curbside" samples, where runoff from individual urban activities entered the public rightof-way. Flow and composite sample data was used to calculate areal nutrient mass loading rates for dry weather flows for each of the study areas. Findings in two study areas were found to be significantly influenced by groundwater infiltration and groundwater remediation discharge. Available data from these additional sources was used to quantify their contribution and to adjust observed flow and composite sample data to represent the urban runoff component. Mean areal urban runoff flow rates for the four study areas ranged between 8 – 85 gpd/acre. Mean annual areal loading rates for the study areas ranged between 0.029 - 0.415 lb/acre-yr for total inorganic nitrogen (TIN); 0.242 – 1.769 lb/acre-yr total nitrogen (TN), and 0.019 – 0.232 lb/acre-yr for total phosphorus (TP). No meaningful nutrient loading differences could be discerned between residential and business urban areas. Watershed-specific loadings observed were substantially lower than the literature loading rates used in the development of the Newport Bay Nutrient TMDL baseline allocation for urban areas. Irrigation overspray/overwatering was the most frequent runoff-generating urban activity observed, constituting over 70% of curbside events and 49% of runoff volume observed. Car washing and residential washdowns were second tier activities in both number and volume. Review of runoff nutrient concentrations by activity did not identify a single category requiring priority management attention; field observations suggested there were a small number of highnutrient incidents within each runoff-generating category.


Document Type: Research Article


Publication date: October 1, 2007

More about this publication?
  • Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed.

    WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access.
  • Subscribe to this Title
  • Membership Information
  • About WEF Proceedings
  • WEFTEC Conference Information
  • ingentaconnect is not responsible for the content or availability of external websites

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more