Nonpoint source pollution of urban stormwater runoff: a methodology for source analysis

Area of Science:

• Environmental Science
• Urban Hydrology
• Water Quality Management

Background:

• Nonpoint source pollution from urban runoff poses significant risks to aquatic ecosystems.
• Characterizing and controlling these pollution sources is crucial for environmental protection.
• Existing methodologies often lack detailed source apportionment and uncertainty analysis.

Purpose of the Study:

• To develop and validate a methodology for quantifying urban nonpoint source pollution.
• To analyze the uncertainties associated with pollutant source identification.
• To apply the methodology to identify sources of specific pollutants (Cu, Pb, Zn, PAH) in a residential catchment.

Main Methods:

• Development of a novel methodology for source apportionment of urban runoff pollutants.
• Application of the methodology to a 228 ha residential catchment in the Paris region.
• Estimation of pollutant contributions from various sources, including roof accessories and activity-related sources.

Main Results:

• Roof accessories were identified as the primary source of lead (Pb) and a significant source of zinc (Zn).
• Activity-related sources, such as traffic and heating, were dominant for copper (Cu) and polycyclic aromatic hydrocarbons (PAH).
• The methodology provided a quantitative assessment of pollutant sources and associated uncertainties.

Conclusions:

• The proposed methodology effectively quantifies urban runoff pollutant sources and their uncertainties.
• Roof accessories represent a critical, often overlooked, source of heavy metal pollution in urban catchments.
• Understanding source contributions is essential for targeted pollution control strategies in urban environments.