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Center for Advancing Research in Transportation Emissions, Energy, and Health (CARTEEH)

A USDOT University Transportation Center

The Concentration of Pollutants in the Runoff

The concentration of pollutants in stormwater runoff is be a measurable indicator of environmental pollution levels. These pollutants include chemicals, sediment, oil and grease, bacteria, and viruses. They affect the quality of water in rivers and streams, which indirectly affects human health by potentially contaminating our drinking water supply. A reduction in the concentration of pollutants indicates that measures have been put in place to reduce stormwater runoff.1,2

This indicator helps determine the effectiveness of the following objectives

  • Less Contamination
  • Less Emissions
  • Less Traffic Noise
  • Connectivity and Inclusion
  • Healthy Destinations
  • Less Traffic Violence
  • Active Transportation
  • Green Space

Data Collection

There are a few key methods for collecting data on the concentration of pollutants in the runoff:

– Influent and effluent sampling: Sampling at the point where water enters and leaves a treatment facility can provide important data on pollutant concentrations.
– Composite sampling: This method involves taking multiple samples over time and combining them to create a “composite” sample. This is often done when measuring pollutants that fluctuate in concentration over time.
– Grab sampling: As the name suggests, this method involves quickly grabbing a sample of water (typically from a river or stream) at a specific location. Grab samples can help determine instantaneous concentrations of pollutants.3

Examples

Study on pollution characteristics of urban pavement runoff

Qian et al. (2021) conducted research to analyze the variation of pollutants with road-deposited sediment (RDS). The research revealed the concentration of pollutants based on the study. The components of these pollutants, such as suspended solids, heavy metals, and others, were measured during the study. The results showed that the concentration of different pollutants have different relationships with rainfall and runoff time. While the concentration of heavy metals first rises and then falls, that of suspended solids (SS) declines continuously with runoff time. The outcome offered a helpful guide for the management of pavement runoff pollution.

https://iwaponline.com/wst/article/84/7/1745/83998/Study-on-pollution-characteristics-of-urban

1. Haseena, M., Malik, M.F., Javed, A., Arshad, S., Asif, N., Zulfiqar, S., Hanif, J. Water pollution and human health. Environmental Risk Assessment and Remediation. 2017;1(3). https://doi.org/10.4066/2529-8046.100020
2. Han, Y., Lau, S.L., Kayhanian, M., Stenstrom, M.K. Characteristics of highway stormwater runoff. Water Environment Research. 2006 Nov;78(12):2377-88. https://doi.org/10.2175/106143006x95447
3. Lee, D.H., Kim, J.H., Mendoza, J.A., Lee, C.H., Kang, J-H. Characterization and source identification of pollutants in runoff from a mixed land use watershed using ordination analyses. Environ Sci Pollut Res Int [Internet]. 2016;23(10):9774–90. Available from: http://dx.doi.org/10.1007/s11356-016-6155-x