Evaluation of Storm Water Surface Runoff and Road Debris as Sources of Water Pollution

Street sweeping is regularly performed within cities and residential communities to reduce roadway debris and ensure properly functioning storm water management systems. Given removal of plant and soil debris, street sweeping may also reduce nonpoint source pollution through removal of leachate source material. To assess the influence of street sweeping on storm water pollutants, 36 storm water collection devices were installed within six residential communities in Central Florida and subjected to varying municipal sweeping regimes. Additionally, precipitation and storm water retention pond leachate samplers were installed to quantify pollutant sources that may enter and leave selected urban communities. Despite high variability in percentage of impervious surfaces, population density, and volume of road debris among communities, no significant (P ≤ 0.05) differences were observed for total Kjeldahl nitrogen (TKN), nitrate + nitrite (NOx), and total phosphorus (TP) concentrations in storm water among communities or between swept and unswept areas of roadways. Similarly, no significant differences were observed for TKN, NOx, and TP concentrations in precipitation and storm water. Significant differences in orthophosphate (ortho-P), however, were observed between communities and precipitation. Additionally, storm water TP concentrations were greater than discharge estimated to originate from communities within the study area. Although street sweeping may be effective at reducing volume of roadway debris, our data did not find it reduced N or P in storm water.