title: Priority pollutants in urban stormwater: part 2 - case of combined sewers.
abstract: This study has evaluated the quality of combined sewer overflows (CSOs) in an urban watershed, such as Paris, by providing accurate data on the occurrence of priority pollutants (PPs) and additional substances, as well as on the significance of their concentrations in comparison with wastewater and stormwater. Of the 88 substances monitored, 49 PPs were detected, with most of these also being frequently encountered in wastewater and stormwater, thus confirming their ubiquity in urban settings. For the majority of organic substances, concentrations range between 0.01 and 1 μgl(-1), while metals tend to display concentrations above 10 μgl(-1). Despite this ubiquity, CSO, wastewater and stormwater feature a number of differences in both their concentration ranges and pollutant patterns. For most hydrophobic organic pollutants and some particulate-bound metals, CSOs exhibit higher concentrations than those found in stormwater and wastewater, due to the contribution of in-sewer deposit erosion. For pesticides and Zn, CSOs have shown concentrations close to those of stormwater, suggesting runoff as the major contributor, while wastewater appears to be the main source of volatile organic compounds. Surprisingly, similar concentration ranges have been found for DEHP and tributyltin compounds in CSOs, wastewater and stormwater. The last section of this article identifies substances for which CSO discharges might constitute a major risk of exceeding Environmental Quality Standards in receiving waters and moreover indicates a significant risk for PAHs, tributyltin compounds and chloroalkanes. The data generated during this survey can subsequently be used to identify PPs of potential significance that merit further investigation.
authors: Université Paris-Est, LEESU, UMR MA 102 - AgroParisTech, 61 avenue du Général de Gaulle, 94010 Créteil Cedex, France. gasperi@u-pec.fr
authors: Johnny
authors: J
authors: Gasperi
authors: Sally
authors: S
authors: Zgheib
authors: Mathieu
authors: M
authors: Cladière
authors: Vincent
authors: V
authors: Rocher
authors: Régis
authors: R
authors: Moilleron
authors: Ghassan
authors: G
authors: Chebbo
mesh_terms: D002947:Cities; D004323:Drainage, Sanitary; D004784:Environmental Monitoring / Q000379:methods; D011891:Rain; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000145:classification*
chemical_list: D014874:Water Pollutants, Chemical