Water Quality in Urban Creeks During Storm Events

In general, urban stormwater runoff is a poorly characterized and little understood source of pollution to the aquatic environment. New analytical tools are beginning to address this data gap, with improved identification capabilities for chemical contaminants and toxicants which contribute to pervasive impairment of water quality. Here, we use high-resolution quadrupole time-of-flight mass spectrometry to characterize the occurrence and fate of known and novel organic contaminants in stormwater runoff and urban receiving waters. These research efforts especially focused on characterizing water quality in samples where acute toxicity (urban runoff mortality syndrome) is observed in coho salmon upon exposure to urban stormwaters and roadway runoff. By comparing water quality during baseflow conditions and storm events, these data indicate that significant water quality degradation arises from high strength sources of roadway-derived contaminants. In particular, chemicals associated with tire rubbers leachates were especially abundant in urban receiving waters and often dominated detection profiles which demonstrate little evidence of dilution during rainfall. Such “transport limited” chemicals and associated sources should be prioritized for water quality management