Pesticides Associated with Suspended Sediments Entering San Francisco Bay Following the First Major Storm of Water Year 1996

摘要: Estuaries receive large quantities of suspended sediments following the first major storm water year. The first-flush events transport majority in any given year, and because their relative freshness hydrologic system, these may carry a significant amount sediment-associated pesticide load transported into estuaries. To characterize pesticides during event, sus- pended sediment samples were collected at head San Francisco Bay peak concentration that followed 1996 Samples analyzed for variety parameters as well 19 degradation products span wide range hydrophobicity. Tidal mixing estuary mixed relatively fresh down rivers with waters. Segregation groups similar degrees between river revealed from Sacramento-San Joaquin drainage basin strongly influenced distribution entering Bay. less-mixed contained different than exposed to greater mixing. Temporal trends evident content after segregated according history. These results indicate sampling strategies collect low frequency or do not compare histories will elucidate processes. Despite considerable influence mixing, number found asso- ciated sediments. Few concurrent concentrations much lower predicted equilibrium partitioning aqueous sedimentary phases. observed reflect disequilibria phases resulting long equilibration times locations where applied, short transit over which re-equilibration occur.