title: A simplified approach for monitoring hydrophobic organic contaminants associated with suspended sediment: methodology and applications.
abstract: Hydrophobic organic contaminants, although frequently detected in bed sediment and in aquatic biota, are rarely detected in whole-water samples, complicating determination of their occurrence, load, and source. A better approach for the investigation of hydrophobic organic contaminants is the direct analysis of sediment in suspension, but procedures for doing so are expensive and cumbersome. We describe a simple, inexpensive methodology for the dewatering of sediment and present the results of two case studies. Isolation of a sufficient mass of sediment for analyses of organochlorine compounds and PAHs is obtained by in-line filtration of large volumes of water. The sediment is removed from the filters and analyzed directly by standard laboratory methods. In the first case study, suspended-sediment sampling was used to determine occurrence, loads, and yields of contaminants in urban runoff affecting biota in Town Lake, Austin, TX. The second case study used suspended-sediment sampling to locate a point source of PCBs in the Donna Canal in south Texas, where fish are contaminated with PCBs. The case studies demonstrate that suspended-sediment sampling can be an effective tool for determining the occurrence, load, and source of hydrophobic organic contaminants in transport.
authors.affiliation: U.S. Geological Survey, 8027 Exchange Drive, Austin, Texas 78754, USA. bjmahler@usgs.gov
authors.forename: B J
authors.initials: BJ
authors.lastname: Mahler
authors.forename: P C
authors.initials: PC
authors.lastname: Van Metre
mesh_terms: D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D005618:Fresh Water / Q000737:chemistry; D019015:Geologic Sediments / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D011078:Polychlorinated Biphenyls / Q000032:analysis; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis; D011786:Quality Control; D013048:Specimen Handling; D013781:Texas; D014877:Water Pollution, Chemical / Q000032:analysis*
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons; D011078:Polychlorinated Biphenyls