2014-06-03: Environmental Dinner Meeting

Abstract: Sediments on the Palos Verdes Shelf (PVS), CA are contaminated with DDT as a result of the historical (1947-1971) discharge of DDT-bearing wastes through a submarine wastewater outfall system. Pursuant to a decade-long environmental lawsuit in the 1990s, part of the PVS was designated a Superfund site and is now being remediated by the USEPA. Microbially-mediated reductive dechlorination occurs within the sediments, resulting in conversion of the major DDT compound, DDE, to DDMU and DDMU to DDNU. Spatial variations in dechlorination rates have been observed in both field and laboratory, but the factors controlling the rates remain obscure. As part of natural recovery studies currently underway at the site, concentrations of ten DDT compounds were measured in the pore water and solid phase of contaminated shelf sediments of PVS sediments. Although concentrations and compositions of the DDT compounds exhibit strong variations vertically within the sediment column and across the shelf, apparent solid-water distribution coefficients (KD) are remarkably uniform. Comparison of DDE inventories in cores collected from 1981 to 2010 indicates that reductive dechlorination in PVS sediments can be modeled by first-order kinetics. This may provides a means of predicting when the Remedial Action Objectives identified by EPA as part of the interim remedy will be met.

Biography: Robert P. Eganhouse is a research chemist in the National Research Program of the U.S. Geological Survey in Reston, Virginia. Previously, he was head of chemistry at the Southern California Coastal Water Research Project in Long Beach, CA (1987-1991) and, prior to that, assistant professor in the Environmental Sciences Program at the University of Massachusetts, Boston (1983-1987). He received a B.S. in Chemistry from Iowa State University (1970), an M.S. in Chemical Oceanography from Florida State University (1974), and a Ph.D. in Geochemistry from UCLA (1982).

His research entails the application of organic geochemical techniques to a broad range of environmental problems. A principal interest has been the identification and development of molecular markers of municipal waste and their use in aquatic ecosystems. In addition to providing a means of tracking wastes into the environment, molecular markers can, under certain conditions, facilitate quantitative source apportionment of contaminants of concern. Much of his career has been devoted to increasing understanding of processes affecting the transport and fate of organic contaminants in coastal marine sediments and shallow aquifers. This has involved both laboratory and field-based studies including the determination of physico-chemical properties of hydrophobic organic contaminants (DDTs, PAHs, long-chain alkylbenzenes, PCBs), transport and degradation of volatile organic compounds in ground water, and the use of in situ techniques for determining contaminant degradation rates. Recent research has focused on the development of methods for characterizing and quantifying constituents in complex mixtures of natural and man-made organic chemicals using comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GCxGC/ToFMS). Examples of such mixtures include technical nonylphenol, synthetic detergent alkylates, and semi-volatile organic contaminants present in Hurricane Katrina flood sediments. Currently, he is involved in a multidisciplinary investigation of the natural attenuation of p,p’-DDE in sediments of the Palos Verdes Shelf, CA, a Superfund site. He has served as an Associate Editor for Applied Geochemistry (1996-2007) and is a Designated Country Expert for the United States on Persistent Organic Pollutants, Arctic Monitoring and Assessment Program (AMAP; since 2006).

Cost: There is a family style Italian dinner with farfalle (bowtie) pasta with a seasonal vegetable tomato sauce and chicken breast. Salad, killer garlic rolls and wine are included. The cost is $28 including tax and tip payable at the door with cash or check. Please RSVP to Nancy Paradiso at office@scalacs.org or 310 327-1216 by Thursday, May 29th. Please honor your reservation. If you make a reservation and do not attend, you may be liable for the cost of the dinner.

Directions: C&O Cucina is located in Marina del Rey at Washington and Thatcher, one block west of Lincoln Blvd. For google maps and directions, go to their website at: http://www.cocucina.com/. There is free street parking or valet parking for $4.75. Please note there is a C&O Trattoria also on Washington Blvd. (two restaurants owned by the same company).