Publications

The detection of the sulfonic acid metabolites of the chloroacetanilide herbicides acetochlor, alachlor, butachlor, propachlor, and, more recently, metolachlor in surface and ground water suggests that a common mechanism for dechlorination exists via the glutathione conjugation pathway. The identification of these herbicides and their metabolites is important due to growing public awareness and co

Herbicides were detected in rainfall throughout the midwestern and northeastern United States during late spring and summer of 1990 and 1991. Herbicide concentrations exhibited distinct geographic and seasonal patterns. The highest concentrations occurred in midwestern cornbelt states following herbicide application to cropland. Volume-weighted concentrations of 0.2−0.4 μg/L for atrazine and alach

Rain and surface water samples from Southern Germany were investigated from 1991 to 1995 for terbuthylazine and one of its major metabolites, deethylterbuthylazine. The concentrations observed were compared to the concentrations found for atrazine and deethylatrazine in the same water samples. Concentrations ranged from < 0.02 μg/L to 0.7 μg/L for terbuthylazine and from < 0.02 μg/L to 0.6 μg/L fo

Herbicide compounds were prevalent in ground water across Iowa, being detected in 70% of the 106 municipal wells sampled during the summer of 1995. Herbicide degradation products were three of the four most frequently detected compounds for this study. The degradation product alachlor ethanesulfonic acid was the most frequently detected compound (65.1%), followed by atrazine (40.6%), and the degra

This study tested the hypothesis that sorption of hydroxylated atrazine degradation products (HADPs: hydroxyatrazine, HA; deethylhydroxyatrazine, DEHA; and deisopropylhydroxyatrazine, DIHA) to soils occurs by mixed-mode binding resulting from two simultaneous mechanisms: (1) cation exchange and (2) hydrophobic interaction. The objective was to use liquid chromatography and soil extraction experime

The vulnerability of a shallow aquifer in south-central Kansas to contamination by atrazine (2-chloro-4-ethylamino-6-isopropylamines-triazine) was assessed by analyzing unsaturated zone soil and sediment samples from about 60 dryland and irrigated sites using an ultrasensitive immunoassay (detection level of 0.02 µg/kg) with verification by gas chromatography/mass spectrometry (GC/MS). Samples wer

The effect of tributary inflows on metal concentrations in <63-μm sediments and benthic insects was examined on two scales (380 km and <2 km) in a river impacted by mining. A dilution−mixing model effectively described large-scale dispersion of Cd, Cu, and Pb in the sediments of the river. Input of metal from contaminated flood plains may introduce additional contamination in the middle reaches of

Laboratory, field, and digital solute-transport- modeling studies demonstrate that microorganisms indigenous to the shallow ground-water system at Laurel Bay Exchange, Marine Corps Air Station Beaufort, South Carolina, can degrade petroleum hydrocarbons in gasoline released at the site. Microorganisms in aquifer sediments incubated in the laboratory under aerobic and anaerobic conditions mineraliz

No abstract available.

This report presents the results of a study conducted at Picatinny Arsenal, Morris County, New Jersey, to (1) determine whether streambed sediments in Green Pond Brook and its tributaries are contaminated with inorganic or organic constituents, (2) determine the extent of contamination in those reaches, and (3) characterize the quality of water in the brook. Shallow auger samples and results of an

A steady-state, three-dimensional numerical model coupled with a particle-tracking algorithm was developed to simulate the complex hydrogeologic conditions affecting ground-water flow and contaminant migration in the Cape Cod aquifer beneath the Massachusetts Military Reservation, Massachusetts. The known extents of the contaminant plumes beneath the reservation were incorporated into a particle-t

No abstract available.