A unifying theme of USGS Toxic Substances Hydrology Program investigations is the characterization of the natural response of hydrologic systems to contamination. This makes the sites where the investigations are conducted ideally suited to assessing potential long-term impacts, evaluating the potential and the limitations of remediation by monitored natural attenuation, and designing systems to monitor the performance of remediation where monitored natural attenuation is being relied upon. The information presented on this page cuts across lines drawn by individual investigations and projects so that information on the natural attenuation of contaminants can be presented in one place.
Investigations and Research Activities
- Natural Attenuation Remediation-Related Activities
USGS scientists installing diffusion samplers
and microcosms to study subsurface bacteria that degrade trichloroethylene
at the Naval Air Warfare Center
Research Site, West Trenton, NJ (circa 2005). The samplers will
help USGS and U.S. Navy scientists evaluate the performance of a
biostimulation and bioaugmentation experiment.
USGS scientists assisted the U.S. Navy with the design and assessment of an innovative remediation system that involved the injection of an oxygen-release compound in the source area of a chlorobenzene and benzene plume at the Naval Air Station, Pensacola, Florida. The two transects are along ground-water flow paths.
Collecting ground-water samples anaerobically in a glove bag as part of a study of the biogeochemistry of a landfill leachate plume at the Norman Landfill Research Site, OK. The glove bag helps preserve sensitive redox species so an accurate determination of the processes that control the natural attenuation of the leachate can be made.
Collecting pore water from cores to identify natural attenuation processes in ground water at the Bemidji Crude Oil Spill Site, MN. The scientists are withdrawing water with a syringe from a core encased in polycarbonate tubing. The bottom of the core was frozen to prevent fluid from escaping the core. This technique allows for closely spaced samples that enable scientists to study the biogeochemical heterogeneity of contaminant plumes.
Science Feature Articles
USGS scientist collecting an unsaturated-zone gas sample with a syringe from a vapor sampling well at the Bemidji Crude Oil Spill Research Site, Bemidji, MN. The sample was used to study the natural attenuation of hydrocarbon vapors in the unsaturated zone.