Processes that Control the Natural Attenuation of Chlorinated Solvents--Wurtsmith Air Force Base, Oscoda, Michigan

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Wintertime sampling at a multi-level well used to monitor vertical biogeochemical gradients in a naturally degrading plume of chlorinated solvents in the subsurface

A technician is pumping water from a multi-level well during an investigation of the natural attenuation of a chlorinated solvent plume under a fire training pit. Tubing from the well leads to an in-line multi-parameter probe that records pH, dissolved oxygen, Eh, and temperature

A technician is collecting water-quality samples from a multi-level well. The samples were analyzed for chemical constituents that are indicators of natural attenuation processes

Extracting DNA from aquifer samples in preparation for polymerase chain reaction (PCR) analysis of microbial DNA structure. Information on how DNA varies with location and time helps scientists understand how bacterial community structure controls the extent and effectiveness of the natural attenuation of chlorinated solvents in the subsurface

DNA was extracted from aquifer solids and was analyzed for patterns of microbial diversity in a plume of chlorinated solvents undergoing natural microbial biodegradation

Hydrogen gas in ground water was measured using the bubble strip method. A bubble of gas was trapped in the glass tube pictured and was removed with a syringe inserted into a septum

Hydrogen gas stripped from ground-water samples was measured in a building on the Wurtsmith Air Force Base using a portable hydrogen gas analyzer

Hydrogen gas in ground water was measured using the bubble strip method. The amount of hydrogen gas in ground water can be used to infer the types of bacteria that are actively degrading contaminants in the subsurface

Researchers measured a variety of chemical constituents in the field, using portable test kits, in order to evaluate real-time conditions and choose appropriate sampling times

Aquifer sediments were retrieved from up to 40 feet deep using hydraulic punch technology. DNA was extracted from the sediments to evaluate the community structure of microorganisms actively degrading contaminants in the subsurface