Galloway Township, New Jersey Research Site

Toxic Substances Hydrology Program

Research Objectives

The research objectives for this site are to:

• Characterize the ground-water geochemistry to identify the important biogeochemical processes and microbial degradation pathways
• Develop field and laboratory methods to quantify rates of hydrocarbon transport and microbial degradation in the subsurface
• Determine the factors controlling the performance of vapor-extraction remediation

Approach

Field experiments were performed to quantify the fate of gasoline hydrocarbons associated with engineered (vapor extraction)- and natural-attenuation remediation. A network of vapor probes and ground-water wells were sampled to obtain detailed resolution of the biogeochemical signatures of hydrocarbon degradation above and below the water table. Vapor extraction wells were sampled to determine hydrocarbon biodegradation and mass-removal rates.

Laboratory column experiments were performed to examine the direct response of microbes in controlled systems, emulative of field conditions. The column experiments were also used to determine air-phase permeabilities and effective diffusion coefficients of unsaturated-zone sediments. Open and closed microcosm experiments were conducted to investigate stoichiometric-degradation relations and biodegradation pathways.

Mathematical models provide a means to predict and quantify the transport and biodegradation of hydrocarbons in the subsurface. These models are applied to analyze field and laboratory experiments and to test microbial-kinetic hypotheses. The mathematical models help insure maximum transfer value of the methods to the public.