Disposal of secondary-treated wastewater from the Massachusetts Military Reservation to the Cape Cod sand and gravel aquifer by rapid infiltration from 1935 to 1995 resulted in a contaminant plume that is more than 6 kilometers long. The plume is characterized by distinct biogeochemical zones, including an anoxic central core, in which dissolved oxygen has been consumed by the oxidation of organic compounds. The anoxic core is surrounded by a suboxic mixing zone between the wastewater-contaminated and the uncontaminated groundwater. In the uncontaminated groundwater, dissolved oxygen concentrations are near saturation (about 10 mg/L).

The research team is studying the occurrence and interactions of many contaminants of global concern, such as nitrate, phosphate, toxic metals, and organic compounds, that are present in the plume to increase understanding of the physical, chemical, and microbiological processes that affect the fate and transport of these contaminants in the subsurface. In addition, the team is studying how these processes affect many other types of contaminants, including microbial pathogens, metals such as chromium, and biologically active organic compounds, by conducting field experiments in the anoxic, suboxic, and oxic biogeochemical zones in and near the plume.

Biogeochemical fate of nitrogen and organic carbon

Microbial transport and groundwater ecosystems

Fate of trace metals in groundwater

Occurrence and fate of trace-level organic compounds in water

Transport of phosphorus in the wastewater plume

Mapping aquifer heterogeneity using geophysical and hydraulic data

Long-term fate of ammonium in groundwater

Influence of groundwater chemistry on naturally occurring arsenic