Contaminant Fate and Transport Studies in Fractured Sedimentary Rock Aquifers at the former Naval Air Warfare Center (NAWC), West Trenton, N.J.

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Contaminants associated with industrial, airport, and other activities are present in groundwater in fractured-rock aquifers, posing long-term hazards to drinking-water supplies and ecosystems. The heterogeneous character of fractured rock challenges our understanding, monitoring, and remediation of such sites.

Since 1993, USGS has been providing technical assistance to the U.S. Navy and conducting research at the former Naval Air Warfare Center (NAWC) in West Trenton, N.J., where trichloroethene (TCE) has migrated in fractures and diffused into, and adsorbed onto, low-permeability mudstone strata, acting as a long-term residual source of contaminants. These studies have helped the Navy efficiently monitor the ongoing natural attenuation of TCE and improve the pump and treat system to remove contaminants and contain impacted groundwater. 

USGS scientists studying groundwater

USGS and University at Buffalo Scientists injecting tracers to study diffusion (Public domain).

Current (2020) investigations are focused on understanding flow and transport processes affecting per- and polyfluoroalkyl substances (PFAS) in fractured-rock aquifers. 

Research results include development of field methods to measure rates and coefficients associated with desorption, reaction, and diffusion of TCE and its degradation products in low-permeability strata (read more). In addition to research by USGS hydrologists, geochemists, and microbiologists, a broad range of studies on characterization, monitoring, and remediation of TCE in fractured rock have been conducted in collaboration with EPA, SERDP and ESTCP, academia, and private industry. 

Background information and results prior to 2018 are provided in our Archive.

Recent research findings

 

Groundwater Levels and Generalized Potentiometric Surfaces, Former Naval Air Warfare Center, West Trenton, New Jersey, 2018

Map of 2018 groundwater levels in saprolie and fill, June 2018, NAWC NJ

Groundwater levels, water-level potentiometric-surface contours, and groundwater-flow directions in the saprolite and fill, June 2018.  (Public domain.)

Groundwater-level conditions, generalized groundwater potentiometric surfaces, and generalized flow directions at the decommissioned Naval Air Warfare Center in West Trenton, New Jersey, were evaluated for calendar year 2018. Groundwater levels measured continuously in five on-site wells and one nearby off-site well were plotted as hydrographs for January 1, 2018, through December 31, 2018. Groundwater levels measured in 110 wells on June 18, 2018, were contoured as generalized potentiometric surfaces on maps and sections. Generalized groundwater-flow directions inferred from the June 2018 data are shown in the maps and sections.

 

 

Enhancement of Trichloroethene (TCE) Biodegradation in a Simulated Groundwater System    

This laboratory study showed that when TCE and acetylene are present, addition of acetylene-fermenting bacteria can enhance bioremediation of TCE and reduce its harmful breakdown products. (Also see journal article by Mao and others, 2017. (Acetylene fuels TCE reductive dechlorination by defined Dehalococcoides/Pelobacter consortia: Environmental Science and Technology) 

 

USGS scientist at a laboratory fume hood preparing experiments

Shaun M. Baesman, a USGS scientist, at a laboratory fume hood preparing experiments to test if adding acetylene-fermenting bacteria to microcosms can enhance the biodegradation of trichloroethylene (TCE) in groundwater. (Credit: Ronald Oremland, USGS. Public domain.)

 

USGS scientist with equipment used to inject fluids for a bioaugmentation experiment

The set up and equipment used for the bioaugmentation experiment.

USGS scientists updated research progress through presentations at the 2017 National Groundwater Association Conference on Fractured Rock and Groundwater, October 2-3, 2017, in Burlington, Vermont. Project scientists Paul Hsieh and Dan Goode served as Technical Advisors for the conference. Presentations included:

Research at NAWC was also featured by the conference keynote speaker Lee Slater (Rutgers), and in a presentation by Carl Keller (FLUTe Inc.).