• Site Characterization
• Natural Attenuation Evaluation

Naval Submarine Base Bangor, Washington

Naval Facilities Engineering Command, U.S. Navy

• The potential contribution of microbial RDX degradation to observed decreases in RDX concentrations in the contaminant plume at NSB Bangor – Laboratory experiments involved the use of radiochemically labeled RDX (carbon 14) in microcosms under oxic (with oxygen) and anoxic (without oxygen) conditions. Quantitative polymerase chain reaction (Q-PCR) was used to identify the types of bacteria active in the microcosm studies. Greater than 85 percent of 14C-RDX converted to radioactive carbon dioxide ( 14CO 2) was observed in the microcosms under native, manganese-reducing, anoxic conditions. The results indicate that microbial degradation of RDX may contribute to natural attenuation of RDX in metal-reducing aquifer systems.
• Characterization of redox conditions and identification of RDX transformation products – Field experiments involved the characterization of ambient redox conditions in ground water and analyses of water samples for possible RDX transformation products. Although metal-reducing redox conditions were identified, ground-water chemistry data overall did not clearly indicate RDX degradation (see above site . The unique intermediate degradation products hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine (MNX), hexahydro-1,3-dinitroso-5-nitro-1,3,5-triazine (DNX), hexahydro-1,3,5-trinitroso-1,3,5-triazine (TNX) were not detected in any ground-water sample, but those compounds were also not detected in the laboratory experiments (see above). The non-unique RDX mineralization products CO 2 and N 2O were elevated in many wells within and down-gradient from the RDX plume. There was a clear depression in RDX concentrations in the center of the plume, possibly due to RDX degradation, although those results may reflect that the wells are screened in a finer-grained and relatively stagnant portion of the shallow aquifer.

• RDX Biodegradation Under Metal-Reducing Conditions
• Navy Investigations and Technical Oversight and Scientific Investigations at U.S. Navy Facilities in Washington and Alaska
• Microbial Degradation of Chloroethenes in Ground Water Systems
• SUBASE Bangor Hydrologic Investigations
• Bangor Naval Submarine Base (CERCLIS EPA ID WA5170027291), U.S. Environmental Protection Superfund Information System (Comprehensive Environmental Response, Compensation, and Liability Information System CERCLIS)
• Public Health Assessment, Bangor Naval Submarine Base and Bangor Ordnance Disposal (U.S. Navy), Silverdale, Kitsap County, Washington, Agency for Toxic Substances and Disease Registry

• Paul M. Bradley, USGS South Carolina Water Science Center,
• Richard S. Dinicola, USGS Washington Water Science Center,

• Bradley, P.M., and Dinicola, R.S., 2005, RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) biodegradation in aquifer sediments under manganese-reducing conditions: Bioremediation Journal, v. 9, no. 1, p. 1-8, doi: 10.1080/10889860590929574.

• Natural Attenuation, Crosscutting information on natural attenuation and biodegradation of contaminants
• Microbial Degradation of Chloroethenes in Ground Water Systems
• Application of Molecular Methods in Microbial Ecology to Understand the Natural Attenuation of Chlorinated Solvents
• Processes Affecting the Natural Attenuation of Fuel Oxygenates in Ground Water Fuel, Laurel Bay, South Carolina
• Processes Affecting the Natural Attenuation of Gasoline in Ground Water, Galloway Township, New Jersey