Characterization of Intrinsic PAH Biodegradation in Groundwater During Tidal Cycles at the Naval Station Norfolk: Interim Report
Abstract
From July 1999 through July 2001, NRL sampled a single groundwater monitoring well located at the Naval Station Norfolk over the course of several tidal cycles. Groundwater at the site is impacted by subsurface fuel spill(s). Groundwater was assessed for fuel hydrocarbon concentrations, stable carbon isotope fingerprints, temperature, salinity, total microbial carbon demand, and PAH mineralization rates. The following was discovered: PAH concentrations were negligible in groundwater although alkanes were detected and used for stable carbon isotope analysis. PAH mineralization rates and bacterial productivity suggest active microbial communities degrade fuel hydrocarbons in the subsurface. Because different parameters (salinity, DO) influence phenanthrene and fluoranthene mineralization independently, there may be distinct bacterial assemblages involved in their biodegradation. There was little tidal recharge at the sampled monitoring well. There was no significant delivery of dissolved oxygen from the adjacent river water (groundwater was hypoxic during entire tidal cycle). There were indications that overall bacterial production varied with season. PAH mineralization rates were independent of season. It appears that fuel hydrocarbons are a larger component of microbial carbon diet during cooler seasons.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 17, 2002
- Accession Number
- ADA406731
Entities
People
- Catherine V. Badger
- Michael T. Montgomery
- Richard B. Coffin
- Sheila R. Reatherford
- Thomas J. Boyd
Organizations
- United States Naval Research Laboratory