Enhanced detection of groundwater contamination from a leaking waste disposal site by microbial community profiles
Article first published online: 2 DEC 2010
Copyright 2010 by the American Geophysical Union.
Water Resources Research
Volume 46, Issue 12, December 2010
How to Cite
2010), Enhanced detection of groundwater contamination from a leaking waste disposal site by microbial community profiles, Water Resour. Res., 46, W12506, doi:10.1029/2010WR009459., , , , , , and (
- Issue published online: 2 DEC 2010
- Article first published online: 2 DEC 2010
- Manuscript Accepted: 17 AUG 2010
- Manuscript Revised: 20 JUL 2010
- Manuscript Received: 21 APR 2010
- molecular methods
 Groundwater biogeochemistry is adversely impacted when municipal solid waste leachate, rich in nutrients and anthropogenic compounds, percolates into the subsurface from leaking landfills. Detecting leachate contamination using statistical techniques is challenging because well strategies or analytical techniques may be insufficient for detecting low levels of groundwater contamination. We sampled profiles of the microbial community from monitoring wells surrounding a leaking landfill using terminal restriction fragment length polymorphism (T-RFLP) targeting the 16S rRNA gene. Results show in situ monitoring of bacteria, archaea, and the family Geobacteraceae improves characterization of groundwater quality. Bacterial T-RFLP profiles showed shifts correlated to known gradients of leachate and effectively detected changes along plume fringes that were not detected using hydrochemical data. Experimental sediment microcosms exposed to leachate-contaminated groundwater revealed a shift from a β-Proteobacteria and Actinobacteria dominated community to one dominated by Firmicutes and δ-Proteobacteria. This shift is consistent with the transition from oxic conditions to an anoxic, iron-reducing environment as a result of landfill leachate-derived contaminants and associated redox conditions. We suggest microbial communities are more sensitive than hydrochemistry data for characterizing low levels of groundwater contamination and thus provide a novel source of information for optimizing detection and long-term monitoring strategies at landfill sites.