2004 Denver Annual Meeting (November 7–10, 2004)

Paper No. 3
Presentation Time: 8:30 AM

IMPACTS OF NEAR MOUNTAIN GEOLOGY ON AN IN SITU BIODENITRIFICATION SYSTEM


HUDSON, Amy L and GARRETT, Kevin E, MACTEC Engineering and Consulting, Inc, 1627 Cole Boulevard, Golden, CO 80401, alhudson@mactec.com

In situ treatment of contaminated groundwater has received increased attention throughout the environmental industry. One of the greatest challenges with in situ techniques is the delivery of the amendments to the areas that need treatment. In situ treatment techniques require a detailed understanding of the subsurface geology, hydrogeology, and surface water interactions to be effective. Contaminated sites located in the area of uplift of the Rocky Mountains require a more detailed investigation to fully and effectively treat the groundwater using an in situ system.

Presented here is an in situ biodenitrification approach to remediate groundwater nitrate contamination on 48 acres of a closed mineral processing Facility along the front range of the Rockies. Nitrate contaminated groundwater and its remediation continues to be of concern among regulators. In situ biodenitrification techniques have been applied to remediate nitrate in groundwater, but most have been applied to bench scale tests and small pilot scale sites. Simple scaling up of a small scale pilot test to a full scale field remediation does not address the potential impacts of localized heterogeneities in the subsurface geology due to uplift, fracturing, and depositional environment. Through detailed investigation and characterization of the geology and hydrogeology of the site, a better understanding of the contamination sources and transport has been gained. This has allowed for an effective large scale in situ biodenitrification treatment system in an area of complex geology.