Software Provides Estimates of How Long it Will Take for Remediation Efforts to Achieve Their Goals

Scientists from the U.S. Geological Survey, Virginia Polytechnic Institute and State University (Virginia Tech), and the U.S. Navy have developed a software package that helps practitioners estimate how far plumes will migrate and how long natural attenuation processes will take to clean up contamination. The package, called Natural Attenuation Software (NAS), is based on a decision-making framework for assessing the efficiency of monitored natural attenuation (MNA), and provides a methodology for designing monitoring strategies and estimating timeframes required for natural attenuation processes to lower contaminant concentrations to regulatory goals. NAS is an interactive computer-screening tool written in user-friendly Microsoft Visual Basic (see note) that prompts the user for information concerning the site's hydrogeology, contaminant characteristics, and site-specific remediation goals. This tool allows remediation practitioners to:

• Determine to what degree contaminant concentrations in the source area must be lowered (if at all) in order for natural attenuation to be protective of the environment.
• Estimate how long it will take a contamination plume to shrink to an acceptable configuration when contaminant concentrations in the source area are lowered using engineered methods.
• Estimate how long it will take for a given mass of contaminant NAPLs, such as chlorinated solvents and petroleum hydrocarbons, to dissolve and disperse at a given site.

Example NAS Applications

• A chlorinated solvent spill at the U.S. Naval Air Station in Pensacola, Florida
• A leaking underground gasoline storage tank at Laurel Bay, South Carolina
• A landfill leaking chlorinated solvents at the U.S. Naval Submarine Base Kings Bay, Georgia

More Information

• New Version of NAS (Natural Attenuation Software) Available
• Chapelle, F.H., Widdowson, M.A., Brauner, J.S., Mendez, E., Casey, C.C., 2003, Methodology for estimating times of remediation associated with monitored natural attenuation: U.S. Geological Survey Water-Resources Investigations Report 03-4057, 51 p.
• NAS Information
• NAS Training Information

Related Headlines

• New Report Presents a Framework for Assessing the Sustainability of Monitored Natural Attenuation
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• RDX Biodegradation Under Metal-Reducing Conditions
• New Information on the Long-Term Fate of Ammonium in Ground Water
• Microorganisms Degrade MTBE Even at Winter Ground-Water Temperatures
• Does NDMA Biodegrade at Ground-Water Recharge Facilities?
• Ground-Water Recharge Affects Fate of Petroleum Contaminant Plumes
• History and Ecology of Chloroethene Biodegradation--A Review
• Using Oxygen to Enhance Biodegradation of Contaminants -- Lessons Learned
• USGS Scientists Contribute to the Landmark "Treatise on Geochemistry"
• A Unique Approach to Evaluating Natural Attenuation is Applied Worldwide
• Landmark Book Published on the Fate of Contaminants in the Environment: Partition and Adsorption of Organic Contaminants in Environmental Systems
• Using Oxygen to Clean Up Ground-Water Contamination
• MTBE Can Degrade Naturally Without Oxygen
• How Do You Clean Up Gasoline Spills Naturally?
• Relying on Nature to Clean Up Contaminated Ground Water
• MTBE Biodegrades Naturally in Stream Sediments
• Natural Attenuation for Groundwater Remediation
• Can a Sewage-Contaminated Aquifer Naturally Clean Itself?
• Natural Attenuation of MTBE at Laurel Bay, South Carolina

USGS Information on Natural Attenuation

• Microbial Degradation of Chloroethenes in Ground Water Systems
• Topical Information on Natural Attenuation
• Listing of Toxics Program Natural Attenuation Remediation-Related Activities
• Listing of Other USGS Natural Attenuation Remediation-Related Activities

Note: Use of trade names does not imply endorsement by the U.S. Geological Survey. Trade names are used for information purposes only.

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