Software Provides Estimates of How Long it Will Take for Remediation Efforts to Achieve Their Goals
The main menu of the Natural Attenuation Software (NAS) package. NAS is based on a decision-making framework for assessing the efficiency of monitored natural attenuation (MNA).
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
- 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 Science Features
USGS Information on Natural Attenuation
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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