Natural Attenuation

Definitions

Monitored Natural Attenuation - "Reliance on natural attenuation processes (within the context of a carefully controlled and monitored site cleanup approach) to achieve site-specific remediation objectives within a time frame that is reasonable compared to that offered by other more active methods. The 'natural attenuation processes' that are at work in such a remediation approach include a variety of physical, chemical, or biological processes that, under favorable conditions, act without human intervention to reduce the mass, toxicity, mobility, volume, or concentration of contaminants in soil or groundwater. These in-situ processes include biodegradation; dispersion; dilution; sorption; volatilization; radioactive decay; and chemical or biological stabilization, transformation, or destruction of contaminants." - U.S. Environmental Protection Agency, 1999

Natural Attenuation - "Reduction in mass or concentration of a compound in groundwater over time or distance from the source of constituents of concern due to naturally occurring physical, chemical, and biological processes, such as; biodegradation, dispersion, dilution, adsorption, and volatilization." - American Society for Testing and Materials, 2003

Natural Attenuation - [The processes resulting] "from the integration of several subsurface attenuation mechanisms that are classified as either destructive or nondestructive. Biodegradation is the most important destructive attenuation mechanism. Nondestructive attenuation mechanisms include sorption, dispersion, dilution from recharge, and volatilization." - U.S. Air Force Center for Environmental Excellence, 1999

Natural Attenuation - "The reduction of contaminant concentrations in the environment through biological processes (aerobic and anaerobic biodegradation, plant and animal uptake), physical phenomena (advection, dispersion, dilution, diffusion, volatilization, sorption/desorption), and chemical reactions (ion exchange, complexation, abiotic transformation). Terms such as intrinsic remediation or bio-transformation are included within the more general natural attenuation definition." - U.S. Army, 1995

Text in brackets ("[text]") are additions by the editor

Related Definitions

Biodegradation

Aerobic

Aerobic Biodegradation

Anaerobic

Anaerobic Biodegradation

USGS Information on Natural Attenuation

• Topical Information on Natural Attenuation
• Listing of Toxics Program Natural Attenuation Remediation Related Activities
• Listing of Other USGS Natural Attenuation Remediation Related Activities
• Natural Attenuation Strategy for Groundwater Cleanup Focuses on Demonstrating Cause and Effect: Bekins and others, 2001: EOS
• Bioremediation--Nature's Way to a Cleaner Environment: USGS Fact Sheet FS-054-95.
• Bibliography on Natural Attenuation and Biodegradation, Toxics Program
• Search the Toxic Substances Hydrology Program's Bibliography for "natural attenuation"

Related Headlines

• Do Natural Processes Mitigate Contamination from Landfill Leachate?
• New Version of NAS (Natural Attenuation Software) Available
• Decades Required for Natural Processes to Clean Wastewater-Contaminated Ground Water
• New Information on the Long-Term Fate of Ammonium in Ground Water
• Does NDMA Biodegrade at Ground-Water Recharge Facilities?
• Predicting Plume Growth Rates - A Simple Method for Calculating Growth Rates of Petroleum Plumes
• History and Ecology of Chloroethene Biodegradation–A Review
• The Changing Face of Microbial Communities in Contaminant Plumes
• A Unique Approach to Evaluating Natural Attenuation is Applied Worldwide
• Relying on Nature to Clean Up Contaminated Ground Water
• Can a Sewage-Contaminated Aquifer Naturally Clean Itself?
• How do you Clean Up Gasoline Spills Naturally?
• Landmark Book Published on the Fate of Contaminants in the Environment: Partition and Adsorption of Organic Contaminants in Environmental Systems

Other Information on Natural Attenuation

• Natural Attenuation for Groundwater Remediation, 2000: National Academies Press
• In Situ Bioremediation--When Does it Work?,1993: National Academies Press
• U.S. Environmental Protection Agency
• Technology Focus--Natural Attenuation, Clu-In, Technology Innovation Office
• A Citizen's Guide to Natural Attenuation, Clu-In, Technology Innovation Office
• Monitored Natural Attenuation--It's Much More Than Watching The Grass Grow!, Office of Underground Storage Tanks
• Technical Protocol for Evaluating Natural Attenuation of Chlorinated Solvents in Ground Water: Office of Research and Development, EPA/600/R-98/128
• Use of Monitored Natural Attenuation at Superfund, RCRA Corrective Action, and Underground Storage Tank Sites, An U.S. EPA directive (April 21, 1999) on the use of monitored natural attenuation for the remediation of contaminated soil and groundwater
• Proceedings of the Symposium on Natural Attenuation of Chlorinated Organics in Ground Water
• Monitored Natural Attenuation (A list of EPA research and documents), Ground Water and Ecosystems Restoration Research
• U.S. Department of Energy
• Monitored Natural Attenuation (MNA) Toolbox, Sandia National Laboratories
• Natural Attenuation Of Organic Compounds, Center for Public Environmental Oversight, San Francisco State University
• Natural Attenuation Software (NAS)

References

ASTM International, 2003, E1943-98 Standard guide for remediation of ground water by natural attenuation at petroleum release sites: ASTM Book of Standards, v. 11.04, 43 p.

U.S. Army, 1995, Interim army policy on natural attenuation for environmental restoration: Washington, DC, Department of the Army, Assistant Chief of Staff for Installation Management, DAIM-ED-R (200-1c), September 12, 1995.

U.S. Environmental Protection Agency, 1999, OSWER Directive 9200.4-17P -- Use of monitored natural attenuation at Superfund, RCRA corrective action, and underground storage tank sites -- April 21, 1999: Office of Solid Waste and Emergency Response, 41 p.

Wiedemeier, T.H., Wilson, J.T., Kampbell, D.H., Miller, R.N. and Hansen, J.E., 1999, Technical protocol for implementing intrinsic remediation with long-term monitoring for natural attenuation of fuel contamination dissolved in groundwater: U.S. Air Force Center for Environmental Excellence, v. 1 & 2, A324248, A324247a, A324247b.

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