Research on Monitored Natural Attenuation (MNA)
MNA is the use of natural attenuation processes within the context of a carefully controlled and monitored site cleanup approach that will reduce contaminant concentrations to levels that are protective of human health and the environment within a reasonable time frame. There are three primary applications: fuel components from leaking underground storage tanks, chlorinated solvents from hazardous waste sites, and metals and other inorganic substances. Major sources include landfills, uncontrolled hazardous waste sites, and spills of gasoline from service stations.
![Microcosm Study of Anaerobic Biodegradation of MTBE in Aquifer Sediment](pics/mna.jpg)
Microcosm Study of Anaerobic Biodegradation of MTBE in Aquifer Sediment
You will need the free Adobe Reader to view some of the files on this page. See EPA's PDF page to learn more about PDF, and for a link to the free Acrobat Reader.
Current activities include:
- Inorganic contaminants and radionuclides. Development of a framework document for MNA of inorganic contaminants. Due in 2005, point of contact Robert Puls (puls.robert@epa.gov).
- Arsenic. Evaluate site characterization tools and data requirements for assessing MNA as a partial remedy for arsenic contamination (PDF) (1 pg, 21K). Due in 2004, point of contact Robert Ford (ford.robert@epa.gov).
- MTBE and TBA. Measure the rate of natural biodegradation of MTBE and TBA (PDF) (2 pp, 30K) in a large number of gasoline spills, learn to predict the contribution of natural biodegradation from the isotope geochemistry of the ground water, confirm natural biodegradation of MTBE in controlled laboratory studies (PDF) (2 pp, 154K). Summary report due 2004, point of contact John Wilson (wilson.johnt@epa.gov).
![](https://webarchive.library.unt.edu/web/20090508224743im_/http://www.epa.gov/ada/tsc/pics/microscope_sm.gif)
Links to documents and computer applications:
Site Characterization to Support Use of Monitored Natural Attenuation for Remediation of Inorganic Contaminants in Ground Water (PDF) (16 pp, 704 KB) (EPA/600/R-08/114) November 2008 - Abstract
Calculation and Use of Rates Constants for MNA (PDF) (28 pp, 750K)
Microbial Processes Affecting MNA (PDF) (18 pp, 151K)
MNA of Hexavalent Chromium (PDF) (12 pp, 456K)
Anaerobic Biodegradation of BTEX (PDF) (9 pp, 92K)
Monitoring Redox Processes (PDF) (148 pp, 1.5MB)
Protocol for MNA of Chlorinated Solvents (PDF) (248 pp, 2.5MB)
Evaluation of Protocol for MNA of Chlorinated Solvents (PDF) (49 pp, 1.5MB)
MNA of MTBE in Methanogenic Ground Water (PDF) (59 pp, 1.5MB)