What does monitored natural attenuation mean?
Monitored Natural Attenuation (MNA) is an important, common groundwater remediation technology used for treating some dissolved groundwater contaminants. MNA relies on natural attenuation processes to achieve site-specific remediation objectives within a reasonable time frame compared to more active approaches.
What does natural attenuation mean?
Natural attenuation relies on natural processes to clean up or attenuate pollution in soil and groundwater. Natural attenuation occurs at most polluted sites. Scientists monitor or test these conditions to make sure natural attenuation is working. This is called monitored natural attenuation or MNA.
What is monitored natural attenuation MNA in the contaminated land remediation context?
Definition of Monitored Natural Attenuation (MNA) Application of natural attenuation requires demonstration that natural processes are occurring at a rate that a) protects the wider environment and b) achieves remedial objectives within a reasonable time-frame.
What is MNA process?
Monitored natural attenuation (MNA) can be an effective and low-cost approach for remediation of contaminated sites. MNA includes physical, chemical and biological processes that reduce contaminant mass or concentration in soil or groundwater under intrinsic condtions.
How does monitored natural attenuation work?
Natural attenuation relies on natural processes to decrease or “attenuate” concentrations of contaminants in soil and groundwater. Monitoring typically involves collecting soil and groundwater samples to analyze them for the presence of contaminants and other site characteristics.
Is natural attenuation economical?
Natural attenuation utilizes the natural soil environment to decontaminate a petroleum hydrocarbon-impacted soil. It is popular, because it is one of the most cost-efficient technologies available. However, it may not be the most time-effective approach available.
What is natural attenuation in bioremediation?
Natural attenuation refers to processes that naturally transform contaminants to less harmful forms or immobilize contaminants so that they are less of a threat to the environment; see “Natural Attenuation for Groundwater Remediation” by the National Research Council (National Research Council, 2000).
What is the process of phytoremediation?
Phytoremediation is a bioremediation process that uses various types of plants to remove, transfer, stabilize, and/or destroy contaminants in the soil and groundwater. In this process, chemical compounds produced by the plant immobilize contaminants, rather than degrade them.
What type of microbial evidence is required during natural attenuation?
The EPA [18] of the United States was the first to propose that three lines of evidence for natural attenuation should be applied to demonstrate that natural attenuation is taking place: (1) documented decrease in contaminant concentrations at the site, (2) documented geochemical or geomicrobiological conditions …
What is natural attenuation bioremediation?
Natural attenuation and bioremediation are methods to treat polluted environments, in which microorganisms contribute to pollutant degradation. For risk assessments and endpoint forecasting, natural attenuation sites are carefully monitored (monitored natural attenuation).
What is enhanced natural attenuation?
Sites can get “stuck” in the process, delaying achievement of long-term groundwater cleanup goals. • Enhanced Attenuation (EA) is a plume remediation strategy to achieve groundwater. restoration goals by providing a “bridge” between source zone treatment and MNA and/or between MNA and slightly more aggressive methods.
Is phytoremediation a natural process?
Phytoremediation is a bioremediation process that uses various types of plants to remove, transfer, stabilize, and/or destroy contaminants in the soil and groundwater. In this process, the plant releases natural substances through its roots, supplying nutrients to microorganisms in the soil.
How is natural attenuation used in Superfund cleanup?
The Citizen’s Guide series is a set of 22 fact sheets that summarizes cleanup methods used at Superfund and other sites. Natural attenuation relies on natural processes to decrease or “attenuate” concentrations of contaminants in soil and groundwater.
How is natural attenuation used in soil remediation?
Monitored Natural Attenuation. When chlorinated solvents are spilled or leak into soil or groundwater, natural processes occur to destroy or alter the chemicals. This natural attenuation is recognized by the EPA as a viable method of remediation for soil and groundwater.
When does natural attenuation occur in a spill?
Monitored Natural Attenuation When chlorinated solvents are spilled or leak into soil or groundwater, natural processes occur to destroy or alter the chemicals. This natural attenuation is recognized by the EPA as a viable method of remediation for soil and groundwater.
How does MNA work in the natural environment?
MNA can work with other more active remedial tools at some sites where biogeochemical conditions favor natural processes that degrade or immobilize harmful contaminants. Inorganic Contaminants and Radionuclides – developed a framework document for MNA of inorganic contaminants.