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.
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 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 crude oil remediation?
Remediation could be done ex situ or in situ through various technologies. The ex situ method involves the removal of the contaminated soil and/or water to clean up on another surface, while the in situ method refers to decontaminating the soil and/or water at the site of pollution.
What is an example of Bioaugmentation?
An example of how bioaugmentation has improved an environment, is in the coke plant wastewater in China. In the enhanced microbial community indigenous microorganisms broke down the contaminants in the coke plant wastewater, such as pyridines, and phenolic compounds.
What are MNA parameters?
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.
What is enhanced bioremediation?
Enhanced anaerobic bioremediation is the practice of adding hydrogen to soil and groundwater to increase the number and vitality of indigenous microorganisms performing anaerobic bioremediation on any anaerobically degradable compound.
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 do you mean by bioremediation?
Bioremediation is a process that uses mainly microorganisms, plants, or microbial or plant enzymes to detoxify contaminants in the soil and other environments.
What is monitored natural attenuation (MNA)?
Monitored natural attenuation (MNA) consists of a range of naturally-occurring in situ physical, chemical, and biological processes that attenuate contaminant concentrations in groundwater to achieve remedial goals within a reasonable timeframe, and protect human health and the environment.
Can site COCs be remediated via natural attenuation processes?
Three lines of evidence may be evaluated to confirm that site COCs can be remediated via natural attenuation processes: Examine historical contaminant trends to determine if contaminant mass and/or concentrations are decreasing over time or have reached plateau levels due to matrix diffusion or other mass transfer limitations.
Is MNA a viable remedy at a site?
Appropriate institutional controls or point-of-use treatment may be required until natural attenuation reaches remedial goals. To assess whether MNA is a viable remedy at a site, the following lines of evidence should be demonstrated by site data (NAVFAC, 2008; ITRC, 2008; EPA, 2008; AFCEE, 2007):
How are monitoring wells used to assess the effectiveness of MNA?
A typical monitoring well network needed to demonstrate the effectiveness of MNA includes four different types of monitoring wells, each with a distinct purpose: Background wells are monitored to confirm areas that are not impacted by COCs. Field parameters/geochemical data are compared to data from impacted wells to assess MNA.