natural attenuation Articles

  • Natural Attenuation

    Introduction: Natural subsurface processes such as dilution, volatilization, biodegradation, adsorption, and chemical reactions with subsurface materials are allowed to reduce contaminant concentrations to acceptable levels. Natural attenuation is not a 'technology' per se, and there is significant debate among technical experts about its use at hazardous waste sites. Consideration of this ...

  • Natural Attenuation in Soils

    Introduction Surface and subsurface soils have different characteristics in natural attenuation. Mobile contaminants in subsurface soils diffuse into soil vapor and aqueous phase and thus are relatively easily subject to natural subsurface processes that can attenuate these contaminants. Most high-molecular-weight (persistent) organic and many inorganic contaminants will be immobilized in the ...

  • A Citizen`s Guide to Natural Attenuation

    What is natural attenuation?Natural attenuation makes use of natural processes to contain the spread of contamination from chemical spills and reduce the concentration and amount of pollutants at contaminated sites. Natural attenuation—also referred to as intrinsic remediation, bioattenuation, or intrinsic bioremediation—is an in situ treatment method. This means that environmental contaminants ...

  • Abiotic and Biotic Pathways in Chlorinated Solvent Natural Attenuation

    ABSTRACT: Abiotic degradative pathways are often overlooked when evaluating natural attenuation at chlorinated solvent sites. Yet, at many sites, significant degradation of parent compounds such as 1,1,1-TCA, PCE and TCE is observed without the corresponding accumulation of daughter products, a sure indication of abiotic reactions. The problems in integrating abiotic processes into MNA are how to ...


  • Case Study - Monitoring Natural Attenuation - Catalonia, Spain

    Researchers at Universitat de Barcelona and University of Waterloo made use of EnviroInsite's advanced data visualization capabilities to contour hot-spots of TCE contamination and carbon isotopes. The results from multi-level sampling devices were then shown on a x-section to illustrate the loss of PCE in the direction of flow and variability of PCE and TCE isotopes vertically across the ...


    By EI LLC

  • Consideration of the Effects of Remediation Technologies on Natural Attenuation.

    ABSTRACT: We have long understood and continue to improve our understanding of the geochemical conditions that favor biodegradation of petroleum hydrocarbons. Over the last several years our understanding of the conditions that are necessary for and/or promote reductive dechlorination of chlorinated hydrocarbons has improved substantially. Over this time in situ remediation technologies have ...


    By REGENESIS

  • Bioremediation/natural attenuation continues after ISCO treatment

    Scientists and engineers from the private sector and EPA are evaluating the potential for in situ bioremediation and/or natural attenuation to successfully treat residual soil and ground-water contamination after source-area in situ chemical oxidation (ISCO) treatment. The studies were prompted by concerns that the two treatment technologies may be incompatible due to detrimental impacts on ...

  • Natural attenuation: better than groundwater extraction?

    Monitored natural attenuation (MNA) was evaluated and implemented in May 2000 as a replacement for groundwater extraction and treatment as the long-term remedy for a chlorinated ethene plume at a Superfund site in Washington (Lehmicke et al. 2000). MNA was approved because the plume met the first two lines of evidence in EPA’s protocol on natural attenuation for chlorinated solvents (U.S. EPA ...


    By Hargis + Associates Inc

  • Risk-Based Closure Considerations For Monitored Natural Attenuation

    ABSTRACT Recent advances in both the chemistry- and hydrogeology-based aspects of monitored natural attenuation (MNA) and in toxicology research have changed some of the traditional approaches to MNA for petroleum and chlorinated groundwater plume management. For MNA to be approved as a remedial approach, human health and the environment must still be protected. To demonstrate protection, ...


    By Weston Solutions, Inc

  • TCE plume management through edible oil injection and natural attenuation

    Two pilot-scale edible oil barriers were constructed in the upper portion of a 1,500 m long chlorinated solvent plume at Dover Air Force Base (AFB), DE. Edible soybean oil was injected into two 6.1 m-long barriers with monitoring wells spaced up to 4.6 m downgradient. Barrier 1 was treated by low pressure, direct injection of soybean oil into ten wells spaced 0.6 m apart. After eight months, a ...


    By Terra Systems, Inc. (TSI)

  • A simple method to check for natural attenuation downstream of abandoned waste disposal sites

    Evaluations of waste sites are based on the assessment of whether conditions for Natural Attenuation (NA) processes are favourable. A method is proposed as a first check for effects of NA in the groundwater emissions. For the application of the method, concentrations of the concerned substance and of a tracer must be available at observation wells at different distances from the source, ...


    By Inderscience Publishers

  • Natural attenuation potential of selected hydrokarst systems in the Carpathian Mountains (Romania)

    We examined the potential for natural attenuation of ten hydrokarst systems (HKS) in three mountain units in the Carpathian Mountains. We sampled in places where water enters below ground and where water emerges back to the surface in springs and is used as drinking water by the local communities. Water samples were used to assess the degree of chemical and microbiological pollution. Although ...


    By IWA Publishing

  • Technical protocol for evaluating natural attenuation of chlorinated solvents in ground water

    The U.S. Environmental Protection Agency is charged by Congress with protecting the Nation’s land, air, and water resources. Under a mandate of national environmental laws, the Agency strives to formulate and implement actions leading to a compatible balance between human activities and the ability of natural systems to support and nurture life. To meet these mandates, EPA’s research ...


    By RNAS Remediation Products

  • Confirming Natural Attenuation Processes at a Coastal Site - Case Study

    Past waste disposal practices at a California coastal site resulted in a groundwater plume containing CVOCs (mainly chlorinated ethenes [CEs] and 1,1-dichloroethane) migrating offshore towards a marine harbor. CVOCs are present in the sediment porewater adjacent to the shoreline, but concentrations decreased significantly between 2000 and 2015, and NA in the marine sediments was suspected. To ...


    By SIREM

  • FATE 5: A Natural Attenuation Calibration Tool for Groundwater Fate and Transport Modeling

    A new groundwater attenuation modeling tool (FATE 5) has been developed to assist users with determining site-specific natural attenuation rates for organic constituents dissolved in groundwater. FATE 5 is based on and represents an enhancement to the Domenico analytical groundwater transport model (Domenico, 1987). These enhancements include use of an optimization routine to match results from ...


  • Historical and Retrospective Survey of Monitored Natural Attenuation Line of Inquiry Supporting Monitored Natural Attenuation and Enhanced Passive Remediation of Chlorinated Solvents

    Overview The Department of Energy (DOE) is sponsoring an initiative to facilitate efficient, effective and responsible use of Monitored Natural Attenuation (MNA) and Enhanced Passive Remediation (EPR) for chlorinated solvents. This Office of Environmental Management (EM) “Alternative Project,” focuses on providing scientific and policy support for MNA/EPR. A broadly representative working group ...


  • Surgical Site Closure: Integrating Natural Attenuation and Focused Source Treatment (PDF)

    “Surgical site closure” is an innovative remedial strategy designed to intelligently integrate natural attenuation, risk-based cleanup goals, and focused source removal/treatment to cost-effectively remediate hydrocarbon-impacted sites. The first step in a surgical site closure is to develop a thorough understanding of site-specific groundwater geochemistry, via an evaluation of the presence and ...


    By REGENESIS

  • Using FTIR spectroscopy to measure hydrocarbon pollution in water

    According to the World Health Organization (WHO) and UNICEF’s 2015 Progress on Sanitation and Drinking Water report almost 700 million people around the world don’t have access to clean drinking water [1]. Poor water quality is beginning to return to the developed world too. The strain of population growth, intensified agricultural practices and continued industrial expansion have are ...


    By Specac Limited

  • Site Characterisation in Support of Monitored Natural Attenuation of Fuel Hydrocarbons and MTBE in a Chalk Aquifer in Southern England

    This Case Study Bulletin describes a research project, which was carried out to determine whether monitored natural attenuation was a viable option for managing fuel hydrocarbon contamination in a chalk aquifer in southern England. The research, which was carried out from February 2000 to March 2001, was undertaken by the University of Sheffield on behalf of TotalFinaElf at a petrol filling ...


    By Solinst Canada Ltd.

  • Tuning the performance of a natural treatment process using metagenomics for improved trace organic chemical attenuation

    By utilizing high-throughput sequencing and metagenomics, this study revealed how the microbial community characteristics including composition, diversity, as well as functional genes in managed aquifer recharge (MAR) systems can be tuned to enhance removal of trace organic chemicals of emerging concern (CECs). Increasing the humic content of the primary substrate resulted in higher microbial ...


    By IWA Publishing

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