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Site Characterization
Quickfinder
Innovative methods and techniques to solve difficult site characterization problems are needed by EPA’s Office of Solid Waste and Emergency Response (OSWER) and the Agency’s Regional Offices across the country that work with states to clean up contaminated sites. The Land Research Program (LRP) in EPA’s Office of Research and Development conducts research to develop:
- Analytical Methods
- Field Sampling Guidance
- Statistical software
- Oil spill dispersal modeling and remediation
- Monitoring and remediation technologies for mining sites (specifically bioreactors).
Analytical Methods
An important step in site characterization is to understand the types of contaminants present and the extent of their dispersal in the environment. This information is needed before predictions of contaminant fate and transport can be made, risk assessments performed, or remediation options evaluated.
Analytical methods research supports this understanding by improving cost, accuracy, portability, and speed of analysis for the most common or most difficult to analyze inorganic and organic contaminants. Immunochemical and other bioanalytical methods can allow rapid on-site characterization and monitoring of remediation and cleanup activities at Superfund sites. Immunoassay detection, immunoaffinity chromatography sample preparations, electrochemical immunosensors, and coupled immunoassay detection/chromatography/mass spectrometry methods will be developed that allow for rapid, accurate, and precise quantification of various contaminants in the field.
The use of these field methods will allow real time decisions to be made on additional sampling needs, delineating contaminant distributions, and determining the effectiveness of remedial actions. Future bioanalytical work will include development of dioxin assays for soil and sediments and a shift in focus to real-time and more cost-effective groundwater analytical methods.
Additional analytical method development will include methyl mercury analyses in liver and muscle tissues for fish taken from Superfund mercury-impacted areas and the use of semi-permeable membranes and isotope dilution mass spectrometry for PCB analyses.
Field Sampling Guidance
The assessment and cleanup of sites contaminated with multiple contaminants in multiple media is a complex process in which many factors can influence the validity and confidence in the final data used to decide on future actions at the site. Research by the LRP in statistical sampling and data analysis is aimed at improving or developing statistical methods to reduce data uncertainty in the experiment or measurement process for environmental decision making.
Peer-reviewed journal publications, book chapters, and guidance documents on robust data analysis, including multivariate outlier testing, causal outlier variable methods, principal component analysis, discriminant analysis, censored data analysis, multivariate geostatistical methods, and methods in parallel space are being developed.
Statistical Software Research
For site managers, the SCOUT statistical software package developed by the LRP will be upgraded with new robust statistical procedures and a geostatistical model that allow for more advanced statistical techniques to be used in the assessment of the validity of analytical data. A field-sampling guidance document to identify methods and techniques to eliminate bias that occurs during field sampling will also be developed. This research will help site managers understand the driving factors and tradeoffs affecting environmental sampling design and to assess the validity (with increased confidence) of the data used during decision making on site characterization and remediation efforts.
Oil Spills Research
The LRP conducts oil spills research to support the preparedness and response functions of EPA’s Oil Spills Program. Research is focused in three areas: developing a better understanding of fate and effects of spilled oil; development of testing protocols for spill control; and development of response options.
Developing modeling methodologies to assess the fate and effects of oil spills in fresh and saline waters will provide important tools, methods, models, data, guidance, and technical support to site managers and other decision makers and stakeholders to use in assessing and cleaning up spills of petroleum and non-petroleum oils. This work will provide essential information on dispersion and effects of dispersant treatments on spilled petroleum, non-petroleum oils, and their constituents. Some of the major outputs of this work will be a report on linkage of the EPA research object-oriented-oil spill model (ERO3S) oil spill model to surface water transport and quality models, assessments of optimal parameters for nutrient application for oil spill bioremediation on beaches, and assessments of optimal conditions for the bioremediation of wetlands. A major goal of this research effort is to develop a multicomponent mass-balance-based model for simulating transport of spilled oils with and without dispersant treatments.
Selection of appropriate risk management options in oil spill scenarios is supported through the development of protocols to evaluate spill response products and through development of new risk management strategies for petroleum and non-petroleum oil spills in fresh and saline environments. Research includes work on petroleum and fuel emulsions, chemical and biological treatment, climatic effects on oil spills, dispersant modeling, and ecosystem exposure as a function of various response scenarios.
In addition, risk management strategies are being developed for non-petroleum oil spills. EPA’s Office of Research and Development, in collaboration with Fisheries and Oceans Canada, has funded the construction of a wave tank in Halifax, Nova Scotia, which generates breaking waves. The wave tank will allow quantification of dispersant efficacy as a function of sea turbulence and the development of correlations between laboratory and wave tank data. In collaboration with Canada, work is also underway to develop a surface-washing agent to remove oil from coated surfaces, followed by round-robin validation testing.
Mining Research
One of the highest priorities and needs of many of the EPA Regional offices across the country has been mine water remediation. It is estimated that there are over 400,000 abandoned mine sites in the western United States, and almost all of these sites contain contaminated waste and water. In the past five years, technical assistance for active and passive treatment of mine water has accounted for upwards of 25 percent of the engineering assistance requests. While active treatment has been utilized at the larger mining mega sites, there is a need for treatment systems that can be located in remote areas and at higher elevations. In these areas, there is no power source, access is restrictive, and the treatment season is very short because of winter weather. The LRP has been actively supporting the research and acceptance of passive systems that require little power, have an acceptable operational life, and rely on chemical precipitation and adsorption as well as biological processes (sulfate-reducing bacteria and other microorganisms) to treat the water. The science is still in its infancy and has to be proven effective to meet effluent criteria and sustainable over longer periods of time.