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Select a search operator (AND or OR) and desired properties for each category, then press the SEARCH button. Located below are instructions about Using the Tech Chart and definitions for the Tech Chart Properties.

Note: If a category is left unchecked, all properties will be selected.

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Contaminant Media Technology
Unexploded Ordnance
Not Specific
Ground Water
Surface H2O/Sediment
Landfill Materials
Building Surfaces
Indoor Air/Soil Gas
In-situ treatment

The Technology Tree Matrix is a tool for identifying technology used to characterize and clean up hazardous waste sites. Technologies and the problems that they address can be looked up by checking appropriate boxes in the matrix. Property definitions are included at the end of the page.

You can find what you're looking for by by selecting any combination of media, contaminants, and technology types in the Technology Chart, and displays a sorted list of technologies meeting those criteria. When you select a specific technology from the sorted list, the Tree also displays a Technology Description Summary and all Descriptions offer WWW links to more detailed information

Contaminant Type
Energetics This category includes the chemicals that constitute propellants, explosives, and pyrotechnics, and refers to issues associated with toxic exposure.
Fuel (F) This category includes gasoline, jet fuel, grease and other petroleum hydrocarbons, as well as fuel additives such as MTBE (methyl tertiary butyl ether)
Volatile Organic Compounds (VOC) This category includes solvents that easily change phases, or evaporate. This attribute often makes the compound easier to detect and remove. Very frequently, these compounds are chlorinated. Typical contaminants of this type are Trichloroethene (TCE) and its daughter products such as vinyl chloride.
Semi-volatile Organic Compounds (SVOC) This category includes contaminants that are more difficult to remove because they do not easily change phases, and often adsorb onto soil particles. Typical contaminants of this type are Polychlorinated Biphenyls (PCB), and polynuclear aromatic hydrocarbons (PAHs), such as coal tars and creosote.
Pesticides and Herbicides (Pe) This category includes contaminants that by design are very toxic or damaging to the environment.
Metals (M) This category includes metals such as lead, chromium and arsenic, but does not include radioactive metals.
Radionuclides (R) This category includes contaminants that are radioactive. Typical contaminants include tritium (radioactive hydrogen) and uranium.
Unexploded Ordnance (UXO) This category includes unexploded bombs and shells. as well as discarded military munitions, that may be found at impact ranges and disposal site, as well as randomly in the environment. Contaminants in this category present hazards due to explosion.
Not Specific (NS) This category covers any situation for which the selection of the technology does not depend upon the contaminant type.
Media Type
Off-gas (OG) This category consists of the vapors that are emitted from extraction and treatment systems. For example, typical pump-and-treat systems extract groundwater and strip it of contaminants. These contaminants are usually vaporized, and can either be discharged directly to the atmosphere or captured or destroyed.
Groundwater and Leachate (GW) The subsurface environment consists of layers of granular materials, clay and rock. When all the void spaces in these materials all filled with water, the material is saturated. The water flowing in these spaces is called groundwater. In landfills, liquids that run through the fill material and collect in pockets in or below the landfill is called leachate.
Surface Water and Sediment (SW) This category consists of waters that flow on top of the ground surface (surface waters) and the sediments that lie underneath this water. Often, surface waters carry a large variety of contaminants that have been carried off from the land surface and are deposited in sediments.
Soil (S) This category is the zone either at or below the ground surface that is above saturated zones. This is referred to as the unsaturated subsurface or the vadose zone.
Landfill Materials (L) This category contains the diverse materials found in solid and hazardous waste landfills. Wastes may still be in containers. Landfills are man-made and deliberate locations where a variety of wastes may be located.
Building Surfaces (Su) This category includes building surfaces and pipes. Contaminants may range from asbestos to lead paint.
Indoor Air/Soil Gas
This refers to contaminant vapors found inside structures, in the vadose zone (between groundwater and the surface), and at times the ambient (outdoor) air.
Technology Types
Advanced Analytical Methods, Characterization, and Monitoring (ACM) Before, during and after a site is remediated, contaminants are continually analyzed, and the site must be characterized and monitored. Typical technologies in this category are the cone pentrometer and advanced sensors. To reduce costs, innovative analytical methods that can be performed in the field have been developed and are included in this category.
In-situ Treatment (IT) After it is decided that contamination is present, one of the first questions that is asked is whether the contaminants can be treated in place (i.e., in-situ). Treatment could include destruction, or reduction in mobility or mass. Typical in-situ methods range from phytoremediation (absorption and metabolism by plants) to permeable barrier walls (walls of material that react with an agent to render it harmless).
Removal (R) If contaminants cannot be successfully treated or destroyed in place, they have to be removed and treated, contained, or disposed of. This category includes removal enhancements such as directional drilling and electrokinetics.
Treatment and Destruction (T) After removal, contaminants must be treated or destroyed. A typical technology in this category is an incinerator.
Containment (CT) Containment is remediation strategy that is selected when treatment is impractical. It is often used, or in combination with in-situ treatment. The most common containment measures are capping landfills and placing barriers in the subsurface to impede migration. Some technologies apply to more than one contaminant or media. For example, if a technology addresses two contaminant types, it may be found by checking either of the appropriate boxes. In some cases, technologies are not specific to contaminant or media. In this case there is a box in each column that addresses these technologies. Also, some technologies are a combination of technology types. In this case, the technology can be found in either appropriate category.
Mitigation Mitigation generally refers to a remedial response that eliminates or reduces an exposure pathway without removing or treating the source.

This page was last updated September, 2010.
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