Make your own free website on Tripod.com

Matrix of Alternatives

                         
Technology   Contaminant Destruction or Transfer? Complete Technology or Part of Treatment Train? End Products Effectiveness Ability to work in clay type soils Installation Notes Ease of O&M1   Regulatory acceptance   Notes
CURRENT TECHNOLOGY                        
Pump and Treat   Transfer Part of treatment train or complete technology Clean water and air as a complete technology. Contaminated water as part of a treatment train. Takes a long time to reach cleanup goals Not very efficient Fairly Easy Lengthy O&M period   Yes   Losing favor as a preferred alternative
Air Stripping (used in conjunction with Pump and Treat)   Transfer - Contaminant vented into atmosphere or transferred to carbon filter Part of treatment train Clean water and contaminated off gas Effective treatment Not Applicable Fairly Easy Requires periodic maintenance and filter changes   Yes   Doesn't provide TCE destruction
Air Sparging   Both - Volatizes TCE and enhances bioremediation Can be complete technology or part of treatment train May create contaminated off gas. Soil vapor extraction may be required to further remediate the site. Effective in porous geology May create preferential channels or be ineffective Fairly Easy Simple O&M   Yes    
Air Sparging with Soil Vapor Extraction   Mostly Transfer - Volatizes TCE and enhances bioremediation Can be complete technology   Effective in porous geology May create preferential channels Fairly Easy Requires off-gas treatment   Yes   More effective than air sparging alone
Carbon Adsorption (vapor phase)   Transfer Part of treatment train Clean air and TCE-contaminated carbon Effective treatment Not Applicable Fairly Easy Requires periodic change of carbon   Yes    
Flameless Thermal Oxidizer   Contaminant destruction - 99% achievable Part of treatment train Clean air and hydrochloric acid that may require use of a caustic scrubber. Effective treatment Not Applicable Fairly Easy Requires periodic maintenance and catalyst replacement   Yes   Not as effective on TCE as petroleum hydrocarbons
Catalytic Oxidation   Contaminant destruction - 99% achievable Part of treatment train Clean air Effective treatment Not Applicable Fairly Easy Requires periodic maintenance and catalyst replacement        
                         
EMERGING TECHNOLOGY                        
                         
Natural Attenuation   Contaminant Destruction Can act alone or be enhanced Clean ground water Effective over a long period of time Effective Not Applicable Not Applicable   Very Limited   Sampling and modeling required to demonstrate conditions are appropriate
In Situ Air Sparging with Horizontal Wells   Both - Volatizes TCE and enhances bioremediation. VOCs transferred via extraction wells Can be complete technology or part of treatment train May create contaminated off gas. Soil vapor extraction may be required to further remediate the site. Effective in porous geology Not very efficient Horizontal well placement may be difficult Requires off-gas treatment   Limited, due to youth of technology   More efficient than vertical air sparging
Methane Enhanced Bioremediation Using Horizontal Wells   Both - Volatizes TCE and enhances bioremediation. VOCs transferred via extraction wells Can be complete technology or part of treatment train Should be clean ground water. May create contaminated off gas. Soil vapor extraction may be required to further remediate the site. Effective in most geologies Effective, due to methanogenesis Horizontal well placement may be difficult Requires off-gas treatment   Limited, due to youth of technology   More efficient than horizontal air sparging alone. Enhances bioremediation
Reactive Walls or Cells (Iron Filings)   Contaminant destruction via reductive dehalogenation Complete technology Clean ground water Effective in shallow aquifer underlain by confining layer Effective with sufficient groundwater flow Requires in-depth knowledge of site hydrology and heavy equipment to install No moving parts to maintain or filters to change   Limited. In field test phase   Provides for complete destruction of TCE and harmful daughter products
UV Oxidation   Contaminant destruction Part of treatment train Clean ground water, carbon dioxide, and salts Effective Not Applicable May require pre-treatment of water if turbid Requires handling and storage of powerful oxidizers   Limited. In field test phase    
Six-Phase Soil Heating   Both - Sterilizes soil and drives off volatile TCE which is removed via SVE Can be complete technology Contaminated off gas Effective in clay soils Effective Requires large power source and site restrictions Requires off-gas treatment and maintenance of electrodes   Limited. In field test phase    
Dynamic Underground Stripping of Volatile Organic Compounds   Both - Sterilizes soil and drives of volatile TCE which is removed by SVE Part of treatment train Contaminated off gas and ground water Provides rapid remediation Effective Fairly Easy Requires off-gas treatment   Limited. In field test phase   25 to 40 times more effective than pump and treat alone
Lasagna Process   Can be both Can be complete technology or part of treatment train If used in-situ, the end products are clean ground water and soils. As part of a treatment train, contaminated off gas and water may be extracted. Effective in clay soils Very Effective Moderate Difficulty Short O&M period   Limited. In field test phase   Field tested at Rickenbacker ANGB, Ohio
Phytoremediation   Can be both Can be complete technology or part of treatment train Clean groundwater is an end product. Contaminated plant tissues may also occur. Effective in clay soils Effective Fairly Easy O&M may be limited to LTM   Limited. In field test phase   Field tested at Naval Air Station Fort Worth, Texas
Vacuum Vapor Extraction   Both - remediates ground water and vadose zone while volatile TCE is treated ex situ Part of treatment train TCE-contaminated off gas. Ground water remains in-situ. Effective in clay soils Effective Fairly Easy Requires off-gas treatment   Limited    
Oxygen Enhancement with Hydrogen Peroxide   Contaminany Destruction/Bioremediation Can be complete technology Clean ground water Effective Moderately effective Fairly Easy Requires delivery of hydrogen peroxide   Limited    
RESEARCH NOT YET FIELD TESTED                        
                         
Silent Discharge of Plasma Decomposition   Contaminant destruction Complete technology Carbon dioxide and chlorine Still in laboratory              
Fixed-Bed Photocatalysts for Solar Decontamination of Water   Contaminant destruction Part of treatment train Clean ground water Still in laboratory              
                         
1. All remedial actions require some amount of long-term monitoring (LTM) that may be considered O&M.                        
Items in this column reflect requirements above and beyond standard LTM.                        


Last Updated on 1/10/98
By DH