Groundwater contamination remediation

Groundwater contaminated with chlorinated hydrocarbons is being remediated by a conventional air stripper or a rotary stripper, producing an air stream containing the halogenated hydrocarbon vapors and saturated with water vapor (45), which is then passed through a catalyst bed. 

A permeable reactive barrier (PRB) is defined as an in situ method for remediating contaminated groundwater that combines a passive chemical or biological treatment zone with subsurface fluid flow management. Treatment media may include zero-valent iron, chelators, sorbents, and microbes to address a wide variety of groundwater contaminants, such as chlorinated solvents, other organics,... 

From the 323 projects in U.S. EPA s MTBE Treatment Profiles dataset, 85 projects were identified where MTBE in groundwater was remediated using pump-and-treat along with 15 additional projects that treated MTBE in drinking water (collectively referred to as pump-and-treat projects). Information on the treatment of other oxygenates was reported for 20 of these 100 projects 16 projects reported TBA, 6 projects reported TAME, 2 projects reported ethanol, and 1 project reported DIPE as a contaminant in addition to MTBE. 

Rau, B. V., Vass, T., and Stachle, W. J., 1992, DNAPL Implications to Investigation and Remediation of Groundwater Contamination In Proceedings of the Hazardous Materials Control Research Institute, HMC-South 92, New Orleans, LA, pp. 84—94. 

Vanloocke, R., DeBorger, R., Voets, J. P, and Verstraete, W., 1975, Soil and Groundwater Contamination by Oil Spills Problems and Remedies International Journal of Environmental Studies, No. 8, pp. 99-111. 

Residual hydrocarbons will continue to serve as a source of groundwater contamination thus, remediation strategies for DNAPLs should emphasize long-term control and management (i.e., source containment, pool control, and recovery) vs. short-term fixes. Regardless of an increased level of effort (i.e., additional wells, increased pumping rates, etc.), the overall time for remediation is not expected to shorten by more than a factor of five. 

LNAPL product was found to be distributed over the central portion of the site with measured apparent thicknesses of approximately 0.2 to 0.5 ft. Concluding that additional work was warranted at the site, two goal-oriented objectives were developed (1) consideration of on-site remedial alternatives to prepare the site for other industrial uses and (2) determination of the extent of off-site groundwater contamination. 

Petroleum hydrocarbons are commonly found in environmental contaminants, although they are not usually classified as hazardous waste. However, soil and groundwater contamination by petroleum hydrocarbon has spurred various analytical and site remediation developments (e.g., risk-based corrective actions). 

At the Environmental Protection Agency s (EPA s) Perham Arsenic Superfund Site in Perham, Minnesota, a continuous-backwash filtration unit is used to treat groundwater contaminated with arsenic. In 1994, according to the EPA Record of Decision (ROD) at the site, the present worth costs of the remediation were 2,548,776. The annual operations and maintenance (O M) costs were projected to be 217,805 (D17114C, pp. 2-3). 

The vendor states that bioinfiltration technology was used at a gasoline service station in New lersey to remediate soil and groundwater contaminated with fuel oil. The technology treated 2000 yd of soil as well as the contaminated groundwater. The depth of contamination ranged from 8 to 12 ft. The total project cost was 125,000 (D15646R, pp. 8-11). 

The two-phase vacuum extraction (TPVE) technology allows for the in situ remediation of soils and groundwater contaminated with volatile organic compounds (VOCs). Two-phase vacuum extraction is similar to conventional vapor extraction in the equipment required, with the exception that it is designed to actively remove contaminated groundwater from the extraction well along with the vapor-phase contamination. 

Dual-phase extraction accelerates site remediation by simultaneously extracting contaminated liquid and soil vapor from the subsurface. The technology can be used to treat soil or groundwater contaminated with chlorinated solvents and petroleum hydrocarbons. 

CESAR was developed to address the problem of locating, characterizing, and removing dense non-aqueous-phase liquids (DNAPLs) from contaminated aquifer systems. The process is particularly suited to remediating groundwater contaminated with chlorinated solvents, such as trichloroethylene (TCE), tetrachloroethene (PCE), trichloroethane (TCE), and carbon tetrachloride (CCE). According to the vendor, CESAR can also be applied to sites contaminated with creosote, polychlorinated biphenyls (PCBs), Freon 113, volatile organic compounds (VOCs),... 

The process of anaerobic biotransformation with steam injection is a technology for the in situ remediation of soils and groundwater contaminated with dense non-aqueous-phase liquids (DNAPLs). Using this approach for remediation, steam is injected into the soil to volatilize and remove DNAPLs, with the simultaneous introduction of nutrients. The resulting subsurface conditions are suitable for biotransformation of the dissolved phase, into compounds that are more easily removed by vapor and groundwater extraction. 

In 1991, an EXXFLOW/EXXPRESS system was combined with an air stripper to remediate groundwater contaminated with chromium and trichloroethene (TCE) beneath an abandoned manufacturing plant in Newbury Park, California. System equipment cost approximately... 

At the Mustang-Shadow Mountain Gas Station, in Grand Lake, Colorado, FOREMOST installed 3 BioNets containing 3 BioLuxes to remediate soils and groundwater contaminated with BTEX. The design and installation of this system cost 130,000 (D213332, Appendix... 

The Geo-Cleanse process remediates soil and groundwater contaminated with organic compounds including fuel oils, gasoline, solvents, halogenated compounds, pesticides, polychlorinated biphenyls (PCBs), and other organic contaminants. 

Quick-Purge is a patented, commercially available, in situ technology for the remediation of soil and groundwater contaminated with organic compounds. The technology is primarily used for the remediation of sites contaminated with hydrocarbon constituents associated with diesel fuel, gasoline, kerosene, solvents, and creosote. 

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