Laserfiche WebLink
1 ` <br /> l <br /> 19 June 2000 <br />• AGE-NC Project No 96-0232 <br /> Page 28 of 35 <br /> 915 Duration <br /> Air spargmg in low permeable aquifers generally result in inefficient clean-up and prolonged <br /> remediation rates Based on existing site conditions, a remediation period cannot be predicted <br /> 9 16 Cost <br /> Installation of an IAS system generally requires the installation of additional IAS wells, an IAS <br /> piping system and IAS equipment Setup costs would likely range from $35,000 to $45,000 <br /> Sparging equipment maintenance and monitoring would range from$5,000 to $10,000 annually for <br /> an undetermined duration Total cost cannot be predicted <br /> If air sparging is chosen for ground water remediation, a vapor extraction system would be utilized <br /> for vapor recovery and migration control, significantly increasing annual costs <br /> 9 2 GROUND WATER EXTRACTION <br /> There are several different methods for treatment of extracted ground water, which are collectively <br /> called "pump and treat" All methods of pump and treat involve extraction and transfer of <br /> contaminated ground water from the aquifer to an above-ground treatment or disposal/recycling <br /> facility The extraction Is performed using an automatic pump system to maintain capture <br /> characteristics In the aquifer and to assure that process volume requirements are maintained After <br /> treatment,the water can be discharged into a storm dram or sanitary sewer A waste discharge permit <br /> would be required for discharge <br /> 9 2 1 Treatment Methods <br /> The documented concentrations of dissolved hydrocarbons on the site will trigger a requirement for <br /> treatment of the extracted water Two of the most common methods of water treatment are air <br /> stripping and carbon adsorption Air stripping Involves removal of volatile organic compounds from <br /> ground water by promoting the transfer of contaminants from the dissolved phase to the vapor phase <br /> Carbon adsorption utilizes granular activated carbon to simply"filter" organic compounds out of <br /> ground water _ <br /> A third, but less common method of above-ground treatment of water Is bioremediation <br /> Contaminated ground water is "treated" by adding hydrocarbon-degrading microbes or by <br /> augmenting natural hydrocarbon degradation activities with the introduction of nutrients <br /> Advanced GecEn%tronmcntal,Inc <br />