Laserfiche WebLink
' it February 2003 AGE-NC Project No'. 98-0520 <br /> ' Page 10 of 21 <br /> ' 6.2.6. Estimated Cost of Soil Vapor Extraction <br /> The costs for SVE systems vary greatly, depending upon the particular system utilized for <br /> ' destruction of the extracted hydrocarbon.vapor(thermal destruction, carbon adsorption, etc.). The <br /> cost to operate, maintain, monitor and sample an SVE system could vary from $25,000.00 to <br /> $30,000.00 per year. Maintenance costs can vary significantly, depending upon the specific unit <br /> ' utilized. However, periodic costs (including maintenance, electricity and supplemental fuel) can <br /> range from $12,000.00 to $30,000.00 annually. <br /> . 6.3. IN SITU SOIL BIOREMEDIATION <br /> ' Local acceptance of this treatment technology by the regulatory community has grown recently,due <br /> to documented success for remediation of petroleum hydrocarbon.contaminants at a number of sites <br /> in.California and elsewhere.However,the CVRWQCB has been reluctant to issue discharge permits <br /> required to inject bacterial inoculum and/or nutrients into the.subsurface. <br /> ' 6.3.1. Principles <br /> Hydrocarbon-degrading bacteria metabolize hydrocarbons and assimilate the resulting organic <br /> ' chemicals into biomass for reproduction and growth,and release water and carbon dioxide as waste <br /> products. The light-end hydrocarbons are typically consumed first, followed by "heavier" <br /> hydrocarbori molecules_ <br /> For in-situ bioremediation, hydrocarbon-degrading bacteria are propagated in a liquid medium, <br /> ' which is then injected into inoculation wells screened in the interval of contamination. If ground <br /> water has been impacted, strategically located ground water monitoring wells can be used for <br /> inoculation.Once in the contaminant plume,the bacteria metabolize and degrade hydrocarbons and <br /> ' spread laterally and vertically by migrating and reproducing, thereby creating an advancing <br /> remediation front. . <br /> ' 6.3.2. Nutrient Requirements and Toxicity <br /> ' The hydrocarbon-degrading bacteria require certain essential nutrients, which are commonly <br /> available in native soil. If supplemental nutrients are needed, the.quantities and concentrations are <br /> generally very low, comparable to the quantities and concentrations utilized for light agricultural <br /> ' use. <br /> Advanced GeoEnviron mental,Inc. <br /> 1 <br />