ARCHIVED REPORTS_XR0009415 - Laserfiche WebLink

Home Browse Search

I . r ' 18 July 2002 AGE-NC Project No 96-0254 Page 14 of 17 degrade hydrocarbons and spread laterally by migrating and reproducing, creating an advancing ' remediation front 6 2 1 Nutrient Requirements And Toxicity ' The bacteria are not tolerant to a wide range of ground water conditions For instance, pH should range from 6 to 8 5 In addition, the possible presence of high concentrations of pesticides or fumlcldes at the site may have a biotoxic effect on some bacteria ' The microbes require certain essential nutrients that are commonly available In ground water If supplemental nutrients are required, such as nitrogen and phosphorus as ammonium phosphate in ' liquid phase,the quantity is usually very low However, a Waste Discharge Permit is required by the RWQCB for the infection of nutrients into ground water Typically,the microbes utilized in bioremediation are aerobic and usually require additional oxygen to supplement dissolved oxygen concentrations in ground water Generally, several air sparging or in-well aeration sources are sufficient to provide the necessary oxygen In some cases, addition of hydrogen peroxide is beneficial ' 6 2 2 Monitoring Activities After inoculation,the inoculation wells and ground water monitoring wells should be monitored for several months by periodic field measurements of organic vapor, carbon dioxide, and dissolved oxygen concentration Ground water samples should be collected and analyzed for petroleum hydrocarbons, bacterial populations and nutrient availability If monitoring indicates areas of slow Iremediation, additional inoculum and/or nutrients may be required ' 6 2 3 Feasibility Studies ' A limited feasibility study for in-situ bioremediation of the ground water at the site was performed in January 2002 Microbiological analysis of an impacted water sample indicated that populations of indigenous hydrocarbon-degrading bacteria constitute 29%ofthe total microbiological population ' at the site, and that some degree of contaminant biodeegradation is likely to be occurring The contaminant biodegradation is moderate to high due to high levels of nitrogen and phosphates The rate of contaminant biodegradation may be stimulated by the addition of nutrients into the ground Iwater Results of the microbiological and physicochemical analysis are Included in Appendix D Advanced GeoEnvironmental,Inc