Laserfiche WebLink
15 June 1999 <br /> . AGE-NC Project No 98-0450 <br /> Page 22 of 27 <br /> are Infected through ground water monitoring wells The microbes degrade hydrocarbons and spread <br /> laterally and vertically by migration and reproduction Typically, the light-end (gasoline-range) <br /> hydrocarbons are degraded first, followed by heavier compounds <br /> 5 3 2 Requirements <br /> The most Important parameters In (aerobic) biostimulation of subsurface environments Is the <br /> transport and dispersion of dissolved oxygen through the aquifer Typically, In-situ air sparging can <br /> ' be utilized to provide oxygen to an aquifer, and/or the oxygen content In ground water can be <br /> Increased by the addition of hydrogen peroxide to ground water monitoring wells In addition to <br /> oxygen, microbes require certain essential nutrients that are commonly available In ground water <br /> If supplemental nutrients are required, such as nitrogen and phosphorus as ammonium phosphate In <br /> liquid phase,the quantity Is usually very low A Waste Discharge Permit would be required by the <br /> RWQCB for the Injection of nutrients Into ground water <br /> 5 3 3 Monitoring Activities <br /> Subsequent to Initial Inoculation, ground water from the Inoculation and monitoring wells would <br />' need to be periodically monitored for petroleum hydrocarbons, bacterial populations, dissolved <br /> oxygen content, and nutrient availability If monitoring Indicates areas of slow remediation, <br /> additional Inoculations may be required <br /> 5 3 4 Feasibility <br />' No feasibilitystudies to Ics for In-situ bioremediation of the dissolved hydrocarbons have been performed <br /> at the site Prior to conducting bioremediation, ground water samples would need to be collected and <br /> analyzed for physicochemical properties to evaluate nutrient levels, blotoxlclty, and microbial <br /> activity for bioremediation effectiveness Based on Information obtained from boring logs(Appendix <br /> A), the subsurface saturated zone consists primarily of sand, suggesting a relatively high Intrinsic <br /> permeability The permeability of saturated zone soil may be conducive to the migration of <br /> microorganisms and the dispersion of supplemental oxygen and nutrients through the aquifer <br /> 53 5 Duration <br /> • Clean-up durations for in-situ situ bloremedlahon vary depending upon site-specific characteristics <br /> Based on the relatively high concentrations of dissolved hydrocarbons at the site, a treatment period <br /> Adianced GeoEnrironmenlal,Inc <br />