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' 29 April 2005 ; AGE-NC Project No. 9870440 Page I.J.of 18 distilled water'to each well. The hydrocarbon-degrading bacteria are also tolerant to a wide range of soil conditions.For instance, p1l can range from 4.0 to 9.5 and-electrical conductivity has;'little or no effect unless:sodium ' concentrations exceed 5% on a weight basis: , 6.2.3.' .Inoculation Wells ' The cffective radius of influence in soil of inoculation wells is typically 15 feet.-Existing monitoring wells can be used for inoculation of the smear zone as.well as ground water, but the inoculum will tend.to go to.the bottom of a monitoring well and pass.into the saturated ground water-zone from the annular space near the bottom.Although a greater radius of influence is usually obtained for ground ' water inoculation, since,ground water movement can assist the bacterial migration, additional. inoculation points would be needed.for in-situ soil treatment of the vadose zone,utilizing temporary ' inoculation points or soil borings. '6.2.4. Monitoring Activities After inoculation,the inoculation wells and ground water monitoring wells should be monitored over , ' a period of several months through periodic field measurements.of organic vapor, carbon dioxide, and oxygen concentrations. Quarterly or semi-annual monitoring activities should also include the installation of soil borings to, collect soil'samples to monitor bacterial populations, nutrient ' availability and sail remediation progress. If monitoring indicates areas. of slow remediation, additional inoculation or addition of nutrients may be required.e(; 6.2.5. Duration Duration.(and cost).is dependent on the volume of soil-and water to be remediated, the number of inoculation and monitoring wells,the average concentrations,of contaminants and nutrients,and the temperature and permeability of the soil'.Theoretically,the radius-of influence of the inoculation well should increase'.rapidly-at first, then gradually decline as the affected volume increases and,the- 'bacteria encounter decreasing hydrocarbon concentrations toward-the margins of the hydrocarbon plume.Shorter-chain hydrocarbons are typically consumed firstand longer-chain hydrocarbons later. , Remediation at sites with similar soil composition typically,takes'between 12 and 48 months. . „ Advanced GeoEnvironmental,Inc.