Laserfiche WebLink
N <br /> 22 November 2006 <br /> AGE-NC Project No. 95-0167 <br /> I <br /> Page 13 of 15 <br /> li <br /> 6.2.3 . FEASIBILITY TESTING <br /> I <br /> Aquifer testing has not been performed at the site. However, sand is present from just below the <br /> -� ground water surface to 15 feet below ground water surface. <br /> l <br /> There are several disadvantages to "pump and treat" methods. The most serious disadvantages <br /> include: 1 ) extended cleanup periods, resulting in increased total costs, although the maintenance <br /> for this method is relatively cost-effective and 2) regulatory cleanup goals are rarely attainable, <br /> mostly due to persistent hydrocarbons detected in subsequent sampling events. Ground water <br /> extraction is generally not a desirable method for remediation. However, this technology is useful <br /> __. for hydraulic control to prevent spreading of the contaminant plume. <br /> ? 6.2.4. DURATION <br /> 1 Experience has shown that all systems involving ground water extraction require much more time <br /> J than would be anticipated from aquifer tests and calculations of ground water discharge rates, and <br /> seldom achieve regulatory goals for ground water clean-up. Systems typically operate for several <br /> years. During this time, pumps and other equipment may need replacement several times. Currently, <br /> - the primary utility of pump-and-treat systems is in control migration of contaminated ground water. <br /> 6.2.5. COST <br /> JGround water extraction is usually a very costly method of ground water treatment. Costs for <br /> installation of a "pump and treat" system typically ranges from $20,000.00 to $30,000.00, including <br /> the installation of one or more large-diameter extraction wells. Once extracted, the contaminated <br /> water must be treated or disposed. Treatment is highly dependant upon the concentrations of <br /> dissolved hydrocarbons in the ground water. For the Guardino and Crawford site, the cost per gallon <br /> could be as great as $2 .00, based upon the extraction/treatment of approximately 100,000 gallons <br /> J of contaminated ground water. Costs for the entire treatment project would likely be between <br /> $ 100,000 .00 and $300,000.00 . <br /> 7.0. RECOMMENDATIONS FOR REMEDIATION OF HYDROCARBON - <br /> Ll IMPACTED SOIL <br /> Significant petroleum-hydrocarbon impact to soil in the vadose zone appears to be limited to the area <br /> containing soil borings P-2, P-3 , P-7, and MW- 1 , in the area of the former USTs dispenser area <br /> �I (Table 1 ). The greatest concentrations of hydrocarbons were detected beneath the former fuel <br /> Advanced GeoEnvironmental, Inc. <br /> CI <br />