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gradient ranging from 0 000746 (March 16, 2000) to 0 001635 (August 19, 2000), the groundwater velocity will range between 0 462 and 0 686 feet per day Based on the capture zone analysis, the spacing of wells to ensure capture of all groundwater crossing the downgradient property boundary would be between 42 5 and 63 0-feet, depending on the potentiometric surface gradient However, in the interest of being conservative, a more appropriate well spacing would be approximately 30-feet Groundwater samples were collected every 240-minutes throughout the pump test The samples were contained in 40-m1 volatile organic analysis vials (VOAs), preserved with hydrochloric acid and sealed without headspace The samples were labeled and placed on ice for transport to Kiff Analytical, LLC for analyses of TPH-U, BTEX, oxygenates and HVOCs by EPA Method 8260 The analytical results are tabulated in the Tables Section as Table One The certified analytical report and chain of custody is attached in Appendix E 5 .3 Air Sliarging lest On August 24, 2000, ASE senior project manager David Allen, in conjunction with Jonathan Walden of Solleco, conducted an air sparging test at the site Beginning at 10 25, filtered compressed air was infected into the air sparging well at a rate of 2 5 cubic feet per minute (cfm) at 5 pounds per square inch (psi) Pressure and water levels in the five surrounding piezometers and monitoring well MW-5 were monitored/measured to determine whether there was any pressure increase in the vadose zone or mounding of the water table Within lust a I few minutes, each of the observation points showed positive pressure increases After 100 minutes, the flow rate of air being injected into t h e air sparge well was increased to 4 cfm at 10 psi Once again, pressure a n d water levels in the surrounding wells were monitored until a stabilization was achieved Once again, the increase was obvious only minutes after the flow was increased The positive pressure test data is tabulated as Table Two in the Tables Section When reviewing the data sheet, o n e should be aware that the positive pressure influence on nearby monitoring well MW-5 started out with only a slight increase However, Iafter approximately 50 minutes into the test, the pressure was significantly higher This increase was caused by capping nearby vapor I extraction well EW-1, which was purposely left open at the beginning of the test to allow the vapors to escape from the subsurface Once this well was capped, monitoring well MW-5 showed a higher positive pressure influence Frank's One Stop Interim Remediation System Workplan — September 2000 I -11-