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C~ <br />April 21, 2004 <br />Mr. Brad Janes <br />Varna Companies <br />8120 Gage Street <br />Frederick, CO 80516 <br />Subject: Carbatugh Well <br />Durham Pit <br />Greeley, Colorado <br />CGRS Project No. 1-135-9540aa <br />Dear Mr. Janes: <br />I have completed the drawdown analysis for your Greeley mining operations. However, Cheryl Signs <br />indicated to me that the Carbaugh well is completed with a Jet Pump and not a submersible pump. If <br />this is indeed the case, the apparent diminished pump capacity of the Carbaugh well is likely due to <br />the type of pump and not the well's ability to yield water. <br />Jet pumps draw water from a well by creating a vacuum in a tail pipe, which then draws water. The <br />vacuum is created by pushing water under pressure through a fitting called an ejector, which houses <br />a Venturi. The ejector is normally placed at the pump motor for shallow well systems. At sea level the <br />maxim theoretical pumping depth is 33.9 feet below the ejector. At our attttude the maximum <br />practical suction lift is probably on the order of 22 feet. With a measured depth to water of 17 feet a <br />shallow well jet pump would probably produce 20 to 40 percent of the rated pump capacity. The <br />pumping rate would decrease with increased drewdown. For these types of pump systems the ejector <br />can be placed lower in the well to increase the pumping rate. <br />I hope th15 information helps. <br />Sincerely, <br />CGRS, INC <br />Joby L. Adams, P.G. <br />PrincipaVHydrogeologist <br />C:\WINDOWS\Temporary Internet Files\ConteM.lE5V+FIQEW1UetPump.doc <br />