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Except when drilling is in progress , the top of the well shall be kept securely capped , both night and day, in such a manner as to effectively prevent either tampering with the well or entrance of foreigh matter. Within 48 hours after the casing has been set and perforated , an engine driven test pump unit shall be installed , consisting of a deep well trubine type pump with a minimum capacity of 1000 gallons per minute. It should have a setting of 20 feet below standing water level , plus one foot for each 40 gallons per minute of specified test rate , unless local conditions indicate otherwise. The test pumping equipment shall be equipped with such devices as are necessary for rapidly changing the rate o" pumping. The well shall be thoroughly developed .by surging and sand pumping. Disposal of all development and test water should be provided for, as well as the tailings from the well when developing and testing are completed.. Before starting the test , the static water shall be accurately measured with a steel tape. After starting the test , there shall be no shutdown, unless the-re is failure of the pumping equipment . Should a shutdown become necessary, test pumping shall be resumed and continued for at least four hours at the next lower rate of discharge below that during which the shutdown occurred. The water level shall be measured at the beginning of the shutdown and every 30 minutes during the shutdown. Test pumping shall consist of pumping at increments of 200 gallons per minute beginning at 200 gallons per minute and contin;iing until a discharge of double the permanent pump capacity has been reached . Each increment of 200 gallons per minute shall be pumped for a period of three hours or until the water maintains a uniform level for this period , when it shall be considered as stabilized for the discharge capacity at the increment. The test shall then be increased to the next 200 gallons per minute increment, and the same procedure followed . After the water level has been stablized at 50 percent over the capacity of the permanent pump, the rate of pumping shall be increased to double the capacity of the permanent pump and the test shall be run for 10 hours at that capacity. During all test pumping, the water level shall be measured at intervals of 30 minutes to determine the drawdown and depth of stabilization for each test. This information shall be recorded and furnished the -,,7ngineer. The water developed shall be measured over a weir or through an orifice , or by another reliable method approved by the Engineer. A sufficient number of points shall be determined to fully develop the draw-dorm curve, but in no event shall less than Lour points be determined . The points determined shall be approximately equally spaced from minimum to maximum discharge conditions . (39)