OAR 690-217-0025: Pump Test Specifications for Wells Other than Flowing Artesian Wells

The pump tests for wells other than flowing artesian wells shall be conducted such that the following minimum specifications are met: (1) The well shall be idle for a period of at least sixteen hours prior to the pump test. (2) The static water level in the well shall be measured within the hour prior to the test at least three times no less than 10 minutes apart. (3) The pumping phase of the test shall be at least four hours. (4) The pump discharge shall be controlled as much as possible to maintain a constant rate during the test and shall be as close as reasonably possible to the anticipated pumping rate during normal use of the well. Discharge shall be recorded at the beginning of the test and once every hour thereafter. (5) Water level measurements during the first 10 minutes of pumping shall be timed no more than two minutes apart. Water level measurements from 10 to 30 minutes of pumping shall be timed no more than five minutes apart. After 30 minutes of pumping, drawdown measurements shall be taken no more than 15 minutes apart for the duration of the test. (6) After pumping stops, water level measurements shall be taken for four hours or until the well reaches 90 percent recovery from the maximum drawdown, whichever occurs first. Recovery water level measurements shall be taken on the same schedule as described in section (5) of this rule for drawdown measurements.