WORK PLANS - Laserfiche WebLink

Home Browse Search

Aquifer Testing Standard Operating Procedure SWE-FSOP-500,•Revision 0 Ahtna Southwest Environmental Operations • Obtain a water level depth measurement and sound the bottom of the well according to the procedures outlined in SWE-FSOP-602. Compare the measured total depth to the bottom of the well with the well construction diagram to determine if sediment is at the bottom of the well. It is important not to set the pressure transducer in the sediment. • Calculate the height of the water column in the well as follows: (h1- h2) = height of water column in well Where: h1=total depth of well from the top of casing(in feet) h2= depth to water from the top of casing(in feet) • The water column height should be sufficient to immerse the slugging rod and allow concurrent use of a pressure transducer or other measuring equipment during the testing. • Connect the pressure transducer to the data logger. Install the pressure transducer in the water column to a depth that will not interfere with the insertion or withdrawal of the slugging rod during testing but also not exceed the maximum head limitation of the transducer. • Obtain a barometric pressure measurement if testing(water level recovery) is expected to take longer than 30 minutes. Station barometric pressure may be recorded from onsite equipment or obtained from a local weather station. • Turn on the pressure transducer/data logger and set the frequency that the recorder stores data measured from the transducer and displays a reading) for pre-test monitoring to that specified by the project work plans. • Measure the water level with an electric tape (or equivalent) and record along with the measurement time. Commence pre-test monitoring with the pressure transducer/data logger. The time the pre-test measurements are made will be specified in the project work plans.The total time should be roughly equal to or greater than twice the time expected to run the slug test. • Once the pre-test monitoring period is ended, remeasure the water level using the electric tape and record along with the measurement time. • Change the recording frequency on the data logger for the slug-in test as specified in the project work plans. Lower the slugging rod to just above the static water level. Record the test's initiation time on the appropriate form, as outlined in the project work plans. • The slugging rod should be completely submerged. However, it is best to lower the rod only enough to make sure it is submerged and not more.This will reduce the chance of pinching the transducer cables, dragging the transducer, or sticking the rod. • Continue to monitor water level decline with the pressure transducer/data logger,taking periodic water level measurements with the electric tape. Data logger and tape readings should be conducted by the schedule outlined in the project work plans. • The slug-in test may be terminated once the water level has declined to within 90 percent of the pre-test static or as specified in the project work plans. Once the slug-in test is terminated,take a physical water level measurement with the electric tape. Record the measurement and time on the appropriate form. Continue to the slug withdrawal ("slug-out")test. • The slug withdrawal test should not be initiated until the water level has recovered to within 90 percent of static or as specified in the project work plans. Page 10 of 17