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SOP-008 Standard Operating Procedure <br />Well Development Page 3 of 5 REVISION NO. 0 March 2020 <br /> The cap and all internal components of the well casing above the water table shall be rinsed with deionized water to remove all traces of soil, sediment, and cuttings, before and/or during well development. Dedicated materials shall be used for well development. <br />1. Measure and record the water level and total depth of the well using a water level indicator. Note any accumulated sediment thickness, and record all information in a field notebook and on the Well Development Log. 2. Begin well development by removing any accumulated sediment from the bottom of the well using the bailer. Repeat this process until accumulated sediment has been removed from the bottom of the monitoring or extraction well. 3. Begin surging at the bottom of the monitoring or extraction well. A general rule for well development is to start slowly and gently, and gradually increase agitation as the well is developed. After several surge strokes of five feet or less, remove the surge block and immediately begin to pump or bail the sediment-laden water. Contain all development water for proper disposal, according to the site-specific work plan. 4. Repeat surging and bailing or pumping, developing the well from the bottom of the screened interval upward by alternately using the surge block and the bailer or pump. Lower the surge block to the base of the well screen interval and rapidly raise and lower the surge block across a 2- to 10-foot interval above the base of the well screen for approximately 10 minutes or more. However, do not overdevelop the well with overly aggressive surging. Record the surge interval and duration of surging. 5. During development, monitor the clarity of the water removed from the well. Put some water in a clear glass jar to observe turbidity, if necessary. Measurements can be collected using a calibrated turbidity meter, with results recorded on the development log or in a notebook. 6. After the water clarity improves, move the surge block up in 5-foot intervals, and the previous steps until the entire screened interval has been developed. 7. If the well is purged dry at any point during development, approximately one well casing of clean, potable water can be introduced into the well and surging can continue. Add water only as a last resort and only add non-formation water as necessary. After surging, purge the well dry again to complete the development process by removing at least the amount of potable water added to the well. If the well will recover naturally, continue development with formation water only. 8. The well will be considered adequately developed and sampling may occur as soon as the groundwater has re-equilibrated, is free of visible sediment, water quality parameters have stabilized, or 24 hours have passed following development. 9. Measure and record a final depth to water and total well depth measurement after well development. 10. Record all well development data on the Well Development Log and/or in a field notebook. <br />5.1 Documentation <br />The following shall be recorded for development on the Well Development Record: