Laserfiche WebLink
Page 2 of 6 <br />SOP NUMBER 0.0 Well Development <br />• Surge block <br />• Teflon® or Teflon -lined polyethylene tubing <br />Stainless steel or Teflon® bailer <br />o Mechanical reel or truck - mounted wireline rig (for deep wells) <br />• Water quality meters for temperature, conductivity, pH and turbidity <br />a Plastic sheeting <br />o Decontamination equipment and supplies (see SOP No. *x Decontamination) <br />• Personal protective equipment (PPE) as outlined in the Health and Safety Plan (HSP) <br />• Methane detector (on wells scheduled for methane analysis) <br />• Graduated 5- gallon bucket <br />• Drlutrs or other large container for storing development water <br />• Water -level probe <br />o Weighted tape measure <br />s Calculator <br />5.0 MONITORING WELL DEVELOPMENT PROCEDURES <br />Before developing any well where samples will be collected for volatile organic compound <br />(VOC) analysis, the head space in the well must be measured using an organic vapor detector as <br />described in the Health and Safety Plan (HSP). The initial static water level will also be <br />measured before development begins and well purge volume requirements will be calculated. <br />Monitoring well development will be accomplished using a surge block and/or a bailer and a <br />submersible pump to flush the screen, sand pack material, and borehole wall of drilling fluids <br />and fine sediment resulting from well drilling and installation activities. This procedure also <br />allows for the removal of fine sediment, which may have accumulated within the inner well <br />casing. <br />The surge block will initially be operated with short, gentle strokes above the well screen <br />intake. Development will begin at the static water level and move progressively downward to <br />prevent the surge block from becoming sand locked. The surge energy shall be gradually <br />increased at each depth. Surging shall be alternated with removal of the fries with a pump or <br />bailer. Note that surging of low - permeability formations can result in a collapsed well screen. <br />Development of fine- grained materials will be accomplished by a gentle action to avoid <br />reducing the natural hydraulic conductivity. <br />Well development will begin no sooner than 24 hours after the well as been grouted and will <br />consist of removing approximately 3 to 10 well casing volumes from the well, plus a volume of <br />water equal to any additional potable water added to the borehole during drilling or well <br />installation. A well casing volume is determined by the following formula for 4 -inch diameter <br />wells: <br />0 -2 <br />