Laserfiche WebLink
r <br /> GROUNDWATER TECHNOLOGY <br /> STANDARD OPERATING PROCEDURE <br /> CONCERNING MONITORING WELL INSTALLATION, <br /> Sop 13 <br /> < The boreholes for the monitoring wells shall be drilled <br /> using a truck mounted hollow stem auger- -drill _rig. The <br /> outside diameter (O.D. ) of the auger should be a minimum <br /> of eight inches when installing 4-inch well screen. The <br /> hollow stem auger provides minimal interruption of <br /> drilling while permitting soil sampling at specific <br /> intervals . <br /> Soil samples can be taken at desired depths by hammering <br /> a conventional split barrel sampler containing precleaned <br /> 2 inch brass sample tubes . <br /> The construction details of the monitoring wells to be <br />' drilled at the site are graphically depicted in the <br /> attached figure titled "Typical Detail of Monitoring Well <br /> Construction" ( See Figure 1 ) . The wells should be cons- <br /> tructed of 4 inch PVC, . 020 inch machine slotted screen <br /> and blank casing. The screened portion of the well will <br /> extend 5 feet above and 10 feet below the present water <br /> table. An appropriate sand pack as determined by grain <br /> I size analysis shall be placed in the annular space between <br /> i the casing and drilled hole to inhibit silt buildup around <br /> the well . An annular seal installed above the sand pack <br /> should consist of be pellets overlain by neat <br /> cement or cement grout to the surface. The wellhead shall <br /> be protected below grade within a traffic rated street box. <br /> Each well shall have a permanently attached identification <br /> plate containing the following information ( 1 ) Well Number, <br /> ( 2 ) Wellhead Elevation, ( 3 ) Depth of Well , ( 4 ) Screened <br /> r Interval . <br /> G <br /> Subsequent to installation the wells shall be developed <br /> to remove silts. -and improve well performance. The well <br /> € deve lopment,A&'�i r* e"'conducted`b air ,.liftin. the;.water: ,-,,.., .L <br /> 3�` <br /> within the. rrell until grocndwater pumped from the we <br /> is silt fk'e.e. <br /> To assure that cross contamination does not occur between <br /> the drilling and development of successive wells all <br /> k equipment contacting subsurface soils or ground water <br /> shall be steam cleaned. The steam cleaned equipment <br /> should include but not limited to the following ( 1 ) <br /> Drilling Augers, (2 ) Split Barrel Sampler, ( 3 ) Ground- <br /> water Monitoring and Sampling Equipment, ( 4 ) Well <br /> Development Piping and Sparging Equipment. <br />