Laserfiche WebLink
GROUNDWATER TECHNOLOGY <br /> STANDARD OPE-RATING PROCEDURE <br /> CO2ICERNI2IG MONITORING WELL INSTALLATION <br /> SOP 13 <br /> The boreholes for the monitoring wells shall be drilled <br /> using a truck mounted hollcw 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 /> hallow stem auger prov=.des 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 /> size analysis shall be placed in titer annular space between <br /> 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 bentonite 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 /> interval. <br /> Subsequent to installation the wells shall be developed <br /> to remove silts and improve well performance. The well <br /> development shall be conducted by air lifting the water <br /> w4l h4 n�-he well until groundwater pumped from the wells <br /> is silt fres. <br /> To assure that cross contamination does not occur between <br /> the drilling and development of successive wells all <br /> ecu-ment contact'_rg subsurface scils or ground water <br /> shall be steazcleaned. The steam cleaned equipment <br /> should include buy Aar lir„ited to the °ollcwing (1) <br /> Drilling Augers, (2) Solit Barrel Sampler, (3) Grounc- <br /> water Monitoring and Sampling -c_U-pmentr (Y) well:f Development ?ipinc and S_argi^.g E:;u'.pent. <br /> i;' <br />