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{,z���..� � t .�" �- � �..r �vr,{{pp :3-"�.i�c=�,�H• ',�, "'may y;. � --s-�; �'� ."�.: c�. y.-.� 3�;�,a <br /> San Joaquin County PHS/EHD <br /> 551 South Tracy Blvd. -- PAR <br /> April 10, 1990 <br /> Page 3 <br /> minimum of one selected sample per boring will be retained for <br /> chemical analysis, properly labeled and placed in an ice <br /> cooler for transport to a state certified laboratory. Chain <br /> of custody protocol will be maintained on all samples retained <br /> for chemical analysis. At least one sample of each water <br /> bearing lithology will be retained for particle size analysis <br /> (ASTM D422) . <br /> Typical well construction is shown on Figure 2. All wells <br /> Will be constructed of two ch diameter, schedule 40, PVC <br /> blank casing and �► <br /> of <br /> T l <br /> perforated casing wi l extend above theexistingistatictwater <br /> level to detect floating product that may bepresent. <br /> perforated,:' a8isz 9� will:•be :extended.'belowYthe �* <br /> statfc watee <br /> level=into:the=water bearing::�anit".:.to a::maxi�ium=depthof, five <br /> feet flow "the.;statac. a r. lervel,: .vel,: -a::chsnge /U in ' <br /> lith�sl Y <br /> :encountered'P The annular space between the <br /> r orated-9-4sincr and the boring wall will be sand packed with <br /> a is us is san (see Figure 3) to a level two feet above <br /> op of the screened interval. A spacer will be placed <br /> above the top of the sand pack to-joarevent infiltration of the <br /> rout seal into the sand pack. Sili <br /> cp <br /> bentonl a natural <br /> lbe used for thi®purpose. This spacer will have a maximum may be <br /> accness The remaining annular space w1.11. then <br /> "S be Z ed with a cement/bentonite grout containing no less <br /> than 1,034 pounds of cement and no more than 50 pounds of <br /> bentonite per cubic yard of grout.- Bentonite is added to <br /> reduce shrinkage cracks in the <br /> ' grout seal. All depths and <br /> thicknesses of sand- pack and seals will be verified by <br /> sounding with a weighted tape. All as built construction <br /> IR details will be recorded and presented in the final report: <br /> s Surface completions of all wells shall be below grade. the .,,- 1")d"' �f <br /> ��?:��?f•;;�ach�"aarsi-ng�,ta�13z��oeq►�.ppm-,;�;.•t!'r�a+w€�'C^screw*�cap <br /> i iderct `:.grotective tetaa,; bow. Each protective metal box <br /> will be fitted with a locking mechanism to guard against <br /> unauthorized tampering of the well. The surface elevation of <br /> each well will be determined to the nearest 0.01 foot. <br /> r u i <br /> III. Well Development and Ground Water Sampling: <br /> All wells will be developed to improve hydraulic continuity , i <br /> with the native soil. q�fl <br /> PUMFi r Bailin lament<o�iii^'b� 'p ormed- img <br /> g..and/or...surgi ng-or,,.the.,,s rel LtCw:a <br /> r"'The volume of all water extracted during development <br /> will b re_cgrded_along_with-regular-pH-measurements.- <br /> - - Develop t will be continued until the well <br /> produces little <br /> or no fineN sediment and pH readings have stabilized. At least <br /> i „n _ . '417 <br />