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SOP No. 5.0 Monitoring Well Installation <br />Any leaks from the drill rig occurring during well installation will be fixed or contained in such a <br />way that they will not contaminate the borehole. <br />Care will be taken not to contaminate the well casing or the borehole with diesel fluid, hydraulic <br />fluid, WD-40, oil, dirty tools, and so forth. <br />Drillers will use gloves when handling downhole equipment. Different gloves will be used for <br />performing activities such as fueling, adding oil, and working on equipment. <br />As defined in 20.6.2 NMAC, pipe lubricants that are used should not introduce contaminants <br />into the borehole. Lubricants that are environmentally acceptable include: Green Stuff; King <br />Stuff®; vegetable oil; CriscoTM; and some Teflon TM-based lubricants. Lubricants that are not <br />acceptable include petroleum-based and most metal-based lubricants. The Project Manager, <br />Field Geologist, or the Powertech Environmental Staff will pre-approve lubricants that will be <br />used, and the Material Safety Data Sheets (MSDS) for these lubricants will be provided for <br />reference. <br />All well casing and screen will be free of foreign material. Casing and screen will be stored off <br />the ground in the original manufacturer's shipping containers until they are installed in the <br />borehole. Before installation, well casing, screen, and centralizers will be certified clean from <br />the manufacturer or will be decontaminated according to SOP 10.0, Decontamination of <br />Sampling Equipment. Acid rinse solutions should not be used for PVC decontamination. Clean <br />latex or nitrile gloves will be worn when handling the well materials. <br />5.2 MONITORING WELL DESIGN AND COMPLETION <br />Procedures for installing three types of monitoring wells are presented in this section: water table <br />wells in unconsolidated materials; water table wells in bedrock; and deep bedrock wells below <br />the water table. Installation of water table wells in unconsolidated material and bedrock is <br />discussed in Section 5.2.2. Monitoring well installation in deeper bedrock borings is described <br />in Section 5.2.3. <br />5.2.1 General Well Installation Procedures <br />Monitoring wells will be constructed in open boreholes or through the hollow stem augers or <br />surface casing, depending on the stability of the borehole and materials encountered during <br />drilling (ASTM 1996, EPA 1990). <br />For boreholes that may need to be backfilled to a certain depth before well installation, clean <br />sand with a 3-foot bentonite seal will be added to fill the borehole to the depth desired for well <br />installation. Wax coated pellets may be used if the saturated water column in the borehole is <br />greater than 50 feet. <br />The annular space between the well string and the borehole wall will be filled with a filter pack <br />(adjacent to the well screen), a bentonite seal, and casing grout. As the annular space is being <br />filled, the well string will be centered and suspended such that it does not rest on the bottom of <br />the hole. At least two stainless steel centralizers will be used if the well is deeper than 50 feet- <br />one at the bottom of the well screen and one at the top of the well screen. For deep bedrock <br />7/28/08 Page 3 of 5 R Squared Inc. <br />Attachment A