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to construct a new alluvial monitoring well located down gradient of the mining <br />operations in the Chandler Creek alluvium for monitoring purposes. We aze not <br />proposing to construct a monitoring well up gradient of the permit boundary because it is <br />our opinion that the alluvium is not regionally saturated up gradient of the permit <br />boundary. <br />Item 14 (BB): The DRMS noted that cross section labels were not included on <br />Appendix 4 of our Apri125, 2007 letter report. The attached updated version of Appendix <br />4 shows the cross-section labels. <br />Item 15: Edited completion diagrams aze provided as Exhibit AJ. <br />Item 15a: Please recall during exploration activities that two (NF-O1 and NF-03) of the <br />three initial monitoring and exploration holes constructed according to SEO design and <br />installation criteria collapsed due to depth and stratigraphic characteristics. Upon sealing <br />the collapsed wells, two twin wells were constructed by a licensed well driller with steel <br />casing as diagramed in order to withstand 2000 psi rather than the 240 psi limit of SEO <br />design criteria. These steel casing was placed in the hole upon drilling to the top of the <br />monitoring zone. The bottom of the casing, equipped with a hazdened steel drive shoe, <br />was driven into competent rock as a bottom seal. The entire annulus was then grouted to <br />seal the full length of the hole prior to drilling an open hole through the monitoring zone. <br />Regarding the consistency of water level measurements (Exhibit L) at NF-O1 and NF-03 <br />compazed to NF-02, Northfield's baseline monitoring data indicates that well levels have <br />shown similar changes since static levels stabilized at different rates following well <br />completion. Following is a summary of monitoring data through the 2"d quarter of 2007 <br />in support of this statement: <br />Northfield Partners LLC <br />Depth to Water level in Feet <br />Date NF-01A NF-02 NF-03A <br />11-Jul-05 <br />28-Dec-05 <br />7-Feb-06 <br />4-May-06 <br />15-Aug-06 <br />15-Dec-06 <br />14-Mar-07 <br />1-Jun-07 <br /> 135.6 <br /> 136.3 <br /> 136.1 <br />430.7 135.9 399 <br />430.6 136.8 399.5 <br />431.9 138.5 401 <br />432.8 139.3 402 <br />433.3 139.4 402.2 <br />Regazding future monitoring and exploration hole construction, Northfield will submit <br />proposed construction criteria based on anticipated depth and stratigraphy experience in <br />the azea. Design of any new deep wells may conform to the methods used to construct <br />existing NF-OlA and NF-03A monitoring wells. <br />~~viiP®~m~~~~®u ~au~~~m~l~iv~~,, u~~. ~ Il~c„ <br />a `- 402 Valley Rd, Suite G, Canon City, CO 81212 ~ $1212 <br />snan.net <br />Phone: 719-275-8951 • Cell: 719-429-8950 <br />