2008-09-04_HYDROLOGY - M2007044 (2)

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Page 5 September 2, 2008 The Lumsden Creek UP and Lumsden Creek DN samples were collected to help assess water quality baseline in Lumsden Creek above and below the Dutchman Mine waste dump which has encroached on and eroded into Lumsden Creek. Lumsden Creek DN sampling site is located in Lumsden Creek approximately 100 ft downstream of the Dutchman Mine dump (Photo 11). The Lumsden Creek UP sample is located approximately 50 ft upstream of County Road 5110 (Photo 10). Flow could not readily be measured at the Lumsden Creek UP site because of shallow stream channel conditions, but flow was estimated at 10 to 15 gpm. Turbidity was not directly measured but considered low at both locations based on visual observations. Tahip I FiAd Parnmeterc for Sample Sites (June 19.2008) Oxidation Water Specific Dissolved Reduction Sample Site ID Temperature pH Conductance Oxygen Potential Flow °C s.u. ms/cm (mVjQ m m Whirlwind Mine 11.5 10.26 592 0.78 114 rim WW Sum Whirlwind Mine 13.5 7.90 574 nm 174 Drift Area Pool PR Spring 13.8 8.21 762 9.95 140 4.7 Lumsden Creek 23.7 8.30 342 7.53 225 2.2 DN Lumsden Creek 14.0 8.27 436 9.17 174.3 nm UP Lumsden Creek 18.4 7.18 825 -5.56 214 rim Mouth DP Spring 11.0 7.42' 1 524 7.22 126 7.2 Notes: nm = not measured; 'Data collected on 7/29/06; -1ne pH or the sump may nave OUCH cirVULCU uuc w U,V recent shotcreting of the sump drift. 3Actual mg/L value not recorded. Percent was 51.9 %; DO in mg/L was estimated on basis of plot of DO % versus mg/L for data collected on June 19, 2008. The "Lumsden Creek Mouth" sample site was located in Lumsden Creek approximately 2.7 miles downstream of the Dutchman Mine dump location. This sample site was selected because it had been described as "Lumsden Canyon Spring" and sampled in the past by the U.S. Bureau of Land Management (BLM) and EFR. The site had been sampled at an upper and lower "contact" where water emerged and infiltrated into the stream bed near a grove of cottonwood trees. WWL and EFR sampled what appeared to be the location that corresponded to the upper (emerging) location. Flow during the sampling event was very low - likely less than 1 gpm, and due to the stream geometry, it could not be measured. No stream flow was observed upstream of this point for at least 100 ft. As discussed in the Interpretation section below, this site should not be considered a spring; it simply represents the exposed groundwater surface within the undulating stream bed. A comparison of analytical water quality results to historical data is presented in Table 2, which is an updated version of a table prepared by EFR. The complete analytical results are presented in Attachment C. INTERPRETATION An initial interpretation of hydrologic reconnaissance results is presented below. Additional interpretation of the hydrological reconnaissance will be presented upon completion of the Fall 2008 reconnaissance effort. Underground reconnaissance was limited to a brief tour of the Whirlwind Decline including the newly constructed sump and the drift beyond the bottom of the decline. WWL's findings were consistent Weans090108.doc