Laserfiche WebLink
INTERNAL MEMO <br />TO: Jim Stark <br />FROM: Jim Burnell <br />17 May 2005 <br />SUBJ: North Thompson Creek (C-1981-025) 2004WY AHR Review <br />The review of the North Thompson Creek 2004 AHR has been completed. <br />Following is a review as per the predictions made in the PHC. <br />Probable Hydrologic Consequences <br />Most of the original points in the PHC no longer apply. Of the remaining predictions, the <br />following two relate to mine discharge. <br />(1) Discharge from point 001- the long remaining discharge point -may slightly impact <br />the water quality of North Thompson Creek. <br />This prediction is accurate. Concentrations in total dissolved solids (TDS) in the creek <br />downstream from the discharge point were minor in 2004 -only 4% in May and > 1 % in <br />September. <br />(2) Discharge will be below the limit of I ton/day of salts added to the Colorado River <br />system. <br />This prediction is accurate. Total salt averaged considerably less than 1 ton/day with an <br />average discharge of 17 gpm of water containing 1400 mg/1 total dissolved solids. <br />Other Comments <br />Copper content of the discharge water did not appear to be particularly high in 2004. The <br />copper content has been measured at a similar level for 5 years. Furthermore, the <br />concentration of copper downstream of the discharge was the same as that above the <br />discharge. Looking back at the records, copper levels have been high in North <br />Thompson Creek and variable (e.g. Fig. 3.6.1.2.4 in PAP) with concentration at the <br />monitoring point upstream of the mine higher than that at the downstream monitoring <br />