Laserfiche WebLink
January 14, 2004 <br />Page 4 of 4 Pages <br />was determined not to be a viable alternative to seepage control (permit, page 4-66g). Flow from the <br />#3 Mine was anticipated and is described on page 4-115b of the permit. At this time, gravity <br />dischazges aze evident at the Mine 1 and Mine 3 portals. Portal dischazges, from both the Mine 1 and <br />Mine 3 are collected and treated. <br />"Water discharged will comply with the applicable CDPS permit." (Permit, page 4-126) The report <br />validates this statement for 2003 discharges. <br />A statement that discharges from outfall 001 may slightly impact the quality of water in north <br />Thompson Creek, and a hypothetical case, is described on page 4-122 ofthe permit. An increase of <br />less than 10% in conductivity is considered insignificant (a discharge of 52 gpm, conductivity of <br />2083, stream flow of 5 cfs). A statement on page 4-122 of the PAP, and page 5 of the report, is that <br />the Department of Health can consider a loading of one ton of salt per day a no-salt dischazge. An <br />expected maximum flow rate of 100 gpm from the No. 1 mine, with a TDS concentration of 1500 <br />mg/1 would yield a salt concentration of 0.9 tons per day. The average flow for 2003 was 17.2 <br />gallons per minute (gpm) with a TDS concentration of 1346 mg/l. This equates to a discharge of 0.14 <br />tons of salt per day (page 5 of the report). <br />C:\bgw\ W PDOCS\NorthThompson\ahrrvw03.025.doc <br />