2008-01-15_PERMIT FILE - M2007044 (2)

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could increase to as much as 30 mg/L for FeSO4 and 100 mg/L for BaCI depending on contaminant levels and chemical interference. Most of the sulfate, barium and iron are desi neg d to precipitate out in the sludge. Chloride is relatively soluble and most will enter into solution. The average constituent concentration levels in the existing mine water, the maximum amount of chemicals that may be added, and regulatory limits are listed below for reference purposes. FeSO4: Maximum dosage = 30 mg/L Existing Sulfate Concentration in Water: 100 mglL Total Sulfate Added: 21.6 mg/L Regulatory Limit: 250 mg/L Existing Iron Concentration in Water: 0.10 mg/L Total Iron Added: 8.4 mg/L Regulatory Standard: see below BaCI: Maximum dosage = 100 mgt Existing Barium Concentration in Water: 0.2 mg/L Total Barium Added: 79.5 mg/L Regulatory Limit: none apply Existing Chloride Concentration in Water: 25 mg/L Total Chloride Added: 20.5 mg/L Regulatory Standard: 250 mg/L The data above indicate that the addition of sulfate and chloride cannot result in an exceedance of regulatory standards. Concentrations of both iron and barium could theoretically increase to levels above drinking water standards; however, drinking water standards do not apply to mine water discharge. The 0.3 mg/L secondary iron standard for drinking water is clearly not applicable to this situation, as the standard was established to prevent staining of clothes and fixtures. The State of Colorado has not established an iron standard for the segment of the Dolores River into which Lumsden Canyon discharges. Surface water standards of 0.3 to 1 mg/L are common at other locations where elevated iron levels are problematic. The agricultural standard for iron, which is 5 mg/L, may be the most relevant standard in this case. The only barium standards are for drinking water (1 to 2 mg/I.,) and would not be applicable to the mine discharge. Because of the potential to exceed an applicable regulatory standard, dissolved iron will be added to the weekly sampling and analysis of treated mine water. Iron will not be added to the stormwater sampling program because it is only present in the ore and waste rock in small concentrations and would not be expected to be present in surface water runoff. 1:.i~eig~ I~uc;l5 ltesaar~cs Cc}rporati«~~ ~~ C~ni<~r~ I3c~ulevaed, Staite Ei0{) 6 l.,~al:ew~c~c~c~l. C`O $012 Phc~i7e: 3t}3-97~-21=i0