2013-11-27_REVISION - M1990057 - Laserfiche WebLink

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Mr. Michael Cunningham CDRMS November 26, 2013 • Road construction and maintenance will be routinely conducted to maintain BMP structures, road grades and sediment control structures; and • Regulated materials will be transported by CDOT and USDOT approved vendors. • Non - Stormwater Discharge Locations: Non - stormwater discharges are not anticipated to occur. No man - induced springs, landscape irrigation, construction dewatering or concrete washout exists. • Receiving Waters: The 10.Oac mill permit area is located approximately 850ft north of California Gulch, tributary to the Arkansas River. The unnamed ephemeral channel draining the mill site only flows in response to snow melt and thunderstorm runoff events. • Wetlands: There are no designated wetlands or riparian lands within the permit boundary. 13. Please provide the tank capacities and operating solution volumes for the mill operation as required by 6.3.3(2)(a). The Division must confirm that the secondary and tertiary containment systems are adequate to contain 120% of the volume of the total solution in the mill facility. Response: Operation solution volumes are summarized in Table 4 -6. Primary containment, representing tanks and facilities used in the operation, amount to approximately 26,OOOgal, of which 19,500gal are within the mill building. Secondary containment consists of the sump and is located at the lower level of the mill building. The sump area can hold about 26% (5,OOOgal) of the tanks and facilities located within the mill building. In the event of 100% primary containment failure, the TSF will serve as the tertiary containment facility. The maximum capacity of the TSF assumes a 1ft of the aft freeboard capacity, or approximately 425,OOOgal.. Tertiary containment therefore represents approximately 16 times all primary containment facilities.