Laserfiche WebLink
DURAV SILVER MmES <br /> hydrocarbons can be transported through groundwater and can impact receiving streams and <br /> aquifers. Therefore, it is important to reduce the introduction of contaminants into the <br /> groundwater, and although testing of groundwater is not required under this program, control <br /> measures are implemented to minimize the ability of stormwater to transport petroleum <br /> products and other pollutants into the groundwater system. Also, a separate SPCC plan is in- <br /> place for this site. <br /> Stormwater Management <br /> • Off-site stormwater will be redirected around the site back to natural drainages through <br /> diversion ditches. <br /> • Disturbed areas will have runoff captured and contained in the passive water treatment <br /> system or sediment ponds to allow for settling of sediment prior to discharge. <br /> • The passive water treatment system and sediment ponds have the capacity to fully <br /> contain the runoff from a 10-year 24-hour event from their respective drainage area <br /> plus sediment storage volume. <br /> • Petroleum products will be contained with facilities with the capacity to contain any <br /> spills and prevent contribution of hydrocarbons to stormwater runoff. <br /> • A 35 gallon spill kit will be kept on site near the 10,000 gallon tank (Cl). <br /> The passive water treatment system and sediment ponds are designed to contain the full <br /> stormwater runoff from a 10-year 24-hour event plus sediment storage volume. The drainage <br /> area to Mine Water Pond #2 is 16.53 acres and the drainage area to Mine Water Pond #3 is <br /> 7.39 acres. Mine Water Pond #2 is a sulfate reducing bioreactor that removes metals from the <br /> water. Mine Water Pond #2 discharges to Mine Water Pond #3, but also has an emergency <br /> spillway for stormwater, which is Stormwater Outfall 001. Mine Water Pond #3 discharges to <br /> Sneffels Creek via OF002A, as shown on the SWMP Map. <br /> The Mine Water Ponds contain water that flows from historical tunnels from the Revenue <br /> Mine. Outfall 001A remains a permitted outfall, but no discharge currently occurs from this <br /> location as mine water is directed through the passive water treatment system and discharges <br /> to Sneffels Creek at Outfall 002A. <br /> Sneffels creek upstream of the mine is highly mountainous and drains an area of approximately <br /> 3,927 acres. Stormwater from off-site areas does not drain to the sediment ponds since a <br /> diversion ditch is used to ensure that runoff from the mountains to the south does not enter <br /> the site. <br /> Stormwater Management Plan 8 1 P a o e <br />