2009-08-10_GENERAL DOCUMENTS - M1977300 (2)

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Environmental Protection Plan, Schwartzwalder Mine 11-7 • • • Historical surface water monitoring was conducted at the designated point of compliance in Ralston Creek (Station SW-BPL), and at five other stations for the purpose of understanding upstream sources, further characterizing the creek, and evaluating the potential effects of an ore truck spill on the creek (Station SW- ARH). Two of the historical monitoring stations are located above the point of compliance: Station SW- AWD (located above the waste rock dumps) and Station SW-A001 (located above the former water treatment plant discharge). Three of the stations are located downstream of the point of compliance: SW- ARH (above Red Hill), SW-FBRG (at the first bridge), and SW-LLHG (on Ralston Creek at the Long Lake Head Gate, approximately 1.5 miles downstream from the Schwartzwalder Mine). The period of record extends from approximately 1973 to the present". The data set contains dissolved and total uranium and radium, as well as field parameters (temperature, pH, conductivity, and dissolved oxygen.) A longer suite of parameters was analyzed approximately annually at each station. In addition to the routine historical monitoring described above, an intensive water quality study was conducted from 1998-1999 as part of the mine closure hydrology evaluation conducted by Cotter Corporation and Adrian Brown Consultants. Water quality in Ralston Creek was measured approximately monthly at 10 stations, which are listed in order from downstream to upstream in Table 11-5. The analytical suite included constituents for which drinking water Maximum Contaminant Levels (MCLs) and Colorado instream water quality standards existed at the time. Table 11-4. Historical Monitoring Stations and Non-Routine Sampling Stations in Ralston Creek STATION NORTHING EASTING ELEVATION DESCRIPTION FREQUENCY NAME SW-LLHG ........................ ..................................................... 726,873.63 ....._. ................... 2,065,661.22 ...................... ....... ................. ........ ................ : 6358.0 ..................... _............._.. .... ......... .... ... .. . Lon Lake Head Gate _ . . . . . . . Monthly SW-ARH 729,590.23 2,064,210.64 . . . .. ... . .... 6358.0 . .. .. ... ....... . .......... ... ......................................................................................... Above Red Hill ...._...................... .......................................................... Variable SW-FBRG .......... ................................................................... 731,700.86 ..... ...................................... .............. ................ 2,063,819.07 .......................................................... ........... 6460.0 ..................................... ...................................... First Bridge ...................................... . ................... ......... ........................................................ Variable ....:. SW-BPL .......... ........................................... ..................... 732,105.23 ............................. ......... ........... ............................ 2,063,068.76 _................................... .............................. .... : 6509.0 ...................... ..............._..................................... Below ProPerty Line .,............. ... Monthly SW-DIS001 .......... 733,406.0 2,061,299.0 6585.0 ' Discharge Month SW-A001 .......... ................................................................... 733,650.46 ..... ................................................... ... ... .... .... 2,061,153.05 6590.57 Above Discharge Pt A001 Monthl Y SW-AWD .......... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... . 734,870.0 . . . . . _ . ..................................................................... 2,059,850.0 ............... .................................... ......................................... 6639.9 ........................................................................... . ...................... .................................................. ................. .................................... Above Waste Dum ._.............................................................................................................................. .... . Variable ..................................................................................... SW-Abv PI ............................ Above Plant Site Variable D-MENA ............................................................................. 735,830.0 ...................................................................... .: 2,056,360.0 : 6790.0 Downstream of Mena Variable SHFTMENA ....... ..... ..... ..............._............... ...................... _.... 735,960.0 ..... ....................................................... _.............. 2,055,850.0 .............................. ........... .......................... : 6835.0 : ........................................................................... Mena Shaft . ..................................................................................................................... ............ Variable .... _ ... ..... . .. . .. . . U-MENA 735,940.0 2,055,380.0 6815.0 , . Upstream of Mena : . ... .. ....... ............. .... . . . ............................. Variable Note: Coordinates in NAD 27. Stations listed in order from downstream to upstream 17 The surface water quality data evaluated for this report ranges from 1998 (or 1990 for uranium) to January 2009. 4109C.090807 Whetstone Associates