2013-04-18_PERMIT FILE - C2009087A

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RULE 2 - PERMITS SSLG5 was ori, finally established for the Seneca Il Mine, and is located on Little Grassy Creek just \\est of the Spring Creek Stock Pond, 111 Section 3, T5N R87W. It represents conditions oil Little Glass} Creek just upstream of the existing Seneca II Mine and the proposed PSCM surface disturbance. Little Glassy Creek is intermittent at this location. gout,, dry in the Summer. but prodlIC11111 ? spring peak flo\\ s as hlgh as 2.5 cfs. receding to zero or heal' -zero by late NJay of rani .l Bile. Pond 002. also known as the Wadgc Impoundment and discussed further bolo\\, is a permanent impoundment lying along the reclaimed Seneca II hiallwall. roughly one mile north of the proposed PSCM portals. Its outflo\\ is monitored at station NPDES2. located in Section 34. 'I'5N R87W. Due to inflm\ from the Seneca II spoils. which have enhanced recharge relative to natural terrain. discharoe at NPDES2 is perennial, and Little Grassy Creek is perennial do\wnstreanl of this location. Spring peak flo\ws occur in April or May. and ranged from 3.0 to 4.2 cfs. Late summer low flo\\s rani2ed from 0.06 to 0.4 cfs. Spoil Springs In addition to strearnflo\v monitoring, five spoil springs within the Little Glassy Creek drainage have been monitored biannually since at least 1993 (soiree from 1985). to assess the impacts of the Seneca II Mine. Spoil spring locations are shown on Map 2.04.7 -M1, Hydrology. and hydrographs are shown on Figure 2.04.7 -F15. Recent spoil spring monitoring data (2005 through 2008) is discussed below. in order fi-on1 south to north (upstream to downstream on Little Grassy Creek). Springs SSSPG4 and SSSPG3 are both located in Section 2. T5N R87V,', on an unnamed tributary to Little Grassy Creek, upstream of the Spring Creek Stock Pond. SSSPG4 flows ranged front 15 -pin to 108 gpn1. SSSPG3 produced consistently lover flows than SSSPG4, with May peaks of up to 35 gpm. and a September low of 13 gpin. Spring SSSPG5, located in Section 3. T5N R871A' is the discharge from the Pecoco Pond. and produced flows ranging from 54 gpm to 290 gpm during the reporting period. Spring SSSPGIO (consisting of a series of seeps), in Section 2 and northeast of Pecoco Pond, produced 10 to 16 gpm. Spring SSSPG6 is located in Section 35, T5N R87W, and contributes 0.4 to 5 gpm to an unnamed ephemeral tributary to Little Grassy Creek. Springs and Seeps PSCM performed a spring and seep inventory within and adjacent to the PSCM permit boundary during August of 2009. Maps and aerial phototgraphs were reviewed to determine potential locations of springs and seeps. Historical information related to the occurrence of springs and seeps within the Seneca II permit area was also reviewed, and it was determined that the only springs or seeps that exist within the PSCM permit area are limited to spoil springs that are discussed in the previous section. Based on this assessment, a search and survey of springs and seeps within a one - mile buffer around the PSCM permit boundary was conducted during August 20 and 25, 2008. Drainages emanating from the Tow Creek and Fish Creek Anticlines that are largely ephemeral (some may be intermittent) were emphasized, as well as water - righted springs based on data obtained from the Colorado Division of Water Resources CDSS (Colorado Decision Support Systems) website. Two known water - righted springs, Gerte Spring No. 1, and Livestock Pond No. 2, were not surveyed due to lack of access permission from the local rancher. Midterm Review 2.04 -67 Revision 04/2013