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Require- Require- ment Requirement ment complied Comment citation with ? (yes Ino New Horizon's sediment control ponds discharge into Calamity and Tuttle Draws. Samples taken in February and August of 2004 show discharges from pond 7 (NPDES outfall 007) significantly increased sulfate in Calamity Draw. The increase is apparent by comparing samples from SW-N108 (upstream) to SW-N109 (downstream) and SW-N102 (pond 7 discharge between 108 and 109). Mine pit water is pumped to pond 7. The increased sulfate in Calamity Draw did not constitute material damage or exceedance of a standard, however, because there is no sulfate standazd on Calamity Draw. Calamity and Tuttle Draws are ephemeral streams on Segment 12 of the San Miguel River. The standards on Segment 12 were expanded in 2003 to include the extensive list of standards that has been G. Instream CWQCC applicable for several years on other segments of the San Miguel Numeric regulation yes River. The new sulfate standard of 250 mg/I, or ambient values Standards 3.3.0 as of 1/l/2000, whichever is higher, is of special interest for a coal mine owing to the sulfate-rich leachate created by spoil backfill. This sulfate standard on Segment 12 is applicable, however, only if there is an actual water supply use on a stream. There are no water supply uses on Calamity and Tuttle Draws. The CDPS limitations for the New Horizon Mine are based on parameter values that would not cause exceedances of instream standards. The mine's compliance with the discharge limitations in 2004, and its instream sampling data reported in the AHR, indicate New Horizon's discharges into Calamity and Tuttle Draws in 2004 did not cause the instream flows to exceed Segment 12's numeric standards. (This finding of compliance is subject to verification by the Colorado Water Quality Control Division. H. Antidegradati CWCC New Horizon is not subject to the Antidegradation Rule because on Rule for regulation yes the receiving waters (Segment 12 of the San Miguel River) are Surface s 3.1.9(2) designated "Use-Protected". Water and 3.3.0. L [nterim Narcative CWQCC Standard for regulation yes Ground 41.S.C.6 Water J. Sampling Table frequency at 2.04.7-1 surface water of CDMG yes monitoring mining Permit C- sites 81-008 K. Parameters to Table 13-1 be sampled at of CDMG surface water mining yes permit C- sites 92-081 Page 2