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indicating no impacts from coal mining at Carbon Junction, b) recognition that any coal spoil <br />leachate generated by and migrating from the relatively small (less than 10 -acre) pit area at <br />Carbon Junction would undergo significant attenuation and dispersion in the Animas River <br />alluvium and Pictured Cliffs sandstone within a few hundred feet of the mine pits. <br />The relatively small pit area of the Carbon Junction Mine (less than 10 acres) indicates the mine <br />does not have the potential to negatively impact ground water quality; therefore, a ground water <br />point of compliance has not been established. <br />Surface Water Hydrology <br />The Carbon Junction Mine is located in the Animas River Drainage Basin, in the valley of the <br />upper reach of Carbon Junction Canyon. The channel of Carbon Junction Canyon is deeply <br />incised, has a steep gradient, and carries only ephemeral flows. When flow occurs, it is directly <br />tributary to the Animas River to the southwest. The drainage area of Carbon Junction Canyon is <br />0.8 square miles. Three intermittently flowing natural springs (1, 3, and 4) have occasionally <br />created minimal baseflow in Carbon Junction Canyon. <br />The channel of Carbon Junction Canyon extends along the contact of the Pictured Cliffs <br />Sandstone and the Fruitland Formation. These strata discharge to the channel of Carbon Junction <br />Canyon (via natural springs) during dry periods. When the channel contains surface runoff, it <br />recharges the Pictured Cliffs sandstone and the Fruitland Formation. <br />Flows in Carbon Junction Canyon usually occur only when there has been a thunderstorm or <br />when snow is melting. Highest flows occur during springtime snowmelt and in early summer <br />when precipitation events are more frequent. Water quality in Carbon Junction Canyon <br />fluctuates seasonally, with the best quality occurring during periods of high flow. <br />Historically, flows in Carbon Junction Canyon have not been diverted for flood irrigation of <br />crops. Any use of water from Carbon Junction Canyon would be through diversion of Animas <br />River water downstream of the confluence of these two streams. The mine's approved <br />postmining land uses of industrial /commercial, residential, and recreation are not expected to use <br />surface water. <br />The quantity of water from Carbon Junction Canyon tributary to the Animas River would be <br />insignificant for the overall flow of the river. The drainage basin of Carbon Junction Canyon is <br />only 0.8 square miles compared to over 1090 square miles for the Animas River above the <br />Colorado -New Mexico state line. <br />The Carbon Junction Mine is on Segment 13b of the Animas and Florida River Sub -basin of the <br />San Juan and Dolores River Basin. Colorado Water Quality Control Commission lists numeric <br />standards for this segment in its regulation 34.0. The permittee monitored water at two CDPS <br />outfalls: the south pond, Pond 1 (outfall 001), and the north pond, Pond 2 (outfall 002). Both <br />ponds discharge to Carbon Junction Canyon. Both ponds discharged in January 2005, but did not <br />discharge in subsequent years. The ponds were reclaimed in 2008. Sampling of springs 1, 3, <br />and 4 was terminated in TR -13. <br />10 <br />