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Proposed Decision and Findinos <br />Based on the quantitative cover data documentation and site stability assessment included in this <br />report, the Division proposes to authorize discontinuance of sediment pond maintenance, <br />pursuant to Rule 4.05.2(2). The Division makes the following specific findings: <br />1) The disturbed area has been revegetated and stabilized, and it has been a minimum of 2 <br />years after the last seeding within the affected contributing watershed. <br />As noted in previous sections of this document, the disturbed area was last seeded in the <br />fall of 2000. As further detailed in this document, vegetation cover has been documented <br />to exceed the applicable cover standard, and seeded perennial shrub species are a <br />significant component of the vegetation stand. Total ground cover (including litter and <br />rock in addition to live vegetation) exceeds 75%. The disturbed area does appear to <br />have been properly stabilized. Gully erosion is limited to defined channel locations that <br />convey storm runoff originating higher in the watershed, and the extent of gullying is in <br />character with undisturbed adjacent watersheds along the Bookcliffs. <br />2) The untreated drainage from the disturbed area has ceased to contribute additional <br />suspended solids above natural conditions. <br />Small ephemeral drainages in the Bookcliffs (including those within the watershed that <br />includes the Fruita mine site) flow infrequently, in response to localized, high intensity <br />rainfall events. When flow occurs, it is typically highly turbid, with high levels of <br />suspended solids. Due to the very limited extent of the Fruita Mine disturbed area (less <br />than 12 acres) the mine has had no discernable affect on the flow regime of the two <br />affected ephemeral drainages, which originate on the steep slopes far above the mine <br />site. These drainages will continue flow in response to occasional intense storm events, <br />and the flow will be turbid, as was the case prior to mine disturbance. <br />However, disturbed hillsiopes at the Fruita Mine have been adequately stabilized, with <br />vegetation cover exceeding the approved standard and total ground cover in excess of <br />75%. Based on the extent of cover, absence of gully erosion on the reclaimed slopes, <br />and presence of only minor rill erosion in isolated locations, the Division's assessment <br />concludes that contribution of suspended solids from the disturbed area is not in excess <br />of natural conditions. This conclusion is further bolstered by the fact that the level of <br />sediment in the sediment pond has remained essentially unchanged (4.5 feet below the <br />top of the spillway riser) in the 5 years since the most recent reclamation project was <br />completed. <br />3) The quality of untreated drainage from the disturbed area will meet applicable state and <br />federal water quality standard requirements for receiving streams. <br />There is no discharge of water from the underground workings, and no springs or seeps <br />emanate from the disturbed areas of the Fruita Mine. Storm water runoff is the only <br />potential mechanism for mine site drainage to reach receiving streams, and elevated <br />levels of settleable solids would be the only constituent of potential concern. Based on <br />the minimal contribution of sediment contributed by the reclaimed slopes, as discussed <br />under Items 1 and 2 above, the Division concludes that the untreated drainage from the <br />disturbed area will meet applicable state and federal water quality standard requirements <br />for receiving streams. <br />