2001-02-09_REPORT - C1981025 (2)

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February 9, 2001 Page 3 of 4 Pages It is possible that present and future mining activities may slightly reduce the flow of ground water moving through the coals towards the Piceance Basin (permit, page 3-49). There is no monitoring associated with groundwater flows to the Piceance Basin. No adverse impact is inferred to regional groundwater,but not distinctly stated (permit, page 3-60). There is no monitoring of regional groundwater flows. A soil loss comparison, pages 4-19i through4-19iii of the permit, concludes that untreated drainage (surface) from reclaimed areas would contribute slightly fewer suspended solids that untreated drainage from the natural surrounding areas. There is no monitoring associated with this conclusion. A statement is made that water quality will not be impacted by suspended solids during reclamation or after a large precipitation event (permit, page 4-105). "No discharge" reports (Refuse and Pond 9 sedimentation ponds) indicate performance within this prediction. An analysis after a vegetation survey performed during July 1992 demonstrated that untreated drainage from the reclaimed mine site does not contribute additional suspended solids above natural conditions. No monitoring is accomplished for small areas that have exemptions from sediment pond treatments. Seals (portals) were designed to withstand anticipated hydrostatic heads of flooded mines (permit, page 4-66). However, the seals at Portal 1 did not prevent seepage of mine water, and drainpipes at Portal 3 allow for drainage of mine water. "The flow in North Thompson Creek will not be significantly affected by impoundments, surface disturbances, or surface facilities."(permit, page 4-109) Monitoring through 1985 did not establish depletion to the North Thompson Creek and Middle Thompson Creek, and monitoring was discontinued in 1986 (permit, page 5-115b). "---the effects of the altered infiltration and evapotranspiration rates on the entire watershed's flow rates would be imperceptible due to the minor percentage of watershed area involved." (permit,page 4-110) Monitoring through 1985 did not establish depletion to the North Thompson Creek and Middle Thompson Creek, and monitoring was discontinued in 1986 (permit, page 5-115b). "The refuse pile would have a minimal impact on the water quality of North Thompson Creek." (permit,page 4-114) Surface runoff is directed into the Refuse Pile Sedimentation Pond, discussed earlier. Data obtained for monitor well (refuse pile piezometer, directly below the pile) D-1 A indicates conductivities nearly double those of piezometer D-2A (located to the west of the pile). Impacts on North Thompson Creek, however, are difficult to evaluate. No groundwater flow information of the Refuse Pile is available. North Thompson Creek experiences rise in total dissolved solids across the site (described as primarily from leaching of geologic formations undisturbed by mining operations formations and treated mine water discharges in the PAP). The AHR refers to baseline monitoring data and the discharges from Portal 2 (Abandoned Mined Lands peat bog water treatment system) for explanation for the increases.