2009-02-13_REPORT - C1981047 - Laserfiche WebLink

Home Browse Search

Blue Ribbon Mine - AHR Page 5 HYDROLOGIC IMPACTS The probable hydrologic consequences section of the permit, which begins on page 120, discusses the impact the mine might have on the quality of water in Hubbard Creek. The quality of water in Hubbard Creek is influenced by run-off it receives from the mine property. The mine could contribute both dissolved and suspended solids to the run-off from the property. The primary potential sources of detrimental effects on water quality caused by the mining operation are or were: 1) Increased erosion from land disturbance; 2) Increased oil and grease from use of machinery; and 3) Increased salt load due to water seeping through the mine bench which was reconstructed with underground coal mine waste. The erosion from land disturbance should be minimal to nonexistent because the mine was reclaimed and vegetated in 1986. A demonstration that shows untreated drainage from the reclaimed area will contribute fewer suspended solids to stream flow or runoff outside the permit area as untreated drainage from the natural surrounding pre-mining area was incorporated into the permit by technical revision number 15. The sediment ponds were reclaimed during the fourth quarter 2008. Sediment fences are used to treat run-off from the areas disturbed during sediment pond removal. Oil and grease should not be a factor because there is little use of machinery on the property. An increase in the conductivity measurements in downstream Hubbard Creek would indicate an increased salt load. Enclosed is a graph which presents quarterly conductivity measurements in lower Hubbard Creek from 1982 through 2008. The conductivity measurements vary between 70 and 430 umhos/cm but there is no indication the conductivity in downstream Hubbard Creek has increased since 1982. The 2008 hydrologic monitoring data indicates the hydrologic impact from the reclaimed mine site is minimal to nonexistent.