2015-09-17_PERMIT FILE - C1984065A (2)

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streamflow or runoff outside the permit area as untreated drainage from the natural surrounding area. A similar soil loss comparison was performed to determine if untreated drainage from the irrigated hayland community is contributing suspended solids to streamflow or runoff outside the permit area in excess of premining levels. The study presented on page 4-58vi demonstrates that untreated drainage from the reclaimed irrigated hayland area will contribute the same amount or fewer suspended solids to streamflow or runoff outside the permit area as untreated drainage from the adjacent irrigated hayland field. Restoration of the essential hydrologic function of the Alluvial Valley Floor has been accomplished by restoring flood irrigation to the irrigated hayland portion of the reclaimed area. Productivity of the hayland has been restored and is documented in the vegetation study. For the majority of the site, sedimentation control including small area exemption controls are no longed required based on the fact vegetation at the mine site has been scientifically sampled and it has been determined the reclaimed areas will not contribute suspended solids to streamflow or runoff outside the permit area in excess of premining levels. A six and one half acre section of the site associated with the reclamation of Sediment Pond A is scheduled for reclamation in 2015. Per the terms of discharge permit C00048972, a sediment control plan for the reclamation has been designed and will be installed before reclamation is initiated. The purpose of this plan is to ensure sediment loss associated with the reclamation will be the same or less than sediment loss at pre -mining levels. Details of the plan begin on page 4-58vii. Sediment logs will be used to minimize the impacts of sediment loss during stormwater runoff. The demonstration beginning on page 4-58iii shows that sediment loss from the pre - mining portal and bench area is 1.01 tons per acre per year, and for the irrigated hayland will be 0.06 tons per acre per year. The demonstration beginning on page 4-58vii for the reclaimed borrow area and cropland area shows that after being seeded, mulched and with a sediment log in place, the sediment loss will be zero tons per acre per year. Future land uses, including pasture/wildlife and cropland are delineated on Figure 4.7-2. Please see page 4-58ix for location of sediment logs. Sediment logs will be installed at the toe of all cut slopes, and at the low point of all fill slopes to minimize sediment transport. Sediment logs are installed using a combination of trenching and staking. First, they are placed in a small trench that is any where from 2" to 5" in size. Once the logs are placed in the trench, the area can then be backfilled with soil until they are tightly packed. Sediment logs should be installed side by side until the one end is tightly packed against the end of the adjacent log. After the sediment logs are in place, they can then be staked along every end and every 4 ft. on center. Coal Ridge No. 1 4-58i 07/15