Laserfiche WebLink
METHOD OF DISCHARGE OF STORM WATER FROM SEDIMENT BASIN <br /> Sources of the water in the sediment basin <br /> Water that collects in the sediment basin is not only from storm water. Other sources <br /> include local spraying for dust control and water that drains from rock stockpiles. Thus separating <br /> storm water from other water sources is not possible as, effectively, it all goes into the same <br /> collection pot. There is no way to measure inputs from the different sources as even those that are <br /> not storm water are mixed together. And some of the water that drains from stockpiles has a storm <br /> water source. Thus, storm water here includes rainfall and snowmelt from primarily the area of the <br /> processing plant with very little water coming from the higher reaches of the actual quarry <br /> operation. In very large storms water overflow from Turkey Creek can contribute a large volume <br /> of water such that the sediment basin can potentially overflow its walls and return to Turkey Creek <br /> a very short ways downstream from the sediment basin. Sometimes the flow floods the access road <br /> as well. But these are very rare flood events and are far from the norm. <br /> As a result of this mixed source of the water, determining the exact volume of storm water <br /> that needs to be discharged is essentially impossible because the collection basin also accumulates <br /> fine crushed aggregate from the processing of the mined rock This material, being quite fine, can <br /> retain prodigious amounts of water that cannot be withdrawn except by removing the sediment to <br /> another location to slowly drain out. In fact, this material can retain water so easily that it can be <br /> used as a"sub-soil" layer topped with a more coarse "topsoil" in revegetation of quarry benches. <br /> This layering can produce an excellent revegetation growth medium in the reclamation of the <br /> quarry. Unfortunately, there is not much of these fine materials available for use in this way. In <br /> terms of water right replacement this part of the water in the pond, that includes storm water, is <br /> returned via infiltration over a longer period of time. <br /> Undoubtedly, infiltration into the rocky bed of Turkey Creek occurs under the sediment basin <br /> because the basin is not a sealed basin. How much all the fuses in the sedvnent basin act to seal the <br /> bottom and sides of the basin is unknown, but undoubtedly some infiltration of storm water returns <br /> to Turkey Creek via that pathway on a continuous basis even when there is no pond. <br /> As a result of all of these different sources and different return pathways it is probably not <br /> unreasonable to assume that whatever water is in the sediment basin and resting on top of the <br /> Technical Revision Menzer Quarry M-1973-009-HR June 2021 Page 2 of 7 <br />