2022-07-01_PERMIT FILE - M2022005

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Mr. Connor Drinkard RE: Carr Pit East M-2022-005 June 27, 2022 Ecological Assessment and Conservation Blueprint. Additionally, we consulted with an ecological consultant familiar with the project site. AloTerra Restoration Services, LLC has provided preliminary wetland assessments on both the Carr Pit East site and the adjacent Carr Pit (M-2014-001) site. Additionally, AloTerra performed a jurisdictional wetland delineation and wildlife survey for the Carr Pit temporary crossing of Lone Tree Cree approximately one mile upstream from the Carr Pit East site. We acknowledge that Lone Tree Creek in the project area is a significant ecological resource, but we question the CPW standard buffer distance of 500 feet from the OHWM being applied to the creek. As a general or standard recommendation, the reference of OHWM and a 500-foot buffer seems applicable for perennial eastern plains rivers and streams such as the South Platte River where the river channels are 100 feet wide or more with associated floodplains that may extend a quarter mile away from the riverbank. The Lone Tree Creek channel, however, is generally less than a couple feet wide or even nonexistent. Through the proposed project area, the creek is ephemeral or intermittent at best, flowing primarily in response to substantial stormwater events or snow melt. The narrow channel and pools are generally located in the middle of the drainage bottom which varies from approximately 50 to 100 feet wide. The bottom of the drainage is commonly covered with a mix of wetland and facultative (equally likely to occur in wetlands and non-wetlands) grass species. From the drainage bottom, slopes typically rise abruptly at a 10 percent grade or steeper to the upland plain over 5 to 15 feet above. The adjacent upland plain is characterized by dry, and conditions dominated by short-grass or mixed-grass prairie. Mining is proposed within the upland areas of the project site. These upland areas do not contain suitable habitat for the SGCN referenced by CPW. Lone Tree Creek, the associated wetland area, and the drainage embankment do not contain significant aggregate deposits and are not included in the mining limits. Careful disturbance of the drainage embankment only occurs during reclamation activities to create a smooth and functional transition from the mine excavation to the creek drainage without creating areas where stormwater could pond (see attached photographs). We do not believe that the mining and reclamation activities, as proposed, create a significant threat to the SGCN listed by CPW or other wildlife within the project area. According to the SWAP, the greatest threats to the Northern leopard frog include loss of wetland habitat due to residential and commercial development and the introduction of invasive species such as bullfrogs and sport fish. Similarly, the greatest threats to the Brassy minnow and Northern redbelly dace include incompatible agricultural practices such as intensive livestock grazing, loss of habitat from residential and commercial development, changes to flow regimes from dams, diversions, and dewatering, and the introduction of invasive species. These threats will not be associated with the proposed mining and reclamation activities. During active mining, an overburden berm approximately 3 feet high will separate the Lone Tree Creek drainage area from mine excavations, haul roads, stockpiles, and other mining disturbances. The berm acts as stormwater management and as a safety barrier. Fortunately, mining at the Carr Pit East site produces rock in varying sizes so rock mats, rock dams, rock �b ue ear-th Page 2of12