2003-06-12_REVISION - M1999034 (2)

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1. Application Document Inconsistencies -Geology Paragraph one on page 1 of the revised (05/03) Exhibit D -Mining plan states "The depth of the resources to be mined is approximately 30', and is underlain by Pierre shale bedrock." Reference to Pierre shale bedrock is also cited in paragraph two on page 2 of that plan, "The stratum below the gravel resources is Pierre shale bedrock." This geologic interpretation is grossly in error. The Cretaceous age Pierre shale lies in excess of 1,000 feet deep beneath this site. The alluvial sands and gravels to be mined are underlain by the Arapahoe Formation of the Denver Basin aquifer system This formation consists of sandstone interbedded with shale and siltstone. The Arapahoe aquifer is one of the major aquifers within the Denver Basin, supplying domestic, commercial, and municipal water users. In this vicinity, the Arapahoe aquifer is in hydraulic connection with the overlying alluvium Therefore, activities that may impact the alluvial aquifer could also influence the Arapahoe aquifer. We refer you to U.S. Geological Survey Professional Paper 1257. We request that the Mining Plan state the geology of the site correctly. Application Document Incooaistenciea -Topsoil and Overburden Stockpiling Dimensions of topsoil and overburden stockpiles are only specified in the Mining Plan for stockpiles that are placed in the 100.year floodplain area. For example Exhibit D, page 3, paragraph #4 states "Temporary topsoil and overburden stockpiles ... shall be a maximum of 20' in height and 100' in width with 100' gaps between 300' long piles..." This geometric description is nit consistent with the text of Exhibit C-2, page 2 of 2, paragraph #4. The exhibit specifies that stockpiles "have a maximum height of 30"'. In their original Mining Plan Map, Exhibit C-2, dated December 09, 2002, Aggregate Industries (AI) placed the northern topsoil overbwden storage area along the eastern edge of the property adjacent to the Excel Energy Company ROW. In their revised Exhibit C-2, footnoted per ADCO 5/13/03, the northem stockpile has been moved directly west of the residence on my property. Copies of these two exhibits are enclosed as Attachment 2 for your reference. Given the similarities in topography between the former and latter locations, I feel this change maybe a reaction by AI to my objections in this matter. Obviously, the proximity of such a stockpile of unspecified dimensions creates both a visual and environmental nuisance with airbvme particulates and wind and water erosion. We request that the northernmost topsoil and overburden stockpile be relocated to its Former staging area along the eastern property boundary adjacent to the Ezcel Energy Company ROW. Further, we request that the Division otMinerals and Geology (DMG) require written specification of the dimensions of topsoil and overburden stockpiles. R+e propose the following specification, "Temporary topsoil and overburden stockpiles that are placed outside of the 100 year floodplain area shall be a maairoum of 20' in height and 100' in width wit6100' gaps between 200' long piles, and have a maximum slope of 1H:1 V." 2. Ground Water Quality Concerns My concerns on the issue of ground water quality was documented in my original objection letter of Apri13, 2003 and in a follow-up letter to Mr. Larry Oehler of DMG dated May 26, 2003. Upon my inquiry to the Colorado Department of Health and Environment as to the status of the applicant's wastewater discharge permit. I was surprised to learn that the Water Quality Control Division issued a "general" wastewater discharge permit to AI with an effective date of October 1, 2002. "General" permits for process orator and stormwater are not site specific. This type of permit does sot address the mining operations effect on existing contaminants in the ground water environment. Unlike a site-specifc discharge permit, requests for "general" permits do not have public notification or comment period. As such, the public was not afforded an opportunity to bring the'v coacems forward an¢ the Division did not review the site-specific water quality ramifications ofthis proposed