8.2. SR 11-07-2016 - Laserfiche WebLink

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Table 9-1 Minnesota Noise Standards NAC-1 Daytime Nighttime Lso Lio Lso Lio 60 d BA 65 d BA 50 d BA 55 d BA The Site will comply with the state noise standards by maintaining the setback areas and constructing perimeter berms within the setback areas to provide shielding and reduce sound emissions from the Site at nearby receptors. The equipment will be operated at recessed areas on the mine floor. The surrounding excavation slopes provide additional shielding for sound emissions from the equipment. All structures, equipment, and processing plants will be maintained in proper working order, undergo regular maintenance and be kept in a neat condition. Operating equipment will use standard noise control features such as mufflers. On-site equipment will be fitted with broad band back up alarms where practical. Crushing equipment is fitted with spray bars to mitigate the generation of dust during processing. Unpaved internal haul roads will be watered on a regular basis and routine street and entrance sweeping will be conducted to reduce fugitive dust emissions. The processing equipment operates under a MPCA Non-metallic Mining General Air Permit and is subject to certain operating standards which include limits on the amount of emissions, opacity standards, establishes minimum moisture content of feed material, fugitive dust control measures, equipment controls, record keeping and reporting requirements. Processing operations are established at recessed portions of the Site which further reduces fugitive dust emissions associated with the processing equipment. Perimeter berms and vegetated screening help to further reduce any dust traveling offsite. Weeds and other unsightly or noxious vegetation will be controlled as necessary to preserve the appearance of the area.The Site will be operated in a manner to minimize any land use conflicts and to comply with all applicable local, state, and federal permits, standards, and regulations. 10. Geology, soils and topography/land forms: a. Geology - Describe the geology underlying the project area and identify and map any susceptible geologic features such as sinkholes, shallow limestone formations, unconfined/shallow aquifers, or karst conditions. Discuss any limitations of these features for the project and any effects the project could have on these features. Identify any project designs or mitigation measures to address effects to geologic features. The surficial deposits and topography of the Site result from past regional glacial events. Larger landforms are the result of the advance of the St. Croix phase of the Superior Lobe which deposited a red sandy till across the area. A northwest-southeast trending terminal moraine formed at the edge of the Superior Lobe resulting in large geomorphic features in the area. Later, the advance of the Grantsburg Sublobe of the Des Moines Lobe, deposited a calcareous gray till with shale fragments. The Grantsburg till was the last major depositional event in the region. As the Grantsburg Sublobe melted, an esker complex was formed which provides thick sand and gravel deposits characteristic of the area.' 3 City of Elk River, Elk River Gravel Mining District Environmental Impact Statement, 1994. Environmental Assessment Worksheet Page 10 Elk River Sand and Gravel Mines:Tiller Corporation and Max Steininger, Inc.