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wells will be periodically sampled to verify that the Tunnel City Group bedrock aquifer is still <br />contaminant free. <br />Methane Gas Area of Concern <br />The Methane GasAreaof Concern (MGAOQ isdefined asthe areaof land surrounding a landfill waste <br />footprint where the presence of certain activities, such asconstruction of enclosed structures, may be <br />impacted or precluded by subsurface migration of methane gas. Methane gas is an odorless gas <br />produced when municipal solid waste decomposes, and can be explosive in confined spaces such as <br />basements when mixed in air. The M GAOCis used to inform the public about the risks to current and <br />future landowners regarding certain usesthey may want to consider. The M GAOCis shown in Appendix <br />E <br />Soils in the vicinity of the Anoka/ Ramsey Landfill are generally coarse sands. Depth to the groundwater <br />table is approximately 20 feet below ground surface. The landfill waste footprint is approximately 65 <br />acres and contains approximately 5,700,000 cubic yards of waste. A low permeability cover system is in <br />place. The closest residences are located greater than 300 feet from the waste footprint <br />The cover system has 43 vertical gas extraction wells connected to an enclosed blower /flare unit. A116 <br />gas monitoring probes located around the landfill perimeter have had zero percent methane measured <br />in them for more than 5 years, indicating that there likely is no gas migrating off the property. An <br />investigation of the waste quality conducted in 2011 found the waste to be very dry, confirming that the <br />lower gas generation rate being extracted by the flare system was not due to fouled gas wells, but <br />rather a slower degradation rate due to lack of moisture. <br />Based on the large mass of waste present, the highly permeable soils in the area, the potential for an <br />extended shutdown of the gas extraction system due to unforeseen circumstances, the dry waste <br />present, and recognizing the potential for gasto migrate under seasonal low permeable (frozen) <br />conditions, the M GAOCis revised down from the previous estimate to extend 250 feet beyond the <br />waste footprint. <br />It is important to note that these Areas of Concern can changeover time. Therefore, updated <br />information will be provided to the City when the existing information becomes obsolete or misleading. <br />CU RRBVT ZONI NG FOR THE LM A <br />As listed on the City's Official Zoning Proposed Map updated March 2011, the portion of the LMA <br />containing the waste footprint is zoned Public /Quasi- Public. The intent of this district isto provide for <br />public and private recreational uses, government buildings and facilities, and schools. Two parcelssouth <br />of the waste footprint, but within the LMAare zoned E-2 Employment District. The intent of this district <br />isto provide for the mix of typically large volumes of bulk commercial goods and services, wholesale or <br />warehouse activities and limited retail activities. Three parcels on the east side of the LMAare zoned R- <br />2 Multiple Family Districts. The intent of this district isto accommodate duplexes, twinhomes, <br />townhomes, or multifamily units at a maximum density of seven units per acre and a minimum density <br />of three units per acres. Lastly, seven parcels on the west side, within the LMA are zoned 2030 MUSA <br />9 <br />