Agenda - Council - 03/24/1981 - Laserfiche WebLink

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TECHNICAL FEASIBILITY Landfill gas extraction technology is comparable to the technology used to extract liquids and gases from geological formations. Briefly, a gas extraction well is placed in the landfill approximately one per acre and a lateral collection system of pipes is buried approximately four feet below the surface. On-site pumps create a vacuum which draw the gases from the decomposing waste near the gas recovery wells. The gas is then cleaned to some level of specification, as previously referenced, and utilized for an energy source. Recent engineering reports published indicate the recovery and utilization of landfill gas is generally feasible from an economic perspective with a minimum disposal site of 80 acres with an average depth of 50 feet. A general rule of thumb appears to be that an 80 to 100 acre landfill site will generate approximately two million cubic feet of medium BTU methane gas per day. The current cost of technology for drawing the gas from the landfill of this size is approximately 1.5 to 2 million dollars. If the gas can be used in a raw/medium BTU form, depending on the market, no additional cost is necessary, For example, on-site electrical generation utilizing a modified combustion engine appears to be the most inexpensive form of producing energy from landfill gas. On the other hand, that same 80 to 100 acre landfill site producing approximately 2 million cubic feet of gas per day utilizing the natural gas distribution system as a market may well have a capital cost of somewhere between 8 to 10 million dollars. The variance in capital cost is a direct result of the additional technology necessary to clean the gas to pipeline standards. While the afore-referenced cost figures are not meant to be definitive, they do indicate the more expensive technologies associated with the different types of markets available. Limited documentation is available regarding the feasibility ~f landfill gas recovery in an area where severe winter climates exist. Further, there is limited research on the feasibility of landfill gas recovery in climates where the annual precipitation rate is nearly equal to the annual evaporation rate. This is currently a topic of interest and concern to Anoka County and while landfill gas recovery does appear to be economically viable and feasible for a Minnesota based landfill, there is a need for an engineering feasibility to be conducted which is site specific to Minnesota. ANOKA COUNTY - ENGINEERING LANDFILL GAS FEASIBILITY STUDY Anoka County has recently secured by way of jp~ municipal/Count~x_ resolution, the "gas ri§hts"of--the~Aooka-La-n-~f~-~]] located in the City of Ramsey and under the regulatory control and authority of the Anoka County Environmental Services Division. As a direct result of the interest of the Coumty Board in studying the feasibility of landfill gas recovery and utilization, Anoka County is currently in the process of soliciting funds from a number of sources to support an engineering feasibility study to determine the technical and economic aspects of recovering methane gas as an alternative fuel in the Twin Cities metropolitan area. -4-