5. SPSR 09-09-2009 - Laserfiche WebLink

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Conditional Use Permit and Solid Waste Facility Narrative Large on-site tanks: The ERS facility has three bulk fuel oil tanks. Until recently, these tanks were empty and unused since 1981. As part of the construction of the peaking station, two of the tanks were refurbished; one is used for fuel oil storage and the other is used for demineralized water storage. The third tank remains sealed off and unused. The refurbished fuel oil tank supplies backup fuel to ERS and the peaking station. The demineralized water is used to control NOx emissions when the peaking station combustion turbine is firing fuel oil. 3. Requested Amendments 3.1. Alternate Fuel Description and Scope GRE requests approval to cofire alternate fuels at Elk River station with RDF. The alternate fuels will be limited to TDF, wood and waste wood. A single alternate fuel may be cofired with the RDF or a combination of the alternate fuels may be cofired with the RDF. None of the proposed alternate fuels would be fired without concurrently firing RDF. The ERS will remain primarily aRDF-fired waste-to-energy facility. However, the economics of the overall operations (waste processing and waste combustion) are negatively impacted by an overall low supply of municipal solid waste to feed the RDF production plant or by short term interruptions in the municipal solid waste supply or RDF supply. cofiring alternate fuels is being proposed as a potential opportunity to maintain the overall economic viability of operating the waste to energy plant. Any economic advantages of cofiring will be dependent on the actual cost of any alternate fuels and the impact of the alternate fuel on operating and maintenance costs. GRE has begun to investigate fuel supply costs, but we cannot identify actual operating and maintenance cost impacts without actually cofiring the materials over a period of time. Our initial analyses suggest that the requested opportunity fuels offer some promise for cost savings. The air emissions permit issued for the Elk River campus currently allows ERS to cofire TDF at a rate of "less than or equal to 100 tons/day using [a] 30-day rolling average" but also "less than or equal to 200 tons/day using [a] 24-hour block." If the City feels it is necessary to also restrict the amount of TDF that is cofired, we request that these same restrictions be used in the CUP. The air emissions permit does not explicitly allow for ERS to burn any wood. However, the air permit, in conjunction with Elk River Station's Industrial Solid Waste Management Plan does allow ERS to burn "Excess wood chips from county projects." GRE will have to obtain approval from the MPCA prior to cofiring any wood that is not currently authorized by the permit and Industrial Solid Waste Management Plan. S:\Legal\Environmental\ERSWir\City of ER - Cond.UsePermit\2009 Alt Fuels Amendment\ER CUP Amend Narrative v2.doc Page 3 of 4