Agenda - Council - 01/13/1981 - Laserfiche WebLink

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- 17 - require 318 acres for ash disposal and 10,000 acres of private farmland for landspreading of sludge. The only other feasible alternative is to incinerate all sludge the entire year. This option then requires 388 acres for ash disposal. All of the acreages contained in this report exclude buffer areas. Total incineration would require the most land for ash landf1lling, which would be the worst case. No option requires the MWCC to dispose of sludge on their own land. If the MWCC must temporarily shut down all of the incinerators because of air pollution violations it is assumed that enough private farmland would be available for landspreading of sludge. . It is, therefore, recommended that enough land be purchased imme- diately to accommodate incineration of primary sludge for the entire year. An option to purchase adjoining land to dispose of all the sludge by incineration would also be needed. This would mean the purchase of 226 acres and an option to purchase an additional 162 acres. It is recommended that the MWCC pursue land application of digested sludge from the Anoka, Stillwater, Rosemount, Hastings, Bayport and Cottage Grove treatment plants on private farms. This plan would require no additional land purchase for sludge disposal. If this alternative cannot be implemented at any of these treatment plants, their sludge would be bauled to an interceptor sewer tributary to the Metro Plant. The calculations of the amount of land needed for the various alternatives at the Metro Plant include the sludge produced ~y these plants. Therefore, no additional land would be n.ecessary over and above what is projected for the Metro Plant. . Seneca . The MWCC recommends that the plant continue with total sludge incineration. This alternative costs more than the alternative of incinerating sludge for six months and landspreading sludge on private agricultural land for the remaining six months. The MWCC said the incineration system is a proven technology and they would not have to train staff in a new disposal method. Total incineration would require 51 acres for ash disposal. Combining incineration and landspreading would reqiure 32 acres for an ash landfill and 650 acres of private farmland for land disposal. Choosing total incineration over incineration and land spreading may be reasonable at this time due to inexperience with landspreading. However, this may not be the case for long. Local farmers are watching commercial fertilizer costs junp and more farmers are requesting information about using sludge. The cost of producing commercial fertilizer, an energy intensive industry, will rise as energy costs rise. Therefore, it seems highly probable that within several years there will be a very large demand for sludge like the sludge from the Seneca plant that does not contain large amounts of heavy metals. Also, the MWCC is gaining experience every day from the land spreading ~f the Metro plant sludge and the Empire sludge.