City of Columbia, Missouri Glossary of Terms Questions? Public Works Department Aerobic: living or existing in the presence of oxygen For more information, visit our web page at Airspace: the available space in a cell where trash is placed www.GoColumbiaMo.com (GoLandfill) or call the for disposal Solid Waste Division at 573-874-6290. BIOREACTOR Anaerobic: living or existing in the absence of free oxygen LANDFILL Bioreactor: a controlled landfill or landfill disposal cell MORE INFO: US EPA where liquid and gas conditions are actively managed in WASTE STABILIZATION order to accelerate or enhance biostabilization of waste GENERAL: http://www.epa.gov/garbage/landfill/bioreactors. Biosolids: treated residuals from wastewater treatment htm facilities The City of Columbia Public Works Cell: a contained area of the landfill where waste is SPECIFIC: deposited http://www.epa.gov/epaoswer/nonhw/muncpl/ Department has begun planning for landfill/biowork/index.htm the next sanitary landfill disposal cell. Inorganic: being or composed of matter other than plant As part of this planning process, or animal bioreactor technology is being ACKNOWLEDGEMENTS examined as a means to accelerate LCS: leachate collection system waste biostabilization. We thank the following individuals and Leachate: liquid that filters through MSW organizations for contributions to this brochure. LFG: landfill gas Camp Dresser and McKee Inc. Liner: an engineered impermeable barrier at the bottom of Engineering Consulting Firm the landfill cell to prevent liquid from leaving the landfill University of Missouri Methane: a colorless, odorless, flammable gas produced by Dr. John Bowders decomposition of organic matter Civil Engineering Department MSW: municipal solid waste Organic: relating to or derived from living things (plant or animals), containing carbon compounds City of Columbia Post Closure: covers a regulated (currently 30 years) Public Works Department period after waste is last accepted when the owner is Solid Waste Division financially obligated to maintain the area to the designed P. O. Box 6015 environmental standards Columbia, MO 65205 City of Columbia Seeps: outbreak of liquids Sanitary Landfill, 5700 Peabody Road Public Works Department Solid Waste Division Phone: 573-874-6290 Fax: 573-449-9641 Tel: 573-874-6290 Email: [email protected] Conventional Landfill Design Bioreactor Landfill Design - Wet Cell Missouri Regulations Precipitation Cover WHAT IS A BIOREACTOR • Recirculate leachate System • Add additional liquid LANDFILL? Cover System • Collect gas Horizontal Liquid • Composite Cover Injection/ Gas • Leachate Collection System (LCS) Objective: Extraction Trash • Single Composite Bottom Liner A bioreactor landfill operates to rapidly transform and Degrade and stabilize the Vertical degrade organic waste. The increase in waste degradation waste as rapidly as Liquid Objective: TrTrashash Injection/ Gas and stabilization is accomplished through the addition of possible • Limit infiltration Extraction LCS liquid, and in some cases, air to enhance microbial activity. • Contain leachate (prevent escape LCSLCSLCS Leachate of liquids) Collection HOW IS A BIOREACTOR LANDFILL Bottom System Bottom DIFFERENT FROM Liner Liner CONVENTIONAL LANDFILLS? WASTE STABILIZATION economic potential for beneficial use of methane gas as a green energy source to generate electric and/or direct The principal difference between conventional landfilling Decomposition and biological stabilization of the waste in burn for energy recovery. methods and that of a bioreactor landfill is that current a bioreactor landfill can occur in a much shorter time landfill technology has focused on waste compaction and frame than occurs in a conventional “dry tomb” landfill covering, leaving the waste dry or entombed. By contrast, providing a potential decrease in long-term environ- REDUCE POST CLOSURE AND a bioreactor landfill introduces liquid to accelerate or mental risks, landfill operation and post-closure costs. CARE COSTS enhance waste stabilization. LOWER WASTE TOXICITY Biostabilization is the key to reducing risks. Stable waste Bioreactor is lower in toxicity and mobility. This will decrease Research has shown that municipal solid waste can be the potential long-term environmental risks and landfill rapidly degraded and made less hazardous (due to degra- operating and post-closure costs. Landfill owners are dation of organics and the impounding of inorganics) by responsible to maintain environmentally safe conditions enhancing and controlling the moisture within the landfill of the property for 30 years beyond the end of waste under aerobic and/or anaerobic conditions. acceptance. GAIN IN LANDFILL AIRSPACE SPECIAL CONSIDERATIONS OF A BIOREACTOR Bioreactor landfills have greater waste capacity than • Costs more to construct and operate conventional landfills. Due to the rapid degradation of the • Increased potential for gas emissions due to rapid waste, airspace is recovered, allowing more waste to be waste decomposition added. Think of it like composting. You start out with a Increased potential for odors pile of leaves or grass 3 feet in height, but after the or- • ganic matter decomposes, you are left with a pile height • Landfill’s protective bottom liner could fail under WHY CONSIDER OPERATING A of 6 inches and are able to refill that airspace again, and the extra water weight • Waste column instability due to added liquids BIOREACTOR LANDFILL? possibly again. The same is true for a bioreactor landfill, as the organic matter rapidly decomposes, more waste • Increased potential for fires can be placed in its place. Organics comprise 62% of the The key issues are: waste going into the landfill. (Columbia 1996 Waste • Decomposition and biological stabilization in years vs. WHERE WILL THE LIQUID Characterization Study) COME FROM? decades in “dry tombs” • Lower waste toxicity and mobility due to both aerobic INCREASES THE RATE LANDFILL and anaerobic conditions It is estimated that it will require between 50,000 and GAS IS GENERATED 60,000 gallons of water be added each day to obtain the • A 15 to 40 percent gain in landfill airspace due to an increase in density of waste mass ideal moisture content. Biosolids from Columbia’s An additional benefit of the bioreactor is that it produces Waste Water Treatment Plant could be used in lieu of • Increases landfill gas generation rate landfill gas (LFG) such as methane at an earlier stage in current land farming. Water from on site storm water • Reduced post-closure care the landfill’s life and at an overall much higher rate of basins could be pumped into the waste. Wastewater generation than conventional landfills. This improves the from nearby industry could be used as a water source. .